Exploring Health-Promoting Attributes of Plant Proteins as a Functional Ingredient for the Food Sector: A Systematic Review of Human Interventional Studies

Dietary protein and blood pressure: an umbrella review of systematic reviews and evaluation of the evidence

INTRODUCTION

This umbrella review aimed to investigate the evidence of an effect of dietary intake of total protein, animal and plant protein on blood pressure (BP), and hypertension (PROSPERO: CRD42018082395).

METHODS

PubMed, Embase and Cochrane Database were systematically searched for systematic reviews (SRs) of prospective studies with or without meta-analysis published between 05/2007 and 10/2022. The methodological quality and outcome-specific certainty of evidence were assessed by the AMSTAR 2 and NutriGrade tools, followed by an assessment of the overall certainty of evidence. SRs investigating specific protein sources are described in this review, but not included in the assessment of the overall certainty of evidence.

RESULTS

Sixteen SRs were considered eligible for the umbrella review. Ten of the SRs investigated total protein intake, six animal protein, six plant protein and four animal vs. plant protein. The majority of the SRs reported no associations or effects of total, animal and plant protein on BP (all "possible" evidence), whereby the uncertainty regarding the effects on BP was particularly high for plant protein. Two SRs addressing milk-derived protein showed a reduction in BP; in contrast, SRs investigating soy protein found no effect on BP. The outcome-specific certainty of evidence of the SRs was mostly rated as low.

DISCUSSION/CONCLUSION

This umbrella review showed uncertainties whether there are any effects on BP from the intake of total protein, or animal or plant proteins, specifically. Based on data from two SRs with milk protein, it cannot be excluded that certain types of protein could favourably influence BP.

Regulation of Sacha Inchi protein on fecal metabolism and intestinal microorganisms in mice

Introduction

With the increasing demand for protein utilization, exploring new protein resources has become a research hotspot. Sacha Inchi Protein (SIP) is a high-quality plant protein extracted from Sacha Inchi meal. This study aimed to investigate the impact of SIP on mouse metabolomics and gut microbiota diversity and explore the underlying pathways responsible for its health benefits.

Methods

In this study, the structural composition of SIP was investigated, and the effects of SIP on fecal metabolomics and intestinal microorganisms in mice were explored by LC-MS metabolomics technology analysis and 16S rRNA gene sequencing.

Results

The results showed that SIP was rich in amino acids, with the highest Manuscript Click here to view linked References content of arginine, which accounted for 22.98% of the total amino acid content; the potential fecal metabolites of mice in the SIP group involved lipid metabolism, sphingolipid metabolism, arginine biosynthesis, and amino acid metabolism; SIP altered the microbial composition of the cecum in mice, decreased the Firmicutes/Bacteroidetes value, and It decreased the abundance of the harmful intestinal bacteria Actinobacteriota and Desulfobacterota, and increased the abundance of the beneficial intestinal bacteria Faecalibaculum, Dubosiella.

Discussion

In conclusion, SIP is a high-quality plant protein with great potential for development in lipid-lowering, intestinal health, and mental illness, providing valuable clues for further research on its health-promoting mechanisms.

Development of the lexicon, trained panel validation and sensory profiling of new ready-to-eat plant-based " meatballs" in tomato sauce

Background

Providing educational content for children and parents can promote healthy nutritional habits. During the TITAN project, a pilot digital contest where participants have to developed ready-to-eat meatballs in sauce, using only plant-based ingredients, will be tested. The objective of this study was to develop the lexicon needed to objectively assess the sensory profile of this product.

Methods

Eight judges were recruited and trained. Thirteen 1-hour sessions took place over three months. The steps followed were the selection of commercial reference, generation of descriptors, training of the panel, validation of the trained panel and product characterisation. The judges chose one commercial reference (using simple hedonic evaluation) to serve as a reference. The accepted intensity scale for the generated descriptors was from 0 (low intensity) to 9 (very intense). To test the first versions of the game, food product developers involved in the project, acted as participants, and used a mix of lentils, quinoa, and oats to enhance the commercial version. R-project software was used to analyse the performance of the panel and the sensory profiles.

Results

A glossary with 14 descriptors was generated. The discriminatory capacity of the panel was confirmed by examining the significance of the product effect (p < 0.05). The product-judge interaction was not significant (p > 0.05) for most of the evaluated attributes, indicating a good degree of panel agreement. Overall, the panel was considered reproducible after 9 sessions. Although the appearance, firmness, fragility and chewiness were considered similar to the reference, juiciness and taste (understood as meaty flavour) of the new product were deemed improved.

Conclusions

According to the panel, two of the most appreciated attributes associated with meat analogues, juiciness and taste, were improved compared to the commercial reference. Therefore, the first approach for further development of the contest/game was validated.

Protein intake and body weight, fat mass and waist circumference: an umbrella review of systematic reviews for the evidence-based guideline on protein intake of the German Nutrition Society

PURPOSE

This umbrella review aimed to assess whether dietary protein intake with regard to quantitative (higher vs. lower dietary protein intake) and qualitative considerations (total, plant-based or animal-based protein intake) affects body weight (BW), fat mass (FM) and waist circumference (WC).

METHODS

A systematic literature search was conducted in PubMed, Embase and Cochrane Database of Systematic Reviews for systematic reviews (SRs) with and without meta-analyses of prospective studies published between 04 October 2007 and 04 January 2022. Methodological quality and outcome-specific certainty of evidence of the retrieved SRs were assessed by using AMSTAR 2 and NutriGrade, respectively, in order to rate the overall certainty of evidence using predefined criteria.

RESULTS

Thirty-three SRs were included in this umbrella review; 29 were based on randomised controlled trials, a few included cohort studies. In studies without energy restriction, a high-protein diet did not modulate BW, FM and WC in adults in general (all "possible" evidence); for older adults, overall certainty of evidence was "insufficient" for all parameters. Under hypoenergetic diets, a high-protein diet mostly decreased BW and FM, but evidence was "insufficient" due to low methodological quality. Evidence regarding an influence of the protein type on BW, FM and WC was "insufficient".

CONCLUSION

"Possible" evidence exists that the amount of protein does not affect BW, FM and WC in adults under isoenergetic conditions. Its impact on the reduction in BW and FM under hypoenergetic conditions remains unclear; evidence for an influence of protein type on BW, FM and WC is "insufficient".

Protein intake and type 2 diabetes mellitus: an umbrella review of systematic reviews for the evidence-based guideline for protein intake of the German Nutrition Society

PURPOSE

Protein-rich foods show heterogeneous associations with the risk of type 2 diabetes (T2D) and it remains unclear whether habitual protein intake is related to T2D risk. We carried out an umbrella review of systematic reviews (SR) of randomised trials and/or cohort studies on protein intake in relation to risks of T2D.

METHODS

Following a pre-specified protocol (PROSPERO: CRD42018082395), we retrieved SRs on protein intake and T2D risk published between July 1st 2009 and May 22nd 2022, and assessed the methodological quality and outcome-specific certainty of the evidence using a modified version of AMSTAR 2 and NutriGrade, respectively. The overall certainty of evidence was rated according to predefined criteria.

RESULTS

Eight SRs were identified of which six contained meta-analyses. The majority of SRs on total protein intake had moderate or high methodological quality and moderate outcome-specific certainty of evidence according to NutriGrade, however, the latter was low for the majority of SRs on animal and plant protein. Six of the eight SRs reported risk increases with both total and animal protein. According to one SR, total protein intake in studies was ~ 21 energy percentage (%E) in the highest intake category and 15%E in the lowest intake category. Relative Risks comparing high versus low intake in most recent SRs ranged from 1.09 (two SRs, 95% CIs 1.02-1.15 and 1.06-1.13) to 1.11 (1.05-1.16) for total protein (between 8 and 12 cohort studies included) and from 1.13 (1.08-1.19) to 1.19 (two SRs, 1.11-1.28 and 1.11-1.28) (8-9 cohort studies) for animal protein. However, SRs on RCTs examining major glycaemic traits (HbA1c, fasting glucose, fasting insulin) do not support a clear biological link with T2D risk. For plant protein, some recent SRs pointed towards risk decreases and non-linear associations, however, the majority did not support an association with T2D risk.

CONCLUSION

Higher total protein intake was possibly associated with higher T2D risk, while there is insufficient evidence for a risk increase with higher intakes of animal protein and a risk decrease with plant protein intake. Given that most SRs on plant protein did not indicate an association, there is possibly a lack of an effect.

Study of amino acids absorption and gut microbiome on consumption of pea protein blended with enzymes-probiotics supplement

The current randomized, double-blind, crossover clinical trial was conducted to evaluate changes in the amino acid absorption and gut microbiota on consumption of pea protein supplemented with an enzymes-probiotics blend (Pepzyme Pro). A total of 15 healthy subjects were instructed to take test (pea protein + Pepzyme Pro) or placebo (pea protein + maltodextrin) for 15 days with a 30-day washout period. Blood samples were analyzed for plasma-free amino acids, insulin, and C-reactive protein (CRP). Additionally, nitrogen levels in urine and feces, along with the composition of gut microbiota, were evaluated. On day 15, the test arm showed a tendency to increase the rate of absorption and total absorption (AUC) of amino acids compared with the placebo arm, though the increase was statistically insignificant. In addition, 15-day test supplementation showed a tendency to reduce Tmax of all the amino acids (statistically insignificant except alanine, p = 0.021 and glycine, p = 0.023) in comparison with the placebo supplementation. There were no changes in urine and fecal nitrogen levels as well as serum CRP levels in the test and placebo arm. The increase in serum insulin level after 4 h was statistically significant in both arms, whereas the insulin level of the placebo and test arm at 4 h was not statistically different. Supplementation showed changes with respect to Archaea and few uncharacterized species but did not show statistically significant variations in microbiome profile at the higher taxonomic levels. A study with large sample size and detailed gut microbiome analysis is warranted to confirm the results statistically as well as to characterize altered species. However, the current study could provide an inkling of a positive alteration in protein digestibility, amino acid absorption, and gut microbiome with regular consumption of protein and enzymes-probiotics blend. Clinical Trial Registration:clinicaltrials.gov/; identifier [CTRI/2021/10/037072].

Effectiveness of Chickpeas on Blood Sugar: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Diabetes affects one in eleven adults globally, with rising cases in the past 30 years. Type 1 and type 2 cause blood sugar problems, increasing cardiovascular risks. Dietary control, including chickpeas, is suggested but needs more research. Comprehensive searches were conducted across multiple databases for the randomized controlled trial efficacy of chickpea consumption to lower blood sugar levels to a healthy range, with data extraction and risk of bias assessment performed independently by two researchers. Statistical analysis was performed using RevMan 5.4, expressing continuous data as mean differences and risk ratios with 95% confidence intervals, and a summary of the findings is provided considering the variations in study characteristics. A total of 118 articles were initially identified from seven databases, primarily from Anglo-American countries, resulting in 12 selected studies after the identification and screening processes. These studies involved 182 participants, focusing on healthy or normoglycemic adults, and assessed the effects of chickpeas compared to various foods such as wheat, potatoes, pasta, sauce, cheese, rice, and corn. A meta-analysis involving a subset of studies demonstrated that chickpeas were more effective in reducing blood glucose iAUC compared to potatoes and wheat. Chickpeas offer the potential for blood sugar control through low starch digestibility, high fiber, protein, and hormonal effects. Although insulin benefits are seen, statistical significance varies, supporting their role in diabetic diets focusing on nutrient-rich foods over processed carbs.

GCMS fingerprints and phenolic extracts of Allium sativum inhibit key enzymes associated with type 2 diabetes

Objectives

Inhibition of carbohydrate digestion enzymes (α-amylase and α-glucosidase) has been reported in studies as a therapeutic approach for the management or treatment of type 2 diabetes mellitus, owing to its potential to decrease postprandial hyperglycemia. The anti-diabetic potential of Allium sativum (also known as garlic) against diabetes mellitus has been established. Therefore, in this study, we assessed the antidiabetic potential of A. sativum using in vitro enzyme assays after which we explored computational modelling approach using the quantified GC-MS identities to unravel the key bioactive compounds responsible for the anti-diabetic potential.

Methods

We used in vitro enzyme inhibition assays (α-amylase and α-glucosidase) to evaluate antidiabetic potential and subsequently performed gas chromatography-mass spectroscopy (GC-MS) to identify and quantify the bioactive compounds of the plant extract. The identified bioactive compounds were subjected to in silico docking and pharmacokinetic assessment.

Results

A. sativum phenolic extract showed high dose-dependent inhibition of α-amylase and α-glucosidase (p < 0.05). Interestingly, the extract inhibited α-glucosidase with a half maximal inhibitory concentration of 53.75 μg/mL, a value higher than that obtained for the standard acarbose. Docking simulation revealed that morellinol and phentolamine were the best binders of α-glucosidase, with mean affinity values of -7.3 and -7.1 kcal/mol, respectively. These compounds had good affinity toward active site residues of the enzyme, and excellent drug-like and pharmacokinetic properties supporting clinical applications.

Conclusions

Our research reveals the potential of A. sativum as a functional food for the management of type 2 diabetes, and suggests that morellinol and phentolamine may be the most active compounds responsible for this anti-diabetic prowess. Therefore these compounds require further clinical asessment to demonstrate their potential for drug development.

Current Status and Nutritional Value of Green Leaf Protein

Green leaf biomass is one of the largest underutilized sources of nutrients worldwide. Whether it is purposely cultivated (forage crops, duckweed) or upcycled as a waste stream from the mass-produced agricultural crops (discarded leaves, offcuts, tops, peels, or pulp), the green biomass can be established as a viable alternative source of plant proteins in food and feed processing formulations. Rubisco is a major component of all green leaves, comprising up to 50% of soluble leaf protein, and offers many advantageous functional features in terms of essential amino acid profile, reduced allergenicity, enhanced gelation, foaming, emulsification, and textural properties. Nutrient profiles of green leaf biomass differ considerably from those of plant seeds in protein quality, vitamin and mineral concentration, and omega 6/3 fatty acid profiles. Emerging technological improvements in processing fractions, protein quality, and organoleptic profiles will enhance the nutritional quality of green leaf proteins as well as address scaling and sustainability challenges associated with the growing global demand for high quality nutrition.

Application of emerging technologies to obtain legume protein isolates with improved techno-functional properties and health effects

Current demand of consumers for healthy and sustainable food products has led the industry to search for different sources of plant protein isolates and concentrates. Legumes represent an excellent nonanimal protein source with high-protein content. Legume species are distributed in a wide range of ecological conditions, including regions with drought conditions, making them a sustainable crop in a context of global warming. However, their use as human food is limited by the presence of antinutritional factors, such as protease inhibitors, lectins, phytates, and alkaloids, which have adverse nutritional effects. Antitechnological factors, such as fiber, tannins, and lipids, can affect the purity and protein extraction yield. Although most are removed or reduced during alkaline solubilization and isoelectric precipitation processes, some remain in the resulting protein isolates. Selection of appropriate legume genotypes and different emerging and sustainable facilitating technologies, such as high-power ultrasound, pulsed electric fields, high hydrostatic pressure, microwave, and supercritical fluids, can be applied to increase the removal of unwanted compounds. Some technologies can be used to increase protein yield. The technologies can also modify protein structure to improve digestibility, reduce allergenicity, and tune technological properties. This review summarizes recent findings regarding the use of emerging technologies to obtain high-purity protein isolates and the effects on techno-functional properties and health.

Sustaining Protein Nutrition Through Plant-Based Foods

Proteins are essential components of the human diet. Dietary proteins could be derived from animals and plants. Animal protein, although higher in demand, is generally considered less environmentally sustainable. Therefore, a gradual transition from animal- to plant-based protein food may be desirable to maintain environmental stability, ethical reasons, food affordability, greater food safety, fulfilling higher consumer demand, and combating of protein-energy malnutrition. Due to these reasons, plant-based proteins are steadily gaining popularity, and this upward trend is expected to continue for the next few decades. Plant proteins are a good source of many essential amino acids, vital macronutrients, and are sufficient to achieve complete protein nutrition. The main goal of this review is to provide an overview of plant-based protein that helps sustain a better life for humans and the nutritional quality of plant proteins. Therefore, the present review comprehensively explores the nutritional quality of the plant proteins, their cost-effective extraction and processing technologies, impacts on nutrition, different food wastes as an alternative source of plant protein, and their environmental impact. Furthermore, it focuses on the emerging technologies for improving plant proteins' bioavailability, digestibility, and organoleptic properties, and highlights the aforementioned technological challenges for future research work.

Plant-Based Proteins: The Good, Bad, and Ugly

Our global population is growing at a pace to exceed 10 billion people by the year 2050. This growth will place pressure on the agricultural production of food to feed the hungry masses. One category that will be strained is protein. Per capita protein consumption is rising in virtually every country for both nutritional reasons and consumption enjoyment. The United Nations estimates protein demand will double by 2050, and this will result in a critical overall protein shortage if drastic changes are not made in the years preceding these changes. Therefore, the world is in the midst of identifying technological breakthroughs to make protein more readily available and sustainable for future generations. One protein sourcing category that has grown in the past decade is plant-based proteins, which seem to fit criteria established by discerning consumers, including healthy, sustainable, ethical, and relatively inexpensive. Although demand for plant-based protein continues to increase, these proteins are challenging to utilize in novel food formulations.

Expected final online publication date for the Annual Review of Food Science and Technology, Volume 13 is March 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Proteins in Food Systems-Bionanomaterials, Conventional and Unconventional Sources, Functional Properties, and Development Opportunities

Recently, food companies from various European countries have observed increased interest in high-protein food and other products with specific functional properties. This review article intends to present proteins as an increasingly popular ingredient in various food products that frequently draw contemporary consumers’ attention. The study describes the role of conventional, unconventional, and alternative sources of protein in the human body. Furthermore, the study explores proteins’ nutritional value and functional properties, their use in the food industry, and the application of proteins in bionanomaterials. Due to the expected increase in demand for high-protein products, the paper also examines the health benefits and risks of consuming these products, current market trends, and consumer preferences.

Sweet-flavored peptides with biological activities from mulberry seed protein treated by multifrequency countercurrent ultrasonic technology

To increase the reuse of food residues, multifrequency countercurrent ultrasonic treatment was used to enhance the extraction yield of defatted mulberry seed protein (DMSP), and sweet-flavored peptides from DMSP hydrolysates (DMSPHs) were obtained for the first time. Here, the DMSP yield was increased by 16.2% (p < 0.05) while the power density was halved compared with single-frequency ultrasonic treatment. According to Fick's second law, a molecular diffusion dynamics model was developed to be suitable for predicting the pretreatment conditions (R² = 0.9785). After that, the sweet-flavored peptides were purified and the main amino acid sequences were identified, i.e., FEGGSIE, KDFPEAHSQAT, and GSQPAEGAK. Moreover, the antioxidant activities of DMSPHs prepared with tri-frequency treatment was higher than 60%. The DMSPHs retarded the growth of HepG2 cells in vitro, increased the necrotic quadrant (Q1-UL), and extended the S phase. Therefore, the sweet-flavored peptides prepared from DMSPHs using the multifrequency-ultrasonic treatment have significant biological activities.

Effect of supplementing fava bean (Vicia faba L.) on ulcerative colitis and colonic mucosal DNA content in rats fed a high-sucrose diet

Ulcerative colitis (UC) is an inflammatory bowel disease with high morbidity. Acetic acid-induced damage of colonic mucosa in rats is a commonly used experimental animal model of UC. This research aimed to explore for the first time the ameliorative effect of dietary supplementation with fava bean on the incidence of UC in rats fed with sucrose containing diet. Rats were divided into five groups as follows: G1, control healthy rats; G2, colitic rats; G3, colitic rats fed diets containing 30% sucrose, G4, healthy rats fed diets containing 30% sucrose and G5, colitic rats fed diets containing 30% sucrose supplemented with dried ground fava bean. Colonic injury and inflammation were evaluated through a disturbance of oxidative biomarkers, a significant increase in inflammatory biomarkers and inflammatory cytokines, and histological abnormalities in colonic tissues accompanied by colonic mucosal DNA damage. Colitic rats fed on sucrose containing diet demonstrated additional histological, biochemical, and DNA alterations in colonic mucosa of rats. Dietary supplementation with dried ground fava bean significantly corrected the impaired oxidative and inflammatory biomarker levels and modulated histological features and DNA alterations. Finally, fava bean attenuated the oxidative damage and colonic injury induced by acetic acid, which confirmed its high anti-oxidant and anti-incendiary properties.

Plant Proteins: Assessing Their Nutritional Quality and Effects on Health and Physical Function

Consumer demand for plant protein-based products is high and expected to grow considerably in the next decade. Factors contributing to the rise in popularity of plant proteins include: (1) potential health benefits associated with increased intake of plant-based diets; (2) consumer concerns regarding adverse health effects of consuming diets high in animal protein (e.g., increased saturated fat); (3) increased consumer recognition of the need to improve the environmental sustainability of food production; (4) ethical issues regarding the treatment of animals; and (5) general consumer view of protein as a "positive" nutrient (more is better). While there are health and physical function benefits of diets higher in plant-based protein, the nutritional quality of plant proteins may be inferior in some respects relative to animal proteins. This review highlights the nutritional quality of plant proteins and strategies for wisely using them to meet amino acid requirements. In addition, a summary of studies evaluating the potential benefits of plant proteins for both health and physical function is provided. Finally, potential safety issues associated with increased intake of plant proteins are addressed.