Bound phenolics in foods, a review

Profiles of Free and Bound Phenolics and Their Antioxidant Capacity in Rice Bean (Vigna umbellata)

Rice bean (Vigna umbellata) is a medicinal and dietary legume rich in polyphenols. In this study, the free and bound phenolics in rice bean were extracted by water, 80% methanol, and acid, base, and composite enzymatic hydrolysis, respectively. The polyphenol profiles of the extracted fractions were analyzed. The outcome demonstrated that base hydrolysis was the most effective way to liberate bound phenolics from rice bean (14.18 mg GAE/g DW), which was 16.68 and 56.72 folds higher than those extracted by acid and enzymatic hydrolysis, respectively. The bound polyphenols released by base hydrolysis contributed to 71.15% of the total phenolic content. A total of 35 individual phenolics was identified, of which isoquercitrin, procyanidin B1, rutin, taxifolin, and catechin were the main monomeric phenolics in the free fraction, while gallic acid, protocatechuic acid, p-hydroxybenzoic acid, catechin, and phloroglucinol were the main monomeric phenolics in the bound fraction. In comparison to the free phenolics extracted by water and 80% methanol and the bound phenolics extracted using acid and composite enzymatic hydrolysis, the bound phenolics from base hydrolysis had a superior antioxidant capacity. The antioxidant activity of rice bean is primarily attributed to individual phenolics such as catechin, abundant both in free and bound fractions, and also p-hydroxybenzoic acid, gallic acid, and protocatechuic acid in bound fractions. The bound phenolics of rice bean were first reported and showed large differences with the composition of free phenolics. This work suggests that the bound fraction of rice bean must be taken into account in assessing its potential benefits to health.

Optimizing extraction conditions and isolation of bound phenolic compounds from corn silk (Stigma maydis) and their antioxidant effects

During the processing of maize, Stigma maydis, also known as corn silk, is normally discarded as waste. Phytochemical research was carried out on the S. maydis to use it as a valuable source of bioactive components. This research aimed to maximize the recovery of free and bound phenolic compounds from corn silk under optimal experimental conditions. Response surface design was operated to optimize the alkaline hydrolysis extraction of bound phytochemicals from corn silk based on total phenolic content and DPPH radical scavenging activity. The optimum conditions (i.e., NaOH concentration 2 M, digestion time 135 min, digestion temperature of 37.5°C, the solid-to-solvent ratio of 1:17.5, and acetone) were obtained. The optimum parameters were used to extract the corn silk. The structures of two compounds isolated from ethyl acetate extracts were then identified as friedelin (1) and (E)-4-(4-hydroxy-3-methoxyphenyl) but-3-en-2-one (2). The DPPH, H₂ O₂ , and ABTS % inhibition of the compounds is as follows: compound (1) 74.81%, 76.8%, 70.33% and compound (2) 70.37%, 56.70% and 57.46%, respectively. The current study has opened previously unexplored perspectives of the composition of bound compounds in corn silk and established the foundations for more effective processing and utilization of corn waste. PRACTICAL APPLICATION: Bound phenolic compounds from corn silk under optimal experimental conditions were obtained. Corn silk can be utilized as a type of medicinal herb as well as a source of inexpensive natural antioxidants.

Nutritional assessment of nixtamalized maize tortillas produced from dry masa flour, landraces, and high yield hybrids and varieties

In the scientific literature there are different analyses of the nutritional profiles of maize tortillas, whether they are landraces or hybrid maize versus those made with dry masa flour (DMF). In general terms, there is agreement in the reported content of moisture. However, for the other nutrients, a great disparity is reported for each type of tortilla which may be due to various factors such as the type of maize or processing methods. In this study, the nutritional aspects of maize tortillas made with different genotypes (five hybrids, two varieties, five landraces, six hybrid mixtures and six dry masa flours) under controlled conditions, were compared. More than 30 characteristics were analyzed. High performance hybrids and varieties (HPHV) and landraces had the highest (p < 0.05) antioxidant capacity (58.8% free, 150.2% bound). In terms of vitamins contents, the tortillas produced from DMF contained 11.2 and 3.5 times more B1, 18.6 and 7.8 times more B2, and 2.7 and 5.3 times more B3 than HPHV and landraces respectively; and only in these samples was detected folic acid. DMF tortilla samples contained 1.75 times more sodium and 2.75 times more iron than the other groups, and 0.75 times less calcium than HPHV. Zinc was present in higher concentration (p < 0.05) in DMF tortilla samples. The landraces had the highest protein content (average 10.28%), but the tortillas produced from DMF presented the highest protein quality evaluated by protein digestibility-corrected amino acid score (PDCAAS) (p < 0.05) that represents 27, 25 and 19% more than hybrids mixture, HPHV and landraces, respectively. This work gives valuable information on how different types of grains differ in the nutritional quality affecting the final product to provide more elements in the decision-making of processors. There is no a perfect maize, but there are genotypes that can be combined as mixtures and the processing method to design superior nutritional tortillas and related products for populations that highly consume them and improve their human health.

Determination of nine bioactive phenolic components usually found in apple juice by simultaneous UPLC-MS/MS

The functional food ingredients of apple juice can significantly change during processing, transportation, and storage, thus affecting the quality of the product. A simple and derivation-free analytical method based on ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed and optimized for the simultaneous determination of functional food ingredients in apple juice bought in the market. Cleanup steps and chromatographic conditions were optimized to remove interference and decrease the matrix effect. The nine target analytes were separated on an Acquity UPLC system equipped with a BEH C18 column and detected by electrospray ionization source (ESI) operating in positive subsection acquisition mode under multiple reaction monitoring (MRM) conditions. The results showed that p-hydroxybenzoic acid, protocatechuate, caffeic acid, chlorogenic acid, epicatechin, phloridzin, hyperoside, procyanidin B₂, and rutin could be sufficiently separated for content determination within 6 min. In the concentration range of 20 μg/L-50 mg/L, nine standard samples exhibited a good linear fit with correlation coefficients above .985.

In vivo antidiabetic effects of phenolic compounds of spinach, mustard, and cabbage leaves in mice

Leafy vegetables are considered to have health-promoting potentials, mainly attributed to bioactive phenolic compounds. The antidiabetic effects of spinach, mustard, and cabbage were studied by feeding their phenolic-rich aqueous extracts to alloxan-induced diabetic mice. The antioxidant, biochemical, histopathological, and hematological indices of the control, diabetic, and treated mice were studied. Phenolic compounds present in the extracts were identified and quantified using HPLC-DAD. Results showed ten, nineteen, and eleven phenolic compounds in spinach, mustard, and cabbage leave aqueous extracts, respectively. The body weight, tissue total glutathione (GSH) contents, fasting blood sugar, liver function tests, renal function tests, and lipid profile of the mice were affected by diabetes and were significantly improved by the extract treatments. Likewise, hematological indices and tissues histological studies also showed recovery from diabetic stress in treated mice. The study's findings highlight that the selected leafy vegetables potentially mitigate diabetic complications. Among the studied vegetables, cabbage extract was comparatively more active in ameliorating diabetic stress.

Metabolic engineering of plant secondary metabolites: prospects and its technological challenges

Plants produce a wide range of secondary metabolites that play vital roles for their primary functions such as growth, defence, adaptations or reproduction. Some of the plant secondary metabolites are beneficial to mankind as nutraceuticals and pharmaceuticals. Metabolic pathways and their regulatory mechanism are crucial for targeting metabolite engineering. The clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-mediated system has been widely applied in genome editing with high accuracy, efficiency, and multiplex targeting ability. Besides its vast application in genetic improvement, the technique also facilitates a comprehensive profiling approach to functional genomics related to gene discovery involved in various plant secondary metabolic pathways. Despite these wide applications, several challenges limit CRISPR/Cas system applicability in genome editing in plants. This review highlights updated applications of CRISPR/Cas system-mediated metabolic engineering of plants and its challenges.

Lichen-Derived Actinomycetota: Novel Taxa and Bioactive Metabolites

Actinomycetes are essential sources of numerous bioactive secondary metabolites with diverse chemical and bioactive properties. Lichen ecosystems have piqued the interest of the research community due to their distinct characteristics. Lichen is a symbiont of fungi and algae or cyanobacteria. This review focuses on the novel taxa and diverse bioactive secondary metabolites identified between 1995 and 2022 from cultivable actinomycetota associated with lichens. A total of 25 novel actinomycetota species were reported following studies of lichens. The chemical structures and biological activities of 114 compounds derived from the lichen-associated actinomycetota are also summarized. These secondary metabolites were classified into aromatic amides and amines, diketopiperazines, furanones, indole, isoflavonoids, linear esters and macrolides, peptides, phenolic derivatives, pyridine derivatives, pyrrole derivatives, quinones, and sterols. Their biological activities included anti-inflammatory, antimicrobial, anticancer, cytotoxic, and enzyme-inhibitory actions. In addition, the biosynthetic pathways of several potent bioactive compounds are summarized. Thus, lichen actinomycetes demonstrate exceptional abilities in the discovery of new drug candidates.

Bioprocessed Wholegrain Spelt Flour Improves the Quality and Physicochemical Characteristics of Wheat Bread

In the present study, the partial substitution of common white wheat flour for a bread recipe with variously bioprocessed wholegrain spelt was investigated. The addition of 1% and pasteurised 5% "germinated + enzymatic treated" spelt flour to wheat flour significantly improved the specific volume of the bread, but their texture profile analysis and sensory evaluation were not satisfactory. A higher percentage of added bioprocessed spelt flour darkened the colour of the bread. Breads with the addition of more than 5% of bioprocessed spelt flour were unacceptable in terms of quality and sensory parameters. The highest extractable and bound individual phenolics were found in breads with 5% "germinated + fermented" spelt flour (GFB5) and 5% pasteurised "germinated + enzymatic treated" spelt flour (GEB5P). A strong positive correlation was determined between trans-ferulic acid and TPC and DPPH^• radical scavenging activity. The GEB5P bread showed the highest increase in extractable and bound trans-ferulic acid content, by 320% and 137%, respectively, compared to the control bread. Principal component analysis showed differences between the control bread and enriched breads in terms of their quality, sensory and nutritional properties. Breads with 2.5% and 5% "germinated + fermented" spelt flour had the most acceptable rheological, technological and sensory characteristics, in addition to a substantial improvement in their antioxidant content.

Polyphenols—Ensured Accessibility from Food to the Human Metabolism by Chemical and Biotechnological Treatments

Polyphenols are plant-based compounds famous for their positive impact on both human health and the quality of food products. The benefits of polyphenols are related to reducing cardiovascular diseases, cholesterol management, cancers, and neurological disorders in humans and increasing the shelf life, management of oxidation, and anti-microbial activity in food products. The bioavailability and bio-accessibility of polyphenols are of the highest importance to secure their impact on human and food health. This paper summarizes the current state-of-the-art approaches on how polyphenols can be made more accessible in food products to contribute to human health. For example, by using food processing methods including various technologies, such as chemical and biotechnological treatments. Food matrix design and simulation procedures, in combination with encapsulation of fractionated polyphenols utilizing enzymatic and fermentation methodology, may be the future technologies to tailor specific food products with the ability to ensure polyphenol release and availability in the most suitable parts of the human body (bowl, intestine, etc.). The development of such new procedures for utilizing polyphenols, combining novel methodologies with traditional food processing technologies, has the potential to contribute enormous benefits to the food industry and health sector, not only reducing food waste and food-borne illnesses but also to sustain human health.

Improving the Yield of Feruloyl Oligosaccharides from Rice Bran through Enzymatic Extrusion and Its Mechanism

Rice bran, rich in feruloyl arabinoxylan, is a good source of feruloyl oligosaccharides (FOs). To prepare FOs, bran was often hydrolyzed by amylase and protease to remove starch and protein and then hydrolyzed by xylanase, which was time-consuming and had a low yield. To solve the above problems, enzymatic extrusion was used to treat rice bran, and the effects of traditional hydrolysis, a combination of traditional extrusion and hydrolysis (extrusion-hydrolysis) and enzymatic extrusion on the yield of FOs were investigated and compared in this study. It was found that traditional extrusion and enzymatic extrusion significantly increased the yield of FOs. Particularly, the yield of FOs resulting from enzymatic extrusion was increased to 5.78%, while the yield from traditional hydrolysis was 4.23%. Microscopy analysis showed that extrusion damaged the cell wall of bran, which might increase the accessibility of xylanase to arabinoxylan and the yield of FOs. Spectroscopy analysis suggested that FOs obtained by different pretreatments had similar structures. It was obvious that enzymatic extrusion saved the time for removal of starch and protein and increased the yield of FOs. In addition, the highest yield of FOs was found at the moisture content of 30% and the screw speed of 50 rpm. This study provided an efficient method for the preparation of FOs that is suitable for industrial production.

Relationship between Dietary Polyphenols and Gut Microbiota: New Clues to Improve Cognitive Disorders, Mood Disorders and Circadian Rhythms

Cognitive, mood and sleep disorders are common and intractable disorders of the central nervous system, causing great inconvenience to the lives of those affected. The gut-brain axis plays a vital role in studying neurological disorders such as neurodegenerative diseases by acting as a channel for a bidirectional information exchange between the gut microbiota and the nervous system. Dietary polyphenols have received widespread attention because of their excellent biological activity and their wide range of sources, structural diversity and low toxicity. Dietary intervention through the increased intake of dietary polyphenols is an emerging strategy for improving circadian rhythms and treating metabolic disorders. Dietary polyphenols have been shown to play an essential role in regulating intestinal flora, mainly by maintaining the balance of the intestinal flora and enhancing host immunity, thereby suppressing neurodegenerative pathologies. This paper reviewed the bidirectional interactions between the gut microbiota and the brain and their effects on the central nervous system, focusing on dietary polyphenols that regulate circadian rhythms and maintain the health of the central nervous system through the gut-brain axis.

Investigation of some bioactive compounds, in vitro bioaccessibility, and sensory acceptability of couscous produced by pre-gelatinized rice flour

BACKGROUND

The purpose of this study was to investigate the sensory properties, antioxidant capacities, total phenolic content, and their bioaccessibility in gluten-free rice couscous that is produced without additives. Since rice does not contain gluten, pre-gelatinized rice flour (GRF) was added instead of gum and enzymes in order to provide the desired structure in the couscous samples.

RESULTS

According to the results, the total phenolic content of couscous samples was increased with GRF addition. The highest extractable and hydrolyzable antioxidant capacity values were observed in the couscous samples supplemented with 30% GRF using the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation, cupric-reducing antioxidant capacity, and ferric reducing antioxidant capacity methods. The bioaccessibility of antioxidant capacity was found to be significantly higher (P < 0.05) than the control sample in all methods except the 1,1-diphenyl-2-picrylhydrazyl free radical method in the couscous samples.

CONCLUSION

According to the data obtained, it has been determined that couscous, which has a very small round shape, can be produced with GRF without additives. In this context, gluten-free rice couscous could be used as an alternative valuable food in terms of nutrition and can be an alternative traditional food for celiac diseases as well as for individuals preferring the consumption of gluten-free products. © 2022 Society of Chemical Industry.

The Influence of Flavonoid Dihydroquercetin on the Enzymatic Processes of Dough Ripening and the Antioxidant Properties of Bread

Bread is an integral part of the diet of the world population. Development of bread enriched with biologically active substances, including antioxidants, could be good nutritional support for human health. Among well-studied antioxidants, we can highlight dihydroquercetin, a flavonoid with outstanding antioxidant properties, such as anti-inflammatory activity, immunostimulatory properties, anti-cancer properties, and others. At the same time, the technology of bread enrichment must consider the possible negative effects of the additive on the technological processes and properties of the final product. The present work was carried out to evaluate the effect of dihydroquercetin on the enzymatic processes occurring during dough maturation and the antioxidant properties of the finished bread. Dihydroquercetin was added in amounts of 0.05 g, 0.07 g, and 0.1 g per 100 g of wheat flour and fermented with commercial baker’s yeast (Saccharomyces cerevisiae). The kinetics of pH and total titratable acidity (TTA) during dough fermentation showed that dihydroquercetin caused slight slowing of enzymatic processes. However, the dosage of dihydroquercetin did not cause statistically significant changes in the yeast concentration, which reached a level of 108 KOU/g after 2 h in all dough samples. Loss of dihydroquercetin during fermentation was established at a level of 20–25%. At the same time, an increase in the total amount of flavonoids in the dough after 2 h of fermentation and an increase in values of antioxidant activity were noted. The antioxidant properties of the bread also increased when it was enriched with dihydroquercetin (about 3.5–4 times) despite the fact that the total quantitative loss of antioxidant in the technological process was considerable (about 40%). A protective effect of the bread matrix on flavonoids during digestion was shown. Dihydroquercetin loss was about 25% regardless of the amount applied. This work clearly showed that addition of dihydroquercetin to a bread formulation represents a promising strategy for increasing the antioxidant properties of bread.

Characterization of isogenic mutants with single or double deletions of four phenolic acid esterases in Lactiplantibacillus plantarum TMW1.460

In plants, hydroxycinnamic and hydroxybenzoic acids occur mainly as esters. This study aimed to determine the contribution of individual phenolic acid esterases in Lp. plantarum TMW1.460, which encodes for four esterases: TanA, Lp_0796, Est_1092 and a homolog of Lj0536 and Lj1228 that was termed HceP. To determine which of the phenolic acid esterases present in Lp plantarum TMW1.460 are responsible for esterase activity, mutants with deletions in lp_0796, est_1092, tanB, hceP, or hceP and est_1092 were constructed. The phenotype of wild type strain and mutants was determined with esters of hydroxycinnamic acids (chlorogenic acid and ethyl ferulate) and of hydroxybenzoic acids (methyl gallate, tannic acid and epigallocatechin-3-gallate). Lp. plantarum TMW1.460 hydrolysed chlorogenic acid, methyl ferulate and methyl gallate but not tannic acid or epigallocatechin gallate. The phenotype of mutant strains during growth in mMRS differed from the wild type as follows: Lp. plantarum TMW1.460ΔhceP did not hydrolyse esters of hydroxycinnamic acids; Lp. plantarum TMW1.460ΔtanB did not hydrolyse esters of hydroxybenzoic acids; disruption of est_1092 or Lp_0796 did not alter the phenotype. The phenotype of Lp. plantarum TMW1.460ΔΔhceP/est_1092 was identical to Lp. plantarum TMW1.460ΔhceP. The metabolism of phenolic acids during growth of the mutant strains in broccoli puree and wheat sourdough did not differ from metabolism of the wild type strain. In conclusion, esters of hydroxycinnamic and hydroxybenzoic acids each are hydrolysed by dedicated enzymes. The hydroxycinnamic acid esterase HceP is not expressed, or not active during growth of Lp. plantarum TMW1.460 in all food substrates.

Polyphenol-Dietary Fiber Conjugates from Fruits and Vegetables: Nature and Biological Fate in a Food and Nutrition Perspective

In the past few years, numerous studies have investigated the correlation between polyphenol intake and the prevention of several chronic diseases. Research regarding the global biological fate and bioactivity has been directed to extractable polyphenols that can be found in aqueous-organic extracts, obtained from plant-derived foods. Nevertheless, significant amounts of non-extractable polyphenols, closely associated with the plant cell wall matrix (namely with dietary fibers), are also delivered during digestion, although they are ignored in biological, nutritional, and epidemiological studies. These conjugates have gained the spotlight because they may exert their bioactivities for much longer than extractable polyphenols. Additionally, from a technological food perspective, polyphenols combined with dietary fibers have become increasingly interesting as they could be useful for the food industry to enhance technological functionalities. Non-extractable polyphenols include low molecular weight compounds such as phenolic acids and high molecular weight polymeric compounds such as proanthocyanidins and hydrolysable tannins. Studies concerning these conjugates are scarce, and usually refer to the compositional analysis of individual components rather than to the whole fraction. In this context, the knowledge and exploitation of non-extractable polyphenol-dietary fiber conjugates will be the focus of this review, aiming to access their potential nutritional and biological effect, together with their functional properties.

Identification of volatile compounds and metabolic pathway during ultrasound-assisted kombucha fermentation by HS-SPME-GC/MS combined with metabolomic analysis

The current work combines headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC/MS) with multivariate analysis fusion metabonomics for examining metabolite profile changes. The correlation with metabolic pathways during the fermentation of kombucha tea were comprehensively explored. For optimizing the fermentation process, ultrasound-assisted factors were explored. A total of 132 metabolites released by fermented kombucha were detected by HS-SPME-GC/MS. We employed the principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) to present the relationship between aroma components and fermentation time, of which the first two principal components respectively accounted for 60.3% and 6.5% of the total variance. Multivariate statistical analysis showed that during the fermentation of kombucha tea, there were significant differences in the phenotypes of metabolites in the samples, and 25 characteristic metabolites were selected as biomarkers. Leaf alcohol was first proposed as the characteristic volatile in the fermentation process of kombucha. Furthermore, we addressed the generation pathways of characteristic volatiles, their formation mechanisms, and the transformational correlation among them. Our findings provide a roadmap for future kombucha fermentation processing to enhance kombucha flavor and aroma.

Changes in the Bioaccessibility of Antioxidants after Simulated In Vitro Digestion of Bioprocessed Spelt-Enhanced Wheat Bread

The aim of the study was to determine whether the partial replacement of wheat flour with bioprocessed spelt flour contributes to a higher bioaccessibility of the antioxidants in bread. The results showed that the type and amount of bioprocessed spelt flour in a bread recipe has a major impact on the extractable and bound TPC, the content of individual phenolics, their antioxidant activity, and their bioaccessibility as determined by in vitro digestion. Extractable p-coumaric and trans-ferulic acids in breads decreased after digestion, while extractable cis-ferulic and p-hydroxybenzoic acids increased. The bioaccessibility of TPC in the control bread (100% wheat flour), and in bread enriched with 5% "germinated + fermented" spelt flour (GFB5), did not differ. However, the digested GFB5 bread contained 5.2-times more extractable, and 1.3-times more bound, trans-ferulic acid than the digested control bread. trans-Ferulic acid showed the lowest bioaccessibility, up to 2.8%. In GFB2.5 and GFB5 breads, the bioaccessibility of p-coumaric, trans-ferulic, and cis-ferulic acids was higher than in other digested breads. PCA visualized the difference between the undigested and digested breads. The incorporation of germinated and fermented, or germinated and enzymatic, treated spelt flour in a white bread recipe could be an attractive way of providing consumers with nutritionally interesting foods.

Effect of Dietary Amaranth (Amaranthus hybridus chlorostachys) Supplemented with Enzyme Blend on Egg Quality, Serum Biochemistry and Antioxidant Status in Laying Hens

A feeding trial was performed to assess the effects of dietary raw amaranth (Amaranthus hybridus chlorostachys) grain (RAG), with or without an enzyme blend, on the productive performance, blood biochemistry, and antioxidant status in laying hens. The trial was conducted following a completely randomized design by factorial method, including five levels of RAG (0, 10, 20, 30, and 40%, respectively) and two levels of enzyme blend (0 ^-E and 0.025 ^+E %). A total of 960 White Leghorn (Hy-line W-36) laying hens (56 weeks of age) were divided into 10 groups with eight repetitions, including 12 birds. The trial period was ten weeks. Results showed that RAG levels in feed (>10%) led to a significant decrease in blood total cholesterol (TC), but they also significantly decreased feed conversion ratio (FCR) (p ˂ 0.05) as measured by feed intake (FI), hen daily production (HDP), egg weight (EW), and mass (EM), leading to overall worse productivity compared to the control group. On the contrary, the addition of the enzyme blend led to an improvement in the investigated production traits (p ˂ 0.05), with the exception of HDP. The enzyme blend was also capable of recovering productive performance when combined with low concentrations of RAG (10%) (p ˂ 0.05), and RAG × enzyme blend groups showed the lowest values of TC (p ˂ 0.05). Moreover, the interaction effects for atherogenic index (LDL/HDL) indicated a significant and promising reduction in response to the addition of RAG both in the presence and absence of the enzyme blend (p ˂ 0.05), and this additive also significantly reduced levels of egg yolk cholesterol (p ˂ 0.05). In summary, the evidence gathered in this trial showed that dietary RAG had positive effects on egg quality characteristics, leading to the production of low-cholesterol eggs, and, at the same time, it may improve the health status of laying hens. Furthermore, the addition of an enzyme blend allowed feeding up to 10% RAG in the diet, leading to an optimal balance between animal productivity and the beneficial effects of RAG.

Hemp Flour Particle Size Affects the Quality and Nutritional Profile of the Enriched Functional Pasta

The rheological and chemical quality of pasta samples, which were obtained using the durum wheat semolina fortified with the hemp seed solid residue, after oil extraction, sieved at 530 μm (Hemp 1) or 236 μm (Hemp 2) at different percentages of substitution (5%, 7.5%, and 10%, were evaluated. The total polyphenolic content in hemp flour was quantified in the range of 6.38-6.35 mg GAE/g, and free radical scavenging was included in the range from 3.94-3.75 mmol TEAC/100 g in Hemp 1 and Hemp 2, respectively. The phenolic profiles determined by UHPLC-ESI/QTOF-MS showed that cannabisin C, hydroxycinnamic and protocatechuic acids were the most abundant phenolic compounds in both hemp flours. Among the amino acids, isoleucine, glutamine, tyrosine, proline, and lysine were the most abundant in raw materials and pasta samples. Although the hemp seeds were previously subjected to oil extraction, hemp flours retain about 8% of oil, and the fatty acids present in the largest amount were linoleic acid and α-linolenic acid. Characterization of the minerals showed that the concentration of macro and trace elements increased according to fortification percentage. Sensory evaluation and cooking quality indicated that the best performance in terms of process production and consumer acceptance was obtained using Hemp 2 at 7.5%. Hemp supplementation could be a potential option for producing high-quality, nutritionally rich, low-cost pasta with good color and functionality.

Metabolomic analysis and ecofriendly enrichment of sunflower meal extract

BACKGROUND

The presence of phenolic compounds in sunflower is well reported in the literature; however, knowledge is scarce when it comes to the composition of other secondary metabolites in this species and their by-products. This work evaluated, for the first time, the phytochemical composition of sunflower meal produced in Brazil. A combination of mixture design and central composite rotatable design 2³ models was then applied to maximize the recovery of bioactive compounds using ecologically friendly solvents and concentrating by applying activated carbon, a sustainable adsorbent. The product of this extraction-concentration was also evaluated by an untargeted metabolomic approach using ultra-performance liquid chromatography coupled to mass spectrometry.

RESULTS

A diverse and abundant profile of phenolic compounds was obtained from Brazilian sunflower meal: in total, 51 natural products were tentatively identified, 35 of which for the first time in sunflower. The sorption capacity of the activated charcoal, in the optimized process conditions, was effective in the separation and concentration of minority secondary metabolites. The ecofriendly extract proved to be enriched in plumberoside, p-coumaric acid, and alkaloids.

CONCLUSIONS

Investigation of the phytochemical profile of sunflower meal produced in Brazil pointed to several secondary metabolites reported for the first time in sunflower samples, including phenolic compounds, alkaloids, and terpenes. The use of activated charcoal in an alkaline medium as an adsorbent for the concentration of these phytochemicals, from an aqueous extract, generated a potentially cost-effective, ecofriendly extract, enriched in minor metabolites, indicating a possible innovative way to selectively obtain these compounds from sunflower meal. © 2022 Society of Chemical Industry.

Millet Bran Protein Hydrolysate Displays the Anti-non-alcoholic Fatty Liver Disease Effect via Activating Peroxisome Proliferator-Activated Receptor γ to Restrain Fatty Acid Uptake

Non-alcoholic fatty liver disease (NAFLD) is a serious health problem worldwide. Impeding fatty acid uptake may be an attractive therapeutic strategy for NAFLD. In the current study, we found that millet bran protein hydrolysate (MBPH) prepared by in vitro gastrointestinal bionic digestion exhibits the potential of anti-NAFLD in vitro and in vivo, characterized by the alleviation of hepatic steatosis and the reduction of lipid accumulation. Further, MBPH significantly decreased the expression levels of fatty acid uptake related genes (FABP1, FABP2, FABP4, CD36, and CPT-1α) of liver tissue in a NAFLD mice model through activating peroxisome proliferator-activated receptor γ (PPARγ) and efficiently restrained the fatty acid uptake of liver tissue, thus exerting anti-NAFLD activity. As expected, the anti-NAFLD effect induced by MBPH, characterized by the alleviation of hepatic vacuolar degeneration, hepatic steatosis, and fibrosis, was effectively abrogated with PPARγ inhibitor (GW9662) treatment. These results indicate that the retardant of fatty acid uptake induced by PPARγ activation may be the critical factor for the anti-NAFLD effect of MBPH. Collectively, MBPH has the potential as a next-generation dietary supplementation for the prevention and treatment of NAFLD.

Application of Cellulase for Contributing Phenolic Release and Conversion in Oats (Avena sativa L.) During Microbial Fermentation

In this work, Monascus fermentation and cellulase hydrolysis (MCF) of oats (Avena sativa L.) to release and convert phenolic fraction was investigated. Results showed the fungus Monascus grew well with a biomass of 27.03 mg/g glucosamine equivalent in MCF, following the destruction of oat cellular structures. SDS-PAGE revealed lots of enzymes were regulated with the α-amylase and FPase activity achieved 139.25 U/g and 1.84 U/g in MCF, respectively. Compared with unfermented oats, content of the total phenolic fractions was increased by 19.2 times in MCF, suggesting a phenolic release process occurred during fermentation. Moreover, the soluble-free chlorogenic acid upregulated to 510.00 mg/kg whereas the insoluble-bound ferulic acid downregulated to 193.36 mg/kg in MCF, indicating a transformation process of chlorogenic acid from ferulic acid in oats was enhanced. Based on this, a possible pathway of phenolic release and conversion in oats during fermentation with Monascus spp. was revealed. This study was helpful to enrich the theory of microbial metabolism and transformation in grain materials.

Conversion of (poly)phenolic compounds in food fermentations by lactic acid bacteria: Novel insights into metabolic pathways and functional metabolites

Lactobacillaceae are among the major fermentation organisms in most food fermentations but the metabolic pathways for conversion of (poly)phenolic compounds by lactobacilli have been elucidated only in the past two decades. Hydroxycinnamic and hydroxybenzoic acids are metabolized by separate enzymes which include multiple esterases, decarboxylases and hydroxycinnamic acid reductases. Glycosides of phenolic compounds including flavonoids are metabolized by glycosidases, some of which are dedicated to glycosides of plant phytochemicals rather than oligosaccharides. Metabolism of phenolic compounds in food fermentations often differs from metabolism in vitro, likely reflecting the diversity of phenolic compounds and the unknown stimuli that induce expression of metabolic genes. Current knowledge will facilitate fermentation strategies to achieve improved food quality by targeted conversion of phenolic compounds.

Valorization of Peels of Eight Peach Varieties: GC-MS Profile, Free and Bound Phenolics and Corresponding Biological Activities

Sustainability, becoming essential for food processing and technology, sets goals for the characterization of resources considered as food waste. In this work, information about the GC-MS metabolites of peach peels was provided as a tool that can shed more light on the studied biological activities. In addition, distribution patterns and contribution of the chemical profile and free and bound phenolic compounds as antioxidant, antimicrobial, and enzymatic clusters in peach peels of different varieties of Bulgarian origin were studied. The two applied techniques (alkaline and acid hydrolysis) for releasing the bound phenolics reveal that alkaline hydrolysis is a better extraction approach. Still, the results indicate the prevalence of the free phenolics in the studied peach peel varieties. Total phenolics of peach wastes were positively correlated with their antioxidant activity. The antioxidant activity results certainly defined the need of an individual interpretation for each variety, but the free phenolics fractions could be outlined with the strongest potential. The limited ability of the peels' extracts to inhibit α-amylase and acetylcholinesterase, and the moderate antimicrobial activity, on the other hand, indicate that the potential of peach peels is still sufficient to seek ways to valorize this waste. Indeed, this new information about peach peels can be used to characterize peach fruits from different countries and/or different food processes, as well as to promote the use of this fruit waste in food preparation.

Importance of Insoluble-Bound Phenolics to the Antioxidant Potential Is Dictated by Source Material

Insoluble-bound phenolics (IBPs) are extensively found in the cell wall and distributed in various tissues/organs of plants, mainly cereals, legumes, and pulses. In particular, IBPs are mainly distributed in the protective tissues, such as seed coat, pericarp, and hull, and are also available in nutritional tissues, including germ, epicotyl, hypocotyl radicle, and endosperm, among others. IBPs account for 20-60% of the total phenolics in food matrices and can exceed 70% in leaves, flowers, peels, pulps, seeds, and other counterparts of fruits and vegetables, and up to 99% in cereal brans. These phenolics are mostly covalently bound to various macromolecules such as hemicellulose, cellulose, structural protein, arabinoxylan, and pectin, which can be extracted by acid, alkali, or enzymatic hydrolysis along with various thermal and non-thermal treatments. IBPs obtained from various sources exhibited a wide range of biological activities, including antioxidant, anti-inflammatory, antihypertensive, anticancer, anti-obesity, and anti-diabetic properties. In this contribution, the chemistry, distribution, biological activities, metabolism, and extraction methods of IBPs, and how they are affected by various treatments, are summarized. In particular, the effect of thermal and non-thermal processing on the release of IBPs and their antioxidant potential is discussed.

Pharmacokinetics of active compounds of a Terminalia chebula Retz. Ethanolic extract after oral administration rats using UPLC-MS/MS

Terminalia chebula Retz. (TC) is a well-known Chinese herbal medicine and rich in chemical components with multiple pharmacological effects. In this study, an ultra-performance liquid chromatography-tandem mass spectroscopy (UPLC-MS/MS) method was developed and used to determine the blood concentrations of nine active compounds (chebulic acid, gallic acid, protocatechuic acid, corilagin, chebulagic acid, chebulinic acid, 1,2,3,4,6-O-pentagalloylglucose, ellagic acid and ethyl gallate) after oral administration of TC extracts in rats. Pretreatment of plasma samples with protein precipitate with methanol was carried out, and caffeic acid was used as the internal standard (IS). Compounds precisions of intra- and inter-day were less than 14.6%, and the accuracy ranged from -11.7% to 13.5%. The extraction recoveries of compounds were between 84.9% and 108.4%, while matrix effects occurred between 86.4% and 115.9%. Stability tests showed that all nine analytes had been stable under four storage conditions, and statistically significant the relative standard deviations were under 13.7%. The validated UPLC-MS/MS method was applied with great success to plasma pharmacokinetics analysis of the TC extracts, and the pharmacokinetic results showed that among the nine components, the area under the concentration-time curve (AUC_(0-tn), 231112.38 ± 64555.20 h ng/mL) and maximum concentration (C_max, 4,983.57 ± 1721.53 ng/mL) of chebulagic acid were relatively large, which indicated that it had a higher level of plasma exposure. The half-life of elimination (T_1/2) of chebulinic acid, corilagin and chebulagic acid were 43.30, 26.39 and 19.98 h, respectively, suggesting that these analytes showed prolonged retention and metabolize more slowly in vivo. This study would deliver a theoretical foundation for the further application of TC in clinical practice.

Grain Germination Changes the Profile of Phenolic Compounds and Benzoxazinoids in Wheat: A Study on Hard and Soft Cultivars

Pre-harvest sprouting is a frequent problem for wheat culture that can be simulated by laboratory-based germination. Despite reducing baking properties, wheat sprouting has been shown to increase the bioavailability of some nutrients. It was investigated whether wheat cultivars bearing distinct grain texture characteristics (BRS Guaraim, soft vs. BRS Marcante, hard texture) would have different behavior in terms of the changes in phytochemical compounds during germination. Using LC-Q-TOF-MS, higher contents of benzoxazinoids and flavonoids were found in the hard cultivar than in the soft one. Free phytochemicals, mainly benzoxazinoids, increased during germination in both cultivars. Before germination, soft and hard cultivars had a similar profile of matrix-bound phytochemicals, but during germination, these compounds have been shown to decrease only in the hard-texture cultivar, due to decreased levels of phenolic acids (trans-ferulic acid) and flavonoids (apigenin) that were bound to the cell wall through ester-type bonds. These findings confirm the hypothesis that hard and soft wheat cultivars have distinct behavior during germination concerning the changes in phytochemical compounds, namely the matrix-bound compounds. In addition, germination has been shown to remarkably increase the content of benzoxazinoids and the antioxidant capacity, which could bring a health-beneficial appeal for pre-harvested sprouted grains.

Comparative Assessment of Functional Components and Antioxidant Activities between Hippophae rhamnoides ssp. sinensis and H. tibetana Berries in Qinghai-Tibet Plateau

The Qinghai-Tibet Plateau is the main production area of Hippophae rhamnoides ssp. sinensis (Rha) and H. tibetana (Tib), but studies on the types and contents of soluble sugars, organic acids, free phenolics, bound phenolics, vitamin C (V_C), tocopherol (V_E) and carotenoids of the two sea buckthorn berries from this region have not been reported. In this paper, we found that the soluble sugars in Rha and Tib were mainly glucose and fructose; Rha exhibited a higher content of total sugar and fructose compared to Tib. The organic acids were mainly quinic acid and malic acid; Rha exhibited a higher content of total acids and quinic acid, but lower tartaric acid and citric acid compared to Tib. Rha also possessed a higher total (free and bound) phenolic as well as total (free and bound) flavonoid content than those in Tib; twelve phenolic compounds were analyzed, among which flavonols were dominant. Catechin, isorhamnetin and quercetin were the main phenolic substances. V_C and V_E (γ-tocopherol (γ-V_E) and δ-tocopherol (δ-V_E)) were higher in Rha than Tib. The total carotenoid, lutein, β-carotene and lycopene content of Tib was remarkably higher than that in Rha. Moreover, both Rha and Tib showed good in vitro and cellular antioxidant activities, and Rha had a stronger antioxidant activity. Taken together, Rha had a higher antioxidant activity, which may be due to its higher content of phenolics, flavonoids, V_C and V_E.

Bioaccessibility of phenolic compounds using the standardized INFOGEST protocol: A narrative review

The INFOGEST protocol creation was a watershed for phenolic bioaccessibility studies. Because of this important initiative to standardize bioaccessibility studies, data comparisons between different laboratories are now expedited. It has been eight years since the INFOGEST protocol creation, and three from the latest update. However, the current status in terms of phenolic bioaccessibility and how far different laboratories are from reaching a consensus are still unrevealed. In this sense, this narrative review considered an evaluation of different studies that applied the INFOGEST protocol to investigate the bioaccessibility of phenolic compounds. The central objective was to compile the main findings and consensus and to identify possible gaps and future opportunities. This approach intends to further facilitate the use of this protocol by professionals in the field of food science and technology and related areas, generating a reflection on the actual level of standardization of the method. Despite the differences in phenolic compounds from diverse food matrices, and their peculiar behavior, some trends could be elucidated, in terms of phenolic release, stability, and/or transformation upon in vivo digestion. In contrast, there was no general consensus regarding sample preparation, how to report results and the form to calculate bioaccessibility, making it difficult to compare different studies. There is still a long road to effectively standardize the results obtained for phenolic bioaccessibility using the INFOGEST protocol, which is also an opportunity in terms of food analysis that can impact the food industry, especially for the development of nutraceuticals and functional foods.

Water Deficit-Induced Changes in Phenolic Acid Content in Maize Leaves Is Associated with Altered Expression of Cinnamate 4-Hydroxylase and p-Coumaric Acid 3-Hydroxylase

The amino acid phenylalanine is a precursor to phenolic acids that constitute the lignin biosynthetic pathway. Although there is evidence of a role of some phenolic acids in plant responses to pathogens and salinity, characterization of the involvement of phenolic acids in plant responses to drought is limited. Drought reduces water content in plant tissue and can lead to decreased cell viability and increased cell death. We thus subjected maize seedlings to water deficit and evaluated relative water content and cell viability together with p-coumaric acid, caffeic acid and ferulic acid contents in the leaves. Furthermore, we measured the enzymatic activity of cinnamate 4-hydroxylase (EC 1.14.13.11) and p-coumarate 3-hydroxylase (EC 1.14.17.2) and associated these with the expression of genes encoding cinnamate 4-hydroxylase and p-coumarate-3 hydroxylase in response to water deficit. Water deficit reduced relative water content and cell viability in maize leaves. This corresponded with decreased p-coumaric acid but increased caffeic and ferulic acid content in the leaves. Changes in the phenolic acid content of the maize leaves were associated with increased enzymatic activities of cinnamate 4-hydroxylase and p-coumarate hydroxylase. The increased enzymatic activity of p-coumarate 3-hydroxylase was associated with increased expression of a gene encoding p-coumarate 3-hydroxylase. We thus conclude that metabolic pathways involving phenolic acids may contribute to the regulation of drought responses in maize, and we propose that further work to elucidate this regulation may contribute to the development of new maize varieties with improved drought tolerance. This can be achieved by marker-assisted selection to select maize lines with high levels of expression of genes encoding cinnamate 4-hydroxylase and/or p-coumarate 3-hydroxylase for use in breeding programs aimed and improving drought tolerance, or by overexpression of these genes via genetic engineering to confer drought tolerance.

Upcycling Rocha do Oeste Pear Pomace as a Sustainable Food Ingredient: Composition, Rheological Behavior and Microstructure Alone and Combined with Yeast Protein Extract

This work explores the potential of Rocha do Oeste pear pomace to be used as a sustainable and healthy food ingredient. Moreover, the enrichment with yeast protein extract (YPE) may be useful to design innovative food products. The main goals of this study were to assess pear pomace concerning: (i) chemical composition and antioxidant capacity; (ii) rheology, texture, and microstructure characterization (alone or enriched with YPE), before and after heating. The results showed that pear pomace was a rich source of dietary fibers (74.5% DW), with phenolic compounds (3.9 mg chlorogenic acid equivalents/g dry weight), also presenting antiradical activity (3.90 μmol Trolox equivalents/g DW). Pear pomace showed a shear thinning behavior and a typical soft-gel behavior, which was not affected by YPE enrichment, thus suggesting that YPE did not affect pear pomace technological properties. Thermal treatment also did not alter pear pomace rheological properties. YPE addition induced a decrease in the apparent viscosity and a destabilizing effect, compared to the samples that were subjected to thermal processing. These results highlight the importance of pear pomace and the use of YPE for protein enrichment, opening new opportunities for their exploitation.

Procyanidins from Cranberry Press Residues-Extraction Optimization, Purification and Characterization

Procyanidins are a polyphenolic group that can be found in a variety of foods such as chocolate, tea, cranberries and others. Type A procyanidins can be found in a handful of sources and one of the richest sources are American cranberries. These compounds possess antioxidative, anticancer and anti-inflammatory activities and are most widely used as prevention for urinary tract infections. Cranberries are utilized for jam and juice production, and the latter produces industrial food waste press residues. Press residues contain free and bound procyanidins which can be extracted for use as nutraceuticals. In this study, the extraction of cranberry press residues has been optimized using RSM and the resulting extracts have been purified and fractionated. The obtained procyanidin fractions have been investigated for their antioxidative potential and analyzed using LC-ESI-FTICR-HRMS to determine individual procyanidins. The optimization showed that the optimal extraction can be conducted using acetone in a concentration of 53% without the addition of an acidifying agent. Strong correlation was observed for procyanidin contents and their antioxidative activity using DPPH, ABTS and FRAP methods. The purified fractions contained 78 individual (65 Type A) procyanidins with the degree of polymerization of up to 9.

In Vitro Gastrointestinal Bioaccessibility, Bioactivities and Colonic Fermentation of Phenolic Compounds in Different Vigna Beans

Beans are widely consumed throughout the world, rich in non-nutrient phenolic compounds and other bioactive constituents, including alkaloids, lectins, and others. However, research about in vitro digestion impacts on the changes of bioactive compounds' release and related antioxidant potential in different Vigna beans is limited. This research aimed to assess the modifications that occur in the content and bioaccessibility of phenolic compounds in four Vigna samples (adzuki bean, black urid whole, black eye bean, and mung bean), their antioxidant properties, and short chain fatty acids (SCFAs) production through static in vitro gastrointestinal digestion and colonic fermentation. Adzuki bean exhibited relatively higher total phenolic content (TPC; 4.76 mg GAE/g) and antioxidant activities after in vitro digestion. The black eye beans' total flavonoid content (0.74 mg QE/g) and total condensed tannins (10.43 mg CE/g) displayed higher tendencies. For colonic fermentation, the greatest TPC value of entire samples was detected through a 2-h reaction. In most selected beans, phenolic compounds were comparably more bioaccessible during the oral phase. Acetic acid showed the highest level through SCFAs production, and the total SCFAs in adzuki beans was the greatest (0.021 mmol/L) after 16-h fermentation. Adzuki beans may be more beneficial to gut health and possess a stronger antioxidant potential after consumption.

Enzymatic lipophilization of bioactive compounds with high antioxidant activity: a review

Food products contain bioactive compounds such as phenolic and polyphenolic compounds and vitamins, resulting in a myriad of biological characteristics such as antimicrobial, anticarcinogenic, and antioxidant activities. However, their application is often restricted because of their relatively low solubility and stability in emulsions and oil-based products. Therefore, chemical, enzymatic, or chemoenzymatic lipophilization of these compounds can be achieved by grafting a non-polar moiety onto their polar structures. Among different methods, enzymatic modification is considered environmentally friendly and may require only minor downstream processing and purification steps. In recent years, different systems have been suggested to design the synthetic reaction of these novel products. This review presents the new trends in this area by summarizing the essential enzymatic modifications in the last decade that led to the synthesis of bioactive compounds with attractive antioxidative properties for the food industry by emphasizing on optimization of the reaction conditions to maximize the production yields. Lastly, recent developments regarding characterization, potential applications, emerging research areas, and needs are highlighted.

Conventional vs. Green Extraction Using Natural Deep Eutectic Solvents—Differences in the Composition of Soluble Unbound Phenolic Compounds and Antioxidant Activity

The aim of this study was to investigate the effect of the use of green solvents, natural deep eutectic solvents (NaDES), in comparison with conventional solvents on the extraction of free unbound phenolic compounds and the antioxidant activity of extracts of dried bilberry fruit, bilberry leaves and green tea leaves. After preparation of the extracts via ultrasound-assisted extraction using NaDES and conventional solvents (water and ethanol), spectrophotometric determination of total phenolic and flavonoid content, HPLC analysis of extracted polyphenols and antioxidant determination using FRAP, DPPH and ABTS assays were conducted. The results showed that NaDES have a great potential as agents for the extraction of phenolic compounds with potent antioxidant activity; the highest values of phenolic content and antioxidant activity were detected in the samples obtained by extraction using the NaDES combination betaine + urea. The bilberry leaves exhibited the highest flavonoid content among all extracts and turned out to be more active than bilberry fruits, to which they are often just a by-product during processing. The most active extract of all was the betaine-urea green tea leaves extract. Further research into the most active NaDES extracts should be performed.