Cassava leaves as an alternative protein source: Effect of alkaline parameters and precipitation conditions on protein extraction and recovery.

Alternative protein sources have been required to meet the significant plant protein demand. Agro-industrial by-products such as leaves have considerable potential as a source of macromolecules once they are mostly discarded as waste. The current study evaluated dried cassava leaves as a protein source. First, alkaline extraction parameters (solid-liquid ratio, pH, and temperature) were optimized and the run that result in the highest protein yield were acidified at pH 2.5 or 4. The influence of carbohydrate solubilized on protein precipitation was also evaluated by removing it via alcoholic extraction prior to precipitation. The experimental design showed that high pH and temperature conditions associated with a low solid-liquid ratio led to increased protein yields. The presence of carbohydrates in the supernatant significantly influenced protein precipitation. The protein concentrate had around 17.51% protein when it was obtained from a supernatant with carbohydrates, while protein content increased to 26.88% when it was obtained from carbohydrate-free supernatant. The precipitation pH also influenced protein content, whereas protein content significantly decreased when pH increased from 2.5 to 4. The natural interaction between carbohydrates and proteins from cassava leaves positively influenced the emulsion stability index and the foaming capacity and stability. Thus, the presented results bring insights into challenges in extracting and precipitation proteins from agro-industrial by-products.

Incorporation of Locust Bean Gum and Solid Lipid Microparticles as Strategies to Improve the Properties and Stability of Calcium-Rich Soy Protein Isolate Gels.

The present study aimed to investigate the properties of calcium-rich soy protein isolate (SPI) gels (14% SPI; 100 mM CaCl2), the effects of incorporating different concentrations locust bean gum (LBG) (0.1-0.3%, w/v) to the systems and the stability of the obtained gels. Also, the incorporation of solid lipid microparticles (SLMs) was tested as an alternative strategy to improve the system's stability and, therefore, potential to be applied as a product prototype. The gels were evaluated regarding their visual aspect, rheological properties, water-holding capacities (WHCs) and microstructural organizations. The CaCl2-induced gels were self-supported but presented low WHC (40.0% ± 2.2) which was improved by LBG incorporation. The obtained mixed system, however, presented low stability, with high syneresis after 10 days of storage, due to microstructural compaction. The gels' stability was improved by SLM incorporation, which decreased the gelled matrices' compaction and syneresis for more than 20 days. Even though the rheological properties of the emulsion-filled gels (EFGs) were very altered due to the ageing process (which may affect the sensory perception of a future food originated from this EFG), the incorporation of SLMs increased the systems potential to be applied as a calcium-rich product prototype.

Pea protein isolate-soluble soybean polysaccharides electrostatic assembly: effect of pH, biopolymer mass ratio and heat treatment.

BACKGROUND: In past years, thousands of protein-polysaccharide complexes have been investigated to modify protein characteristics and functionality in food systems. However, the interaction between pea protein isolate (PPI) and soluble soybean polysaccharide (SSPS) has not been thoroughly characterized yet. RESULTS: In the present study, the phase behavior of PPI and SSPS mixtures was analyzed as a function of PPI:SSPS mixing ratio (1:1 to 1:0.10) and pH (7.0 to 2.0), showing that these biopolymers could be electrostatically assembled at 1:1 to 1:0.25 mixing ratios and 4.0 to 3.0 pH values. Then, the characteristics of the PPI-SSPS complexes were studied before and after heating (90 °C and 30 min) by ζ-potential, surface hydrophobicity, protein solubility, particle size distribution and physical stability for 56 days. By lowering the pH and PPI:SSPS mixing ratio, the complexes showed increased solubility, changed 𝜁-potential and higher physical stability. By heating, the complexes presented increased hydrophobicity and physical stability. CONCLUSION: Overall, PPI-SSPS complexes increased the protein solubility, reduced the particle size, and changed both the ζ-potential and the surface hydrophobicity with respect to PPI control, allowing stabilization of the colloidal system and broadening the possible applications of these high-quality proteins in acidic food systems. © 2024 Society of Chemical Industry.

Saline as solvent and ethanol-based purification process for the extraction of proteins and isoflavones from wet okara.

Okara, the solid byproduct of water-soluble soybean extract production, is a potential source of proteins and isoflavones. This study investigated different experimental configurations for extracting these compounds from wet okara, including lipid removal with ethanol at different stages of the recovery process, sequential crosscurrent extraction, and using a saline MgCl2 solution as the solvent. Three washes with a 60:40 ethanol:water (w/w) solution after isoelectric precipitation significantly increased protein content by reducing lipid content (60 %). The crosscurrent approach using 0.05 M MgCl2 yielded okara proteinaceous material with 248 µg/g daidzein and 236 µg/g genistein, along with a 3 % increase in protein content, attributed to enhanced extraction of 7S globulins. These configurations notably affected the functional properties of the protein materials. Overall, this research provides detailed insights into the composition and properties of proteins extracted from wet okara, facilitating their specialized application in food products.

Plant-based diets and their effects on the metabolism and survival of chronic renal patients undergoing conservative treatment

Diet therapy in conservative treatment of chronic kidney disease involves protein restriction, but there is not enough evidence to recommend a particular type of protein, whether animal or plant based. However, studies suggest that plant-based diets help reduce the consumption of total and animal protein, reduce the need for nephroprotective drugs, improve complications and bring advantages in terms of disease progression and patient survival. The article considers up-to-date data on the effects of this diet and observed that when low in protein, primarily vegetable and in some cases supplemented with ketoanalogues, it can result in positive clinical outcomes, such as: delay in the decrease in the glomerular filtration rate, lower concentrations of urea, reduction of serum creatinine and phosphorus concentrations, lower metabolic acidosis, higher insulin sensitivity and lower systemic inflammation. As a whole, this dietary pattern may be able to postpone the start of dialysis with less progression of renal insufficiency. Additional research is needed to better characterize this dietary pattern.

La dietoterapia en el tratamiento conservador de la enfermedad renal crónica implica la restricción de proteínas, pero aún no hay pruebas suficientes para recomendar un tipo concreto de proteínas, ya sean animales o vegetales. Sin embargo, los estudios sugieren que las dietas basadas en plantas ayudan a reducir la ingesta de proteínas totales y animales, disminuyen la necesidad de fármacos nefroprotectores, mejoran las complicaciones y presentan ventajas con respecto a la progresión de la enfermedad y la supervivencia de los pacientes. En este artículo se consideran datos actualizados sobre los efectos de esta dieta y se observa que, cuando es hipoproteica, principalmente vegetal y en algunos casos se complementa con cetoanálogos, puede dar lugar a resultados clínicos positivos, como una disminución retardada de la tasa de filtración glomerular, concentraciones más bajas de urea, concentraciones reducidas de creatinina y fósforo séricos, menor acidosis metabólica, mayor sensibilidad a la insulina y menor inflamación sistémica. En conjunto, este patrón dietético tiene el potencial de retrasar el inicio de la diálisis con una menor progresión de la insuficiencia renal. Es necesario seguir investigando para caracterizar mejor este patrón dietético.

Analysis of ingredient list and nutrient composition of plant-based burgers available in the global market.

The nutrient composition of plant-based burgers is a key factor when making their purchase/consumption decision to maintain a balanced diet. For this reason, ingredient list and nutritional information of burgers launched in the global market were retrieved from their labels. Products were classified based on the technology development, market position and region of the manufacturer. From the ingredient analysis, we observed a high heterogeneity in the ingredients used, a predominance of soy and wheat as main sources of proteins, and the increasing use of new protein sources (e.g. peas, other types of beans and pseudo-cereals). Oil was the most cited ingredient followed by salt. Nutritional composition varied mainly depending on the region with no clear pattern among countries. To less extent, technology development resulted in traditional products with lower amounts of protein and higher amounts of carbohydrates. Vegan and vegetarian products showed limited differences due to the high intra-heterogenicity.

Combination of Milk and Plant Proteins to Develop Novel Food Systems: What Are the Limits?

In the context of a diet transition from animal protein to plant protein, both for sustainable and healthy scopes, innovative plant-based foods are being developing. A combination with milk proteins has been proposed as a strategy to overcome the scarce functional and sensorial properties of plant proteins. Based on this mixture were designed several colloidal systems such as suspensions, gels, emulsions, and foams which can be found in many food products. This review aims to give profound scientific insights on the challenges and opportunities of developing such binary systems which could soon open a new market category in the food industry. The recent trends in the formulation of each colloidal system, as well as their limits and advantages are here considered. Lastly, new approaches to improve the coexistence of both milk and plant proteins and how they affect the sensorial profile of food products are discussed.

Pereskia aculeata Miller as a Novel Food Source: A Review.

Pereskia aculeata Miller is an edible plant species belonging to the Cactaceae family. It has the potential to be used in the food and pharmaceutical industries due to its nutritional characteristics, bioactive compounds, and mucilage content. Pereskia aculeata Miller is native to the Neotropical region, where it is traditionally employed as food in rural communities, being popularly known as 'ora-pro-nobis' (OPN) or the Barbados gooseberry. The leaves of OPN are distinguished by their nontoxicity and nutritional richness, including, on a dry basis, 23% proteins, 31% carbohydrates, 14% minerals, 8% lipids, and 4% soluble dietary fibers, besides vitamins A, C, and E, and phenolic, carotenoid, and flavonoid compounds. The OPN leaves and fruits also contain mucilage composed of arabinogalactan biopolymer that presents technofunctional properties such as thickener, gelling, and emulsifier agent. Moreover, OPN is generally used for pharmacological purposes in Brazilian folk medicine, which has been attributed to its bioactive molecules with metabolic, anti-inflammatory, antioxidant, and antimicrobial properties. Therefore, in the face of the growing research and industrial interests in OPN as a novel food source, the present work reviews its botanical, nutritional, bioactive, and technofunctional properties, which are relevant for the development of healthy and innovative food products and ingredients.

Processing effects on the protein quality and functional properties of cold-pressed pumpkin seed meal.

Environmental and food security challenges due to a growing world population may be overcome by using alternative protein sources for the human diet. By-products from edible oil processing industries are potential sources due to their high protein content. Pumpkin seed meals were evaluated regarding proximate composition, in vitro protein digestibility (IVPD), amino acid profile and score, and antinutritional factors. Conventional thermal processing, microwave, and ultrasound treatments impact on samples' nutritional quality were assessed using a central composite experimental design. Raw pumpkin seed meal presented up to 45% protein content and 86% IVPD. Processing increased IVPD up to 96%, with optimized conditions of 87.8 °C, pH8.0, and 37 min, for all processes. Lysine was the only limiting amino acid for raw and processed samples. Phytic acid decreased by 31%, while trypsin inhibitory activity was reduced by 84%. Pumpkin seed by-product is a promising high-quality plant protein source for food formulations.

Understanding the Performance of Plant Protein Concentrates as Partial Meat Substitutes in Hybrid Meat Emulsions.

Hybrid meat products are an excellent strategy to incorporate plant proteins into traditional meat formulations considering recent market trends focusing on the partial reduction in red meat content. In this work, we evaluated the effects of different concentrated plant proteins (soy, pea, fava bean, rice, and sunflower) in partially replacing meat in meat emulsion model systems. Soy, pea, and sunflower proteins showed great compatibility with the meat matrix, giving excellent emulsion stability and a cohesive protein network with good fat distribution. Otherwise, adding rice and fava bean proteins resulted in poor emulsion stability. Color parameters were affected by the intrinsic color of plant proteins and due to the reduction in myoglobin content. Both viscoelastic moduli, G' and G″ decreased with the incorporation of plant proteins, especially for rice and fava bean. The temperature sweep showed that myosin denaturation was the dominant effect on the G' increase. The water mobility was affected by plant proteins and the proportion between immobilized and intermyofibrillar water was quite different among treatments, especially those with fava bean and rice proteins. In vitro protein digestibility was lower for hybrid meat emulsion elaborated with rice protein. It is concluded that soy, pea, and mainly sunflower proteins have suitable compatibility with the meat matrix in emulsified products.

Effect of the Concentration, pH, and Ca2+ Ions on the Rheological Properties of Concentrate Proteins from Quinoa, Lentil, and Black Bean.

Given consumer trends propelling a movement toward using plant protein in the food industry and searching for alternative protein ingredients by the industry, this study aimed to assess the influence of factors such as protein concentration, medium pH, and the presence of a divalent ion (Ca2+) upon the rheological properties such as viscosity change and gel formation of dispersion proteins extracted from quinoa, black beans, and lentils. A solution of each protein was prepared by varying its concentration (2.5%, 5.0%, and 10%), the pH (5.0, 7.0, and 9.0), and the incorporation of calcium chloride (0.0% and 1.0%). Each obtained solution was subjected to rheological tests to determine the parameters: consistency index (K), flow behavior (n), the storage (G') and loss (G'') modules, and the phase shift angle (δ). The results demonstrate that the incorporation of Ca2+, the shift in protein levels, and the decrease in pH modified the rheological behaviors of proteins, which were also influenced by the structural characteristics of each protein studied. However, thermal treatment and protein concentrations caused the most significant impact on proteins' rheological behavior, forming gels independently of other conditions. It was possible to study and interpret the studied proteins' rheological variations according to the environment's conditions.

Satiety and consumers' perceptions: What opinions do Argentinian and Brazilian people have about yogurt fortified with dairy and legume proteins?

This study (1) evaluated the perceptions of Argentinian and Brazilian consumers regarding yogurt fortified with dairy proteins, legume proteins, or a combination of both, and (2) determined the satiety expectations of these foods as well as the consumers' intentions to taste and purchase protein-fortified yogurt. A total of 298 Argentinian and 100 Brazilian participants completed an online survey for this study. The free word association technique was used to investigate their perceptions about "satiety" as a verbal stimulus and 6 concepts of yogurt as visual/verbal stimuli (yogurt, set yogurt, skim set yogurt, skim set yogurt with a high content of dairy proteins, skim set yogurt with a high content of legume proteins, and skim set yogurt with a mix of dairy and legume proteins). The expected satiation and intentions to taste or purchase were evaluated using categorical scales. Regardless of their cultural background, participants from both countries expressed similar associations with the stimuli presented. Yogurt and set yogurt were associated with consumption occasions, sensory characteristics, liking, and foods, whereas skim yogurt was associated with diet food. Products fortified with proteins were associated with healthy foods, regardless of the protein source, and they yielded the highest rates for expected satiation. Brazilian participants were more likely to taste the food with a combination of proteins; however, participants from both countries were indifferent to purchasing the product. Important characteristics in the design and marketing of these products were pleasant sensations, such as "fullness," "satisfied," and snacks to eat "on the go," and the vegetarian consumers' segment. The combination with fruits or cereals, creaminess, and vanilla flavor should also be considered. The study findings could have implications for the dairy industry when designing yogurt fortified with proteins and communicating the nutritional and wholesome properties of these products.

An Insulin Receptor-Binding Multifunctional Protein from Tamarindus indica L. Presents a Hypoglycemic Effect in a Diet-Induced Type 2 Diabetes-Preclinical Study.

The objectives of this study were to evaluate the hypoglycemic effect of the trypsin inhibitor isolated from tamarind seeds (TTI) in an experimental model of T2DM and the in silico interaction between the conformational models of TTI 56/287 and the insulin receptor (IR). After inducing T2DM, 15 male Wistar rats were randomly allocated in three groups (n = 5): 1-T2DM group without treatment; 2-T2DM group treated with adequate diet; and 3-T2DM treated with TTI (25 mg/kg), for 10 days. Insulinemia and fasting glucose were analyzed, and the HOMA-IR and HOMA-ß were calculated. The group of animals treated with TTI presented both lower fasting glucose concentrations (p = 0.0031) and lower HOMA-IR indexes (p = 0.0432), along with higher HOMA-ß indexes (p = 0.0052), than the animals in the other groups. The in silico analyses showed that there was an interaction between TTIp 56/287 and IR with interaction potential energy (IPE) of -1591.54 kJ mol-1 (±234.90), being lower than that presented by insulin and IR: -894.98 kJ mol-1 (±32.16). In addition, the presence of amino acids, type of binding and place of interaction other than insulin were identified. This study revealed the hypoglycemic effect of a bioactive molecule of protein origin from Tamarind seeds in a preclinical model of T2DM. Furthermore, the in silico analysis allowed the prediction of its binding in the IR, raising a new perspective for explaining TTI's action on the glycemic response.

Colloidal and Acid Gelling Properties of Mixed Milk and Pea Protein Suspensions.

The present study aims to describe colloidal and acid gelling properties of mixed suspensions of pea and milk proteins. Mixed protein suspensions were prepared by adding pea protein isolate to rehydrated skimmed milk (3% w/w protein) to generate four mixed samples at 5, 7, 9, and 11% w/w total protein. Skimmed milk powder was also used to prepare four pure milk samples at the same protein concentrations. The samples were analyzed in regard to their pH, viscosity, color, percentage of sedimentable material, heat and ethanol stabilities, and acid gelling properties. Mixed suspensions were darker and presented higher pH, viscosity, and percentage of sedimentable material than milk samples. Heat and ethanol stabilities were similar for both systems and were reduced as a function of total protein concentration. Small oscillation rheology and induced syneresis data showed that the presence of pea proteins accelerated acid gel formation but weakened the final structure of the gels. In this context, the results found in the present work contributed to a better understanding of mixed dairy/plant protein functionalities and the development of new food products.

Lectins ConA and ConM extracted from Canavalia ensiformis (L.) DC and Canavalia rosea (Sw.) DC inhibit planktonic Candida albicans and Candida tropicalis.

Lectins participate in the defense against microorganisms and in signaling the damage caused by pathogens to the cell surface and/or intracellular in plants. This study aims to analyze the antifungal potential of lectins extracted from seeds of Canavalia ensiformis (L.) DC and Canavalia rosea (Sw.) DC, against Candida albicans and Candida tropicalis. The antimicrobial tests were performed by microdilution against Candida spp. The test to verify the combined lectin/fluconazole effect was performed using subinhibitory concentrations of lectins and with antifungal ranging from 0.5 to 512 µg/mL. The ability to inhibit the morphological transition of Candida spp. was evaluated by microcultivation in a moist chamber. The results of the minimum inhibitory concentration revealed no antifungal activity against the tested strains. However, lectins modified the action of fluconazole, reducing the IC50 of the drug against C. albicans. Lectins were also able to discretely modulate the morphological transition of the tested strains.

Near-infrared techniques for fraud detection in dairy products: A review.

The dairy products sector is an important part of the food industry, and their consumption is expected to grow in the next 10 years. Therefore, the authentication of these products in a faster and precise way is required for the sake of public health. This review proposes the use of near-infrared techniques for the detection of food fraud in dairy products as they are faster, nondestructive, environmentally friendly, do not require sample preparation, and allow multiconstituent analysis. First, we have described frequent forms of food fraud in dairy products and the application of traditional techniques for their detection, highlighting gaps and counterproductive characteristics for the actual global food chain, as longer sample preparation time and use of reagents. Then, the application of near-infrared spectroscopy and hyperspectral imaging for the detection of food fraud mainly in cheese, butter, and yogurt are described. As these techniques depend on model development, the coverage of different dairy products by the literature will promote the identification of food fraud in a faster and reliable way.

Structural and Physicochemical Characterization of Extracted Proteins Fractions from Chickpea (Cicer arietinum L.) as a Potential Food Ingredient to Replace Ovalbumin in Foams and Emulsions.

Chickpeas are the third most abundant legume crop worldwide, having a high protein content (14.9-24.6%) with interesting technological properties, thus representing a sustainable alternative to animal proteins. In this study, the surface and structural properties of total (TE) and sequential (ALB, GLO, and GLU) protein fractions isolated from defatted chickpea flour were evaluated and compared with an animal protein, ovalbumin (OVO). Differences in their physicochemical properties were evidenced when comparing TE with ALB, GLO, and GLU fractions. In addition, using a simple and low-cost extraction method it was obtained a high protein yield (82 ± 4%) with a significant content of essential and hydrophobic amino acids. Chickpea proteins presented improved interfacial and surface behavior compared to OVO, where GLO showed the most significant effects, correlated with its secondary structure and associated with its flexibility and higher surface hydrophobicity. Therefore, chickpea proteins have improved surface properties compared to OVO, evidencing their potential use as foam and/or emulsion stabilizers in food formulations for the replacement of animal proteins.

Anti-infective activity of Cratylia argentea lectin (CFL) against experimental infection with virulent Listeria monocytogenes in Swiss mice.

BACKGROUND: The lectin from Cratylia argentea (CFL) is able to modulate the immune system response and is thus a potential phytotherapeutic substance. HYPOTHESIS/PURPOSE: In this study, we investigated the role of CFL on control of bacterial infection caused by Listeria monocytogenes, the causative agent of human listeriosis. STUDY DESIGN: Swiss mice were infected with L. monocytogenes and then treated with CFL. METHODS: Adult Swiss mice weighing with 30-40 g were infected intraperitoneally with a bacterial suspension (0.2 ml; 1 × 107 CFU/ml). After 30 min, the mice were treated with CFL intravenously at concentrations of 0.1 or 10 mg/kg. Control mice received phosphate-buffered saline (PBS). The animals were euthanized 24 h after infection. RESULTS: We observed that i.v. administration of CFL to Swiss mice did not cause acute toxicity, and reduced the leukocyte counts in the bloodstream 24 h after infection with virulent L. monocytogenes. There was a reduction in the bacterial burden within peritoneal macrophages after infection in CFL-treated mice. Accordingly, the bacterial counts in the bloodstream, spleen and liver also decreased in comparison with the PBS group. Histological damage in the spleen and liver was lower in mice that received CFL treatment. In vitro antimicrobial assays demonstrated that CFL does not inhibit the growth of L. monocytogenes. The mRNA expression of the anti-inflammatory cytokine IL-10 was enhanced with CFL treatment after infection. CONCLUSION: The lectin from C. argentea (CFL) has immunomodulatory and anti-infective properties of pharmacological interest for control of infectious diseases.

Adiposity and insulin resistance mediate the inverse association between legume intake and blood pressure: a cross-sectional analysis in secondary cardiovascular prevention.

This study aimed to evaluate the association between legume intake and blood pressure, as well as the mediating role of cardiometabolic risk factors in patients in secondary cardiovascular prevention. Socio-demographic, anthropometric, clinical and food intake data were collected from the baseline of the multicentre study Brazilian Cardioprotective Nutritional Program Trial - BALANCE (RCT: NCT01620398). The relationships between variables were explored through path analysis. In total, 2247 individuals with a median age of 63·0 (45-91) years, 58·8 % (n 1321) male and 96·5 % (n 2168) with diagnosis of hypertension were included. Negative associations were observed between histidine intake and systolic blood pressure (SBP) (standardised coefficient (SC) = -0·057; P = 0·012) and between legume intake and BMI (SC = -0·061; P = 0·006). BMI was positively associated with triglycerides-glucose (TyG) index (SC = 0·173; P < 0·001), SBP (SC = 0·144; P < 0·001) and diastolic blood pressure (DBP) (SC = 0·177; P < 0·001), and TyG index was positively associated with DBP (SC = 0·079; P = 0·001). A negative indirect effect was observed between the intake of legumes, SBP and DBP, mediated by BMI (SC = -0·009; P = 0·011; SC = -0·011; P = 0·010, respectively). In addition, an indirect negative effect was found between the intake of legumes and the DBP, mediated simultaneously by BMI and TyG index (SC = -0·001; P = 0·037). In conclusion, legume intake presented a negative indirect association with blood pressure, mediated by insulin resistance (TyG) and adiposity (BMI) in individuals of secondary care in cardiology.

Aqueous Two-Phase Systems for Cleanup and Recovery of Enzymes from Plants and Plant-Derived Extracts.

The increasing interest of the biopharmaceutical industry to exploit plants as a commercially viable production system is demanding the development of new strategies to maximize product recovery. Aqueous two-phase systems (ATPSs) are a primary recovery technique that has shown great potential for the efficient extraction and purification of biological products, from organelles to proteins and low-molecular-weight compounds. The evaluation of different system parameters upon the partitioning behavior can provide the conditions that favor the concentration of contaminants and the desired target protein in opposite phases. The protocols described here provide the basic strategy to explore the use of ATPSs for the isolation and partial purification of native and recombinant proteins from plants and plant-derived extracts.