Phenolic composition and antioxidant potential of grain legume seeds: A review

Is Chickpea a Potential Substitute for Soybean? Phenolic Bioactives and Potential Health Benefits

Legume seeds are rich sources of protein, fiber, and minerals. In addition, their phenolic compounds as secondary metabolites render health benefits beyond basic nutrition. Lowering apolipoprotein B secretion from HepG2 cells and decreasing the level of low-density lipoprotein (LDL)-cholesterol oxidation are mechanisms related to the prevention of cardiovascular diseases (CVD). Likewise, low-level chronic inflammation and related disorders of the immune system are clinical predictors of cardiovascular pathology. Furthermore, DNA-damage signaling and repair are crucial pathways to the etiology of human cancers. Along CVD and cancer, the prevalence of obesity and diabetes is constantly increasing. Screening the ability of polyphenols in inactivating digestive enzymes is a good option in pre-clinical studies. In addition, in vivo studies support the role of polyphenols in the prevention and/or management of diabetes and obesity. Soybean, a well-recognized source of phenolic isoflavones, exerts health benefits by decreasing oxidative stress and inflammation related to the above-mentioned chronic ailments. Similar to soybeans, chickpeas are good sources of nutrients and phenolic compounds, especially isoflavones. This review summarizes the potential of chickpea as a substitute for soybean in terms of health beneficial outcomes. Therefore, this contribution may guide the industry in manufacturing functional foods and/or ingredients by using an undervalued feedstock.

Ailanthus altissima (Miller) Swingle seed oil: chromatographic characterization by GC-FID and HS-SPME-GC-MS, physicochemical parameters, and pharmacological bioactivities

This study aimed to identify the physicochemical and the chemical properties of Ailanthus altissima (Miller) Swingle seed oil and to evaluate its in vitro antioxidant and antibacterial activities and in vivo analgesic and anti-inflammatory activities. The fatty acids' composition was determined using GC-FID. The oil was screened for antioxidant activity by DPPH test. The analgesic and anti-inflammatory activities were determined using the acetic acid writhing test in mice and the carrageenan-induced paw edema assay in rats, respectively. Volatile compounds were characterized by HS-SPME-GC-MS. A. altissima produces seeds which yielded 17.32% of oil. The seed oil was characterized by a saponification number of 192.6 mg KOH∙g of oil, a peroxide value of 11.4 meq O₂∙kg of oil, a K₂₃₂ of 4.04, a K₂₇₀ of 1.24, and a phosphorus content of 126.2 ppm. The main fatty acids identified were palmitic (3.06%), stearic (1.56%), oleic (38.35%), and linoleic acids ones (55.76%). The main aroma compounds sampled in the headspace were carbonyl derivatives. The oil presents an important antioxidant activity (IC₅₀ = 24.57 μg/mL) and a modest antimicrobial activity. The seed oil at 1 g/kg showed high analgesic (91.31%) and anti-inflammatory effects (85.17%). The presence of high levels of unsaturated fatty acids and the noteworthy antioxidant capacity of the seed oil can hypothesize its use as an analgesic and anti-inflammatory agent.

Phytochemical Analysis, Antioxidant and Analgesic Activities of Incarvillea compacta Maxim from the Tibetan Plateau

Incarvillea compacta Maxim is a traditional Tibetan plant widely used to treat rheumatic pain and bruises. We conducted qualitative analyses by liquid chromatography-mass spectrometry and quantitative analyses of the total phenols, flavonoids, and alkaloids content of different extracts of I. compacta Maxim. Antioxidant and analgesic activity were analyzed. The results showed that the methanol extract had the highest content of the various ingredients. A total of 25 constituents were identified, of which compounds 1–23 were found for the first time in this plant. The water extract had the highest capacity to clear free radicals in the antioxidant test. The water extract had dose-dependent analgesic effects in the first and second phase in a formalin test. The latency of pain from a hot-plate test was augmented by the water extract when the dose was greater than or equal to 30 g/kg. The water extract significantly decreased the amount of writhing in a dose-dependent manner compared with the control group in the acetic acid-induced writhing test. These results showed that I. compacta Maxim is a new antioxidant and analgesic agent, and this study provides information on its ingredients for further study.

Comparison of cultivated and wild chickpea genotypes for nutritional quality and antioxidant potential

Fifteen cultivated (Ten desi, five kabuli) and fifteen wild species of chickpea (Cicer arietinum L.) were compared for nutritional traits, antinutritional factors and antioxidant potential. The average crude protein content in desi, kabuli and wild species was found to be 25.31%, 24.67% and 24.30%, respectively; total soluble sugars in these genotypes were 38.08, 43.75 and 33.20 mg/g, respectively and total starch content in these genotypes was 34.43, 33.43 and 28.77%. Wild species had higher antioxidant potential as compared to cultivated genotypes due to higher free radical scavenging activity, ferric reducing antioxidant power and reducing power. Kabuli genotypes had lower antioxidant potential than desi genotypes. Desi genotype, GL 12021 had high crude protein and total starch content, lower phytic acid and saponin content and higher antioxidant potential. GNG 2171 had high crude protein and total soluble sugar content and lower tannin and phytic acid content. Kabuli genotype L 552 possessed high total soluble sugar and total starch content, high Zn and Fe content and lower tannin, saponin and trypsin inhibitor content. Wild species C. pin ILWC 261 had high crude protein, lower phytic acid and trypsin inhibitor content and higher DPPH radical scavenging activity and hydroxyl radical scavenging activity. The observed diversity for quality traits in cultivated and wild genotypes can be further used.

Multifunctional Cellulose Ester Containing Hindered Phenol Groups with Free-Radical-Scavenging and UV-Resistant Activities

Excessive radicals and UV irradiation can trigger oxidative and physiological stresses, which cause tissue aging, human disease, food spoilage, and material degradation. In this study, a multifunctional cellulose ester containing hindered phenol groups, cellulose 3,5-di- tert-butyl-4-hydroxybenzoate (CBH), with free-radical-scavenging and UV-resistant activities was synthesized and used as a functional material. The obtained CBHs can effectively scavenge reactive nitrogen free radicals and hydroxyl free radicals in both solid and solution states. Moreover, CBHs have no cytotoxicity, and, on the contrary, they promote the proliferation of human epidermal keratinocytes. Benefiting from excellent solubility, processability, and formability, CBHs have been readily processed into flexible films, transparent coatings, and nanoribbons membranes. The highly transparent and flexible CBH film completely absorbs the light of 200-300 nm range and partially absorbs the light of 300-400 nm range, indicating a UV-shielding capability. After the CBHs were loaded on an ordinary facial mask by electrospinning or added into a hand cream, the resultant facial mask and hand cream exhibited outstanding free-radical-scavenging properties. In addition, CBHs can also be used to fabricate functional sprays with antioxidative and UV-shielding activities. Accordingly, the obtained CBHs have a huge potential in cosmetics, personal care products, biopharmaceuticals, papermaking, and art protection because of their excellent antioxidation, nontoxicity, UV resistance, formability, and odorless properties.

Seed coat metabolite profiling of cowpea (Vigna unguiculata L. Walp.) accessions from Ghana using UPLC-PDA-QTOF-MS and chemometrics

Cowpea (Vigna unguiculata L. Walp.) is an important grain legume in Africa exhibiting high morpho-genetic diversity. However, not much information exists on the phytochemical profiles of its hulls. This study explored the metabolite profiles of seed-coats from thirteen cowpea accessions of varying phenotypes using UPLC-QTOF-MS and chemometric analysis. A total of 34 secondary metabolites were identified, which comprised phenolic acids, flavonoids, anthocyanins, sphingolipids and fatty acids. Quantification of selected phenolic compounds revealed marked variations among the cowpea accessions. The chemical profiles of the test accessions were distinguished by multivariate analysis, and the results revealed a marked influence of seed-coat pigmentation on the observed differences in their metabolite profiles. Moreover, delphinidin (traces to 2257.6 µg/g), catechin glucoside (traces to 2840.6 µg/g), catechin (traces to 2089.2 µg/g) and epicatechin (26.3 to 3222.7 µg/g) contributed to the segregation amongst the studied samples. The concentrations of the discriminant metabolites were greater in the dark seeded cowpeas compared to their lighter seeded counterparts. The findings represent a useful contribution to the literature on cowpea seed coat metabolites, and also reveal their potential for use in the development of food and pharmaceutical products.

Legume biofortification is an underexploited strategy for combatting hidden hunger

Legumes are the world's primary source of dietary protein and are particularly important for those in developing economies. However, the biofortification potential of legumes remains underexploited. Legumes offer a diversity of micronutrients and amino acids, exceeding or complementing the profiles of cereals. As such, the enhancement of legume nutritional composition presents an appealing target for addressing the "hidden hunger" of global micronutrient malnutrition. Affecting ~2 billion people, micronutrient malnutrition causes severe health effects ranging from stunted growth to reduced lifespan. An increased availability of micronutrient-enriched legumes, particularly to those in socio-economically deprived areas, would serve the dual functions of ameliorating hidden hunger and increasing the positive health effects associated with legumes. Here, we give an updated overview of breeding approaches for the nutritional improvement of legumes, and crucially, we highlight the importance of considering nutritional improvement in a wider ecological context. Specifically, we review the potential of the legume microbiome for agronomic trait improvement and highlight the need for increased genetic, biochemical, and environmental data resources. Finally, we state that such resources should be complemented by an international and multidisciplinary initiative that will drive crop improvement and, most importantly, ensure that research outcomes benefit those who need them most.

Screening Olive Leaves from Unexploited Traditional Greek Cultivars for Their Phenolic Antioxidant Dynamic

Quality characteristics of olive products significantly depend on cultivar (cv), among other factors. In this study, seven traditional, noncommercial Greek cultivars, along with the commercial Spanish Arbequina cv., were examined for the phenolic antioxidant dynamic of their leaves. Polar extracts (aqueous, methanol, and ethanol) were analyzed for Total Phenol (TP), Flavonoid (TFL), Hydroxycinnamic Acid Derivatives (THAD), Flavonol (TFLVN) contents, DPPH radical scavenging ability, and Ferric Reducing Capacity (FRAP). Selective characteristics of olive leaf methanol extracts for all cultivars were re-examined on a second sampling period. Olive leaf is considered a rich source of phenolic antioxidants total phenol content reaching 29.3 ± 1.3, 30.6 ± 0.4, and 27.0 ± 1.1 mg caffeic acid/g dry leaf for aqueous, methanol, and ethanol extracts, respectively) and all cultivars were considered of equal bioactive dynamic. TP data derived from Folin–Ciocalteu and another spectrophotometric assay employed presented a high correlation for all examined cases (R² = 71.5–86.9%). High correlation (R² = 0.92) was also found between TP and FRAP findings of aqueous extracts. Olive leaf is considered a promising source of phenolic antioxidants irrelevant to cultivar and therefore even cultivars less effective for oil or table olive production could be efficiently exploited for the bioactive dynamic of their leaves.

Absorption, metabolism, distribution and faecal excretion of B-type procyanidin oligomers in mice after a single oral administration of black soybean seed coat extract

We investigated the absorption, metabolism, distribution and faecal excretion of 3 B-type procyanidin oligomers, including procyanidin B2, procyanidin C1 and cinnamtannin A2, and their monomeric unit (-)-epicatechin after a single oral administration of black soybean seed coat extract (BE) to male ICR mice at 250 mg per kg body weight. Plasma, tissues and faeces samples were collected within 24 h for the determination of (-)-epicatechin, procyandidin B2, procyanidin C1 and cinnamtannin A2 with or without β-glucuronidase and sulfatase treatment by the high-performance liquid chromatography method. A portion of the B-type procyanidin oligomers and (-)-epicatechin in BE was absorbed from the small intestine after the oral administration of BE. In the plasma, absorbed procyanidins and (-)-epicatechin existed mainly as conjugates. In the tissues, procyanidin B2, procyandin C1 and cinnamtannin A2, in addition to (-)-epicatechin distributed widely, primarily in their free forms. Their conjugation occurred mainly in the small intestine, rather than in the liver. Monomeric unit (-)-epicatechin had the highest bioavailability, followed by procyanidin B2, procyanidin C1 and cinnamtannin A2.

Seed coats as an alternative molecular factory: thinking outside the box

Seed coats as commodities. Seed coats play important roles in the protection of the embryo from biological attack and physical damage by the environment as well as dispersion strategies. A significant part of the energy devoted by the mother plant to seed production is channeled into the production of the cell layers and metabolites that surround the embryo. Nevertheless, in crop species these are often discarded post-harvest and are a wasted resource that could be processed to yield co-products. The production of novel compounds from existing metabolites is also a possibility. A number of macromolecules are already accumulated in these maternal layers that could be exploited in industrial applications either directly or via green chemistry, notably flavonoids, lignin, lignan, polysaccharides, lipid polyesters and waxes. Here, we summarize our knowledge of the in planta biosynthesis pathways of these macromolecules and their molecular regulation as well as potential applications. We also outline recent work aimed at providing further tools for increasing yields of existing molecules or the development of novel biotech approaches, as well as trial studies aimed at exploiting this underused resource.

Bioactivities of phytochemicals present in tomato

Tomato is a wonder fruit fortified with health-promoting phytochemicals that are beneficial in preventing important chronic degenerative disorders. Tomato is a good source of phenolic compounds (phenolic acids and flavonoids), carotenoids (lycopene, α, and β carotene), vitamins (ascorbic acid and vitamin A) and glycoalkaloids (tomatine). Bioactive constituents present in tomato have antioxidant, anti-mutagenic, anti-proliferative, anti-inflammatory and anti-atherogenic activities. Health promoting bioactivities of tomatoes make them useful ingredient for the development of functional foods. Protective role of tomato (lycopene as a potent antioxidant) in humans against various degenerative diseases are known throughout the world. Intake of tomato is inversely related to the incidence of cancer, cardiovascular diseases, ageing and many other health problems. Bioavailability of phytoconstituents in tomato is generally not affected by routine cooking processes making it even more beneficial for human consumption. The present review provides collective information of phytochemicals in tomato along with discussing their bioactivities and possible health benefits.

Phenolic profiles and their contribution to the antioxidant activity of selected chickpea genotypes from Mexico and ICRISAT collections

Chickpea (Cicer arietinum L.) genotypes, nine kabuli from Mexico and 9 desi from other countries, were investigated for their phenolic profiles and antioxidant activity (AA). Phenolics in methanol extracts (ME) were analyzed by ultra-performance liquid chromatography coupled to diode array detection and mass spectrometry (UPLC-DAD-MS), whereas the AA was measured as Trolox equivalents (TE) by ABTS, DPPH and FRAP methods. Twenty phenolic compounds were identified in the ME and their levels showed a great variability among the chickpea genotypes. Phenolic acids and flavonoids were the most abundant compounds in kabuli and desi genotypes, respectively. The AA values (μmol TE/ 100 g dw) by ABTS (278-2417), DPPH (52-1650), and FRAP (41-1181) were mainly associated with the content of sinapic acid hexoside, gallic acid, myricetin, quercetin, catechin, and isorhamnetin, suggesting they are the main compounds responsible for the AA. The sum of the AA obtained for standards of these compounds evaluated at the concentration found in the extracts accounted for 34.3, 69.8, and 47.0% of the AA in the extract by ABTS, DPPH, and FRAP, respectively. In the AA by DPPH, most of the mixtures of these compounds resulted in synergistic interactions. Three desi genotypes with black seeds (ICC 4418, ICC 6306, and ICC 3761) showed the highest AA and flavonoids content, whereas the most promising kabuli genotypes were Surutato 77, Bco. Sin. 92, and Blanoro that showed the highest values of phenolic acids. These genotypes represent good sources of antioxidants for the improvement of nutraceutical properties in chickpea.

Phenolic compounds as beneficial phytochemicals in pomegranate (Punica granatum L.) peel: A review

Pomegranate peel (PoP), a juice byproduct often considered as a waste, comprises nearly around 30-40% portion of the fruit. Phenolic compounds (one class of bioactive phytochemicals) are primarily concentrated in the peel portion of pomegranate fruit. In PoP, the main phenolic compounds reported in the literature include flavonoids (anthocyanins such as pelargonidin, delphinidin, cyanidin along with their derivatives and anthoxanthins such as catechin, epicatechin and quercetin), tannins (ellagitannins and ellagic acid derivatives such as punicalagin, punicalin and pedunculagin) and phenolic acids (such as chlorogenic, caffeic, syringic, sinapic, p-coumaric, ferulic, ellagic, gallic and cinnamic acid). It is generally accepted that phenolic compounds can be more efficiently recovered from PoP by improving the extraction efficiency. The curative relevance of these compounds has been mainly assessed by in vitro experimentation. Therefore, conclusive clinical trials of the phenolic compounds present in PoP are essential for correct validation of their health benefits.