Phenolics and antioxidant activity of lentil and pea hulls

Characterisation of the protein quality and composition of water kefir-fermented casein

This study aimed to assess the technique of natural fermentation by applying water kefir to the casein protein. The diverse microorganisms and their enzymes found naturally in the water kefir can influence casein's characteristics. The fermented casein's protein quality (digestibility and secondary protein structure) and composition (total soluble solids and nutritive and non-nutritive substances) were investigated. Our findings revealed that the fermented casein's protein digestibility and total phenolic content increased from 82.46 to 88.60 % and 7.6 to 8.0 mg gallic acid equivalent/100 g, respectively. In addition, their surface charge and hydrophobicity changed from -30.06 to -34.93 mV and 286.9 to 213.7, respectively. Furthermore, the fermented casein's secondary protein components, α-helix (decreased from 13.66 to 8.21 %) and random coil (increased from 16.88 to 19.61 %), were also altered during the fermentation. Based on these findings, the water kefir fermentation approach could be an effective, practical, non-thermal approach for improving casein's protein quality and composition.

Nutritional, chemical, and antioxidant screening of selected varieties of lentils (Lens culinaris spp.) from organic and conventional agriculture

BACKGROUND

Lentils are an ancient legume established worldwide for direct consumption and with great potential for application in food processing. In addition, it is a sustainable crop owing to its ability to scavenge nitrogen and carbon, and it improves the nutrient status of the soil. A diet rich in lentils has been linked to significant health benefits. However, the composition of lentils can be influenced by both the lentil variety and the growing conditions. The aim of this work was to evaluate the nutritional profiles and antioxidant potential, as well as the impact that the type of cultivation (conventional or organic) and the variety could have on these parameters, in different lentil varieties.

RESULTS

Overall, carbohydrates are the major macronutrients in all varieties, with notable amounts of fibre (11.62-27.36%) and starch (41.98-50.27%). High amounts of protein and ash were also identified, particularly in the Beluga variety, with 21.9-23.3 and 1.38-1.82 g 100 g-1 fresh weight, respectively. Fructose and sucrose were detected (high-performance liquid chromatography (HPLC) with refraction index detection), along with oxalic, quinic, malic, and shikimic acids (ultra-fast liquid chromatography with photodiode array detection), and α- and γ-tocopherol isoforms (HPLC with fluorescence detection). Fatty acid methyl ester assessment showed the prevalence of polyunsaturated fatty acids (33.5-46.3%). Good antioxidant capacity (thiobarbituric acid reactive substances and oxidative haemolysis inhibition assay) was also noted.

CONCLUSION

The results obtained showed that all the varieties analysed are an excellent source of fibre and have a good antioxidant capacity. Lentil variety has a greater influence on its nutritional composition than the type of cultivation. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

From ancient crop to modern superfood: Exploring the history, diversity, characteristics, technological applications, and culinary uses of Peruvian fava beans

The search for plant-based superfoods has shown that many regional populations already have these foods in their diet, with significant potential for production and marketing. This critical review intends to show the history, diversity, characteristics, and uses, emphasizing their significance in traditional diets and potential in the food industry of Peruvian fava beans. As a valuable plant-based protein source, fava beans offer essential micronutrients and have diverse culinary applications. Innovative food industry applications include plant-based meat alternatives, fortified gluten-free products, and a natural color, protein, and fiber source in extruded foods. Key studies have highlighted the successful incorporation of fava beans into various food products, improving their nutritional properties, though some studies also point to limitations in their sensory acceptance. Further research is needed to understand the bioactive components, health effects, and techno-functional characteristics of beans. Challenges facing cultivating and consuming fava beans in Peru include adapting to climate change, enhancing productivity and quality, and promoting consumption and added value. Addressing these challenges involves developing climate-resilient varieties, optimizing agricultural practices, and providing access to resources and financing. In conclusion, this review highlights the promising prospects of Peruvian fava beans as a sustainable, nutritionally rich, and versatile ingredient in the food industry. By harnessing their potential and overcoming challenges, Peruvian fava beans can transition from an ancient crop to a modern superfood, inspiring a global shift towards sustainable and nutritionally balanced diets, aiding the fight against malnutrition, and enriching culinary traditions worldwide.

The in vivo and in vitro protein quality of three hemp protein sources

In this work, the protein quality of defatted hemp hearts and protein-enriched hemp fractions was determined. Protein quality was assessed using a rodent bioassay to evaluate growth and protein digestibility, while amino acid composition was determined via HPLC. A method for determining in vitro protein digestibility was compared to in vivo methodology and used to generate an in vitro protein quality score. The true protein digestibility of hemp protein 2, a hemp protein concentrate, was significantly lower than that of either defatted hemp hearts or hemp protein 1, a hemp protein concentrate (p < .05). While there was no relationship between the in vivo and in vitro measurements of protein digestibility (R 2 = .293, p = .459), there was a significant correlation between the protein digestibility-corrected amino acid score (PDCAAS) determined in vivo and in vitro PDCAAS (R 2 = .989, p = .005). The protein efficiency ratio of hemp protein 1 was significantly lower than that of either defatted hemp hearts or hemp protein 2 (p < .05). These data highlight the nutritional capacity of hemp protein sources while also demonstrating the relationship between in vivo and in vitro methods for determining protein quality.

Nutritional, chemical and antioxidant evaluation of Armuña lentil (Lens culinaris spp): Influence of season and soil

Lentils (Lens culinaris spp.) are a type of edible pulse consumed and produced worldwide; they are known for their valuable nutritional assets. The nutritional and chemical profiles of 34 Armuña lentil samples were assessed together with their antioxidant capacity. In addition, the influence of both the climatic conditions during the growing season and the soil type in which they grow (Luvisol and Cambisol) on nutritional and chemical profiles was also evaluated. Our results showed large amounts of valuable nutrients, such as carbohydrates, of which approximately 47.06 % and 29.11 % consist of fibers and starch respectively and significant amounts of proteins (20.47 to 25.56 g/100 g fw) and ashes. Sucrose stood out as the main free sugar in this variety, and oxalic and γ-tocopherol as the main organic acid and tocopherol isoform respectively. Fatty acid assessment showed the prevalence of PUFAs (45.3 to 63.7 %). A high antioxidant capacity (TBARS and OxHLIA) was also observed. Our results indicate that the growing season has a significant impact on the major nutrients in lentils such as the concentration of fat, ashes, fibers, and fructose and to a lesser extent proteins and sucrose. In addition, the two different soil types in this study do not seem to affect any of the parameters analyzed.

Bioaccessibility and transport of lentil hull polyphenols in vitro, and their bioavailability and metabolism in rats

Polyphenol-rich lentil hulls are a valuable by-product. In this study, lentil hulls were subjected to simulated in vitro digestion and caco-2 cell monolayer models to assess the bioaccessibility, transmembrane transport, and a rat model to examine the bioavailability and metabolism in vivo. Polyphenols were increasingly released during the in vitro digestion, and were found to contribute to the increased antioxidant activity. Among the bioaccessible polyphenols, catechin glucoside, kaempferol tetraglucoside, procyanidin dimer and dihydroxybenzoic acid-O-dipentoside were most efficiently transported across the caco-2 membrane, and responsible for promoting intestinal integrity as a result of enhanced expression of tight junction proteins. When ingested by rats, lentil hull polyphenols underwent extensive I and II phase metabolic reactions in vivo, including hydroxylation, methylation, glucuronidation and sulfation. Overall, results of this study showed that lentil hull polyphenols are bioaccessible and bioavailable, and lentil hulls as a by-product can be a valuable ingredient for future functional foods.

Phytochemical analysis, antioxidant capacities, and in vitro biological activities of the extract of seed coat as by-products of pea

Converting seed coat peas (hulls) (SCP) into beneficial products provides a solution for waste treatment. This study aimed to investigate the phytoconstituents and biological activities of SCP extract. Phytochemical screening, total bioactive compounds, and GC-MS analysis were evaluated. Then, the antioxidant, antibacterial, anticancer, and antiviral activities of SCP extract were determined. The results demonstrate that SCP extract has bioactive compounds such as carbohydrates (29.53 ± 4.23 mg/mL), protein (0.24 ± 0.02 mg/mL), phenolics (27.04 ± 0.94 mg GAE/g extract), and flavonoids (17.19 ± 0.48 mg QE/g extract). The existence of more than 16 substances was determined using GC-MS analysis. The extract showed potential antioxidant activities, with the maximum activity seen for extract (IC50 µg/mL) = 79.16 ± 1.77 for DPPH, 67.40 ± 5.20 for ORAC, and 61.22 ± 4.81 for ABTS assays. The SCP extract showed potent antimicrobial activity against four gram-positive bacteria (Bacillus cereus, Streptomyces sp., Staphylococcus aureus, and Salmonella sp.) and two gram-negative bacteria (Escherichia coli and Pseudomonas sp.). SCP extract exhibited potential anticancer activity against lymphoma U937 and leukemic cells (THP1). The extract exhibited potential antiviral activity, with a selectivity index (SI) equal to 11.30 and 18.40 against herpes simplex-II (HSV-2) and adenovirus (Ad7), respectively. The results demonstrate more accurate information about peas by-products' chemical and antioxidant activities in various applications. The chemical components of peas by-products were found to have an in vitro antioxidant, antibacterial, and antiviral activity against leukemia and lymphoma.

Biochemical Characterization of Rare and Threatened Local Populations of Peas (Pisum sativum L.) Cultivated in the Arid Region of Southern Tunisia

Pea (Pisum sativum L.) is an important legume for human and animal consumption, cultivated in many temperate regions of the world. In the present investigation, the seeds of twelve pea accessions collected from the arid regions of southern Tunisia, characterized by different colors of flowers and seed coats, were evaluated for their proteins, phenolic compounds and antioxidant activities. The protein content determined by the Bradford method ranged from 46.91 to 151.08 mg/g DW. The content of total phenol, total flavonoid and condensed tannin, ranging from 36.85 to 102.52 mg GAE/100 g DW, 6.95 to 48.11 mg QE/100 g DW, and 12.37 to 70.43 mg CE/100 g DW, respectively. These parameters were characterized respectively by the following three methods, the Folin-Ciocalteu reagent, the aluminum chloride and the vanillin assay. The LC-ESI/MS analysis identified the presence of 8 phenolic acids and 9 flavonoids which quinic acid, protocatechuic acid, hyperoside, and quercetin-3-O-rhamnosidewere detected as the most abundant compounds. Moreover, the antioxidant activity of pea seeds was evaluated by the ABTS+and DPPH tests. Indeed, DPPH and ABTS anti-free radical activity values ranged from 1.92 to 14.11 μmoL TEAC/g DW and 2.3 to 14.95 μmoL TEAC/g DW, respectively. The variability across the assessed traits revealed significant differences as computed by ANOVA tests. Else, the results showed significant correlations between seed coat color, seed shape, flower color and phenolic compounds. Therefore, genotypes characterized by a purple flower, brown seed coat, and wrinkled form had the highest levels of phenolic compounds and antioxidant activity. Correlation analysis revealed that phenolic compounds presented a strong positive correlation with antioxidant activities, while being negatively correlated with protein content. UPGMA cluster and Principal component analysis (PCA) revealed two main groups. This work highlights the nutritional value of P. sativum seeds as a good source of natural antioxidant compounds that may be useful in the food and pharmaceutical industries.

Microwave-Assisted Extraction of Bioactive Compounds from Lentil Wastes: Antioxidant Activity Evaluation and Metabolomic Characterization

The recovery of industrial by-products is part of the zero-waste circular economy. Lentil seed coats are generally considered to be a waste by-product. However, this low-value by-product is rich in bioactive compounds and may be considered an eco-friendly source of health-promoting phytochemicals. For the first time, a sustainable microwave-assisted extraction technique was applied, and a solvent screening was carried out to enhance the bioactive compound content and the antioxidant activity of green and red lentil hull extracts. With respect to green lentil hull extracts that were obtained with different solvents, the aqueous extract of the red lentil seed coats showed the highest total phenolic and total flavonoid content (TPC = 28.3 ± 0.1 mg GAE/g dry weight, TFC = 1.89 ± 0.01 mg CE/100 mg dry weight, respectively), as well as the highest antioxidant activity, both in terms of the free radical scavenging activity (ABTS, 39.06 ± 0.73 mg TE/g dry weight; DPPH, IC50 = 0.39 μg/mL) and the protection of the neuroblastoma cell line (SH-SY5Y, IC50 = 10.1 ± 0.6 μg/mL), the latter of which has never been investigated so far. Furthermore, a metabolite discovery analysis was for the first time performed on the aqueous extracts of both cultivars using an HPLC separation which was coupled with an Orbitrap-based high-Resolution Mass Spectrometry technique.

Morphological, Molecular, and Biochemical Characterization of a Unique Lentil (Lens culinaris Medik.) Genotype Showing Seed-Coat Color Anomalies Due to Altered Anthocyanin Pathway

This study reports the identification of a unique lentil (Lens culinaris Medik.) genotype L4717-NM, a natural mutant (NM) derived from a variety L4717, producing brown, black, and spotted seed-coat colored seeds in a single plant, generation after generation, in different frequencies. The genetic similarity of L4717 with that of L4717-NM expressing anomalous seed-coat color was established using 54 SSR markers. In addition, various biochemical parameters such as TPC (total phenolic content), TFC (total flavonoid content), DPPH (2,2-diphenyl-1-picrylhydrazyl), FRAP (ferric reducing antioxidant power), H2O2 (peroxide quantification), TCC (total carotenoids content), TAC (total anthocyanin content), and TAA (total ascorbic acid) were also studied in the seeds, sprouts, and seedlings of L4717, brown, black, and spotted seed-coat colored seeds. Stage-specific variations for the key biochemical parameters were recorded, and seedling stage was found the best for many parameters. Moreover, seeds with black seed coat showed better nutraceutical values for most of the studied traits. A highly significant (p ≤ 0.01) and positive correlation was observed between DPPH and TPC, TAA, TFC, etc., whereas, protein content showed a negative correlation with the other studied parameters. The seed coat is maternal tissue and we expect expression of seed-coat color as per the maternal genotype. However, such an anomalous seed-coat expression, which seems to probably be governed by some transposable element in the identified genotype, warrants more detailed studies involving exploitation of the anthocyanin pathway.

Effect of Lactic Acid Fermentation on Legume Protein Properties, a Review

Legume proteins have a promising future in the food industry due to their nutritional, environmental, and economic benefits. However, their application is still limited due to the presence of antinutritional and allergenic compounds, their poor technological properties, and their unpleasant sensory characteristics. Fermentation has been traditionally applied to counteract these inconveniences. At present, lactic acid fermentation of legumes is attracting the attention of researchers and industry in relation to the development of healthier, tasty, and technologically adapted products. Hence, we aimed to review the literature to shed light on the effect of lactic acid fermentation on legume protein composition and on their nutritional, functional, technological, and sensorial properties. The antimicrobial activity of lactic acid bacteria during legume fermentation was also considered. The heterogenicity of raw material composition (flour, concentrate, and isolate), the diversity of lactic acid bacteria (nutriment requirements, metabolic pathways, and enzyme production), and the numerous possible fermenting conditions (temperature, time, oxygen, and additional nutrients) offer an impressive range of possibilities with regard to fermented legume products. Systematic studies are required in order to determine the specific roles of the different factors. The optimal selection of these criteria will allow one to obtain high-quality fermented legume products. Fermentation is an attractive technology for the development of legume-based products that are able to satisfy consumers’ expectations from a nutritional, functional, technological, and sensory point of view.

Effects of Faba Bean Hull Nanoparticles on Physical Properties, Protein and Lipid Oxidation, Colour Degradation, and Microbiological Stability of Burgers under Refrigerated Storage

The processing of faba beans generates great quantities of hulls, which are high in bioactive compounds with demonstrated radical-inhibiting properties. There is no research on the impact of using faba bean hull nanoparticles (FBH-NPs) to improve the quality and extend the shelf-life of beef products. Hence, the target of this investigation was to assess the inhibiting influence of adding FBH-NPs at two different concentrations (1 and 1.5%) on the physical attributes, lipid and protein oxidation, colour degradation, and microbiological safety of burgers during refrigerated storage (4 ± 1 °C/12 days). The FBH-NPs presented great phenolic content (103.14 ± 0.98 mg GAE/g dw) and antioxidant potential. The water holding capacity and cooking properties in burgers including FBH-NPs were improved during storage. The FBH-NPs significantly (p < 0.05) decreased the reduction rate of redness and lightness during the burger refrigerated storage and the FBH-NPs were more beneficial in preventing cold burger discolouration. In the FBH-NPs-treated burgers, peroxide values, TBARS, and protein carbonyl content were lower than in the control (up to 12 days). The microbiological load of burgers including FBH-NPs was lower than the load of the control during refrigerated storage. The findings revealed that FBH-NPs were more efficient in enhancing the cooking characteristics, retarding lipid or protein oxidation, preventing colour detrition and improving the microbial safety of burgers.

Overview of fermentation process: structure-function relationship on protein quality and non-nutritive compounds of plant-based proteins and carbohydrates

Demands for high nutritional value-added food products and plant-based proteins have increased over the last decade, in line with the growth of the human population and consumer health awareness. The quality of the plant-based proteins depends on their digestibility, amino acid content, and residues of non-nutritive compounds, such as phenolic compounds, anti-nutritional compounds, antioxidants, and saponins. The presence of these non-nutritive compounds could have detrimental effects on the quality of the proteins. One of the solutions to address these shortcomings of plant-based proteins is fermentation, whereby enzymes that present naturally in microorganisms used during fermentation are responsible for the cleavage of the bonds between proteins and non-nutritive compounds. This mechanism has pronounced effects on the non-nutritive compounds, resulting in the enhancement of protein digestibility and functional properties of plant-based proteins. We assert that the types of plant-based proteins and microorganisms used during fermentation must be carefully addressed to truly enhance the quality, functional properties, and health functionalities of plant-based proteins.Supplemental data for this article is available online at here. show.

The Effectiveness of Extruded-Cooked Lentil Flour in Preparing a Gluten-Free Pizza with Improved Nutritional Features and a Good Sensory Quality

Extruded-cooked lentil (ECL) flour was used to fortify (10/100 g dough) gluten-free pizza, which was compared with rice/corn-based pizza (control), and with pizza containing native lentil (NL) flour. Viscoamylograph and Mixolab data evidenced the hydrocolloid properties of ECL flour (initial viscosity = 69.3 BU), which contained pregelatinized starch. The use of ECL flour made it possible to eliminate hydroxymethylcellulose (E464), obtaining a clean label product. Both NL and ECL pizzas showed significantly (p < 0.05) higher contents of proteins (7.4 and 7.3/100 g, respectively) than the control pizza (4.4/100 g) and could be labelled as “source of proteins” according to the Regulation (EC) No. 1924/2006. In addition, NL and ECL pizzas were characterized by higher contents of bioactive compounds, including anthocyanins, and by higher in vitro antioxidant activity (1.42 and 1.35 µmol Trolox/g d.m., respectively) than the control pizza (1.07 µmol Trolox/g d.m.). However, NL and ECL pizzas also contained small amounts of undigestible oligosaccharides, typically present in lentils (verbascose = 0.92–0.98 mg/g d.m.; stachyose = 4.04–5.55 mg/g d.m.; and raffinose = 1.98–2.05 mg/g d.m.). No significant differences were observed in the liking level expressed by consumers between ECL and control pizzas.

Extraction Kinetics of Total Polyphenols, Flavonoids, and Condensed Tannins of Lentil Seed Coat: Comparison of Solvent and Extraction Methods

The lentil seed coat is a waste by-product still rich in phenolic compounds, specifically condensed tannins. The effect of different solvents, as well as different processes, namely conventional solid-liquid extraction (CSLE) and ultrasound-assisted extraction (UAE), on the extraction yield of specific phenolic compound classes was studied. Four empirical two-parameter models were examined to select the one that better fit the experimental data obtained under different operating conditions. Additionally, ultra-high-pressure liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPLC-ESI/QTOF-MS) was employed to profile the phenolic compounds obtained under distinct extraction conditions. In the operative conditions adopted here, the bioactive compounds yield achieved using UAE was lower than that obtained with CSLE. The kinetics of polyphenols, flavonoids, and condensed tannins extraction from the lentil seed coat were successfully fitted to the power-law models, yielding mean values of the root mean square < 5.4%, standard error of estimation < 0.53, and coefficient of determination > 0.8. In addition, the UHPLC-ESI/QTOF-MS of the lentil seed coat extracts allowed the putative recognition of nearly 500 compounds, mainly flavonoids and phenolic acids.

An Untargeted Metabolomics Approach for Correlating Pulse Crop Seed Coat Polyphenol Profiles with Antioxidant Capacity and Iron Chelation Ability

Pulse crop seed coats are a sustainable source of antioxidant polyphenols, but are typically treated as low-value products, partly because some polyphenols reduce iron bioavailability in humans. This study correlates antioxidant/iron chelation capabilities of diverse seed coat types from five major pulse crops (common bean, lentil, pea, chickpea and faba bean) with polyphenol composition using mass spectrometry. Untargeted metabolomics was used to identify key differences and a hierarchical analysis revealed that common beans had the most diverse polyphenol profiles among these pulse crops. The highest antioxidant capacities were found in seed coats of black bean and all tannin lentils, followed by maple pea, however, tannin lentils showed much lower iron chelation among these seed coats. Thus, tannin lentils are more desirable sources as natural antioxidants in food applications, whereas black bean and maple pea are more suitable sources for industrial applications. Regardless of pulse crop, proanthocyanidins were primary contributors to antioxidant capacity, and to a lesser extent, anthocyanins and flavan-3-ols, whereas glycosylated flavonols contributed minimally. Higher iron chelation was primarily attributed to proanthocyanidin composition, and also myricetin 3-O-glucoside in black bean. Seed coats having proanthocyanidins that are primarily prodelphinidins show higher iron chelation compared with those containing procyanidins and/or propelargonidins.

Effects of Fermentation on the Quality, Structure, and Nonnutritive Contents of Lentil (Lens culinaris) Proteins

Protein digestibility, secondary protein structure components, sugars, and phenolic compounds were analysed to investigate the effect of fermentation on the quality, structure, digestibility, and nonnutritive contents of lentil (Lens culinaris) proteins (LPs). Fermentation was carried out using water kefir seed. The initial pH of the unfermented LPs (6.8) decreased to pH 3.4 at the end of the fermentation on day 5. Protein digestibility increased from 76.4 to 84.1% over the 5 days of fermentation. Total phenolic content increased from 443.4 to 792.6 mg of GAE/100 g after 2 days of fermentation, with the sums of the detected phenolic compounds from HPLC analysis reaching almost 500 mg/100 g. The predominant phenolic compounds detected in fermented LPs include chlorogenic and epicatechin, while traces of rutin, ferulic acid, and sinapic acid were observed. Fermentation played a major role in the changes of the components in the secondary protein structure, especially the percentage of $\alpha$ -helices and random coils. In addition, the reduction in $\alpha$ -helix: $\beta$ -sheet ratio with the increase in protein digestibility was related to the prolongation of the fermentation time. The model used in this research could be a robust tool for improving protein quality, protein degradation, and nonnutritive nutrients using water kefir seed fermentation.

Phenolics of Yellow Pea (Pisum sativum L.) Hulls, Their Plasma and Urinary Metabolites, Organ Distribution, and In Vivo Antioxidant Activities

As a byproduct, large amounts of yellow pea hull (YPH) are used as low-value or worthless feed worldwide each year, which is a major waste of these polyphenol-rich hulls. The metabolism, bioavailability, and in vivo activities of these polyphenols have not been reported. In the present study, the chemical profiles of YPH extract, their metabolites, and organ distribution were analyzed with UHPLC-LTQ-OrbiTrap-MS, and their in vivo antioxidant activities were studied using the d-gal model in rats. In summary, a total of 42 ingredients were identified in YPH extracts, and 54 metabolites were found in plasma or urine samples. The distribution of metabolites in plasma and organs may have a positive effect on SOD, GSH-Px, MDA, and T-AOC, and the liver and kidneys were the main distribution organs of these metabolites. Our results are of great significance for the development and utilization of the polyphenol-rich hull of yellow pea.

Role of plant protein in nutrition, wellness, and health

Plant-based diets, and more specifically plant-based proteins, have been the subject of growing interest from researchers and consumers because of their potential health benefits as well as their positive environmental impact. Of course, plant proteins are found in plant foods, and positive health benefits of plant foods are linked to dietary fiber, vitamins, minerals, and phytochemicals. In epidemiological studies it is not possible to separate out the health benefits of plant foods in general as opposed to plant proteins specifically. Additionally, few vegans, who consume only plant-based proteins, are included in existing prospective cohort studies. Isolated plant proteins (soy, pea) have been used in intervention trials, but often to improve biomarkers linked to disease risk, including serum lipids or blood pressure. This review is an overview of plant proteins, the whole foods they are associated with, and the potential health benefits linked to consumption of protein from plant sources. Plant proteins and their potential for reducing the risk of developing metabolic syndrome, diabetes management, cancer prevention, and weight management are each discussed, as are the various rating systems currently used to determine protein quality from plant sources. Although additional research is needed that focuses specifically on the role that plant protein plays in the prevention and management of these chronic illnesses, rather than the role played by a more general plant-based diet, evidence suggests that plant proteins offer nutritional benefits to those who consume them. Limitations to plant proteins, including lower protein quality, must also be considered in this discussion.

High Temperature Rotational Rheology of the Seed Flour to Predict the Texture of Canned Red Kidney Beans (Phaseolus vulgaris)

The pasting profile of starchy tissues is conventionally measured by recording the apparent viscosity (η) in heating/cooling cycles. However, conventional rheometers show critical limitations when the starch is embedded in compact protein-rich cotyledon matrices, as occurs in pulses. In this work, the pasting profile of 13 red kidney beans (Phaseolus vulgaris) from the same cultivar but different growing locations was investigated using a heating/cooling cycle at higher temperature (130 °C) and pressurized conditions, using both water and brine as cooking solvents. It was hypothesized that the continuous measure of η at these conditions of flours from the dry seed would correlate with the texture, as determined by the mini-Kramer cell, of the beans after the entire process of soaking and canning. Furthermore, mechanistic answers were obtained by investigating their composition (starch, protein, and ash content) and physical properties (water holding capacity, seed ratio and weight). Interestingly, as opposed to the pasting profile at 95 °C, pasting indicators at 130 °C, including trough and final viscosity, strongly correlated with starch and protein content, seed coat ratio and, remarkably, with the firmness of the beans after canning when brine was incorporated. These results clearly show that small beans with a high protein content would bring about a more compact matrix that restricts starch from swelling and results in canned beans with a hard texture, which can be predicted by a lower pasting profile of the whole bean flour.

Polyphenol profile comparisons of seed coats of five pulse crops using a semi-quantitative liquid chromatography-mass spectrometric method

INTRODUCTION

Pulse crops are nutritious and therefore widely grown. Pulse seed coats are typically discarded, despite their high content of polyphenols that are known for their antioxidant properties and health benefits. A better understanding of polyphenol diversity and biochemical pathways will ultimately provide insight into how polyphenols are linked to health benefits, which will help to better utilise these seed coats.

OBJECTIVES

To explore polyphenol profiles among seed coats of diverse genotypes of five pulse crops using a targeted liquid chromatography mass spectrometry (LC-MS) method.

METHODS

Four genotypes of each of common bean, chickpea, pea, lentil and faba bean seed coats were selected for analysis. Following extraction, polyphenols were quantified using LC-MS.

RESULTS

An LC-MS method was developed to quantify 98 polyphenols from 13 different classes in 30 min. The low-tannin seed coats had the lowest concentrations of all polyphenols. Chickpea and pea seed coats had the most similar polyphenolic profiles. The black common bean showed the most diverse seed coat polyphenol profile, including several anthocyanins not detected in any of the other seed coats.

CONCLUSION

The LC-MS method reported herein was used to show polyphenol diversity within several polyphenol classes among the pulse crop seed coats. Detected in all seed coats, flavonols and hydroxybenzoic acids appear well-conserved in the edible Fabaceae. The presence of anthocyanins, flavan-3-ols and proanthocyanins in the coloured seed coats suggests that unique divergent branches were introduced in the flavonoid biosynthetic pathway, possibly in response to environmental stressors.

A comprehensive profiling of free, conjugated and bound phenolics and lipophilic antioxidants in red and green lentil processing by-products

A systemic approach was taken in profiling the hydrophilic and lipophilic antioxidants in lentil hulls using a combination of HPLC, LC-ESI-MS2 and GC techniques. A total of 37 phenolics were tentatively identified in the hydrophilic fractions, while four carotenoids and three tocopherols were found in the lipophilic fraction. Results showed that in addition to the high free extractable phenolics, phenolic compounds in conjugated and bound forms also exist in similar amounts. Information on conjugated and bound phenolics are particularly important as these forms of phenolics often go unnoticed by chromatographic profiling of extractables. All phenolic, carotenoid and tocopherol fractions contributed to antioxidant activities. Information about bioactives from lentil hulls, specifically conjugated and bound phenolics are reported here for the first time. The comprehensive profiling of these bioactives lays a good foundation for further assessment of the value-added uses of lentil hulls which are by-products of pulse processing.

Effect of Instant Controlled Pressure-Drop on the Non-Nutritional Compounds of Seeds and Sprouts of Common Black Bean (Phaseolus vulgaris L.)

The common bean is an important caloric-protein food source. However, its nutritional value may be affected by the presence of non-nutritional compounds, which decrease the assimilation of some nutrients; however, at low concentrations, they show a beneficial effect. Germination and treatment by controlled pressure-drop (DIC, French acronym of Détente Instantanée Contrôlée) are methods that modify the concentration of these components. The objective of this work was to evaluate the change in the non-nutritional composition of bean seeds and sprouts by DIC treatment. The results show that with the germination, the concentration of phenolic and tannin compounds increased 99% and 73%, respectively, as well as the quantity of saponins (65.7%), while phytates and trypsin inhibitors decreased 26% and 42%, respectively. When applying the DIC treatment, the content of phytates (23-29%), saponins (44%) and oligosaccharides increased in bean sprouts and decreased phenolic compounds (4-14%), tannins (23% to 72%), and trypsin inhibitors (95.5%), according to the pressure and time conditions applied. This technology opens the way to new perspectives, especially to more effective use of legumes as a source of vegetable protein or bioactive compounds.

Phenolics of Green Pea (Pisum sativum L.) Hulls, Their Plasma and Urinary Metabolites, Bioavailability, and in Vivo Antioxidant Activities in a Rat Model

Increased processing of pulses generates large volumes of hulls, which are known as an excellent source of phenolic antioxidants. However, the bioavailability and in vivo activity of these phenolics are rarely reported. This research was therefore carried out to study the absorption, metabolism, and in vivo antioxidant activities of green pea hull (GPH) phenolics using ultrahigh-pressure liquid chromatography with a linear ion trap-high-resolution Orbitrap mass spectrometry and an oxidative stress rat model. A total of 31 phenolics, including 4 phenolic acids, 24 flavonoids, and 3 other phenolics, were tentatively identified. Ten of these phenolics and 49 metabolites were found in the plasma and urine of rats, which helped to explain the favorable changes by GPH phenolics in key antioxidant enzymes (superoxide dismutase, glutathione peroxidase, and glutathione) and indicators (total antioxidant capacity, malondialdehyde) in the plasma and different tissues of rats. This is the first comprehensive report on dry pea hull phenolics and their bioavailability, metabolic profiles, and mechanisms of in vivo antioxidant activities.

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.

Characterization of polyphenols in Australian sweet lupin (Lupinus angustifolius) seed coat by HPLC-DAD-ESI-MS/MS

Seeds of the legume lupin (Lupinus spp.) are becoming increasingly important as human food. The seed coat, at ~25% of the whole seed of Lupinus angustifolius (Australian sweet lupin, ASL), is the main by-product of lupin kernel flour production. The primary market for lupin seed coat is low value feed with very limited use in foods. In this study, seed coats of six ASL commercial varieties from two growing sites were sampled for identification and quantification of polyphenols using a high-performance liquid chromatography (HPLC) with diode array detector (DAD) and coupled with a triple quadrupole mass spectrometer which equipped with electrospray ionization source (ESI-MS/MS). Three flavones (apigenin-7-O-β-apiofuranosyl-6,8-di-C-β-glucopyranoside, vicenin 2, and apigenin-7-O-β-glucopyranoside), one isoflavone (genistein) and one dihydroflavonol derivative (aromadendrin-6-C-β-d-glucopyranosyl-7-O-[β-D-apiofuranosyl-(1 → 2)]-O-β-D-glucopyranoside), and several hydroxybenzoic and hydroxycinnamic acid derivatives were identified. Considerable variations in levels of individual polyphenols were found but apigenin-7-O-β-apiofuranosyl-6,8-di-C-β-glucopyranoside was the predominant polyphenol in all samples accounting for 73.08-82.89% of the total free polyphenols. These results suggest that ASL seed coat could be valuable dietary source of polyphenols.

The health-nutrition dimension: a methodological approach to assess the nutritional sustainability of typical agro-food products and the Mediterranean diet

BACKGROUND

The aim of this paper is to provide a methodological approach to evaluate the nutritional sustainability of typical agro-food products, representing Mediterranean eating habits and included in the Mediterranean food pyramid.

RESULTS

For each group of foods, suitable and easily measurable indicators were identified. Two macro-indicators were used to assess the nutritional sustainability of each product. The first macro-indicator, called 'business distinctiveness', takes into account the application of different regulations and standards regarding quality, safety and traceability as well as the origin of raw materials. The second macro-indicator, called 'nutritional quality', assesses product nutritional quality taking into account the contents of key compounds including micronutrients and bioactive phytochemicals. For each indicator a 0-10 scoring system was set up, with scores from 0 (unsustainable) to 10 (very sustainable), with 5 as a sustainability benchmark value. The benchmark value is the value from which a product can be considered sustainable. A simple formula was developed to produce a sustainability index.

CONCLUSION

The proposed sustainability index could be considered a useful tool to describe both the qualitative and quantitative value of micronutrients and bioactive phytochemical present in foodstuffs. This methodological approach can also be applied beyond the Mediterranean, to food products in other world regions. © 2018 Society of Chemical Industry.

Content of Minerals and Fatty Acids and Their Correlation with Phytochemical Compounds and Antioxidant Activity of Leguminous Seeds

The aim of the study was to determine the mineral composition and fatty acid profile in the seeds of selected Fabaceae species and cultivars and to assess their correlations with phytochemicals and antioxidant activity. The Andean lupine was characterised by a particularly high level of Mg and K as well as Cu, Zn, and Fe (P < 0.05). There were various correlations (P < 0.05) between the total phenols and tannins and these elements. The highest contribution of α-linolenic acid (ALA, 18:3, n-3) in total fatty acids was noted in the lentil (13.8 in 100 g^-1 fat), common bean (11.9 in 100 g^-1 fat), and pea seeds (10.4 in 100 g^-1 fat) (P = 0.028). In turn, the white lupine contained the highest content of ALA-0.67 g 100 g^-1 seeds; its lowest level was determined in the broad bean-0.03 g 100 g^-1 seeds. The seeds exhibited a high proportion of hypocholesterolemic fatty acids (on average 86%). The 2,2-diphenyl-1-picrylhydrazyl antiradical activity was positively correlated with UFA and PUFA (P < 0.05). This indicates great protective potential of legume seeds for prevention and treatment of diet-dependent diseases.

Effect of Processing on the in Vitro and in Vivo Protein Quality of Yellow and Green Split Peas (Pisum sativum)

In order to determine the effect of extrusion, baking, and cooking on the protein quality of yellow and green split peas, a rodent bioassay was conducted and compared to an in vitro method of protein quality determination. The Protein Digestibility-Corrected Amino Acid Score (PDCAAS) of green split peas (71.4%) was higher than that of yellow split peas (67.8%), on average. Similarly, the average Digestible Indispensable Amino Acid Score (DIAAS) of green split peas (69%) was higher than that of yellow split peas (67%). Cooked green pea flour had lower PDCAAS and DIAAS values (69.19% and 67%) than either extruded (73.61%, 70%) or baked (75.22%, 70%). Conversely, cooked yellow split peas had the highest PDCCAS value (69.19%), while extruded yellow split peas had the highest DIAAS value (67%). Interestingly, a strong correlation was found between in vivo and in vitro analysis of protein quality (R2 = 0.9745). This work highlights the differences between processing methods on pea protein quality and suggests that in vitro measurements of protein digestibility could be used as a surrogate for in vivo analysis.

Effect of acid pretreatment and the germination period on the composition and antioxidant activity of rice bean (Vigna umbellata)

This research evaluated effect of germination period and acid pretreatment on chemical composition and antioxidant activity of rice bean sprouts. Moisture, total phenolics, reducing sugar and B vitamins (thiamine, riboflavin, and niacin) content of steamed sprouts increased with increasing germination time (p⩽0.05). Pretreatment with 1% (w/v) citric acid for 6h significantly increased the total phenolic content. The 18-h-germinated rice beans showed the highest crude protein content, as determined using the Kjeldahl method. During germination, acid pretreatment led to a significant decrease in the intensity of the 76-kDa band. Germination caused a significant increase in radical scavenging activity and ferric reducing antioxidant power, especially in sprouts from citric acid-treated seeds. The antioxidant activities of the ethanolic extracts from both pretreated beans and the control were 1.3-1.6 times higher than those obtained from the water extracts. Major phenolics found in both 0-h and 18-h-germinated rice beans were catechin and rutin.

Determination of the protein quality of cooked Canadian pulses

A study to determine the protein digestibility-corrected amino acid score and protein efficiency ratio of nine different cooked Canadian pulse classes was conducted in support of the establishment of protein quality claims in Canada and the United States. Split green and yellow pea, whole green lentil, split red lentil, Kabuli chickpea, navy bean, pinto bean, light red kidney bean, and black bean were investigated. Protein digestibility-corrected amino acid score (PDCAAS) and the protein efficiency ratio (PER) were determined using the appropriate rodent models. All pulses had high digestibility values, >70%, with PDCAAS values greater than 0.5, thereby qualifying as a quality protein in the United States, but only navy beans qualified as a good source of protein. All pulses except whole green lentils, split red lentils, and split green peas would qualify as sources of protein with protein ratings between 20 and 30.4 in Canada. These findings support the use of pulses as protein sources in the regulatory context of both the United States and Canada.

Impact of Processing on the Protein Quality of Pinto Bean (Phaseolus vulgaris) and Buckwheat (Fagopyrum esculentum Moench) Flours and Blends, As Determined by in Vitro and in Vivo Methodologies

Blending of protein sources can increase protein quality by compensating for limiting amino acids present in individual sources, whereas processing grain flours by extrusion or baking can also alter protein quality. To determine the effect of baking and extrusion on the protein quality of blended flours from buckwheat and pinto beans, a rodent bioassay was performed and compared to an in vitro method of protein quality determination. Overall, extruded products had higher protein efficiency ratio values, increased digestibility, and greater protein digestibility corrected amino acid score (PDCAAS) values than baked products, with the extruded buckwheat/pinto blend having the greatest PDCAAS value of the experimental diets investigated. A correlation was found between both digestibility and PDCAAS values generated from in vitro and in vivo methods. The use of in vitro digestibility analysis should be investigated as a potential replacement for the current rodent assay for nutrient content claim purposes.

Determination of fourteen polyphenols in pulses by high performance liquid chromatography-diode array detection (HPLC-DAD) and correlation study with antioxidant activity and colour

Pulses, which include lentils, beans, chickpeas, peas, and soybeans, provide an important source of proteins, dietary fibers, minerals and vitamins, as well as such important bioactive molecules as polyphenols. The presence of polyphenols is often related to the colour of the pulse and to its antioxidant activity. The aim of this work was to set up a new HPLC-DAD method for simultaneously analysing 14 polyphenolic compounds, including two anthocyanins, in different varieties of pulses and to correlate the polyphenol content with the seed coat colour and the antioxidant activity. The total content of the analysed polyphenols ranged from 3mg/kg for dehulled red lentils to 1630.5mg/kg for ruviotto beans. Samples with dark testa (or seed coat), namely black lentils and diavoli beans, had higher antioxidant activity than those with pale testa, and a positive correlation was found between total phenolic content (TPC) and IC50 for dark coloured varieties.

Identification of Phenolic Compounds from Seed Coats of Differently Colored European Varieties of Pea (Pisum sativum L.) and Characterization of Their Antioxidant and In Vitro Anticancer Activities

To date little has been done on identification of major phenolic compounds responsible for anticancer and antioxidant properties of pea (Pisum sativum L.) seed coat extracts. In the present study, phenolic profile of the seed coat extracts from 10 differently colored European varieties has been determined using ultrahigh-performance liquid chromatography-linear trap quadrupole orbitrap mass spectrometer technique. Extracts of dark colored varieties with high total phenolic content (up to 46.56 mg GAE/g) exhibited strong antioxidant activities (measured by 2,2-diphenyl-1-picrylhydrazyl or DPPH assay, and ferric ion reducing and ferrous ion chelating capacity assays) which could be attributed to presence of gallic acid, epigallocatechin, naringenin, and apigenin. The aqueous extracts of dark colored varieties exert concentration-dependent cytotoxic effects on all tested malignant cell lines (human colon adenocarcinoma LS174, human breast carcinoma MDA-MB-453, human lung carcinoma A594, and myelogenous leukemia K562). Correlation analysis revealed that intensities of cytotoxic activity of the extracts strongly correlated with contents of epigallocatechin and luteolin. Cell cycle analysis on LS174 cells in the presence of caspase-3 inhibitor points out that extracts may activate other cell death modalities besides caspase-3-dependent apoptosis. The study provides evidence that seed coat extracts of dark colored pea varieties might be used as potential cancer-chemopreventive and complementary agents in cancer therapy.