7S protein is more effective than total soybean protein isolate in reducing plasma cholesterol

The structure-function relationships and techno-functions of β-conglycinin

β-conglycinin (β-CG) is a prominent storage protein belonging to the globulin family in soybean (Glycine max) seeds. Along with other soybean proteins, it serves as an important source of essential amino acids and high-quality nutrition. However, the digestibility and nutritional value of β-CG are key factors affecting the nutritional profile of soy-based foods. The heterotrimeric, secondary, and quaternary structures of β-CG, particularly the spatial arrangement of its α, α', and β subunits, influence its functional properties. Considering these aspects, β-CG emerges as a significant protein with diverse applications in the food and health sectors. Therefore, this review explores β-CG's composition, structure, function, health implications, and industrial uses. Salient discussions are presented on its molecular structure, nutrition, digestibility, allergenicity, and techno-functions including emulsification, solubility, gelling, and structure-function complexities. Overall, the multifaceted potential of β-CG in the healthcare sector and the food industry is evident.

Physicochemical and Functional Properties of DND358 (A Hypocholesterolemic Soybean) Protein Isolate

The properties and applications of soybean protein isolates (SPIs) have been extensively investigated. In this study, we determined the optimal conditions for the preparation of the DND358 soybean protein isolate (DND358-SPI), assessed its physicochemical and functional properties, and investigated its potential applications in the food industry. According to the results, the highest extraction rate of DND358-SPI was observed when the pH was 9.5, the temperature was 55 °C, the duration was 80 min, and the material-to-liquid ratio was 1:20 (w/v). With regard to the functional properties, the water-holding capacity (WHC) and oil-binding capacity (OBC) of DND358-SPI were higher than those of other varieties, reaching 4.73% and 11.04%, respectively. In addition, the hardness, adhesiveness, chewiness, and resilience of DND358-SPI were higher than those of other varieties, reaching 159.27 g, 186.07 g, 6.78 mj, and 1.88, respectively. These findings indicate that DND358-SPI can reduce cholesterol levels and may be used to produce cholesterol-lowering food products.

Are oilseeds a new alternative protein source for human nutrition?

This review focuses on the potential use, nutritional value and beneficial health effects of oilseeds as a source of food protein. The process of extracting oil from oilseeds produces a by-product that is rich in proteins and other valuable nutritional and bioactive components. This product is primarily used for animal feed. However, as the demand for proteins continues to rise, plant-based proteins have a real success in food applications. Among the different plant protein sources, oilseeds could be used as an alternative protein source for human diet. The data we have so far show that oilseeds present a protein content of up to 40% and a relatively well-balanced profile of amino acids with sulphur-containing amino acids. Nevertheless, they tend to be deficient in lysine and rich in anti-nutritional factors (ANFs), which therefore means they have lower anabolic potential than animal proteins. To enhance their nutritional value, oilseed proteins can be combined with other protein sources and subjected to processes such as dehulling, heating, soaking, germination or fermentation to reduce their ANFs and improve protein digestibility. Furthermore, due to their bioactive peptides, oilseeds can also bring health benefits, particularly in the prevention and treatment of diabetes, obesity and cardiovascular diseases. However, additional nutritional data are needed before oilseeds can be endorsed as a protein source for humans.

Condensation of Soy Protein Peptides Contributes to Sequester Bile Acids and Mitigate LPS-Induced Inflammation

Soy protein is widely known to have serum triglyceride (TG) and cholesterol-lowering effects associated with a reduced risk of cardiovascular disease. Recent studies highlighted that the extension region (ER) domain of soy 7S globulin (β-conglycinin) is a key component responsible for the serum TG-lowering effect via modulation of bile acid (BA) homeostasis. Here, we studied the sequestration of BAs by ER peptides during intestinal digestion in vitro and assessed the anti-inflammatory effects of ER peptides using Caco-2/HT29-MTX/RAW264.7 triple-cell cocultures as an intestine cell model. Results show that ER peptides, which share characteristics of intrinsically disordered regions (IDRs), are capable of forming peptide condensates and exhibit the capability to sequester BA-containing colloidal structures during intestinal digestion in vitro. Moreover, BAs enhance the penetration of peptide condensates within the mucus layer, enabling ER peptides to mitigate lipopolysaccharide (LPS)-induced gut inflammation. These results provide a possible explanation for the molecular mechanisms underlying the modulation of BA homeostasis by soybean proteins.

Exploring the Interactions of Soybean 7S Globulin with Gallic Acid, Chlorogenic Acid and (-)-Epigallocatechin Gallate

In this study, the noncovalent interaction mechanisms between soybean 7S globulin and three polyphenols (gallic acid (GA), chlorogenic acid (CA) and (-)-epigallocatechin gallate (EGCG)) were explored and compared using various techniques. Fluorescence experiments showed that GA and EGCG had strong static quenching effects on 7S fluorescence, and that of CA was the result of multiple mechanisms. The interactions caused changes to the secondary and tertiary structure of 7S, and the surface hydrophobicity was decreased. Thermodynamic experiments showed that the combinations of polyphenols with 7S were exothermic processes. Hydrogen bonds and van der Waals forces were the primary driving forces promoting the binding of EGCG and CA to 7S. The combination of GA was mainly affected by electrostatic interaction. The results showed that the structure and molecular weight of polyphenols play an important role in their interactions. This work is helpful for developing products containing polyphenols and soybean protein.

Extension Region Domain of Soybean 7S Globulin Contributes to Serum Triglyceride-Lowering Effect via Modulation of Bile Acids Homeostasis

SCOPE

Soybean 7S globulin (β-conglycinin), a major soybean storage protein, has been demonstrated to exert remarkable triglyceride (TG) and cholesterol-lowering effects, yet the underlying mechanism remains controversial.

METHODS AND RESULTS

A comparative investigation is performed to assess the contribution of different structural domains of soybean 7S globulin, including core region (CR) and extension region (ER) domains, to biological effects of soybean 7S globulin using a high-fat diet rat model. The results show that ER domain mainly contributes to the serum TG-lowering effect of soybean 7S globulin, but not for CR domain. Metabolomics analysis reveals that oral administration of ER peptides obviously influences the metabolic profiling of serum bile acids (BAs), as well as significantly increased the fecal excretion of total BAs. Meanwhile, ER peptides supplementation reshapes the composition of gut microbiota and impacts the gut microbiota-dependent biotransformation of BAs which indicate by a significantly increased secondary BAs concentration in fecal samples. These results highlight that TG-lowering effects of ER peptides mainly stem from their modulation of BAs homeostasis.

CONCLUSION

Oral administration of ER peptides can effectively lower serum TG level by regulating BAs metabolism. ER peptides have potential to be used as a candidate pharmaceutical for the intervention of dyslipidemia.

Encapsulating vitamins C and E using food-grade soy protein isolate and pectin particles as carrier: Insights on the vitamin additive antioxidant effects

Functional factors show additive effects in the same nutraceutical food. In this study, a core-shell structure based on soy protein isolate (SPI) and pectin was constructed as a delivery system for vitamins C and E under neutral (pH 7.0) and acidic environment (pH 4.0). The SPI-vitamin-pectin complex formed at pH 4.0 showed larger particle size, higher turbidity, lower fluorescence intensity, and higher vitamin E encapsulation efficiency than those formed at pH 7.0. Also, the addition of vitamin C significantly enhanced the vitamin E encapsulation efficiency in the particles. Furthermore, the antioxidant properties of DPPH, ABTS, and hydroxyl radicals were increased by the addition of vitamin C, maximum values of 77%, 82%, and 65%, suggesting that vitamins C and E have additive antioxidant effects. These findings proposed a simple, structured protein-polysaccharide-based food-grade delivery system, which could serve as the basis for the design of products having multiple functional factors.

Selected Soybean Varieties Regulate Hepatic LDL-Cholesterol Homeostasis Depending on Their Glycinin:β-Conglycinin Ratio

Clinical studies indicate that the consumption of soybean protein might reduce cholesterol and LDL levels preventing the development of atherosclerotic cardiovascular diseases. However, soybean variety can influence soybean protein profile and therefore affect soybean protein health-promoting properties. This study investigated the composition and effects of nineteen soybean varieties digested under simulated gastrointestinal conditions on hepatic cholesterol metabolism and LDL oxidation in vitro. Soybean varieties exhibited a differential protein hydrolysis during gastrointestinal digestion. Soybean varieties could be classified according to their composition (high/low glycinin:β-conglycinin ratio) and capacity to inhibit HMGCR (IC50 from 59 to 229 µg protein mL−1). According to multivariate analyses, five soybean varieties were selected. These soybean varieties produced different peptide profiles and differently reduced cholesterol concentration (43−55%) by inhibiting HMGCR in fatty-acid-stimulated HepG2 hepatocytes. Selected digested soybean varieties inhibited cholesterol esterification, triglyceride production, VLDL secretion, and LDL recycling by reducing ANGPTL3 and PCSK9 and synchronously increasing LDLR expression. In addition, selected soybean varieties hindered LDL oxidation, reducing the formation of lipid peroxidation early (conjugated dienes) and end products (malondialdehyde and 4-hydroxynonenal). The changes in HMGCR expression, cholesterol esterification, triglyceride accumulation, ANGPTL3 release, and malondialdehyde formation during LDL oxidation were significantly (p < 0.05) correlated with the glycinin:β-conglycinin ratio. Soybean varieties with lower glycinin:β-conglycinin exhibited a better potential in regulating cholesterol and LDL homeostasis in vitro. Consumption of soybean flour with a greater proportion of β-conglycinin may, consequently, improve the potential of the food ingredient to maintain healthy liver cholesterol homeostasis and cardiovascular function.

Protective effect of isoflavone enriched soy β-conglycinin on osteoporosis in ovariectomized rats

Research shows that the consumption of soybean foods can reduce the incidence rate of bone fractures in women after menopause. The aim of this study was to investigate the effects of different complex of soy β-conglycinin (7S) and isoflavones (7S-ISO) on osteoporosis in ovariectomized rats. All treatments were administrated intragastrically to the groups every afternoon for 3 months. The treatments were administrated at 1 mL·(100 g)^-1 , the animals were given 50 mg·kg^-1 ·d^-1 ISO, and the concentration of protein was about 2 wt. %. The bone mineral density (BMD) and the bone biomechanics results of left tibia' maximum load in the 7S-ISO group is significantly higher than in the ovariectomized group and the 7S group (p < .05). Otherwise, the serum tartrate-resistant acid phosphatase (s-TRACP), serum osteocalcin (s-BGP), and serum estradiol (s-E₂ ) levels in 7S-ISO were all significantly different from the OVX, OVX + casein, and the OVX + 7S group (p < .05). The serum calcium (s-Ca) level was not significantly different among all the groups. 7S-ISO may exhibit moderate estrogenic activities and as compared to 7S and ISO in osteoporosis (OP) of ovariectomized rats. PRACTICAL APPLICATIONS: The effects of soy proteins on the health of females have always been a concern. It has been extensively reported soy 7S globulin (7S) as a type of trimer glycoprotein can depress blood fats. The aim of this study was to investigate the effects of different complex of soy β-conglycinin and isoflavones (ISO), the main storage proteins and polyphenols in soy, on osteoporosis in ovariectomized rats.

Soy protein isolates: A review of their composition, aggregation, and gelation

Considering that a series of complex issues such as environmental problems, sustainable development, animal welfare, and human health are on a global scale, the development of vegetable protein-based meat substitutes provides a potential solution to the disparity between meat consumption demand and supply. The research and development of vegetable protein-based meat substitutes have become a major commercial activity, and the market is expanding to meet the growing consumer demand. Soy protein isolates (SPI) are often used as a raw material for vegetable meat substitutes because of their potential to form fiber structures. Although significant initial success has been achieved, it is still a challenge to explain how the composition and aggregation of SPI influence gel properties and the mechanism(s) involved. This article reviews the latest research about SPI. The relationship between the composition, aggregation, and gelation properties of SPI is based on a through literature search. It focused on the application of SPI in heat- and cold-induced gels, given the diversified market demands. The research on cold gel has helped expand the market. The methods to improve the properties of SPI gels, including physical, chemical, and biological properties, are reviewed to provide insights on its role in the properties of SPI gels. To achieve environmentally friendly and efficient ways for the food industry to use SPI gel properties, the research prospects and development trends of the gel properties of SPI are summarized. New developments and practical applications in the production technology, such as for ultrasound, microwave and high pressure, are reviewed. The potential and challenges for practical applications of cold plasma technology for SPI gel properties are also discussed. There is a need to transfer the laboratory technology to actual food production efficiently and safely.

Effects of ultrasound-assisted sodium bisulfite pretreatment on the preparation of cholesterol-lowering peptide precursors from soybean protein

In order to take full advantage of the gastrointestinal digestive function, the effects of S-type ultrasound-assisted sodium bisulfite (UASB) pretreatment on the preparation of cholesterol-lowering peptide precursors derived from soybean protein were investigated and the structural characterizations of pretreated proteins were explored. UASB pretreatment with the operational mode of mono-frequency ultrasound at 28 kHz, ultrasonic power density of 200 W/L and ultrasonic time of 50 min exhibited the highest cholesterol-lowering activity (56.90%) of soybean protein hydrolysates (SPH) after simulated gastrointestinal digestion, which increased by 87.17% compared to the control. Under these conditions, the peptide content of SPH after simulated gastrointestinal digestion was not significantly different (p > 0.05) compared to the control. Further FTIR analysis showed that UASB pretreatment increased β-turn and β-sheet content and decreased α-helix and random coil content. The changes in the surface hydrophobicity and microstructures of soybean protein indicated that UASB pretreatment loosened soybean protein structure and exposed more hydrophobic groups. SDS-PAGE indicated that the restriction sites changed after UASB pretreatment. In conclusion, UASB pretreatment is an efficient method for the preparation of cholesterol-lowering peptide precursors.

Chromatography-Independent Fractionation and Newly Identified Molecular Features of the Adzuki Bean (Vigna angularis Willd.) β-vignin Protein

Adzuki seed β-vignin, a vicilin-like globulin, has proven to exert various health-promoting biological activities, notably in cardiovascular health. A simple scalable enrichment procedure of this protein for further nutritional and functional studies is crucial. In this study, a simplified chromatography-independent protein fractionation procedure has been optimized and described. The electrophoretic analysis showed a high degree of homogeneity of β-vignin isolate. Furthermore, the molecular features of the purified protein were investigated. The adzuki bean β-vignin was found to have a native size of 146 kDa, and the molecular weight determined was consistent with a trimeric structure. These were identified in two main polypeptide chains (masses of 56-54 kDa) that are glycosylated polypeptides with metal binding capacity, and one minor polypeptide chain with a mass 37 kDa, wherein these features are absent. The in vitro analysis showed a high degree of digestibility of the protein (92%) and potential anti-inflammatory capacity. The results lay the basis not only for further investigation of the health-promoting properties of the adzuki bean β-vignin protein, but also for a possible application as nutraceutical molecule.

Vinegars but not acetic acid are effective in reducing plasma cholesterol in hamsters fed a high-cholesterol diet

The present study compares the effect of two types of vinegars, Balsamic vinegar of Modena (BV) and Chinese Shanxi vinegar (SV), with acetic acid on plasma cholesterol using hamsters as a model. Hamsters (n = 40) were divided into five groups (n = 8 each) with two control groups being fed a low-cholesterol diet (LCD) or a high-cholesterol diet containing 0.2% cholesterol (HCD). The three experimental groups were given a HCD diet and gavaged with 8 ml of BV, SV, and acetic acid solution (AC) per kg body weight, respectively. Acetic acid in BV, SV, and AC solutions was adjusted with water to be 20 mg ml-1. The whole experiment lasted for 9 weeks. Plasma total cholesterol (TC) in BV and SV groups but not in the AC group was reduced by 17% and 20%, respectively, compared with that in HCD hamsters. BV and SV significantly reduced cholesterol in the liver and increased the fecal excretion of neutral sterols and bile acids. Real-time PCR analysis demonstrated that BV and SV significantly up-regulated the mRNA of cholesterol 7 alpha-hydroxylase (CYP7A1) in the liver. In conclusion, BV and SV but not AC were effective in reducing plasma TC and non-HDL-C concentrations at least in hypercholesterolemic hamsters.

Serum phytosterols associate with T helper 1 cytokine concentration in pregnant women

The dietary phytosterols have been demonstrated to modulate CD4+ T-cell polarization in cells, animals, and humans. However, T helper (Th)1/Th2 dichotomy has rarely been correlated with phytosterols during pregnancy. The present study investigated associations between the serum cytokines and serum phytosterols in 100 pregnant women at 34- to 37-week gestation and their offspring. The results showed that serum concentrations of interferon (IFN)-γ, tumor necrosis factor (TNF)-α, and total Th1 cytokines were positively associated with serum β-sitosterol level, adjusting for age, BMI, and serum cholesterol. Serum IFN-γ and total Th1 cytokine concentrations positively correlated with total phytosterol concentration, controlling age, BMI, and serum cholesterol. Moreover, none of the cytokines measured correlated with phytosterol concentration in the newborns. Our results show that serum Th1 cytokine concentrations, but not Th2 levels, are positively associated with serum phytosterols in pregnant women. These findings implicate that phytosterols modulate Th1/Th2 balance by inducing Th1 secretions in pregnant women.

Plasma Cholesterol-Lowering Activity of Soybean Germ Phytosterols

Soybean germ phytosterols (SGP) largely exist in soybean germ oil. Our previous study demonstrated that soybean germ oil was effective in reducing plasma cholesterol. However, it remains unknown if its phytosterols are the active ingredients responsible for the plasma cholesterol-lowering activity. The present study aimed to test the effect of SGP on plasma cholesterol and to investigate its associated underlying mechanisms using hamsters as animal model. Male hamsters (n = 40) were randomly divided into five groups (n = 8/group) and fed one of the five diets: a non-cholesterol diet (NCD), a high cholesterol diet (HCD), a HCD diet containing 0.5% cholestyramine (PC), and two HCD diets containing 0.1% (LP) and 0.2% (HP) SGP, respectively, for six weeks. Results showed that SPG reduced plasma cholesterol level in a dose-dependent manner, whereas it dose-dependently increased the excretion of both fecal neutral and acidic sterols. SGP was also effective in displacing cholesterol from micelles. It was concluded that SGP possessed hypocholesterolemic activity, likely by inhibiting cholesterol absorption in the intestine and promoting fecal sterol excretion.

Isoflavones enhance the plasma cholesterol-lowering activity of 7S protein in hypercholesterolemic hamsters

Previous studies have shown that 7S protein is the active ingredient responsible for the plasma cholesterol-lowering activity of soybean. It is hypothesized that isoflavones in soybean could enhance the blood cholesterol-lowering activity of 7S protein. Forty-eight hamsters were divided into six groups and fed a non-cholesterol diet or one of the five high-cholesterol diets containing 12.1% 7S protein with 0-15.62 mg g-1 isoflavones. The results showed that addition of isoflavones in diets dose-dependently enhanced the plasma total cholesterol-lowering activity of 7S protein. Addition of isoflavones in 7S protein-based diets significantly reduced hepatic cholesterol accumulation by 12.6-26.1%, compared with the high cholesterol control diet. Isoflavones could also facilitate excretion of neutral sterols in a dose-dependent manner. Supplementation of isoflavones in diets favourably modulated mRNA expression and the protein mass of HMG-CoA reductase. It was concluded that the enhancing effect of isoflavones on the blood cholesterol-lowering activity of 7S protein was mediated by inhibiting the cholesterol absorption and de novo cholesterol synthesis in hypercholesterolemic hamsters.

Modulation of Gut Microbiota by Soybean 7S Globulin Peptide That Involved Lipopolysaccharide-Peptide Interaction

Soybean protein exhibits nutritional significance for the control of metabolic syndrome, and evidence suggests that gut microbiota are implicated in the control of metabolic disorders. This study aimed to investigate the modulation of pepsin-released peptides of soybean 7S globulin on gut microbiota and possible association between changes of gut microbiota composition and lipopolysaccharide (LPS)-peptide interaction. In vitro fermentation experiments showed that the extension region (ER) fragments of soybean 7S globulin selectively suppressed proinflammatory Gram-negative bacteria. ER peptides also promoted the highest production of short-chain fatty acids (SCFAs), which were associated with increase of the relative abundance of Lachnospiraceae and Lactobacillaceae. Isothermal titration calorimetry (ITC) and Langmuir monolayer studies demonstrated that ER peptides exhibited high affinity to LPS in the presence of Ca²⁺ and developed into β-sheet-rich aggregate structures, thus weakening the stability of LPS monolayers. This finding supplies a possible explanation for improvement of the effects of soybean 7S globulin on metabolic disease.

Soybean germ oil reduces blood cholesterol by inhibiting cholesterol absorption and enhancing bile acid excretion

Soybean germ oil is beneficial in management of hypercholesterolemia in hamsters fed a high cholesterol diet.

Interaction of Soybean 7S Globulin Peptide with Cell Membrane Model via Isothermal Titration Calorimetry, Quartz Crystal Microbalance with Dissipation, and Langmuir Monolayer Study

To understand the underlying molecular mechanism of the cholesterol-lowering effect of soybean 7S globulins, the interactions of their pepsin-released peptides (7S-peptides) with cell membrane models consisting of dipalmitoylphosphatidylcholine (DPPC), dioleoylphosphatidylcholine (DOPC), and cholesterol (CHOL) were systematically studied. The results showed that 7S-peptides were bound to DPPC/DOPC/CHOL liposomes mainly through van der Waals forces and hydrogen bonds, and the presence of higher CHOL concentrations enhanced the binding affinity (e.g., DPPC/DOPC/CHOL = 1:1:0, binding ratio = 0.114; DPPC/DOPC/CHOL = 1:1:1, binding ratio = 2.02). Compression isotherms indicated that the incorporation of 7S-peptides increased the DPPC/DOPC/CHOL monolayer fluidity and the lipid raft size. The presence of CHOL accelerated the 7S-peptide accumulation on lipid rafts, which could serve as platforms for peptides to develop into β-sheet rich structures. These results allow us to hypothesize that 7S-peptides may indirectly influence membrane protein functions via altering the membrane organization in the enterocytes.

In vitro and in silico studies of 3-hydroxy-3-methyl-glutaryl coenzyme A reductase inhibitory activity of the cowpea Gln-Asp-Phe peptide

Previous studies have shown that cowpea protein positively interferes with cholesterol metabolism. In this study, we evaluated the ability of the fraction containing peptides of <3 kDa, as well as that of the Gln-Asp-Phe (QDF) peptide, derived from cowpea β-vignin protein, to inhibit HMG-CoA reductase activity. We established isolation and chromatography procedures to effectively obtain the protein with a purity above 95%. In silico predictions were performed to identify peptide sequences capable of interacting with HMG-CoA reductase. In vitro experiments showed that the fraction containing peptides of <3 kDa displayed inhibition of HMG-CoA reductase activity. The tripeptide QDF inhibits HMG-CoA reductase (IC₅₀ = 12.8 μM) in a dose-dependent manner. Furthermore, in silico studies revealed the binding profile of the QDF peptide and hinted at the molecular interactions that are responsible for its activity. Therefore, this study shows, for the first time, a peptide from cowpea β-vignin protein that inhibits HMG-CoA reductase and the chemical modifications that should be investigated to evaluate its binding profile.

Dietary Wheat Bran Oil Is Equally as Effective as Rice Bran Oil in Reducing Plasma Cholesterol

Rice bran oil (RBO) possesses a plasma cholesterol-lowering activity, while effect of wheat bran oil (WBO) on plasma cholesterol remains unknown. The present study compared the cholesterol-lowering activity of WBO with that of RBO in hamsters. Fifty-four male hamsters were divided into seven groups fed either a noncholesterol diet (NCD) or one of six high-cholesterol diets, namely HCD diet (0.2% cholesterol +9.5% lard), HCD+C diet (0.2% cholesterol +9.5% lard +0.5% cholestyramine), WL diet (0.2% cholesterol +4.8% Lard +4.8% WBO), WH diet (0.2% cholesterol +9.5% WBO), RL diet (0.2% cholesterol +4.8% Lard +4.8% RBO), and RH diet (0.2% cholesterol +9.5% RBO). Plasma total cholesterol (TC) in HCD group was 327.4 ± 31.8 mg/dL, while plasma TC in two WBO and two RBO groups was 242.2 ± 20.8, 243.1 ± 31.7, 257.1 ± 16.3, and 243.4 ± 46.0 mg/dL, respectively, leading to a decrease in plasma TC by 22-26% ( P < 0.01). No significant difference in cholesterol-lowering potency was seen between WBO and RBO. Plasma cholesterol-lowering activity of WBO and RBO was accompanied by down-regulation of hepatic 3-hydroxy-3-methylglutaryl-CoA reductase and fatty acid synthase, while up-regulation of cholesterol-7α-hydroxylase. WL, WH, RL, and RH diets increased the fecal excretion of total neutral sterols by 72.8%, 106.9%, 5.4%, and 36.8% ( P < 0.01) respectively. Results indicated WBO and RBO could inhibit cholesterol absorption via down-regulation of intestinal Niemann-Pick C1 like 1 protein, acyl CoA:cholesterol acyltransferase 2, and ATP binding cassette transporter 5. In summary, WBO was equally effective as RBO in decreasing plasma cholesterol in hypercholesterolemia hamsters.

Recent trends and analytical challenges in plant bioactive peptide separation, identification and validation

Interest in research into bioactive peptides (BPs) is growing because of their health-promoting ability. Several bioactivities have been ascribed to peptides, including antioxidant, antihypertensive and antimicrobial properties. As they can be produced from precursor proteins, the investigation of BPs in foods is becoming increasingly popular. For the same reason, production of BPs from by-products has also emerged as a possible means of reducing waste and recovering value-added compounds suitable for functional food production and supplements. Milk, meat and fish are the most investigated sources of BPs, but vegetable-derived peptides are also of interest. Vegetables are commonly consumed, and agro-industrial wastes constitute a cheap, large and lower environmental impact source of proteins. The use of advanced analytical techniques for separation and identification of peptides would greatly benefit the discovery of new BPs. In this context, this review provides an overview of the most recent applications in BP investigations for vegetable food and by-products. The most important issues regarding peptide isolation and separation, by single or multiple chromatographic techniques, are discussed. Additionally, problems connected with peptide identification in plants and non-model plants are discussed regarding the particular case of BP identification. Finally, the issue of peptide validation to confirm sequence and bioactivity is presented. Graphical representation of the analytical workflow needed for investigation of bioactive peptides and applied to vegetables and vegetable wastes Graphical Abstract.