UVA, UVB Light, and Methyl Jasmonate, Alone or Combined, Redirect the Biosynthesis of Glucosinolates, Phenolics, Carotenoids, and Chlorophylls in Broccoli Sprouts

Mechanism of endogenous hormones regulating gallic acid biosynthesis during the development of buds and leaves in tea plant (Camellia sinensis)

Gallic acid (GA), as a precursor of Epigallocatechin-3-gallate (EGCG) biosynthesis in tea plant, is one of the important components of tea flavor and has various health benefits. However, the mechanism of endogenous hormones regulating GA biosynthesis during the development of buds and leaves of tea shoots is still unclear. In this study, the buds and leaves of five different developmental stages of tea shoots were used as test materials to explore the mechanism of endogenous hormone signaling pathway regulating GA biosynthesis. The results showed that the decrease of D-erythrosyl-4-phosphate content and the increase of shikimic acid content affected the accumulation of GA content during the development of tea shoots. Jasmonic acid, abscisic acid, auxin, cytokinin, and gibberellin inhibited GA biosynthesis by down-regulating the expression of two CsaroDEs through twenty-three plant hormone signal transduction factors, such as CsMYC2, CsSNRK2, CsARR-A, and CsDELLA, respectively, which mediated the downregulation of sixteen transcription factors, such as CsMYB44, CsMYB108, and CsC2C2. CsMYC2 and CsSNRK2 co-mediated the downregulation of the expression of CsMYB44 and CsMYB108 in response to changes in endogenous JA and ABA content, respectively, and inhibited the expression of CsaroDE, thereby co-regulating GA biosynthesis. CsMYC2 may be a key interworking site for the endogenous Jasmonic acid and abscisic acid signaling pathways to jointly regulate GA biosynthesis. Our findings revealed the potential mechanism of endogenous hormones regulating GA biosynthesis during the development of buds and leaves of tea shoots and provided a scientific basis for the regulation of tea quality.

A transplantation study in the high-altitude ecosystem of Ladakh suggests site-specific microenvironment is key for physiological adaptation than altitude

Transplantation experiments conducted in high altitude ecosystems are rising as key strategy to examine the response of individual plant transplanted across distinct elevations. However, plant physiological and biochemical performance in response to changes in abiotic factors across different species and mountain ranges is still lacking. So in the present study, we have made an attempt to link the physiological performance with that of altitudinal gradient in Ladakh by transplanting Lepidium latifolium at four different altitudinal sites. The plant was found to maintain photosynthesis even at high altitudes by modulating photochemical efficiency of photosystem II. Various physiological processes including performance index (PIABS), increase in energy fluxes, closing of the reaction centres and decrease in chlorophyll content play a crucial role in the adaptation of this plant. The efficient and dynamic non-photochemical quenching (NPQ) involving carotenoids particularly zeaxanthin mediated dissipation of excess light energy at high altitudinal sites of Ladakh led the plant to withstand with extremely strong light radiation. As a photoprotective mechanism, decreases in chlorophyll content and increase in carotenoids could lead to a reduction in the absorption of high light energy and avoid photo damage to the chloroplasts. Higher content of redox metabolites such as GSH, ASC, GSH/GSSG ratio and ASC/DHA ratio in plants transplanted at high altitudinal sites further suggests the resilience ability of Lepidium latifolium against harsh environmental stresses. Furthermore, increase in glucosinolate content in plants transplanted at high altitudes suggests the involvement of GLS in the establishment of Lepidium latifolium in Ladakh. Overall, no specific altitudinal trend was observed in the present study indicating the adaptation strategy of Lepidium latifolium to different altitudinal sites can be attributed to the combined effects of multiple environmental factors/microenvironment.

Methods of Modifying the Content of Glucosinolates and Their Derivatives in Sprouts and Microgreens During Their Cultivation and Postharvest Handling

Sprouts and microgreens which belong to the Brassicaceae family contain significantly more glucosinolates than mature vegetables, and their composition often differs too. These plant growth stages can be a valuable supplement of the aforementioned compounds in the diet. The content and proportion of individual glucosinolates in sprouts and microgreens can be regulated by modifying the length and temperature of cultivation, the type of light, the use of mineral compounds, elicitation, primming, and cold plasma as well as storage conditions. The way in which sprouts are prepared for consumption affects the yield of glucosinolate hydrolysis. Genetic variation leading to different plant responses to the same factors (e.g., type of light) makes it necessary to conduct detailed studies involving species and variety diversity. Heat stress and the use of cold plasma appear to be fairly universal methods for increasing glucosinolate content. Studies on the use of light at different wavelengths do not provide unequivocal results. Despite experiments on the use of seed soaking solutions (e.g., sulfur and selenium compounds), there are no studies in the available literature on the effects of chemical and thermal seed disinfection methods on the glucosinolate content of the obtained sprouts and microgreens.

The Role of Polyphenols in Abiotic Stress Tolerance and Their Antioxidant Properties to Scavenge Reactive Oxygen Species and Free Radicals

Plants have evolved complex mechanisms to cope with diverse abiotic stresses, with the phenylpropanoid pathway playing a central role in stress adaptation. This pathway produces an array of secondary metabolites, particularly polyphenols, which serve multiple functions in plant growth, development, regulating cellular processes, and stress responses. Recent advances in understanding the molecular mechanisms underlying phenylpropanoid metabolism have revealed complex regulatory networks involving MYB transcription factors as master regulators and their interactions with stress signaling pathways. This review summarizes our current understanding of polyphenol-mediated stress adaptations in plants, emphasizing the regulation and function of key phenylpropanoid pathway compounds. We discussed how various abiotic stresses, including heat and chilling stress, drought, salinity, light stress, UV radiation, nanoparticles stress, chemical stress, and heavy metal toxicity, modulate phenylpropanoid metabolism and trigger the accumulation of specific polyphenolic compounds. The antioxidant properties of these metabolites, including phenolic acids, flavonoids, anthocyanins, lignin, and polyphenols, and their roles in reactive oxygen species scavenging, neutralizing free radicals, membrane stabilization, and osmotic adjustment are discussed. Understanding these mechanisms and metabolic responses is crucial for developing stress-resilient crops and improving agricultural productivity under increasingly challenging environmental conditions. This review provides comprehensive insights into integrating phenylpropanoid metabolism with plant stress adaptation mechanisms, highlighting potential targets for enhancing crop stress tolerance through metabolic adjustment.

Phyto-nutraceutical promise of Brassica vegetables in post-genomic era: a comprehensive review

MAIN CONCLUSION

Brassica vegetables are one of the possible solutions to tackle the emerging human diseases and malnutrition due to their rich content of phyto-nutraceutaical compounds. The genomics enabled tools have facilitated the elucidation of molecular regulation, mapping of genes/QTLs governing nutraceutical compounds, and development of nutrient-rich Brassica vegetables. The enriched food products or foods as whole termed as functional foods are intended to provide health benefits. The 2500 year old Hippocratic phrase 'let thy food be thy medicine and thy medicine be thy food' remained in anonymity due to lack of sufficient evidence. However, today, we are facing reappraisal of healthy nutritious functional foods in battling diseases. In this context, the Brassica vegetables represent the most extensively investigated class of functional foods. An optimal consumption of Brassica vegetables is associated with lowering the risks of several types of cancer, chronic diseases, cardiovascular disease, and help in autism. In the post-genomic era, the integration of genetic and neoteric omics tools like transcriptomics, metabolomics, and proteomics have illuminated the downstream genetic mechanisms governing functional food value of Brassica vegetables. In this review, we have summarized in brief the phyto-nutraceutical profile and their functionality in Brassica vegetables. This review also highlights the progress made in identification of candidate genes/QTLs for accumulation of bioactive compounds in Brassica vegetables. We summarize the molecular regulation of major phytochemicals and breeding triumphs in delivering multifunctional Brassica vegetables.

Combination of light quality and melatonin regulates the quality in mustard sprouts

Mustard sprouts is a new form of vegetable product that is gaining attention due to its high content of health-promoting compounds such as glucosinolates. This study investigated the effects of different light qualities (white, red, and blue) alone and in combination with 100 μmol L-1 melatonin on the growth and health-promoting substance content of mustard sprouts. The results showed that white light + melatonin treatment promoted the accumulation of glucosinolates in sprouts (compared with white light increased by 47.89%). The edible fresh weight of sprouts treated with red light + melatonin was the highest, followed by white light + melatonin treatment. In addition, the sprouts treated with blue light + melatonin contained more ascorbic acid, flavonoids, and total phenolics. Therefore, the combined treatment of light quality (especially white light) and melatonin can provide a new strategy to improve the quality of mustard sprouts.

Boosting Health Benefits in Vegetables: A Novel Ultraviolet B (UVB) Device for Rapid At-Home Enhancement of Phytochemicals and Bioactivity

The consumption of vegetables is essential for reducing the risk of noncommunicable diseases, yet global intake falls short of recommended levels. Enhancing the nutraceutical content of vegetables through postharvest abiotic stress, such as ultraviolet B (UVB) radiation, offers a promising solution to increase health benefits. This study developed a user-friendly, at-home UVB device designed to increase the phytochemical content in common vegetables like carrots, lettuce, and broccoli. The device applies UVB radiation (305-315 nm) to fresh-cut vegetables, optimizing exposure time and intensity to maximize nutraceutical enrichment. The results demonstrated that UVB exposure increased the phenolic content by 44% in carrots, 58% in broccoli, and 10% in lettuce, with chlorogenic acid levels rising by 367% in lettuce, 547% in broccoli, and 43% in carrots after 48 h of storage. UVB treatment also enhanced antioxidant activity by up to 41% in broccoli and anti-inflammatory potential by 22% in carrots. In terms of gene expression, UVB treatment upregulated UCP-1 expression by 555% in carrots, enhanced thermogenesis, and increased SIRT-1 and ATGL expression by over 200%, promoting lipid metabolism. This process provides a convenient and efficient method for consumers to boost the health benefits of their vegetables. The study concludes that UVB-induced abiotic stress is an effective strategy to improve vegetable nutritional quality, offering a novel approach to increasing bioactive compound intake and aiding in the prevention of diet-related diseases.

Mitigating salt stress by conditioning seeds with ultraviolet light (UV-C) in white oats (Avena sativa L.)

Seed conditioning with ultraviolet light (UV-C) might (1) improve crop yield and quality, (2) reduce the use of agrochemicals during cultivation, and (3) increase plant survival in high salinity environments. The aim of this study was to examine the effects of UV-C conditioning of white oat seeds at two doses (0.85 and 3.42 kJ m-2) under salinity stress (100 mM NaCl). Seeds were sown on germination paper and kept in a germination chamber at 20°C. Germination and seedling growth parameters were evaluated after 5 and 10 days. Data demonstrated that excess salt reduced germination and initial growth of white oat seedlings. In all the variables analyzed, exposure of seeds to UV-C under salt stress exerted a positive effect compared to non-irradiated control. The attenuating influence of UV-C in germination was greater at 0.85 than at 3.42 kJ m-2. Thus, data indicate that conditioning white oat seeds in UV-C light produced greater tolerance to salt stress. These findings suggest that UV-C conditioning of white oat seeds may be considered as a simple and economical strategy to alleviate salt-induced stress.

Effect of UV-A Irradiation on Bioactive Compounds Accumulation and Hypoglycemia-Related Enzymes Activities of Broccoli and Radish Sprouts

In the present study, different intensities of UV-A were applied to compare their effects on growth, bioactive compounds and hypoglycemia-related enzyme activities in broccoli and radish sprouts. The growth of sprouts was decreased after UV-A irradiation. A total of 12 W of UV-A irradiation resulted in the highest content of anthocyanin, chlorophyll, polyphenol and ascorbic acid in broccoli and radish sprouts. The highest soluble sugar content was recorded in sprouts under 8 W of UV-A irradiation, while no significant difference was obtained in soluble protein content among different UV-A intensities. Furthermore, 12 W of UV-A irradiation induced the highest glucosinolate accumulation, especially glucoraphanin and glucoraphenin in broccoli and radish sprouts, respectively; thus, it enhanced sulforaphane and sulforaphene formation. The α-amylase, α-glucosidase and pancrelipase inhibitory rates of two kinds of sprouts were enhanced significantly after UV-A irradiation, indicating UV-A-irradiation-treated broccoli and radish sprouts have new prospects as hypoglycemic functional foods.

Differential response of phenylpropanoid pathway as linked to hormonal change in two Brassica napus cultivars contrasting drought tolerance

Oilseed rape (Brassica napus L.) is a significant agro-economic crop with a wide range of uses. Drought is the most frequent unfavourable environmental stressor restraining its growth and development worldwide. This study was conducted to characterize the drought-responsive phenylpropanoid pathway and its link to hormonal changes in two cultivars, drought-resistant "Saturnin" and drought-susceptible "Mosa." Drought susceptibility in cv. Mosa was confirmed by its lower water use efficiency and higher lipid peroxidation levels with reactive oxygen species (ROS) accumulation. In cv. Saturnin, higher salicylic acid (SA) levels and expression of dehydration-responsive element binding 2 (DREB2) and non-expressor of pathogenesis-related gene 1 (NPR1) led to an upregulation of production of anthocyanin pigment 1 (PAP1) and phenylpropanoid pathway-related gene (CHS, F5H and COMT1) expression, increasing hydroxycinnamic acid and flavonoid compound concentrations. However, in cv. Mosa, higher increases in the activity of lignifying enzymes (polyphenol oxidase, coniferyl alcohol peroxidase, syringaldazine peroxidase, guaiacol peroxidase) and expression of the lignin synthesis-related gene cinnamyl alcohol dehydrogenase 2 (CAD2) were found along with greater increases in abscisic acid (ABA) levels and upregulation of ABA-responsive element binding 2 (AREB2) and basic helix-loop-helix transcription factor MYC2. These results indicate that drought-induced SA-mediated activation of the hydroxycinnamic acid and flavonoid pathways contributes to drought resistance, whereas ABA-mediated lignification contributes to drought susceptibility.

LC-MS methods combination for identification and quantification of trans-sinapoylquinic acid regioisomers in green coffee

The present study aims to both identify and quantify trans-sinapoylquinic acid (SiQA) regioisomers in green coffee by combined UHPLC-ESI-QqTOF-MS/MS and UHPLC-ESI-QqQ-MS/MS methods. Among the various mono-acyl chlorogenic acids found in green coffee, SiQA regioisomers are the least studied despite having been indicated as unique phytochemical markers of Coffea canephora (known as Robusta). The lack of commercially available authentic standards has been bypassed by resorting to the advantages offered by high-resolution LC-MS as far as the identification is concerned. SiQA regioisomers have been identified in several samples of Robusta and Coffea arabica (known as Arabica) commercial lots from different geographical origin and, for the first time, in different samples of coffee wild species (Coffea liberica and Coffea pseudozanguebariae). Quantification (total SiQA ranging from 3 to 5 mg/100 g) let to reconsider these chlorogenic acids as unique phytochemical markers of Robusta being present in the same quantity and distribution in C. liberica as well. Gardeniae Fructus samples (fruits of Gardenia jasminoides) have additionally been characterized as this matrix is recognized as one of the few naturally occurring SiQA sources. The SiQA regioisomer content (total SiQA about 80 mg/100 mg) fully supports the proposal to use this matrix as a surrogate standard for further studies.

Evaluation of Total Isoflavones in Chickpea (Cicer arietinum L.) Sprouts Germinated under Precursors (p-Coumaric Acid and L-Phenylalanine) Supplementation

Cicer arietinum L. (Bengal gram, chickpea) is one of the major pulse crops and an important part of traditional diets in Asia, Africa, and South America. The present study was conducted to determine the changes in total isoflavones during sprouting (0, 3, and 7 days) along with the effect of two precursor supplementations, p-coumaric acid (p-CA) and L-phenylalanine (Phe), in C. arietinum. It was observed that increasing sprouting time up to the seventh day resulted in ≈1282 mg 100 g-1 isoflavones, which is approximately eight times higher than chickpea seeds. The supplementation of Phe did not affect the total length of sprouts, whereas the supplementation of p-CA resulted in stunted sprouts. On the third day of supplementation with p-CA (250 mg L-1), the increase in the total phenolic content (TPC) (80%), daidzein (152%), and genistin (158%) contents were observed, and further extending the supplementation reduced the growth of sprouts. On the seventh day of supplementation with Phe (500 mg L-1), the increase in TPC by 43% and genistin content by 74% was observed compared with non-treated sprouts; however, the total isoflavones content was found to be 1212 mg 100 g-1. The increased TPC was positively correlated with the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (r = 0.787) and ferric-reducing antioxidant potential (FRAP) (r = 0.676) activity. This study suggests that chickpea sprouts enriched in TPC and antioxidants can be produced by the appropriate quantity of precursor supplementation on a particular day. The results indicated major changes in the phytochemical content, especially daidzein and genistin. It was also concluded that the consumption of 100 g of seventh-day sprouts provided eight times higher amounts of isoflavones in comparison to chickpea seeds.

Inducing the Production of Secondary Metabolites by Foliar Application of Methyl Jasmonate in Peppermint

Mentha x piperita is a major source of secondary metabolites (SMs), and developing tools to enhance these compounds would be beneficial to meet the increasing demand in the industry. Elicitation by plant hormones became a new strategy to reach this goal. Three experiments in a climatic chamber and two experiments in an open field were conducted with peppermint to explore the effect of methyl jasmonate (MeJa) on the essential oil (EO) content, EO composition, and the total phenolic content (TPC). The treatment was applied for all experiments by spraying the aerial parts of the plants with a dosage of 2 mM MeJa twice. The treatment influenced all the parameters studied in the trials. The volatile content increased by 9-35%; however, in one trial it remained unchanged. The treatment also affected the main compounds of the EO. Menthone increased significantly in two trials while pulegone and menthofuran decreased. In the case of menthol, the change may also be influenced by the phenological and developmental stages of the plants. In the majority of cases, the TPC was also elevated considerably due to the treatments. MeJa treatments may have promising effects in influencing the accumulation of biologically active compounds and the quality of the drug; therefore, further systematic studies are needed to optimize the technology in vivo.

Post-Harvest Red- and Far-Red-Light Irradiation and Low Temperature Induce the Accumulation of Carotenoids, Capsaicinoids, and Ascorbic Acid in Capsicum annuum L. Green Pepper Fruit

Environmental factors, such as light of different spectral compositions and temperature, can change the level of activated photoreceptors which, in turn, can affect the biosynthesis of secondary metabolites in the cells of green fruit. By briefly irradiating the harvested fruit of Capsicum annuum L. hot peppers with red light (RL, maximum 660 nm) and far-red light (FRL, maximum 730 nm) and by keeping them at a low temperature, we attempted to determine whether the state of phytochromes in fruit affects the biosynthesis of secondary metabolites. Using HPLC, we analysed the qualitative composition and quantitative content of the main carotenoids and alkaloids and the chlorophylls and ascorbate, in pepper fruit exposed to the above factors. We measured the parameters characterising the primary photochemical processes of photosynthesis and the transcript levels of genes encoding capsaicin biosynthesis enzymes. The total carotenoids content in the fruit increased most noticeably after 24 h of RL irradiation (more than 3.5 times compared to the initial value), and the most significant change in the composition of carotenoids occurred when the fruit was irradiated with FRL for 72 h. The capsaicin alkaloid content increased markedly after 72 h of FRL irradiation (more than 8 times compared to the initial value). It was suggested that decrease in the activity of phytochromes due to a low temperature or FRL may result in an increase in the expression of the PAL and CAM genes.

Chlorophylls as Natural Bioactive Compounds Existing in Food By-Products: A Critical Review

Chlorophylls are a group of naturally occurring pigments that are responsible for the green color in plants. This pigment group could have numerous health benefits due to its high antioxidant activity, including anti-inflammatory, anti-cancer, and anti-obesity properties. Many food by-products contain a high level of chlorophyll content. These by-products are discarded and considered environmental pollutants if not used as a source of bioactive compounds. The recovery of chlorophylls from food by-products is an interesting approach for increasing the sustainability of food production. This paper provides insight into the properties of chlorophylls and the effect of different treatments on their stability, and then reviews the latest research on the extraction of chlorophylls from a sustainable perspective.

Do changes in Lactuca sativa metabolic performance, induced by mycorrhizal symbionts and leaf UV-B irradiation, play a role towards tolerance to a polyphagous insect pest?

The increased ultraviolet radiation (UV) due to the altered stratospheric ozone leads to multiple plant physiological and biochemical adaptations, likely affecting their interaction with other organisms, such as pests and pathogens. Arbuscular mycorrhizal fungi (AMF) and UV-B treatment can be used as eco-friendly techniques to protect crops from pests by activating plant mechanisms of resistance. In this study, we investigated plant (Lactuca sativa) response to UV-B exposure and Funneliformis mosseae (IMA1) inoculation as well as the role of a major insect pest, Spodoptera littoralis. Lettuce plants exposed to UV-B were heavier and taller than non-irradiated ones. A considerable enrichment in phenolic, flavonoid, anthocyanin, and carotenoid contents and antioxidant capacity, along with redder and more homogenous leaf color, were also observed in UV-B-treated but not in AMF-inoculated plants. Biometric and biochemical data did not differ between AMF and non-AMF plants. AMF-inoculated plants showed hyphae, arbuscules, vesicles, and spores in their roots. AMF colonization levels were not affected by UV-B irradiation. No changes in S. littoralis-feeding behavior towards treated and untreated plants were observed, suggesting the ability of this generalist herbivore to overcome the plant chemical defenses boosted by UV-B exposure. The results of this multi-factorial study shed light on how polyphagous insect pests can cope with multiple plant physiological and biochemical adaptations following biotic and abiotic preconditioning.

RNA-Seq Analysis Demystify the Pathways of UV-A Supplementation in Different Photoperiods Integrated with Blue and Red Light on Morphology and Phytochemical Profile of Kale

As an indispensable element in the morphology and phytochemical profile of plants, UV-A has proved to help promote the growth and quality of kale. In this study, UV-A supplementation in different photoperiods (light period supplemental UVA = LS, dark period supplemental UVA = DS, and light-dark period supplemental UVA = LDS) contributed to yielding greater biomass production (fresh weight, dry weight, and plant moisture content), thus improving morphology (plant height, stem diameter, etc.) and promoting higher phytochemicals content (flavonoids, vitamin c, etc.), especially glucosinolates. To fathom its mechanisms, this study, using RNA-seq, verified that UV-A supplementation treatments signally generated related DEGs of plant hormone signal pathway, circadian rhythm plant pathway, glucosinolate pathway, etc. Moreover, 2047 DEGs were obtained in WGCNA, illustrating the correlations between genes, treatments, and pathways. Additionally, DS remarkedly up-regulated related DEGs of the key pathways and ultimately contributed to promoting the stem diameter, plant height, etc., thus increasing the pigment, biomass, vitamin c, etc., enhancing the antioxidant capacity, and most importantly, boosting the accumulations of glucosinolates in kale. In short, this study displayed new insights into UV-A supplementation affected the pathways related to the morphology and phytochemical profile of kale in plant factories.

Systematic Description of the Content Variation of Natural Products (NPs): To Prompt the Yield of High-Value NPs and the Discovery of New Therapeutics

Natural products (NPs) have long been associated with human production and play a key role in the survival of species. Significant variations in NP content may severely affect the "return on investment" of NP-based industries and render ecological systems vulnerable. Thus, it is crucial to construct a platform that relates variations in NP content to their corresponding mechanisms. In this study, a publicly accessible online platform, NPcVar (http://npcvar.idrblab.net/), was developed, which systematically described the variations of NP contents and their corresponding mechanisms. The platform comprises 2201 NPs and 694 biological resources, including plants, bacteria, and fungi, curated using 126 diverse factors with 26,425 records. Each record contains information about the species, NP, and factors involved, as well as NP content data, parts of the plant that produce NPs, the location of the experiment, and reference information. All factors were manually curated and categorized into 42 classes which belong to four mechanisms (molecular regulation, species factor, environmental condition, and combined factor). Additionally, the cross-links of species and NP to well-established databases and the visualization of NP content under various experimental conditions were provided. In conclusion, NPcVar is a valuable resource for understanding the relationship between species, factors, and NP contents and is anticipated to serve as a promising tool for improving the yield of high-value NPs and facilitating the development of new therapeutics.

Formation, immunomodulatory activities, and enhancement of glucosinolates and sulforaphane in broccoli sprouts: a review for maximizing the health benefits to human

Broccoli sprouts have been considered as functional foods which have received increasing attention because they have been highly prized for glucosinolates, phenolics, and vitamins in particular glucosinolates. One of hydrolysates-sulforaphane from glucoraphanin is positively associated with the attenuation of inflammatory, which could reduce diabetes, cardiovascular and cancer risk. In recent decades, the great interest in natural bioactive components especially for sulforaphane promotes numerous researchers to investigate the methods to enhance glucoraphanin levels in broccoli sprouts and evaluate the immunomodulatory activities of sulforaphane. Therefore, glucosinolates profiles are different in broccoli sprouts varied with genotypes and inducers. Physicochemical, biological elicitors, and storage conditions were widely studied to promote the accumulation of glucosinolates and sulforaphane in broccoli sprouts. These inducers would stimulate the biosynthesis pathway gene expression and enzyme activities of glucosinolates and sulforaphane to increase the concentration in broccoli sprouts. The immunomodulatory activity of sulforaphane was summarized to be a new therapy for diseases with immune dysregulation. The perspective of this review served as a potential reference for customers and industries by application of broccoli sprouts as a functional food and clinical medicine.

UV Radiation Induces Specific Changes in the Carotenoid Profile of Arabidopsis thaliana

UV-B and UV-A radiation are natural components of solar radiation that can cause plant stress, as well as induce a range of acclimatory responses mediated by photoreceptors. UV-mediated accumulation of flavonoids and glucosinolates is well documented, but much less is known about UV effects on carotenoid content. Carotenoids are involved in a range of plant physiological processes, including photoprotection of the photosynthetic machinery. UV-induced changes in carotenoid profile were quantified in plants (Arabidopsis thaliana) exposed for up to ten days to supplemental UV radiation under growth chamber conditions. UV induces specific changes in carotenoid profile, including increases in antheraxanthin, neoxanthin, violaxanthin and lutein contents in leaves. The extent of induction was dependent on exposure duration. No individual UV-B (UVR8) or UV-A (Cryptochrome or Phototropin) photoreceptor was found to mediate this induction. Remarkably, UV-induced accumulation of violaxanthin could not be linked to protection of the photosynthetic machinery from UV damage, questioning the functional relevance of this UV response. Here, it is argued that plants exploit UV radiation as a proxy for other stressors. Thus, it is speculated that the function of UV-induced alterations in carotenoid profile is not UV protection, but rather protection against other environmental stressors such as high intensity visible light that will normally accompany UV radiation.

Stress induced production of plant secondary metabolites in vegetables: Functional approach for designing next generation super foods

Plant secondary metabolites are vital for human health leading to the gain the access to natural products. The quality of crops is the result of the interaction of different biotic and abiotic factors. Abiotic stresses during plant growth may reduce the crop performance and quality of the produce. However, abiotic stresses can result in numerous physiological, biochemical, and molecular responses in plants, aiming to deal with these conditions. Abiotic stresses are also elicitors of the biosynthesis of plant secondary metabolites in plants which possess plant defense mechanisms as well as human health benefits such as anti-inflammatory, antioxidative properties etc. Plants either synthesize new compounds or alter the concentration of bioactive compounds. Due to increasing attention towards the production of bioactive compounds, the understanding of crop responses to abiotic stresses in relation to the biosynthesis of bioactive compounds is critical. Plants alter their metabolism at the genetic level in response to different abiotic stresses resulting the changes in secondary metabolite production. Transcriptional factors regulate genes responsible for secondary metabolite biosynthesis in several plants under stress conditions. Understanding the signaling pathways involved in the secondary metabolite biosynthesis has become easy with the use of molecular biology. Therefore, aim of writing the review is to focus on secondary metabolite production in vegetable crops, their health benefits and transcription regulation under various abiotic stresses.

Changes in Quercetin Derivatives and Antioxidant Activity in Marigold Petals (Tagetes patula L.) Induced by Ultraviolet-B Irradiation and Methyl Jasmonate

Marigold petals contain numerous antioxidative flavonoids and carotenoids that can be affected by environmental stressors. There is yet no detailed study on the relationship between phytochemical accumulation and stressors in marigold petals. This study evaluated quercetin derivatives and antioxidant activity in marigold petals in response to ultraviolet-B (UV-B) irradiation and methyl jasmonate (MeJA) treatment. The limiting UV-B radiation intensity and MeJA dose that caused no wilting damage under 1-h daily treatment for 10 days were <2 W∙m−2∙s−1 and <10 mM, respectively. Marigold petals contained three major flavonoids, quercetin-7-O-glucoside (Q7G, 6.6 mg∙g−1dw), quercetin-3-O-glucoside (Q3G, 62.7 mg), and quercetin (26.6 mg), possessing different antioxidant potential and exhibiting the highest power in quercetin and next value in Q7G. Single UV-B irradiation exerted a limited effect on the changes in the content of the three quercetin derivatives, whereas combined treatment with 1 W UV-B radiation and 5 mM MeJA resulted in the highest total quercetin content, showing >20% increase compared to that without treatment. This increase primarily resulted in an increase in quercetin content. MeJA treatment positively affected the increase in Q3G and Q7G contents in a dose-dependent manner during the 10-d experimental period but exerted no considerable effect on quercetin accumulation. The antioxidant activity was increased when flowers were exposed to mild MeJA treatment of 5−10 mM. UV-B irradiation decreased the antioxidant activity of marigold petals, but this decrease could be compensated by MeJA treatment.

Multi-Target Alternative Approaches to Promoting Fresh-Cut Carrots' Bioactive and Fresh-like Quality

Fresh-cut fruits and vegetables, as near-fresh foods, are a quick and easy solution to a healthy and balanced diet. The rapid degradation of nutritional and sensory quality during the processing and storage of a product is critical and plant-type-dependent. The introduction of disruptive technological solutions in fresh-cut processing, which could maintain fresh-like quality with less environmental impact, is an emerging research concept. The application of abiotic stress treatments (heat shock and UV-C) induces metabolic responses and microbial effects in plant tissues, potentially slowing down several quality senescence pathways. The previously selected combined and single effects of heat shock (100 °C/45 s; in the whole root) and UV-C (2.5 kJ/m²) treatments and two packaging conditions (oriented polypropylene (OPP) vs. micro-perforated OPP films) on controlling critical degradation pathways of fresh-cut carrots and on promoting bioactive and sensory quality during storage (5 °C, 14 days) were studied. Among the tested combinations, synergistic effects on the quality retention of fresh-cut carrots were only attained for applying heat shock associated with micro-perforated OPP film packaging. Its effects on reducing (3.3 Log₁₀ CFU/g) the initial contamination and controlling microbiological spoilage (counts below the threshold limit of 7.5 Log₁₀ CFU/g), increasing the bioactive content (38% and 72% in total phenolic content and chlorogenic acid, respectively), and preserving fresh quality attributes prove to be a viable alternative technology for shredded carrot processing.

Nrf2 antioxidant pathway and apoptosis induction and inhibition of NF-κB-mediated inflammatory response in human prostate cancer PC3 cells by Brassica oleracea var. acephala: An in vitro study

BACKGROUND

Brassica oleracea var. acephala is a good source of health-promoting biologically active compounds like phenolics, vitamins, and glucosinolates.

METHODS AND RESULTS

This in vitro research was conducted to evaluate the apoptotic, antioxidant, anti-inflammatory, and antiproliferative properties of ethanolic extract of Brassica oleracea var. acephala (EEBO) in PC3 prostate cancer cells. The LC-MS/MS technique was applied to identify the biomolecules of EEBO. The MTT assay was used to evaluate the cytotoxic effects of EEBO on PC3 cells. Moreover, qRT-PCR was used to examine the expression levels of Nrf2, NQO1, HO-1, NF-κB, TNF-α, IL-6, BAX, and BCL-2 in PC3 cell line. MMP was predicted by Rhodamine 123 staining, and release of cytochrome c was detected by an ELISA kit. Further, apoptosis was quantified by DNA fragmentation assay. The Western blotting method was used to detect the protein expression levels, and The DPPH assay was applied to determine the antioxidant effect of EEBO. The formula and structure of 19 biomolecules were predicted by LC-MS/MS. EEBO exhibited scavenging activity for DPPH. The MTT test showed EEBO reduced the viability of PC3 cells. The mRNA and protein levels of NRF2 pathway genes and BAX were increased, but those of the NF-κB pathway genes and BCL-2 were decreased in the EEBO-treated cells. Moreover, EEBO led to the diminution of MMP and enhanced the release of cytochrome c and DNA fragmentation, which resulted in apoptosis.

CONCLUSIONS

Molecular changes due to the anticancer impact of EEBO on PC3 were involved in the induction of Nrf2 antioxidant pathway and apoptosis and inhibition of inflammation.

Phytochemical Characterization of Twenty-Seven Peruvian Mashua (Tropaeolum tuberosum Ruíz & Pavón) Morphotypes and the Effect of Postharvest Methyl Jasmonate Application on the Accumulation of Antioxidants

Tropaeolum tuberosum Ruíz and Pav. “Mashua” is a crop from the Andean region associated with preventing chronic degenerative diseases. This study evaluated the content of bioactive compounds (phenolics, glucosinolates, carotenoids, and ascorbic acid) in twenty-seven Peruvian mashua morphotypes. Furthermore, three morphotypes (MAC 067, MAC 092, and MAC 123) were selected to evaluate further the effect of methyl jasmonate (MeJA) on the accumulation of bioactive compounds. Phenolic content in the mashua morphotypes ranged from 2990.76 ± 273.5 mg/kg to 24,217.36 ± 1144 mg/kg; whereas carotenoids ranged from 12.8 ± 0.6 mg/kg to 85.8 ± 3.1 mg/kg. Moreover, total glucosinolate content ranged from 65 ± 11 mmol/kg to 1289 ± 65 mmol/kg. The different mashua morphotypes showed low levels of ascorbic acid (lower than 5 mg/kg) compared with other crops. Except for glucosinolates, MeJA application augmented the level of bioactive compounds, showing increases of up to 150.1%, 535.0%, and 542% for total phenolics, carotenoids, and ascorbic acid, respectively. Results indicated that mashua is an excellent source of phenolics and glucosinolates, whereas it contains adequate levels of carotenoids and low levels of vitamin C. MeJA application during postharvest represented a simple approach to increase the content of bioactive compounds in mashua.

Selenium, Sulfur, and Methyl Jasmonate Treatments Improve the Accumulation of Lutein and Glucosinolates in Kale Sprouts

Kale sprouts contain health-promoting compounds that could be increased by applying plant nutrients or exogenous phytohormones during pre-harvest. The effects of selenium (Se), sulfur (S), and methyl jasmonate (MeJA) on lutein, glucosinolate, and phenolic accumulation were assessed in kale sprouts. Red Russian and Dwarf Green kale were chamber-grown using different treatment concentrations of Se (10, 20, 40 mg/L), S (30, 60, 120 mg/L), and MeJA (25, 50, 100 µM). Sprouts were harvested every 24 h for 7 days to identify and quantify phytochemicals. The highest lutein accumulation occurred 7 days after S 120 mg/L (178%) and Se 40 mg/L (199%) treatments in Red Russian and Dwarf Green kale sprouts, respectively. MeJA treatment decreased the level of most phenolic levels, except for kaempferol and quercetin, where increases were higher than 70% for both varieties when treated with MeJA 25 µM. The most effective treatment for glucosinolate accumulation was S 120 mg/L in the Red Russian kale variety at 7 days of germination, increasing glucoraphanin (262.4%), glucoerucin (510.8%), 4-methoxy-glucobrassicin (430.7%), and glucoiberin (1150%). Results show that kales treated with Se, S, and MeJA could be used as a functional food for fresh consumption or as raw materials for different industrial applications.

UVA and UVB Radiation as Innovative Tools to Biofortify Horticultural Crops with Nutraceuticals

The consumption of fruits and vegetables is related to the prevention and treatment of chronic–degenerative diseases due to the presence of secondary metabolites with pharmaceutical activity. Most of these secondary metabolites, also known as nutraceuticals, are present in low concentrations in the plant tissue. Therefore, to improve the health benefits of horticultural crops, it is necessary to increase their nutraceutical content before reaching consumers. Applying ultraviolet radiation (UVR) to fruits and vegetables has been a simple and effective technology to biofortify plant tissue with secondary metabolites. This review article describes the physiological and molecular basis of stress response in plants. Likewise, current literature on the mechanisms and effects of UVA and UVB radiation on the accumulation of different bioactive phytochemicals are reviewed. The literature shows that UVR is an effective tool to biofortify horticultural crops to enhance their nutraceutical content.

Supplemental UV-B Exposure Influences the Biomass and the Content of Bioactive Compounds in Linum usitatissimum L. Sprouts and Microgreens

The interest in the pre-harvest ultraviolet-B (UV-B) exposure of crops in indoor cultivation has grown consistently, though very little is known about its influence on the nutraceutical quality of microgreens. Flaxseeds constitute a valuable oilseed species, mostly appreciated for their nutritional properties and the presence of health-promoting compounds. Therefore, although scarcely studied, flaxseed sprouts and microgreens might constitute a high-quality food product to be included in a healthy diet. This study aims to unravel the effects of pre-harvest ultraviolet-B irradiation on the nutritional and nutraceutical quality of flaxseed sprouts and microgreens grown under artificial conditions. The UV-B irradiation decreased the biomass and stem length of microgreens. However, the content of total phenolics and flavonoids and the antioxidant capacity were strongly enhanced by the UV-B treatment in both sprouts and microgreens. Among photosynthetic pigments, chlorophyll a, violaxanthin, antheraxanthin, and lutein in sprouts were reduced by the treatment, while chlorophyll b increased in microgreens. In conclusion, our results showed that growing flaxseed sprouts and microgreens in controlled conditions with supplemental UV-B exposure might increase their nutritional and nutraceutical quality, as well as their antioxidant capacity, making them high-quality functional foods.

Insights into glucosinolate accumulation and metabolic pathways in Isatis indigotica Fort

BACKGROUND

Glucosinolates (GSLs) play important roles in defending against exogenous damage and regulating physiological activities in plants. However, GSL accumulation patterns and molecular regulation mechanisms are largely unknown in Isatis indigotica Fort.

RESULTS

Ten GSLs were identified in I. indigotica, and the dominant GSLs were epiprogoitrin (EPI) and indole-3-methyl GSL (I3M), followed by progoitrin (PRO) and gluconapin (GNA). The total GSL content was highest (over 20 μmol/g) in reproductive organs, lowest (less than 1.0 μmol/g) in mature organs, and medium in fresh leaves (2.6 μmol/g) and stems (1.5 μmol/g). In the seed germination process, the total GSL content decreased from 27.2 μmol/g (of seeds) to 2.7 μmol/g (on the 120th day) and then increased to 4.0 μmol/g (180th day). However, the content of indole GSL increased rapidly in the first week after germination and fluctuated between 1.13 μmol/g (28th day) and 2.82 μmol/g (150th day). Under the different elicitor treatments, the total GSL content increased significantly, ranging from 2.9-fold (mechanical damage, 3 h) to 10.7-fold (MeJA, 6 h). Moreover, 132 genes were involved in GSL metabolic pathways. Among them, no homologs of AtCYP79F2 and AtMAM3 were identified, leading to a distinctive GSL profile in I. indigotica. Furthermore, most genes involved in the GSL metabolic pathway were derived from tandem duplication, followed by dispersed duplication and segmental duplication. Purifying selection was observed, although some genes underwent relaxed selection. In addition, three tandem-arrayed GSL-OH genes showed different expression patterns, suggesting possible subfunctionalization during evolution.

CONCLUSIONS

Ten different GSLs with their accumulation patterns and 132 genes involved in the GSL metabolic pathway were explored, which laid a foundation for the study of GSL metabolism and regulatory mechanisms in I. indigotica.

Sprouts and Microgreens-Novel Food Sources for Healthy Diets

With the growing interest of society in healthy eating, the interest in fresh, ready-to-eat, functional food, such as microscale vegetables (sprouted seeds and microgreens), has been on the rise in recent years globally. This review briefly describes the crops commonly used for microscale vegetable production, highlights Brassica vegetables because of their health-promoting secondary metabolites (polyphenols, glucosinolates), and looks at consumer acceptance of sprouts and microgreens. Apart from the main crops used for microscale vegetable production, landraces, wild food plants, and crops' wild relatives often have high phytonutrient density and exciting flavors and tastes, thus providing the scope to widen the range of crops and species used for this purpose. Moreover, the nutritional value and content of phytochemicals often vary with plant growth and development within the same crop. Sprouted seeds and microgreens are often more nutrient-dense than ungerminated seeds or mature vegetables. This review also describes the environmental and priming factors that may impact the nutritional value and content of phytochemicals of microscale vegetables. These factors include the growth environment, growing substrates, imposed environmental stresses, seed priming and biostimulants, biofortification, and the effect of light in controlled environments. This review also touches on microgreen market trends. Due to their short growth cycle, nutrient-dense sprouts and microgreens can be produced with minimal input; without pesticides, they can even be home-grown and harvested as needed, hence having low environmental impacts and a broad acceptance among health-conscious consumers.

UV and Visible Spectrum LED Lighting as Abiotic Elicitors of Bioactive Compounds in Sprouts, Microgreens and Baby Leaves. A Comprehensive Review Including Their Mode of Action

According to social demands, the agri-food industry must elaborate convenient safe and healthy foods rich in phytochemicals while minimising processing inputs like energy consumption. Young plants in their first stages of development represent great potential. Objective: This review summarises the latest scientific findings concerning the use of UV and visible spectrum LED lighting as green, sustainable, and low-cost technologies to improve the quality of sprouts, microgreens, and baby leaves to enhance their health-promoting compounds, focusing on their mode of action while reducing costs and energy. Results: These technologies applied during growing and/or after harvesting were able to improve physiological and morphological development of sprouted seeds while increasing their bioactive compound content without compromising safety and other quality attributes. The novelty is to summarise the main findings published in a comprehensive review, including the mode of action, and remarking on the possibility of its postharvest application where the literature is still scarce. Conclusions: Illumination with UV and/or different regions of the visible spectrum during growing and shelf life are good abiotic elicitors of the production of phytochemicals in young plants, mainly through the activation of specific photoreceptors and ROS production. However, we still need to understand the mechanistic responses and their dependence on the illumination conditions.

UV-B Radiation as Abiotic Elicitor to Enhance Phytochemicals and Development of Red Cabbage Sprouts

Background: The main objective of this study was to evaluate the effect of periodical UV-B illumination during red cabbage germination on morphological development and the phenolics and carotenoid accumulation. Methods: During a sprouting period of 10 days at 20 °C in darkness, seedlings received 5, 10, or 15 kJ m−2 UV-B (T5, T10, and T15) applied in four steps (25% on days 3, 5, 7, and 10). UV untreated sprouts were used as control (CTRL). After 10 days of germination, the sprouts were harvested and stored 10 days at 4 °C as a minimally processed product. Phenolic and carotenoid compounds were analysed 1 h after each UV-B application and on days 0, 4, 7, and 10 during cold storage. Results: The longest hypocotyl length was observed in T10-treated sprouts. The total phenolic content (TPC), total flavonoid content (TFC), and total antioxidant capacity (TAC) increased during germination following a sigmoidal kinetic, especially in the UV-B-treated samples, which reported a dose-dependent behaviour. In this way, T10-treated sprouts increased the TPC by 40% after 10 days at 4 °C compared to CTRL, while TAC and TFC increased by 35 and 30%, respectively. Carotenoids were enhanced with higher UV-B doses (T15). Conclusions: We found that UV-B stimulated the biosynthesis of bioactive compounds, and a dose of 10 kJ m−2 UV-B, proportionally applied on days 3, 5, 7, and 10 days, is recommended.

CaCl2-HCl electrolyzed water affects glucosinolate metabolism and improves the quality of broccoli sprouts

This study evaluated the effects of CaCl₂-HCl electrolyzed water (CHEW) with different calcium chloride concentrations on broccoli sprouts. CHEW treatment reduced the malondialdehyde (MDA) and H₂O₂ contents of broccoli sprouts. The results showed that 10 kinds of glucosinolates were detected, and glucoraphanin was the dominant component. After hydrolysis, three kinds of isothiocyanates and two kinds of nitriles were detected in broccoli sprouts; however, the corresponding nitrile 4-isothiocyanato-1-butene was not detectable. The sulforaphane content of broccoli sprouts in the 10CHEW (Electrolyte of 10 mM CaCl₂ acidic solution) treatment increased by 34.4%, and the content of sulforaphane nitrile decreased by 53.3% compared with that of the tap water treatment. CHEW changed the metabolism of glucosinolates in broccoli sprouts by promoting the synthesis of glucoraphanin, increasing the activity of myrosinase and decreasing the activity of epithiospecifier protein (ESP) for the generation of more bioactive isothiocyanates. In addition, compared to the tap water treatment, the calcium content in broccoli sprouts treated with 25CHEW (Electrolyte of 25 mM CaCl₂ acidic solution) was dramatically enhanced from 15.8 to 49.7 mg/g DW. CHEW can be a useful tool for enhancing the amount of secondary metabolites and calcium content in broccoli sprouts intended for fresh consumption as a functional food.

Chemical Genetics Applied to Elucidate the Physiological Role of Stress-Signaling Molecules on the Wound-Induced Accumulation of Glucosinolates in Broccoli

Wounding stress is an effective strategy to induce glucosinolate (GS) biosynthesis in broccoli. However, there is insufficient knowledge on the physiological and molecular mechanisms underlying this stress response. Herein, a chemical-genetic approach was applied to elucidate the role of jasmonic acid (JA), ethylene (ET), and reactive oxygen species (ROS) on the wound-induced biosynthesis of GS. Broccoli was processed into chops to induce wounding stress. Broccoli chops were treated with phenidone (PHEN) and diphenyleneiodonium chloride (DPI) as inhibitors of JA and ROS biosynthesis, respectively, whereas 1-methylcyclopropene (1-MCP) was applied as an inhibitor of ET action. Wounding stress induced the expression of genes related to the biosynthesis of indolic and aliphatic GS, which was correlated with the accumulation of GS and modulated by the inhibitors of signaling molecules applied. Results of gene expression analysis indicated that JA played a key role in the activation of most genes, followed by ROS. Furthermore, except for the CYP79B2 gene, PHEN and 1-MCP synergistically downregulated the expression of GS biosynthetic genes evaluated, showing that the interaction between JA and ET was fundamental to modulate GS biosynthesis. Results presented herein increased our knowledge of the physiological and molecular mechanisms governing the wound-induced biosynthesis of GS in broccoli.

Manipulation of Continuous and End-of-Day Red/Far-Red Light Ratios Affects Glucobrassicin and Gluconasturtiin Accumulation in Cabbage (Brassica oleracea) and Watercress (Nasturtium officinale), Respectively

Cabbage (Brassica oleracea) and watercress (Nasturtium officinale) produce glucobrassicin (GBS) and gluconasturtiin (GNST), precursors of chemopreventive compounds. Their accumulation is affected by environmental signals. We studied the impact of the red to far-red light (R/FR) ratio on GBS concentration in red ″Ruby Ball″ and green ″Tiara″ cabbage. Foliar shading, via weed surrogates that competed with cabbage plants for specific durations, induced R/FR variation among treatments. ″Ruby Ball″ GBS concentrations were the highest when R/FR within the canopy was the lowest. ″Tiara″ was unaffected by competition. The same trend was observed in a controlled environment using R and FR LEDs without weeds present. ″Ruby Ball″ subjected to an R/FR = 0.3 treatment had 2.5- and 1.4-fold greater GBS concentration compared to R/FR = 1.1 and 5.0 treatments combined. Watercress given end-of-day (EOD) R and/or FR pulses after the main photoperiod had the lowest GNST concentrations after an EOD FR pulse but the highest concentrations after an R followed by FR pulse.

Elicitation: a new perspective into plant chemo-diversity and functional property

Sprouts are consumed as fresh foods or their flours can be added in processed products as determinants of sensory perception, product differentiation, and shelf life. Elicitation technique can be used to accumulate phytochemicals in plant sprouts thereby improving their functionality. This review summarized the recent state of knowledge on the use of elicitors to produce sprouts with improved functional properties. Elicitation using abiotic or biotic elicitors has been applied to increase the yield of sprout secondary metabolites (glucosinolates, aminobutyric acid, phenolic compounds), biological activities (antioxidant, anti-obesity, antidiabetic properties), and growth. Elicitors trigger the synthesis of plant metabolites by changing enzyme activities or gene expression related to the plant defence system. They also promote sprout growth by enhancing the levels of plant growth hormones. Elicitation is an effective method to produce sprouts with improved health benefits, and enhance their growth. Future studies are needed to identify early plant signaling pathways to fully understand elicitors' mechanisms on plant metabolites. Moreover, further investigation can be impetus in revealing the lower and upper limits of elicitor that can be applied in sprouts without compromising health and environmental safety.

Phytochemical Fortification in Fruit and Vegetable Beverages with Green Technologies

BACKGROUND

Phytochemical, bioactive and nutraceutical compounds are terms usually found in the scientific literature related to natural compounds found in plants linked to health-promoting properties. Fruit and vegetable beverages (mainly juice and smoothies) are a convenient strategy to enhance the consumption of horticultural commodities, with the possibility of being fortified with plant byproducts to enhance the content of bioactive compounds.

OBJECTIVE

This review aims to analyse the different green technologies applied in beverage processing with a fortification effect on their health promoting compounds.

RESULTS

Fortification can be performed by several strategies, including physical elicitors (e.g., processing technologies), plant/algae extract supplementation, and fermentation with probiotics, among others. Thermal processing technologies are conventionally used to ensure the preservation of food safety with a long shelf life, but this frequently reduces nutritional and sensory quality. However, green non-thermal technologies (e.g., UV, high-pressure processing, pulsed electric fields, ultrasounds, cold plasma, etc.) are being widely investigated in order to reduce costs and make possible more sustainable production processes without affecting the nutritional and sensory quality of beverages.

CONCLUSIONS

Such green processing technologies may enhance the content of phytochemical compounds through improvement of their extraction/bioaccessibility and/or different biosynthetic reactions that occurred during processing.

Effect of Methyl Jasmonate on Thymol, Carvacrol, Phytochemical Accumulation, and Expression of Key Genes Involved in Thymol/Carvacrol Biosynthetic Pathway in Some Iranian Thyme Species

Thyme species are a good source of thymol and carvacrol, which play a key role in controlling diseases. For the first time, the expression patterns of γ-terpinene synthase (TPS2), CYP71D178, and CYP71D180 genes and the amount of phenolics compounds were evaluated in T. migricus and T. daenensis after different methyl jasmonate (MeJA) treatments. The highest thymol and carvacrol contents were observed in T. migricus (86.27%) and T. daenensis (17.87%) at MeJA 100 µM, which was consistent with the expression patterns of the three investigated genes. All species treated showed high total phenolic and flavonoid content compared to control plants for which the highest amounts were observed in T. vulgaris treated with 100 µM and 10 µM MeJA. Furthermore, in the 100 µM MeJA treatment, the relative expression of TPS2 and CYP71D178 in T. migricus increased 7.47 and 9.86-fold compared with the control, respectively. The highest level of CYP71D180 transcripts (5.15-fold) was also observed for T. daenensis treated. This finding highlights the notion that thymol was known as the dominant component of the essential oil rather than carvacrol in diffident thyme species. This implies that MeJA at different concentrations influenced metabolic pathways and induced expression changes, resulting in a rise in essential oil levels.

Effects of Light Intensity and Spectral Composition on the Transcriptome Profiles of Leaves in Shade Grown Tea Plants (Camellia sinensis L.) and Regulatory Network of Flavonoid Biosynthesis

Black net shade treatment attenuates flavonoid biosynthesis in tea plants, while the effect of light quality is still unclear. We investigated the flavonoid and transcriptome profiles of tea leaves under different light conditions, using black nets with different shade percentages, blue, yellow and red nets to alter the light intensity and light spectral composition in the fields. Flavonol glycosides are more sensitive to light intensity than catechins, with a reduction percentage of total flavonol glycosides up to 79.6% compared with 38.7% of total catechins under shade treatment. A total of 29,292 unigenes were identified, and the KEGG result indicated that flavonoid biosynthesis was regulated by both light intensity and light spectral composition while phytohormone signal transduction was modulated under blue net shade treatment. PAL, CHS, and F3H were transcriptionally downregulated with light intensity. Co-expression analysis showed the expressions of key transcription factors MYB12, MYB86, C1, MYB4, KTN80.4, and light signal perception and signaling genes (UVR8, HY5) had correlations with the contents of certain flavonoids (p < 0.05). The level of abscisic acid in tea leaves was elevated under shade treatment, with a negative correlation with TFG content (p < 0.05). This work provides a potential route of changing light intensity and spectral composition in the field to alter the compositions of flavor substances in tea leaves and regulate plant growth, which is instructive to the production of summer/autumn tea and matcha.

Bioactive Composition and Nutritional Profile of Microgreens Cultivated in Thailand

Microgreens are young and tender leafy vegetables that have gained wider consumer acceptance. This is attributed to their low caloric composition and rich micronutrient and antioxidant composition. The present study investigated the bioactive composition and proximate analysis of fourteen microgreens belonging to Brassicaceae, Fabaceae, Pedaliaceae, Polygonaceae, Convolvulaceae, and Malvaceae. All the microgreens showed low calories (20.22 to 53.43 kcal 100 g−1) and fat (0.15 to 0.66 g 100 g−1), whilst mung bean and lentil microgreens showed considerable amounts of carbohydrate (7.16 g 100 g−1) and protein (6.47 g 100 g−1), respectively. Lentil microgreens had the highest total chlorophyll (112.62 mg 100 g−1) and carotenoid (28.37 mg 100 g−1) contents, whilst buckwheat microgreens showed the highest total phenolic content (268.99 mg GAE 100 g−1) and DPPH• scavenging activity (90.83 mM TEAC g−1). The lentil microgreens also presented high ascorbic acid content (128.70 mg 100 g−1) along with broccoli, Chinese kale, purple radish, and red cabbage microgreens (79.11, 81.33, 82.58, and 89.49 mg 100 g−1, respectively). Anthocyanin content was only detected in purple radish (0.148 mg CGE 100 g−1) and red cabbage (0.246 mg CGE 100 g−1). The results provide basic information and highlight the benefits of utilizing genetic biodiversity to obtain microgreens with the desired nutrients and antioxidants.

Edible Plant Sprouts: Health Benefits, Trends, and Opportunities for Novel Exploration

The consumption of plant sprouts as part of human day-to-day diets is gradually increasing, and their health benefit is attracting interest across multiple disciplines. The purpose of this review was to (a) critically evaluate the phytochemicals in selected sprouts (alfalfa, buckwheat, broccoli, and red cabbage), (b) describe the health benefits of sprouts, (c) assess the recent advances in sprout production, (d) rigorously evaluate their safety, and (e) suggest directions that merit special consideration for further novel research on sprouts. Young shoots are characterized by high levels of health-benefitting phytochemicals. Their utility as functional ingredients have been extensively described. Tremendous advances in the production and safety of sprouts have been made over the recent past and numerous reports have appeared in mainstream scientific journals describing their nutritional and medicinal properties. However, subjects such as application of sprouted seed flours in processed products, utilizing sprouts as leads in the synthesis of nanoparticles, and assessing the dynamics of a relationship between sprouts and gut health require special attention for future clinical exploration. Sprouting is an effective strategy allowing manipulation of phytochemicals in seeds to improve their health benefits.

The Application of Fe-EDTA and Sodium Silicate Affects the Polyphenols Content in Broccoli and Radish Sprouts

The effects of elicitors on broccoli (Brassica oleracea L. var. Italica) and radish (Raphanus&nbsp;sativus L.) sprouts were evaluated. Seeds and then sprouts were soaked daily for 30 min over 6 days in water (control) or a mixture of FeEDTA and sodium silicate or sodium silicate alone. The contents of the flavonoids and phenolic acids (free, esters, and glycosides) were determined using HPLC-ESI-MS/MS. Phenolic compounds were released from the esters after acid hydrolysis and from the glycosides using alkaline hydrolysis. Quercetin, kaempferol, (‒)-epicatechin, naringenin, apigenin, and luteolin derivatives were found in broccoli and radish sprouts, while derivatives of iso-rhamnetin, orientin, and vitexin were not present at measurable levels. The flavonoid contents, especially derivatives of quercetin, were considerably higher in the broccoli sprouts than in the radish sprouts. The quantitatively major phenolic acid content in the sprouts of both species was found to be p-hydroxybenzoic acid. Its content in the radish sprouts was several times higher than in the broccoli sprouts. The total flavonoid content of broccoli sprouts was 507-734 µg/g DW, while that of the radish sprouts ranged from 155 µg/g DW to 211 µg/g DW. In contrast, total phenolic acids were higher in radish sprouts, ranging from 11,548 to 13,789 µg/g DW, while in broccoli sprouts, they ranged from 2652 to 4527 µg/g DW, respectively. These differences resulted radish sprouts having higher antioxidant activity compared to broccoli sprouts. The applied elicitors increased the content of the total phenolic acids and the antioxidant activity of radish and broccoli sprouts, while they decreased the level of the total flavonoids in broccoli sprouts.

Periodical UV-B radiation hormesis in biosynthesis of kale sprouts nutraceuticals

The objective of the present study was to evaluate the periodical UV-B radiation hormesis during kale seeds germination in their main content of secondary metabolite compounds (phenols; glucosinolates; total antioxidant capacity -TAC-) and their changes during a refrigerated shelf-life. The total UV-B doses received were 0, 5, 10, and 15 kJ m^-2 (CTRL, UVB5, UVB10, and UVB15) in where the 25% was applied on the 3rd, 5th, 7th, and 10th sprouting day. UV radiation did not affect the morphological development of the sprouts. UVB10 and UVB15 treatments increased their phenolic content (>30%). Likewise, TAC was increased by UV-B lighting ~10% (DPPH) and ~20% (FRAP). The hydroxycinnamic acid content in UVB15-treated sprouts increased by 52%, while UVB5 reported an increase of 34% in the kaempferol-3,7-di-O-glucoside concentration, compared to CTRL. After 10 d at 4 °C of shelf-life, content of gallic acid hexoside I and gallic acid increased by 55 and 78% compared to UV-untreated kale sprouts, respectively. Glucoraphanin was the main glucosinolate found in kale sprouts and seeds, followed by 4-hydroxy-glucobrassicin, whose biosynthesis was enhanced by UVB10 (~24 and ~27%) and UVB15 (~36 and ~30%), respectively, compared to CTRL. In conclusion, periodical low UV-B illumination represents a useful tool to stimulate phytochemicals biosynthesis in kale sprouts as an important source of bioactive compounds with potential health benefits.

Combination of Selenium and UVA Radiation Affects Growth and Phytochemicals of Broccoli Microgreens

Addition of selenium or application of ultraviolet A (UVA) radiation for crop production could be an effective way of producing phytochemical-rich food. This study was conducted to investigate the effects of selenium and UVA radiation, as well as their combination on growth and phytochemical contents in broccoli microgreens. There were three treatments: Se (100 μmol/L Na₂SeO₃), UVA (40 μmol/m²/s) and Se + UVA (with application of Se and UVA). The control (CK) was Se spraying-free and UVA radiation-free. Although treatment with Se or/and UVA inhibited plant growth of broccoli microgreens, results showed that phytochemical contents increased. Broccoli microgreens under the Se treatment had higher contents of total soluble sugars, total phenolic compounds, total flavonoids, ascorbic acid, Fe, and organic Se and had lower Zn content. The UVA treatment increased the contents of total chlorophylls, total soluble proteins, total phenolic compounds, and FRAP. However, the Se + UVA treatment displayed the most remarkable effect on the contents of total anthocyanins, glucoraphanin, total aliphatic glucosinolates, and total glucosinolates; here, significant interactions between Se and UVA were observed. This study provides valuable insights into the combinational selenium and UVA for improving the phytochemicals of microgreens grown in an artificial lighting plant factory.

Anything New under the Sun? An Update on Modulation of Bioactive Compounds by Different Wavelengths in Agricultural Plants

Plants continuously rely on light as an energy source and as the driver of many processes in their lifetimes. The ability to perceive different light radiations involves several photoreceptors, which in turn activate complex signalling cascades that ultimately lead to a rearrangement in plant metabolism as an adaptation strategy towards specific light conditions. This review, after a brief summary of the structure and mode of action of the different photoreceptors, introduces the main classes of secondary metabolites and specifically focuses on the influence played by the different wavelengths on the content of these compounds in agricultural plants, because of their recognised roles as nutraceuticals.