Carotenoids, polyphenols and micronutrient profiles of Brassica oleraceae and plum varieties and their contribution to measures of total antioxidant capacity

Brassica vegetables-an undervalued nutritional goldmine

The genus Brassica includes six species and over 15 types of vegetables that are widely cultivated and consumed globally. This group of vegetables is rich in bioactive compounds, including glucosinolates, vitamins (such as vitamin C, folate, tocopherol, and phylloquinone), carotenoids, phenols, and minerals, which are crucial for enriching diets and maintaining human health. However, the full extent of these phytonutrients and their significant health benefits remain to be fully elucidated. This review highlights the nutrient compositions and health advantages of Brassica vegetables and discusses the impacts of various processing methods on their nutritional value. Additionally, we discuss potential strategies for enhancing the nutrition of Brassica crops through agronomic biofortification, conventional breeding, and biotechnological or metabolic engineering approaches. This review lays the foundation for the nutritional improvement of Brassica crops.

Farm to Fork Stability of Phytochemicals and Micronutrients in Brassica oleracea and Allium Vegetables

Brassica oleracea and Allium vegetables are known for their unique, family specific, water-soluble phytochemicals, glucosinolates, and S-alk(en)yl-l-cysteine sulfoxides, respectively. However, they are also important delivery systems of several other health-related compounds, such as carotenoids (lipid-soluble phytochemicals), vitamin C (water-soluble micronutrient), and vitamin K1 (lipid-soluble micronutrient). When all-year-round availability or transport over long distances is targeted for these often seasonal, locally grown vegetables, processing becomes indispensable. However, the vegetable processing chain, which consists of multiple steps (e.g., pretreatment, preservation, storage, preparation), can impact the nutritional quality of these vegetables corresponding to the nature of the health-related compounds and their susceptibility to (bio)chemical conversions. Since information about the impact of the vegetable processing chain is scattered per compound or processing step, this review targets an integration of the state of the art and discusses needs for future research. Starting with a discussion on substrate-enzyme location within the vegetable matrix, an overview is provided of the impact and potential of processing, encompassing a wide range of (nonenzymatic) conversions.

The Effects of Different Drying Methods on the In Vitro Bioaccessibility of Phenolics, Antioxidant Capacity, and Morphology of European Plums (Prunes domestica L.)

Four different drying methods, hot-air-drying (HAD), vacuum-drying (VD), ultrasound-assisted vacuum-drying (US-VD), and freeze-drying (FD), were used to obtain dried plums (Prunes domesticaL.). These prunes were evaluated for their physical properties (such as color, rehydration ratio, and microstructural properties), phenolic compounds, and antioxidant activities before and after being subjected to in vitro digestion. TPC (total phenolic content) of plums ranged from 196.84 to 919.58 mg of GAE (gallic acid equivalent)/100 g of dw, and neochlorogenic acid was the most abundant phenolic compound. FD prunes had the highest levels of phenolics, whereas US-VD caused the most significant loss. During in vitro digestion, the phenolics were present at higher levels at the gastric medium but failed to maintain their stability at the small intestinal stage. Among the samples, FD along with HAD prunes exhibited a higher bioaccessibility index for most of the phenolic compounds. The ratios of TPC, TFC (total flavonoid content), and individual phenolics determined in the digested residues to the initial values of the undigested samples ranged from 0.23 to 31.03%. It could be concluded that the majority of the phenolics were extracted during digestion. Our findings showed that the different drying methods would alter the microstructure, which would affect the extractability and release of phenolics in the simulated digestion model.

Inverse correlations between serum carotenoids and respiratory morbidity and mortality: the Third National Health and Nutrition Examination Survey

The objective was to evaluate the association between serum carotenoid levels and respiratory morbidity and mortality in a nationally representative sample of US adults. We assessed the association of serum carotenoid levels with respiratory morbidity and mortality using logistic regression and proportional hazards regression models. Meanwhile, a series of confounders were controlled in regression models and restricted cubic spline, which included age, sex, race, marriage, education, income, drinking, smoking, regular exercise, BMI, daily energy intake, vitamin E, vitamin C, fruit intake, vegetable intake, diabetes, hypertension, asthma, emphysema and chronic bronchitis. Compared with participants in the lowest tertiles, participants in the highest tertiles of serum total carotenoids, β-cryptoxanthin and lutein/zeaxanthin levels had a significantly lower prevalence of emphysema (ORtotal carotenoids = 0·61, 95% CI: 0·41-0·89, ORβ-cryptoxanthin = 0·67, 95% CI: 0·49-0·92), chronic bronchitis (ORβ-cryptoxanthin = 0·66, 95% CI: 0·50-0·87) and asthma (Q2: ORlutein/zeaxanthin = 0·78, 95% CI: 0·62-0·97); participants in the highest tertiles of total carotenoids, α-carotene, lutein/zeaxanthin and lycopene had a lower risk of respiratory mortality (hazard ratio (HR)total carotenoids = 0·62, 95% CI: 0·42-0·90, HRα-carotene = 0·54, 95% CI: 0·36-0·82, HRlutein/zeaxanthin = 0·48, 95% CI: 0·33-0·71, HRlycopene = 0·66, 95% CI: 0·45-0·96) than those in the lowest tertiles. Higher serum total carotenoids and β-cryptoxanthin levels is associated with decreased prevalence of emphysema and chronic bronchitis, and higher serum total carotenoids, α-carotene, lutein/zeaxanthin and lycopene levels had a lower mortality of respiratory disease.

Elicitation with hydrogen peroxide promotes growth, phenolic-enrichment, antioxidant activity and nutritional values of two hydroponic lettuce genotypes

Dietary vegetables rich in bioactive compounds are major responsible for promoting human health. Herein, the effect of hydrogen peroxide (H2O2), an important signaling compound, on growth and quality of two hydroponic lettuce genotypes was investigated. The maximum enhancement of growth traits was shown in lettuce elicited with 10 mmol/L H2O2, while 40 mmol/L H2O2 significantly reduced above growth traits. H2O2 elicitation increased pigment contents and photosynthetic process, which consequently caused enhancements of phenolic compounds, ascorbic acid, glutathione, carotenoids, soluble sugars, free amino acids, soluble protein, minerals, and antioxidant capacity, while above alterations appeared in a genotype-dependent manner. The phenolic accumulation was correlated with improved activity of phenylalanine ammonia lyase (PAL) and expression levels of genes related to phenolic biosynthesis, including PAL, chalcone synthase, flavanone 3-hydroxylase, dihydroflavonol-4 reductase, and UDP-glucose: flavonoid 3-O-glucosyltransferase. Therefore, elicitation with H2O2 is a promising strategy to develop lettuce with high bioactive compounds and biomass.

Assessment of Bio-Compounds Content, Antioxidant Activity, and Neuroprotective Effect of Red Cabbage (Brassica oleracea var. Capitata rubra) Processed by Convective Drying at Different Temperatures

Parkinson's disease (PD) is the second most common neurodegenerative disorder, and no efficient therapy able to cure or slow down PD is available. In this study, dehydrated red cabbage was evaluated as a novel source of bio-compounds with neuroprotective capacity. Convective drying was carried out at different temperatures. Total phenolics (TPC), flavonoids (TFC), anthocyanins (TAC), and glucosinolates (TGC) were determined using spectrophotometry, amino acid profile by LC-DAD and fatty acid profile by GC-FID. Phenolic characterization was determined by liquid chromatography-high-resolution mass spectrometry. Cytotoxicity and neuroprotection assays were evaluated in SH-SY5Y human cells, observing the effect on preformed fibrils of α-synuclein. Drying kinetic confirmed a shorter processing time with temperature increase. A high concentration of bio-compounds was observed, especially at 90 °C, with TPC = 1544.04 ± 11.4 mg GAE/100 g, TFC = 690.87 ± 4.0 mg QE/100 g and TGC = 5244.9 ± 260.2 µmol SngE/100 g. TAC degraded with temperature. Glutamic acid and arginine were predominant. Fatty acid profiles were relatively stable and were found to be mostly C18:3n3. The neochlorogenic acid was predominant. The extracts had no cytotoxicity and showed a neuroprotective effect at 24 h testing, which can extend in some cases to 48 h. The present findings underpin the use of red cabbage as a functional food ingredient.

Comparative Analysis of Carotenoid Profiles and Biosynthetic Gene Expressions among Ten Plum Cultivars

Plums are good sources of various bioactive phytochemical compounds such as vitamins, anthocyanins, and carotenoids, whereby all of which are noted for multiple potential health benefits. However, knowledge regarding plum carotenoid profiles remains limited. Hence, the total and individual carotenoids in the edible parts (skin and flesh) of ten plum cultivars were determined using a spectrophotometer and high-performance liquid chromatography-diode array detection, respectively. Total and individual carotenoid contents in skin were significantly higher (p < 0.05) than those in flesh among all plum cultivars tested. The cultivars with the highest content of total carotenoids in skin were Naili (36.73 μg/g FW), followed by Yinhongli (21.81 μg/g FW) and Yuhuangli (19.70 μg/g FW), with the lowest in Angeleno (8.97 μg/g FW). Lutein, zeaxanthine, β-cryptoxanthin, α-carotene, and β-carotene were the major types of carotenoids detected, with lutein and β-carotene being the predominant constituents of the skin and flesh tissues, respectively. Lutein, zeaxanthine, and total carotenoid contents were positively correlated with the expressions of PSY, LCYB, and LCYE, and negatively correlated with the expressions of PDS and CRTISO. Characterizing the carotenoid profiles and investigating variations in carotenoid biosynthetic gene expressions among plum cultivars are crucial for advancing genetic improvements in plums.

Wild vs. Cultivated Zingiber striolatum Diels: Nutritional and Biological Activity Differences

Compositional, functional, and nutritional properties are important for the use-value assessments of wild and cultivated edible plants. The aim of this study was to compare the nutritional composition, bioactive compounds, volatile compounds, and potential biological activities of cultivated and wild Zingiber striolatum. Various substances, such as soluble sugars, mineral elements, vitamins, total phenolics, total flavonoids, and volatiles, were measured and analyzed using UV spectrophotometry, ICP-OES, HPLC, and GC-MS methods. The antioxidant capacity of a methanol extract of Z. striolatum, as well as the hypoglycemic abilities of its ethanol and water extracts, were tested. The results showed that the contents of soluble sugar, soluble protein, and total saponin in the cultivated samples were higher, while the wild samples contained higher amounts of K, Na, Se, vitamin C, and total amino acids. The cultivated Z. striolatum also showed a higher antioxidant potential, while the wild Z. striolatum exhibited a better hypoglycemic activity. Thirty-three volatile compounds were identified using GC-MS in two plants, with esters and hydrocarbons being the main volatile compounds. This study demonstrated that both cultivated and wild Z. striolatum have a good nutritional value and biological activity, and can be used as a source of nutritional supplementation or even in medication.

Pro- and Antioxidant Effect of Food Items and Matrices during Simulated In Vitro Digestion

The digestive tract can be considered a bioreactor. High levels of reactive oxygen species (ROS) during digestion may predispose for local and/or systemic oxidative stress and inflammation, e.g., inflammatory bowel diseases. Food items rich in antioxidants may prevent such aggravation. This investigation analyzed pro-and antioxidant patterns of food matrices/items following in vitro digestion. Gastrointestinal digestion reflecting typically consumed quantities was performed on nine food items (orange and tomato juice, soda, coffee, white chocolate, sausage, vitamin C and E, and curcumin) and their combinations (n = 24), using the INFOGEST model. Antioxidant potential was measured by FRAP, DPPH, and ABTS, and pro-oxidant aspects by MDA (malondialdehyde) and peroxide formation. An anti-pro-oxidant score was developed, combining the five assays. Liquid food items showed moderately high antioxidant values, except for coffee and orange juice, which exhibited a high antioxidant potential. Solid matrices, e.g., white chocolate and sausage, showed both high pro-oxidant (up to 22 mg/L MDA) and high antioxidant potential (up to 336 mg/L vitamin C equivalents) at the same time. Individual vitamins (C and E) at physiological levels (achievable from food items) showed a moderate antioxidant potential (<220 mg/L vitamin C equivalents). Overall, both antioxidant and pro-oxidant assays correlated well, with correlation coefficients of up to 0.894. The effects of food combinations were generally additive, i.e., non-synergistic, except for combinations with sausage, where strong quenching effects for MDA were observed, e.g., with orange juice. In conclusion, as especially highlighted by complex matrices demonstrating both pro- and antioxidant potential, only measuring one aspect would result in physiological misinterpretations. Therefore, it is imperative to employ a combination of assays to evaluate both pro- and antioxidant properties of food digesta to ensure physiological relevance.

Enhanced accumulation of phenolics in pea (Pisum sativum L.) seeds upon foliar application of selenate or zinc oxide

Background

Selenium (Se) and zinc (Zn) are essential antioxidant enzyme cofactors. Foliar Se/Zn application is a highly effective method of plant biofortification. However, little is known about the effect of such applications on the concentration of trace elements and phytochemicals with pro-oxidant or antioxidant activity in pea (Pisum sativum L.).

Methods

A 2-year pot experiment (2014/2015) was conducted to examine the response of two pea varieties (Ambassador and Premium) to foliar-administered sodium selenate (0/50/100 g Se/ha) and zinc oxide (0/375/750 g Zn/ha) at the flowering stage. Concentrations of selected trace elements (Fe, Cu, and Mn), total phenolic content (TPC), total flavonoid content (TFC), and total antioxidant activity (ABTS, FRAP) of seeds were determined.

Results and conclusions

Se/Zn treatments did not improve the concentration of trace elements, while they generally enhanced TPC. Among examined treatments, the highest TPC was found in Ambassador (from 2014) treated with 100 g Se/ha and 750 g Zn/ha (2,926 and 3,221 mg/100 g DW, respectively) vs. the control (1,737 mg/100 g DW). In addition, 50 g of Se/ha increased TFC vs. the control (261 vs. 151 mg/100 g DW) in Premium (from 2014), 750 g of Zn/ha increased ABTS vs. the control (25.2 vs. 59.5 mg/100 g DW) in Ambassador (from 2015), and 50 g of Se/ha increased FRAP vs. the control (26.6 vs. 18.0 mmol/100 g DW) in Ambassador (from 2015). In linear multivariable regression models, Zn, Mn, Cu, and TPC best explained ABTS (R = 0.577), while Se, Cu, and TPC best explained the FRAP findings (R = 0.696). This study highlights the potential of foliar biofortification with trace elements for producing pea/pea products rich in bioactive plant metabolites beneficial for human health.

Foliar Selenate and Zinc Oxide Separately Applied to Two Pea Varieties: Effects on Growth Parameters and Accumulation of Minerals and Macronutrients in Seeds under Field Conditions

Though selenium (Se) and zinc (Zn) constitute essential nutrients for human health, their deficiencies affect up to 15% and 17% of the global population, respectively. Agronomic biofortification of staple crops with Se/Zn may alleviate these challenges. Pea (Pisum sativum L.) is a nutritious legume crop that has great potential for Se/Zn biofortification. Herein, two varieties of pea (Ambassador, Premium) were biofortified via foliar application of sodium selenate (0/50/100 g of Se/ha) or zinc oxide (0/375/750 g of Zn/ha) during the flowering stage under field conditions. While no significant differences were found in Se accumulation between seed varieties upon Se treatments, selenate enhanced the accumulation of Se in the two seed varieties in a dose dependent manner. Selenium concentration was most elevated in seeds of Ambassador exposed to 100 g of Se/ha (3.93 mg/kg DW compared to the control (0.08 mg/kg DW), p < 0.001). 375 g of Zn/ha (35.7 mg/kg DW) and 750 g of Zn/ha (35.5 mg/kg DW) significantly and similarly enhanced Zn concentrations compared to the control (31.3 mg/kg DW) in Premium seeds, p < 0.001. Zinc oxide also improved accumulations of Fe, Cu, Mn, and Mg in Premium seeds. Se/Zn treatments did not significantly affect growth parameters and accumulations of soluble solids and protein in seeds. Positive and significant (p < 0.01) correlations were observed between Zn and Fe, Cu, Mn and Mg levels in Premium seeds, among others. Consuming 33 g/day of pea biofortified with Se at 50 g/ha and 266 g/day of pea biofortified with 375 g of Zn/ha could provide 100% of the RDA (55 μg) for Se and RDA (9.5 mg) for Zn in adults, respectively. These results are relevant for enhancing Se/Zn status in peas by foliar biofortification.

Bioactive Compounds from Leaf Vegetables as Preservatives

Trends toward a healthier diet are increasing attention to clean-label products. This has led to the search for new ingredients that avoid the use of chemical additives. Food industries are responding to these demands by incorporating natural preservatives into their products, which consumers perceive as healthy. Leafy vegetables would fit this strategy since they are common components of the diet and are associated with beneficial health effects. The objective of this chapter is to offer an overview of the large number of bioactive compounds (phenolic acids, flavonoids, anthocyanins, glucosinolates, and sulfur compounds) present in these plants, which would be responsible for their activity as potential preservatives. Its incorporation into food would improve the quality and extend the shelf life by reducing oxidative processes and inhibiting or retarding the microbial growth that occurs during processing and storage without reducing the organoleptic characteristics of the product.

Plum supplementation and lipid profile: a systematic review and meta-analysis of randomised controlled trials

Plums are abundant in bioactive compounds which have been associated with numerous health benefits. In the present study, we aimed at examining the impact of plum supplementation on lipid profile of individuals. Electronic bibliographical databases were searched for relevant randomised clinical trials. Articles meeting our eligibility criteria were included for data extraction and final analysis. Weighted mean difference (WMD) was estimated using a random-effect model. Of the total articles retrieved in the initial search, nine articles were found to be eligible to be included in the analysis. Our results show that plum supplementation significantly improves total cholesterols levels in the unhealthy individuals. Moreover, plum supplementation reduces the LDL-c levels in the pooled sample (WMD = -11⋅52 mg/dl; 95 % CI -21⋅93, -1⋅11, P = 0⋅03, I ² = 98⋅7 %) and also in some of the subgroups of individuals (dried plum, unhealthy subjects, duration more than 8 weeks). Moreover, it had a significant reducing effect on TC levels just in unhealthy subjects. Although plum supplementation did not have any significant impact on serum levels of TG nor HDL-c. Our results show that supplementation with plums is potentially effective in reducing serum total cholesterol and LDL-c.

Anti-Inflammatory Potential of Brassicaceae-Derived Phytochemicals: In Vitro and In Vivo Evidence for a Putative Role in the Prevention and Treatment of IBD

Inflammatory bowel disease (IBD) is a group of intestinal disorders, of unknown etiology, characterized by chronic inflammation within the gut. They are gradually becoming critical because of the increasing incidence worldwide and improved diagnosis. Due to the important side effects observed during conventional therapy, natural bioactive components are now under intense investigation for the prevention and treatment of chronic illnesses. The Brassicaceae family comprises vegetables widely consumed all over the world. In recent decades, a growing body of literature has reported that extracts from the Brassicaceae family and their purified constituents have anti-inflammatory properties, which has generated interest from both the scientific community and clinicians. In this review, data from the literature are scrutinized and concisely presented demonstrating that Brassicaceae may have anti-IBD potential. The excellent biological activities of Brassicacea are widely attributable to their ability to regulate the levels of inflammatory and oxidant mediators, as well as their capacity for immunomodulatory regulation, maintenance of intestinal barrier integrity and intestinal flora balance. Possible future applications of bioactive-derived compounds from Brassicaceae for promoting intestinal health should be investigated.

Effect of plum supplementation on blood pressure, weight indices, and C-reactive protein: A systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Metabolic syndrome and its components are major health concerns around the world. Among various factors, overweight/obesity, its consequent inflammation, and hypertension are of special importance. Plums are anti-oxidant-rich fruits which have long been investigated for their health benefits. In this systematic review and meta-analysis, we investigated the possible impact of plum supplementation on obesity, inflammation, and blood pressure.

METHODS

All of the major databases (PubMed, Scopus, Cochrane, and Web of Science, Google Scholar and EMBASE) were searched to obtain the articles eligible for the review. Relevant data was extracted for the final analysis. Weighted mean difference (WMD) was obtained using fixed and random effect models. The main outcomes included systolic and diastolic blood pressure, body weight, body mass index (BMI), body fat percentage, waist circumference (WC) and blood C-reactive protein (CRP) levels. The effect sizes were expressed as weighted mean difference (WMD) and 95% confidence intervals (CI).

RESULTS

Crude search provided 3121 articles, among which 11 were eligible to be included. After crude and subgroup analysis, we were unable to detect any significant impact of plum supplementation on body weight (weight mean difference (WMD) of 0.04 kg; 95% CI: -1.55, 1.63, p = 0.959), BMI (WMD 0.39 kg/m²; 95% CI: -0.11, 0.90, p = 0.125), body fat percentage (WMD = 0.59%; 95% CI: -0.41, 1.59, p = 0.249), waist circumference (WMD = 0.60 cm; 95% CI: -1.83, 3.04, p = 0.627), systolic blood pressure (WMD -1.24 mmHg; 95% CI: -3.08, 0.59, p = 0.185), diastolic blood pressure (WMD -4.32 mmHg (95% CI: -9.29, 0.65, p = 0.089), or inflammation indicated by C-reactive protein (CRP) levels (WMD = 0.23 mg/l; 95% CI: -0.27, 0.73, p = 0.371).

CONCLUSION

Our results show that plum supplementation has no positive effect on factors of metabolic syndrome. We recommend that further research in the form of clinical trials be conducted to make a clear conclusion as of the effectiveness of plum supplementation on parameters of metabolic syndrome.

Vitamin E and carotenoid profiles in leaves, stems, petioles and flowers of stinging nettle (Urtica leptophylla Kunth) from Costa Rica

BACKGROUND

Local leafy vegetables are gaining attention as affordable sources of micronutrients, including vitamins, pro-vitamin carotenoids and other bioactive compounds. Stinging nettles (Urtica spp.) are used as source of fibers, herbal medicine and food. However, despite the relatively wide geographical spread of Urtica leptophylla on the American continent, little is known about its content of vitamin E congeners and carotenoids. We therefore investigated the particular nutritional potential of different plant structures of wild Costa Rican U. leptophylla by focusing on their vitamin E and carotenoid profiles.

RESULTS

Young, mature and herbivore-damaged leaves, flowers, stems and petioles were collected and freeze-dried. Vitamin E and carotenoids were determined by high-performance liquid chromatography after liquid/liquid extraction with hexane. α-Tocopherol was the major vitamin E congener in all structures. Flowers had a high content of γ-tocopherol. Herbivore-damaged leaves had higher contents of vitamin E than undamaged leaves. Lutein was the major and β-carotene the second most abundant carotenoid in U. leptophylla. No differences in carotenoid profiles were observed between damaged and undamaged leaves.

CONCLUSION

The leaves of U. leptophylla had the highest nutritional value of all analyzed structures; therefore, they might represent a potential source of α-tocopherol, lutein and β-carotene. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Hydrogen peroxide regulates the biosynthesis of phenolic compounds and antioxidant quality enhancement in lettuce under low nitrogen condition

Reduced nitrogen availability is an efficient strategy for increasing the accumulation of phenolic compounds in vegetables, but related mechanisms remain unknown. Here, the production of hydrogen peroxide (H₂O₂) and its potential roles in regulating phenolic biosynthesis and enhancing the antioxidant quality of lettuce under low nitrogen (LN) conditions were investigated. The LN treatment caused a rapid production of H₂O₂, which effectively increased lettuce quality by enhancing the levels of phenolic compounds and other nutrients such as ascorbic acid, glutathione, soluble sugar, and soluble protein. The increased phenolic content was related to the higher expression levels of phenolic biosynthesis genes, including PAL, CHS, DFR, F35H, and UFGT, and higher photosynthetic capacity after H₂O₂ addition under LN conditions. However, these positive effects were suppressed by dimethylthiourea (DMTU), a scavenger of H₂O₂. These results suggest that H₂O₂ as an important signal molecular mediates the LN-caused phenolic accumulation and antioxidant quality enhancement in lettuce.

Comparison of Wet Fractionation Methods for Processing Broccoli Agricultural Wastes and Evaluation of the Nutri-Chemical Values of Obtained Products

The main objective of this study was to increase the economic value of broccoli green agro-waste using three wet fractionation methods in the shadow of green biorefinery and the circular economy. Product candidates were obtained directly by using a mechanical press, and indirectly by using microwave coagulation or via lactic acid fermentation of green juice. The leaf protein concentrates (LPC) fractions displayed significantly higher dry matter content and crude protein content (34–39 m/m% on average) than the green juice fraction (27.4 m/m% on average), without considerable changes in the amino acids composition ratio. UHPLC-ESI-ORBITRAP-MS/MS analysis showed that kaemferol and quercetin are the most abundant flavonols, forming complexes with glycosides and hydroxycinnamic acids in green juice. Lacto-ermentation induced a considerable increase in the quantity of quercetin (48.75 μg·g⁻¹ dry weight) and kaempferol aglycons (895.26 μg·g⁻¹ dry weight) of LPC. In contrast, chlorogenic acid isomers and sulforaphane disappeared from LPC after lactic acid fermentation, while microwave treatment did not cause significant differences. These results confirm that both microwave treatment and lacto-fermentation coagulate and concentrate most of the soluble proteins. Also, these two processes affect the amount of valuable phytochemicals differently, so it should be considered when setting the goals.

Separate Effects of Foliar Applied Selenate and Zinc Oxide on the Accumulation of Macrominerals, Macronutrients and Bioactive Compounds in Two Pea (Pisum sativum L.) Seed Varieties

Selenium (Se) and zinc (Zn) are important cofactors for antioxidant enzymes. Foliar Se/Zn application is a highly efficient strategy of plant biofortification. However, its effects on the accumulation of macrominerals, macronutrients and bioactive compounds in the pea plant (Pisum sativum L.) have been poorly investigated. A two-year pot experiment was performed to study responses of two pea varieties (Ambassador, Premium) to foliar-applied sodium selenate (0/50/100 g Se/ha) and zinc oxide (0/375/750 g Zn/ha) at the flowering stage. Concentrations of Ca, Mg, K, Na, soluble solids (SSC), protein, chlorophyll a and b, total chlorophyll, total carotenoids and total condensed tannins (TCT) were determined in seeds. Mg concentration in Ambassador and chlorophyll a concentration in Premium were positively affected, in part, by selenate and zinc oxide, respectively. Selenate and zinc oxide increased, in part, protein concentration in Premium. Highest protein concentration was found in Premium treated with 375 g Zn/ha (27.6% DW) vs. the control (26.6% DW). Significant (all p < 0.001) positive correlations were found, among others, between concentrations of Zn and Mg (r2 = 0.735) and between Zn and protein (r2 = 0.437) for Ambassador, and between Mg and protein (r2 = 0.682), between Zn and Mg (r2 = 0.807), as well as between Zn and protein (r2 = 0.884) for Premium. TCT significantly (all p < 0.05) and positively correlated with SSC (r2 = 0.131), chlorophyll b (r2 = 0.128) and total chlorophyll (r2 = 0.109) for Ambassador. This study provides new nutritional data on Se/Zn biofortified peas, important for improving agronomic biofortification of pea plants.

Are isothiocyanates and polyphenols from Brassicaceae vegetables emerging as preventive/therapeutic strategies for NAFLD? The landscape of recent preclinical findings

Nonalcoholic fatty liver disease (NAFLD) is a lipid impairment-related chronic metabolic disease that affects almost 25% of the worldwide population and has become the leading cause of liver transplantation in the United States of America (USA). NAFLD may progress from simple hepatic steatosis (HS) to nonalcoholic steatohepatitis (NASH), which occurs simultaneously in an inflammatory and fibrotic microenvironment and affects approximately 5% of the global population. Recently, NASH has been suggested to be a relevant driver in progressive liver cirrhosis and a population-attributable factor in hepatocellular carcinoma patients. Moreover, predictions show that NAFLD-related annual health costs in the USA have reached ∼$100 bi., but effective therapies are still scarce. Thus, new preventative strategies for this hepatic disease urgently need to be developed. The Brassicaceae vegetable family includes almost 350 genera and 3500 species and these are one of the main types of vegetables harvested and produced worldwide. These vegetables are well-known sources of glucobrassicin-derivative molecules, such as isothiocyanates and phenolic compounds, which have shown antioxidant and antilipogenic effects in preclinical NAFLD data. In this review, we gathered prominent evidence of the in vivo and in vitro effects of these vegetable-derived nutraceutical compounds on the gut-liver-adipose axis, which is a well-known regulator of NAFLD and may represent a new strategy for disease control.

The hypolipidemic, anti-inflammatory and antioxidant effect of Kavolì® aqueous extract, a mixture of Brassica oleracea leaves, in a rat model of NAFLD

Herein we characterized the bioactive metabolites of the aqueous extract of Kavolì®, a commercial product composed of a mixture of Brassica oleracea leaves, and assessed its potential ameliorating effects in a rat model of non-alcoholic fatty liver disease (NAFLD). Kavolì® extract showed high levels of bioactive compounds and strong in vitro antioxidant activities. Chlorogenic and neochlorogenic acids were identified as the most representative polyphenols. The administration of brassica extract to steatotic rats significantly ameliorated the levels of blood lipids and transaminases, and lipid content and inflammatory markers in liver. Oxidative stress parameters were significantly improved in both liver and brain of steatotic rats. Moreover, plasma and feces levels of short chain fatty acids (SCFAs) were bring back close to control values by Kavolì® treatment, in spite of high fat diet/streptozotocin (HFD/STZ)-induced alterations. The efficacy of Kavolì® in treating hypercholesterolemia, reducing the level of inflammation and cardiovascular disease biomarkers, steatosis and oxidative stress parameters, as well as the ability in modulating SCFAs levels is probably related to the bioactive compounds of the water extract administered to the rat model of NAFLD. In particular, the ameliorating effects are largely attributable to the high content in polyphenols observed in our study.

Cancer protective effects of plums: A systematic review

Plums is one of the most cultivated stone fruits due to its fast growing popularity. It has various traditionally recognized health benefits. There are two main commercial types of plums: the European plum (Prunus domestica) and the Japanese plum (Prunus salicina), each having many varieties. Researchers are gathering further evidence of pharmacological effects for plums by scientifically studying its anti-inflammatory, antioxidant properties. A systematic review analysing the literature related to the effects of plums on prevention and treatment of cancer is warranted. This is the first review examining the cancer-related effects of plums. Antioxidation properties of the active constituents of plum were also compared. Scopus, Google Scholar, PubMed, Medxriv and Cochrane Library databases, from their date of inception until July 2021 were utilized. The risk of bias was assessed using CONSORT checklist. A total of 6639 studies were screened and eventually only 54 studies were included. Full-text review of included studies revealed that plum extracts were rich in antioxidants. Overall, most of the studies that fulfilled the eligibility criteria were in vitro and a few clinical studies involving in vivo work. Therefore, it would be beneficial to perform more studies on animals or humans, to confirm that the result obtained from these in vitro studies are able to be extrapolated in a wider range of applications. Further clinical and in vivo studies are warranted to validate plums as a functional food for treatment and prevention of cancer.

Effect of argon-enriched modified atmosphere on the over quality and bioactive compounds of ready-to-use broccoli rabe (Brassica rapa sylvestris L. var. esculenta) during the storage

This study evaluated the effect of argon-enriched modified atmosphere on the storage extension of ready-to-use broccoli rabe in leaf. Broccoli rabe samples (Brassica rapa sylvestris L. var. esculenta) were packaged in 90% argon and 10% O₂ (modified atmosphere packaging 1); 80% argon, 10% CO₂ and 10% O₂ (modified atmosphere packaging 2) and evaluated for the physicochemical characteristics, microbiological parameters and bioactive compounds (glucosinolates) during the cold storage for 9 days. Results showed significant maintenance of colour, chlorophyll, phenols content and antioxidant activity in modified atmosphere packaging packages with respect to air control ones. An increasing biosynthesis of glucosinolates was observed in all packages to the inductive effect of CO₂ produced; the amount of minerals unchanged during the storage. Overall appearance and odour evaluation pointed out a positive effect of argon atmospheres, in particular modified atmosphere packaging 1, for the keeping of the sensory attributes compared to those evaluated in air packaging.

Cabbage (Brassica oleracea var. capitata): A food with functional properties aimed to type 2 diabetes prevention and management

Type 2 diabetes mellitus (T2DM) is increasing the prevalence worldwide at an alarming rate, becoming a serious public health problem that mainly affects developing countries. Functional food research is currently of great interest because it contributes to developing nutritional therapy strategies for T2DM prevention and treatment. Bioactive compounds identified in some plant foods contribute to human health by mechanisms of action that exert biological effects on metabolic pathways involved in the development of T2DM. Hence, vegetables with high bioactive compounds content may be a source of functional value for the control of T2DM. Cabbages varieties (Brassica oleracea var. capitata) such as green (GCB), white (WCB), and red (RCB) are foods consumed (raw or cooked) and cultivated in different regions of the world. Scientific evidence shows that cabbage has multi-target effects on glucose homeostatic regulation due to its high content of bioactive compounds. It has also been shown to decrease damage to organs affected by T2DM complications, such as the liver and kidney. Additionally, it could contribute as a preventive by attenuating problems underlying the development of T2DM as oxidative stress and obesity. This review highlights the functional properties of cabbage varieties involved in glucose regulation and the main mechanisms of the action exerted by their bioactive compounds. In conclusion, cabbage is a valuable food that can be employed as part of nutritional therapy or functional ingredient aimed at the prevention and treatment of T2DM.

Combined effects of cations in fertilizer solution on antioxidant content in red lettuce (Lactuca sativa L.)

BACKGROUND

Red lettuce is consumed worldwide because it is a great source of natural antioxidants. To design a fertilizer formula to boost its nutritional value, this research simultaneously studied the effects of significant cations among the macronutrients for plant growth (K, Mg and Ca) and the effects of the electrical conductivity (EC) of the nutrient solution on phenolic compound production and mass productivity of hydroponically grown red lettuce.

RESULTS

Red lettuce grown under the control treatment provided the highest mass productivity (under low-stress conditions). The highest antioxidant content, measured as milligrams of phenolic compounds per gram dry weight (at a high-stress condition) via both Folin-Ciocalteu and HPLC analyses, was observed in growth media containing 100 ppmK : 20 ppm Mg : 70 ppm Ca (with EC equal to 1241 μS cm-1 ). It was found that EC within the range of this examination had no significant effect on the mass productivity or on phenolic compound productivity. The phenolic compound productivity, defined as the amount of phenolic compounds produced per unit of planting area per unit of time, was optimized with the optimum formula for maximum phenolic compound productivity of 90 ppm K : 29 ppm Mg : 77 ppm Ca, or a corresponding EC of 1307 μS cm-1 .

CONCLUSIONS

The study demonstrates that health-promoting nutrient production in red lettuce could be stimulated in a practical manner by adjusting the cation concentrations in fertilizer solution. © 2021 Society of Chemical Industry.

Impact of High-Pressure Processing on Antioxidant Activity during Storage of Fruits and Fruit Products: A Review

Fruits and fruit products are an essential part of the human diet. Their health benefits are directly related to their content of valuable bioactive compounds, such as polyphenols, anthocyanins, or vitamins. Heat treatments allow the production of stable and safe products; however, their sensory quality and chemical composition are subject to significant negative changes. The use of emerging non-thermal technologies, such as HPP (High Pressure Processing), has the potential to inactivate the microbial load while exerting minimal effects on the nutritional and organoleptic properties of food products. HPP is an adequate alternative to heat treatments and simultaneously achieves the purposes of preservation and maintenance of freshness characteristics and health benefits of the final products. However, compounds responsible for antioxidant activity can be significantly affected during treatment and storage of HPP-processed products. Therefore, this article reviews the effect of HPP treatment and subsequent storage on the antioxidant activity (oxygen radical absorbance capacity (ORAC) assay), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity assay, ferric reducing antioxidant power (FRAP) assay, 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging capacity assay or Trolox equivalent antioxidant capacity (TEAC) assay), and on the total phenolic, flavonoid, carotenoid, anthocyanin and vitamin contents of fruits and different processed fruit-based products.

Absorption, metabolism and bioavailability of flavonoids: a review

Flavonoids are stored in various plants and widely presented in different kinds of food in variable amounts. Plant roots, stems, leaves, flowers and fruits are known to have high amounts of flavonoids. However, flavonoid aglycones are found less frequently in natural products, as it requires bioconversion through bacteria, which provide β-glucosidase to convert them. Recently, flavonoids and its metabolites were applied in the prevention and treatment of various diseases such as cancers, obesity, diabetes, hypertension, hyperlipidemia, cardiovascular diseases, neurological disorders and osteoporosis in numerous studies. This review focused on absorption, activity, metabolism, and bioavailability of flavonoids. Also authors organized and collected newly-found reports of flavonoids and their absorption barriers of flavonoids in the gastrointestinal tract, providing the latest findings and evidence from the past decade. Particularly, nanoparticles delivery systems are emphasized regarding fabrication methods and their potential benefits on flavonoids. Moreover, the potential challenges of nanoparticles as delivery system for flavonoids in the gastrointestinal tract are also discussed.

New Insights into the Mechanisms of Polyphenol from Plum Fruit Inducing Apoptosis in Human Lung Cancer A549 Cells Via PI3K/AKT/FOXO1 Pathway

Recent studies have been found that polyphenols from plums fruits can inhibit the proliferation of multiple cancer cells, while the molecular mechanism was unclear. This study aimed to investigate the molecular mechanism underlying the pro-apoptotic effect of purified plum polyphenols (PPP) on human lung cancer A549 cells. Quercitrin (quercetin-3-O-glucoside, 814.19 ± 40.71 mg/g) was identified as the primary polyphenol in PPP via ultra high-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UHPLC-QqQ-MS/MS). PPP showed a strong capacity for inhibiting the proliferation of the A549 cells by inducing apoptosis, which was reflected by an increase in the Bax/Bcl-2 ratio. Additionally, the inhibitory rate of PPP on the A549 cells were higher than that of vitamin C when the treatment dose exceeded 160 μg/mL. Transcriptome analysis suggested that PPP-induced apoptosis was closely associated with regulating the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/forkhead box protein O 1 (FOXO1) pathway in the A549 cells. Subsequently, as an activator of AKT, SC79 was applied to confirm that the inhibition of AKT phosphorylation play an important role in the PPP-induced apoptosis of the A549 cells. These results illustrated the potential of PPP as a dietary compound for the prevention of cancer or for use during chemotherapy.

High-Throughput Screening and Characterization of Phenolic Compounds in Stone Fruits Waste by LC-ESI-QTOF-MS/MS and Their Potential Antioxidant Activities

Stone fruits, including peach (Prunus persica L.), nectarine (Prunus nucipersica L.), plum (Prunus domestica L.) and apricot (Prunus armeniaca L.) are common commercial fruits in the market. However, a huge amount of stone fruits waste is produced throughout the food supply chain during picking, handling, processing, packaging, storage, transportation, retailing and final consumption. These stone fruits waste contain high phenolic content which are the main contributors to the antioxidant potential and associated health benefits. The antioxidant results showed that plum waste contained higher concentrations of total phenolic content (TPC) (0.94 ± 0.07 mg gallic acid equivalents (GAE)/g) and total flavonoid content (TFC) (0.34 ± 0.01 mg quercetin equivalents (QE)/g), while apricot waste contained a higher concentration of total tannin content (TTC) (0.19 ± 0.03 mg catechin equivalents (CE)/g) and DPPH activity (1.47 ± 0.12 mg ascorbic acid equivalents (AAE)/g). However, nectarine waste had higher antioxidant capacity in ferric reducing-antioxidant power (FRAP) (0.98 ± 0.02 mg AAE/g) and total antioxidant capacity (TAC) (0.91 ± 0.09 mg AAE/g) assays, while peach waste showed higher antioxidant capacity in 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assay (0.43 ± 0.09 mg AAE/g) as compared to other stone fruits waste. Qualitative and quantitative phenolic analysis of Australian grown stone fruits waste were conducted by liquid chromatography coupled with electrospray-ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS/MS) and HPLC-photodiode array detection (PDA). The LC-ESI-QTOF-MS/MS result indicates that 59 phenolic compounds were tentatively characterized in peach (33 compounds), nectarine (28), plum (38) and apricot (23). The HPLC-PDA indicated that p-hydroxybenzoic acid (18.64 ± 1.30 mg/g) was detected to be the most dominant phenolic acid and quercetin (19.68 ± 1.38 mg/g) was the most significant flavonoid in stone fruits waste. Hence, it could be concluded that stone fruit waste contains various phenolic compounds and have antioxidant potential. The results could support the applications of these stone fruit wastes in other food, feed, nutraceutical and pharmaceutical industries.

Carotenoids: Considerations for Their Use in Functional Foods, Nutraceuticals, Nutricosmetics, Supplements, Botanicals, and Novel Foods in the Context of Sustainability, Circular Economy, and Climate Change

Carotenoids are versatile isoprenoids that are important in food quality and health promotion. There is a need to establish recommended dietary intakes/nutritional reference values for carotenoids. Research on carotenoids in agro-food and health is being propelled by the two multidisciplinary international networks, the Ibero-American Network for the Study of Carotenoids as Functional Foods Ingredients (IBERCAROT; http://www.cyted.org) and the European Network to Advance Carotenoid Research and Applications in Agro-Food and Health (EUROCAROTEN; http://www.eurocaroten.eu). In this review, considerations for their safe and sustainable use in products mostly intended for health promotion are provided. Specifically, information about sources, intakes, and factors affecting bioavailability is summarized. Furthermore, their health-promoting actions and importance in public health in relation to the contribution of reducing the risk of diverse ailments are synthesized. Definitions and regulatory and safety information for carotenoid-containing products are provided. Lastly, recent trends in research in the context of sustainable healthy diets are summarized.

Comparative study of young shoots and the mature red headed cabbage as antioxidant food resources with antiproliferative effect on prostate cancer cells

The increasing knowledge on health benefit properties of plant origin food ingredients supports recommendations for the use of edible plants in the prevention of diet related diseases, including cancer. The beneficial effects of young shoots of red cabbage can be attributed to their mixture of phytochemicals possessing antioxidant and potential anticancer activity. The objective of this study was to compare the content of bioactive compounds, including HPLC analysis of polyphenols and antioxidant activity of young shoots of red cabbage and the vegetable at full maturity. The content of vitamin C and polyphenols in juices obtained from young shoots and the mature vegetable were also determined. The other aim of this study was to confirm the hypothesis that juice of young shoots more effectively, compared to juice of the mature vegetable, reduces the proliferation of prostate cancer cell lines DU145 and LNCaP in vitro. A significantly higher content of vitamin C and carotenoids, as well as a higher antioxidant activity were found in edible young shoots in comparison to the mature vegetable. In addition, studies have shown higher amount of vitamin C in the juice of young shoots than in the juice of the mature vegetable and similar content of polyphenolic compounds. The level of total polyphenol content in the studied plant samples did not differ significantly. Flavonoids were the main polyphenols in young shoots and juice obtained from them, while phenolic acids were dominant in the mature vegetable and in juice obtained from it. The juice of young shoots has shown stronger in vitro anti-proliferation effect against prostate cancer cells than juice of the mature vegetable.

Young shoots of red cabbage could be a good source of phytochemicals with potential anticancer activity.

Variability in the Content of Phenolic Compounds in Plum Fruit

The aim of this study was to determine the composition and content of phenolic compounds in extracts of plum fruit. Fruit of 17 plum cultivars were analyzed. Fruit samples were collected in 2019 from fruit trees with “Myrobalan” (P. cerasifera Ehrh.) and “Wangenheim Prune” (P. domestica L.) rootstocks. The following glycosides of the flavonol group were identified: avicularin, isorhamnetin-3-O-rutinoside, isoquercitrin, hyperoside, rutin, and an aglycone quercetin. Compounds of the flavan-3-ol group were identified, such as (+)-catechin, procyanidin C1, and procyanidin A2, along with chlorogenic acid attributed to phenolic acids and a non-phenolic cyclitol–quinic acid. Of all the analytes identified in plum fruit samples, quinic acid predominated, while chlorogenic acid predominated among all the identified phenolic compounds, and rutin predominated in the flavonol group. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) revealed that fruit samples of “Kubanskaya Kometa”, “Zarechnaya Raniaya”, “Duke of Edinburgh”, “Jubileum”, and “Favorita del Sultano” cultivars had different quantitative content of phenolic compounds from that observed in other samples. The highest total amount of phenolic compounds was found in the European plum samples of the “Zarechnaya Rannyaya” cultivar, while the amount of quinic acid was the highest in plum fruit samples of the “Jubileum” cultivar.

Pre- and Post-harvest Factors Affecting Glucosinolate Content in Broccoli

Owing to several presumed health-promoting biological activities, increased attention is being given to natural plant chemicals, especially those frequently entering the human diet. Glucosinolates (GLs) are the main bioactive compounds found in broccoli (Brassica oleracea L. var. italica Plenck). Their regular dietary assumption has been correlated with reduced risk of various types of neoplasms (lung, colon, pancreatic, breast, bladder, and prostate cancers), some degenerative diseases, such as Alzheimer's, and decreased incidence of cardiovascular pathologies. GL's synthesis pathway and regulation mechanism have been elucidated mainly in Arabidopsis. However, nearly 56 putative genes have been identified as involved in the B. oleracea GL pathway. It is widely recognized that there are several pre-harvest (genotype, growing environment, cultural practices, ripening stage, etc.) and post-harvest (harvesting, post-harvest treatments, packaging, storage, etc.) factors that affect GL synthesis, profiles, and levels in broccoli. Understanding how these factors act and interact in driving GL accumulation in the edible parts is essential for developing new broccoli cultivars with improved health-promoting bioactivity. In this regard, any systematic and comprehensive review outlining the effects of pre- and post-harvest factors on the accumulation of GLs in broccoli is not yet available. Thus, the goal of this paper is to fill this gap by giving a synoptic overview of the most relevant and recent literature. The existence of substantial cultivar-to-cultivar variation in GL content in response to pre-harvest factors and post-harvest manipulations has been highlighted and discussed. The paper also stresses the need for adapting particular pre- and post-harvest procedures for each particular genotype in order to maintain nutritious, fresh-like quality throughout the broccoli value chain.

Microencapsulation by spray-drying of polyphenols extracted from red chicory and red cabbage: Effects on stability and color properties

The research of antioxidants and natural pigments to replace synthetic molecules is increasingly considering wastes from plant food supply chains. Red chicory (RCH) and red cabbage (RCA) are rich sources of polyphenols (PP), especially anthocyanins, well know natural pigments possessing strong antioxidant capacity and beneficial health effects. The aim of this work was to compare different solvents for PP extraction and to evaluate the effect of spray-drying encapsulation using modified starch on PP, antioxidant capacity (AOC) and color properties. Methanol:water (70:30) showed the best extraction capacity, while ethanol:water (70:30) extracts displayed the highest thermal stability. Ethanol:water extracts were spray-dried with a yield of 95-99% for both crops, while the efficiency of PP encapsulation was 79% (RCA) and 88% (RCH). Encapsulation improved retention of PP and AOC upon thermal treatment (RCH: 20-30%, RCA: 44-55%) without altering color properties. This process can be employed for the development of functional foods and supplements.

Changes in Absolute Contents of Compounds Affecting the Taste and Nutritional Properties of the Flesh of Three Plum Species Throughout Development

The characteristics of plum fruits of three different species were investigated throughout their development (including over-ripening). The content of primary and secondary metabolites was expressed as amount per gram DW (dry weight) and per fruit in order to obtain information about the balance between their synthesis and dissimilation at different stages of fruit development. In all the plums, during the first stages of development, glucose was the most abundant sugar, whereas sucrose increased during ripening. There was no decrease in malate content per fruit before the commercial harvesting time of any of the plums, whereas a decrease was observed during over-ripening. In general, both the total phenol content and the contents of individual phenols in the flesh expressed on gram DW decreased throughout development, whereas their content per fruit increased, indicating that these decreases were due to a dilution effect arising from the expansion of the flesh. During the development of the flesh, the increase in the contents of the investigated metabolites per fruit shows that there was no net dissimilation of malate up to commercial harvest and of phenols throughout fruit development. Good correlations between the content of phenols to antioxidant activity were found. Shiro flesh, during the last part of fruit development, had lower total carbohydrate and polyphenol contents, lower antioxidant activities, and a higher malate content than the flesh of the other two genotypes.

Health-Promoting Properties of Fresh and Processed Purple Cauliflower

Plant-based foods should be fresh, safe, and natural, with nutritional value and processed in sustainable ways. Among all consumed vegetables, Brassica vegetables are considered to be the most important ones. As they are eaten in large quantities and frequently, they may constitute an important source of nutrients and bioactive compounds in a daily diet. This work is aimed at assessing the effect of technological processing (blanching and traditional cooking in water and in a convection steam oven) as well as the method of frozen storage (in PE-LD zipper bags and vacuum packing) on the content of selected components in purple cauliflower. The material was examined for the content of dry matter, vitamin C, total polyphenols, anthocyanins, thiocyanates, nitrates, and nitrites, as well as antioxidant activity. All technological processes caused significant changes in the contents of examined nutritive and non-nutritive compounds as well as in antioxidant activity or the level of selected chemical pollutions. A trend was also observed towards lower constituents’ losses as a result of convection steaming, compared to traditional cooking in water. Moreover, the reduction in the content of examined compounds was smaller in vacuum-packed and frozen-stored vegetables then in those stored in zipper PE-LD bags.

Wild edible fool's watercress, a potential crop with high nutraceutical properties

Background

Fool's watercress (Apium nodiflorum) is an edible vegetable with potential as a new crop. However, little information is available regarding the antioxidant properties of the plant and the individual phenolics accounting for this capacity are unknown.

Methods

The antioxidant properties of twenty-five wild populations were analysed and individual phenolics present in the species reported and compared with celery and parsley. The antioxidant activity was measured as the 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) free radical scavenging capacity, and the total phenolics content (TPC) via the Folin-Ciocalteu procedure. The individual phenolics constituents were determined via high performance liquid chromatography (HPLC) as aglycones.

Results

The average DPPH and TPC of fool's watercress were 28.1 mg Trolox g^-1 DW and 22.3 mg of chlorogenic acid equivalents g^-1 DW, respectively, much higher than those of celery and parsley. Significant differences for both DPPH and TPC, which may be explained by either genotype or environmental factors, were detected among groups established according to geographical origin. Quercetin was identified as the major phenolic present in the leaves of the species, unlike parsley and celery, in which high amounts of apigenin and luteolin were determined. Quercetin represented 61.6% of the phenolics targeted in fool's watercress, followed by caffeic acid derivatives as main hydroxycinnamic acids.

Discussion

The study reports the high antioxidant properties of fool's watercress based on a large number of populations. Results suggest that quercetin accounts for an important share of the antioxidant capacity of this potential new crop. The study also provides a basis for future breeding programs, suggesting that selection by geographical locations may result in differences in the antioxidant properties.

Short-Term Nitrate Limitation Prior to Harvest Improves Phenolic Compound Accumulation in Hydroponic-Cultivated Lettuce ( Lactuca sativa L.) without Reducing Shoot Fresh Weight

Long-term exposure to a low nitrogen supply could effectively improve phenolic content in vegetables, but it also greatly decreases the yield. Therefore, it is necessary to develop cost-effective strategies of nitrogen management to overcome these obstacles. Here, we find that decreasing the nitrogen (NO3-) supply from 8.0 to below 2.0 mM during the last 7 days before harvest significantly increases phenolic levels and antioxidant capacity of the soluble fraction in two hydroponic-cultivated lettuces, which is demonstrated by the up-regulation of related genes ( PAL1, CHS, F3H, DFR, F35H, and UFGT) involved in the phenolic synthesis pathway. Importantly, short-term nitrate limitation before harvest does not affect yield production unless nitrogen supply is reduced below 1.0 and 0.5 mM for Ziluoma and Lvluo, respectively. These findings suggest that appropriate short-term nitrate limitation before harvest, considering genotype variation, is feasible for improving the phenolic content and antioxidant capacity of vegetables without reducing their yield.