Waterborne electrospun α-lactalbumin/soy protein isolate nanofibers for wound healing.

Rapeseed protein isolate is used in the food industry, and heating is often used during rapeseed processing. However, the digestible indispensable amino acid score (DIAAS) for heat-treated rapeseed protein isolate is unknown. The present study aimed to test the hypothesis that heating rapeseed protein isolate improves protein quality resulting in DIAAS that is greater than for pea and rice protein concentrates, and comparable to that of soy and whey protein isolates. Standardized ileal digestibility (SID) of amino acids (AA), except leucine and methionine, was not different between heat-treated rapeseed protein isolate and soy protein isolate, but SID of most AA was greater (P < 0.001) for heat-treated rapeseed protein isolate than for brown rice protein concentrate, pea protein concentrate, rapeseed protein isolate and soy protein isolate, but not whey protein isolate. Non-heated rapeseed protein isolate had a reduced (P < 0.001) DIAAS for 6-month-old to 3-year-old children compared with soy protein isolate, but this was greater (P < 0.001) than for pea and brown rice protein concentrates. The DIAAS for heat-treated rapeseed protein isolate was greater (P < 0.001) than for non-heated rapeseed protein isolate for all age groups. Heat-treated rapeseed protein isolate and whey protein isolate had a DIAAS > 100 for individuals older than 3 years. Rapeseed protein isolate had a DIAAS comparable to soy protein isolate, but heat-treated rapeseed protein isolate and whey protein isolate had DIAAS ≥ 100, qualifying these proteins as 'excellent'. Rice and pea protein concentrates had DIAAS < 75. © 2023 Society of Chemical Industry.

This editorial summarizes the recent American Heart Association (AHA) Science Advisory on soy protein and isoflavones (phytoestrogens) published in the February 21, 2006, issue of Circulation .1 Soy protein and isoflavones have gained considerable attention for their potential role in improving risk factors for cardiovascular disease. This scientific advisory report assesses the more recent work published on soy protein and its component isoflavones. In 22 randomized trials, isolated soy protein with isoflavones compared with milk or other proteins decreased LDL cholesterol concentrations in most studies; the average effect was approximately 3%. This reduction is very small compared with the large amount of soy protein tested in these studies, averaging 50 g, approximately half the usual total daily protein intake. No significant effects were evident on HDL cholesterol, triglycerides, lipoprotein(a), or blood pressure. Among 19 studies of soy isoflavones, the average effect on LDL cholesterol and other lipid risk factors was nil. Soy protein or isoflavones have not been shown to lessen vasomotor symptoms of menopause, and results are mixed regarding slowing of postmenopausal bone loss. The efficacy and safety of soy isoflavones for preventing or treating cancer of the breast, endometrium, and prostate are not established; evidence from clinical trials is meager and cautionary as regards a possible adverse effect. For this reason, use of isoflavone supplements in food or pills is not recommended. Thus, earlier research indicating that soy protein compared with other proteins has clinically important favorable effects has not enjoyed confirmation. In contrast, many soy products should be beneficial to cardiovascular and overall health because of their high content of polyunsaturated fats, fiber, vitamins, and minerals and low content of saturated fat. In October 1999, the US Food and Drug Administration (FDA) approved labeling for foods containing soy protein as protective against coronary heart disease.2 …

Functional characterization of enzyme-hydrolysed soy and whey protein isolates: A comparative approach

Research was conducted to investigate the effects of egg white protein and soy protein powder addition on physicochemical properties of banana pasta. The levels of protein fortification were 5, 10, and 15% of banana flour (w/w) for each type of protein. Pasta made from 100% of durum wheat semolina and 100% of banana were used as controls. The addition of soy or egg white protein showed significant differences on physicochemical properties compared with semolina pasta and pure banana pasta. Type of protein, level of protein, and the interaction between type of protein and the level of protein altered protein content. Soy protein gave higher protein content than egg white protein, whereas higher level of protein addition gave higher protein content of pasta. The fortified banana pasta had higher protein content than semolina pasta. There were no significant effects of soy or egg white protein addition to either insoluble or soluble dietary fiber content. It was also observed that the cooking properties of pasta (optimum cooking time, swelling index, water absorption index, and cooking loss) were affected by the level of protein addition and the type of protein. Textural analysis for tension and firmness of the pasta illustrated that protein fortification improved the textural characteristic of banana flour pasta. The addition of soy or egg white protein also improved the protein content of banana pasta making it equal to or even better than semolina pasta. Practical applications Research has been carried out to improve gluten-free products, not only for people with celiac diseases, but also for those who choose a healthy lifestyle. Gluten-free ingredients are challenging to work with as they cannot create a sufficiently strong binding network between their proteins and starch in the dough, especially in some products such as pasta products. The use of an additional protein source has the ability to improve the product quality and contribute to the nutritional values which can give added value to the final gluten-free pasta product. This study reports the effects of the level of egg and soy protein fortification on the physicochemical properties of banana pasta. To the best our knowledge, there is no study which tried to develop banana pasta with protein addition alone such as soy protein isolate or egg protein powder.

Jack beans are one of the legumes with a high protein content to make protein isolates. This research aimed to evaluate the physical, sensory and proximate qualities of chicken sausages with jack bean protein isolate (JBPI) and the combination of JBPI and soy protein isolate (SPI) as a binder to improve the quality of the chicken sausages. This research included the preparation of JBPI and chicken sausages. The treatments were formulated as follows: control (without JBPI and SPI); T1 (SPI: JBPI = 100: 0); T2 (SPI: JBPI = 80:20); T3 (SPI: JBPI = 60:40); T4 (SPI: JBPI = 40: 60); T5 (SPI: JBPI = 20: 80); T6 (SPI: JBPI = 0: 100). The analysis of the physical, sensory, and proximate properties of sausages have been performed. The results showed that the JBPI protein content was high at 93.98% db, and contained higher essential amino acids than the FAO/WHO standards, i.e., leucine, lysine, phenylalanine + tyrosine, threonine. The combination of JBPI and SPI improved emulsion stability, lightness, yellowness, texture properties, protein content, and reduced cooking loss and redness of chicken sausages compared to control (p&lt;0.05). The results of the sensory evaluation showed that the overall preference, slice properties, and texture attributes of chicken sausage with the addition of a combination of SPI and JBPI were 40:60 (T4) significantly different from the control received by the panellists (p&lt;0.05). The formulation with the addition of a combination of SPI and JBPI of 40:60 was the optimal treatment because it improves the overall physical, sensory, and chemical characteristics of the resulting chicken sausage. JBPI had the potential as an alternative to substitution for SPI.

Evaluation of the functional properties of a protein isolate from Arthrospira maxima and its application in a meat sausage

A closed cavity rheometer was employed to assess the properties of concentrated protein materials before, during and after thermal treatment, using conditions that are relevant to the production of meat analogues. Pea and soy protein isolate and wheat gluten were used as model matrices. The analysis was done using Lissajous curves, both for small and large amplitude oscillatory shear deformation. The energy dissipation ratios based on the enclosed area inside the Lissajous curves characterize the plasticity of the materials. The results show that the modulus of wheat gluten increases during heating and remains elevated after cooling. In contrast, the moduli of pea and soy protein isolates decrease during heating. Subsequent cooling leads to properties that are similar to the rheological properties of unheated pea and soy protein isolates. Lissajous curves and energy dissipation ratios provide insight in the non-linear response. At 30 °C, pea and soy protein isolate have a higher dissipation ratio than wheat gluten. Upon a heat treatment and even after cooling, the dissipation ratio was smaller at similar strain amplitude compared with 30 °C. This indicates that heating induced more elasticity. Upon heating, pea protein isolate loses its elastic properties faster than soy protein isolate, while wheat gluten showed abrupt dissipation after extensive deformation. The observed characteristics are consistent with the behaviour during extrusion and shearing, in which wheat gluten forms extended filaments, while soy and pea protein isolates form a homogeneous matrix. Studying the large oscillatory shear behaviour during and after thermal treatment provides a more detailed picture of the rheological changes during processing, than one would obtain through classical rheology. The dissipation ratio summarizes the information in the Lissajous curves. These insights help to better identify material-structure-process relationships for concentrated plant protein materials during thermomechanical conversions, such as extrusion.

The adsorption of proteins at oil/water interfaces can reduce interfacial tension and increase emulsion stability. However, emulsions stabilized by soy protein isolate (SPI) are not sufficiently stable. Using SPI as a control, a theoretical basis for the adsorption behavior of mixed SPI and whey protein isolate (WPI) at the oil/water interface was established and the effects of the protein ratio and content on the emulsion stability were studied. Compared to SPI solution, SPI-WPI mixed solutions were found to reduce the size distribution of emulsion droplets and significantly improve the emulsion stability. Among the studied protein contents and ratios, the protein content of 0.2 g kg-1 and SPI/WPI mass ratio of 1:9 offered the lowest creaming stability index (15%), the smallest droplet size (278 nm), and the largest absolute value ζ-potential (35 mV), i.e. the emulsion stability was excellent. The largest dilatational modulus (10.08 mN m-1 ), dilatational elasticity (10.01 mN m-1 ), and dilatational viscosity (1.18 mN m-1 ), were observed with a protein content of 0.15 g kg-1 (SPI/WPI ratio of 1:9), along with a high interfacial protein adsorption capacity (47.33%). SPI-WPI complexes form a thick adsorption layer around oil droplets, resulting in an increase of the expansion modulus of the interfacial layer. SPI-WPI complexes can form a thick adsorption layer around oil droplets, resulting in increased expansion modulus of the interfacial layer, which improves emulsion stability. © 2020 Society of Chemical Industry.

Rice dreg protein could be a valuable source of plant-based proteins, as an alternative to soy proteins in some food products. Here, nutritional properties of rice dreg protein were compared with those of soy protein isolate. The protein content of rice dreg protein was approximately 62.6 g/100 g sample, with large amounts of fat, carbohydrate, and ash. The denaturation temperatures of rice protein isolate from rice dreg protein were 47.4 and 97.2°C, respectively. This indicated that these proteins could be denatured during rice syrup processing to form aggregates, but were relatively more stable than rice endosperm protein and soy protein isolate. The main amino acids in rice dreg protein and rice protein isolate were Glu, Pro, Arg, Asp, and Leu, with Lys as the lowest content. Most of essential amino acids and nutritional parameters of rice protein isolate and rice dreg protein met the suggested nutritional requirements for a child according to FAO/WHO, and were relatively higher than those of soy protein isolate. In addition, rice protein isolate showed better digestibility than soy protein isolate during four hours sequential pepsin and pancreatin digestions. The final digestibility value was 96.66% for rice protein isolate compared to 91.41% for soy protein isolate. Thus rice dreg protein could potentially replace soy proteins as a good source of value-added protein for human nutrition in response to the increasing demand for plant proteins.

Background/Objectives: To date, few studies have investigated the therapeutic effects of soy versus whey protein supplementation on obesity and insulin resistance (IR), yielding inconsistent findings. The aim of the present study was to compare the therapeutic efficacy of soy versus whey protein on obesity and IR and to elucidate their potential molecular mechanisms. Methods: Forty male C57BL/6J mice were randomly divided into two groups and fed either a normal diet (n = 8) or a high-fat diet (HFD, n = 32) for 16 weeks to induce obesity. After 16 weeks, HFD-induced obese mice were further randomized into three groups: HFD control, HFD + 20% whey protein isolate (WPI), and HFD + 20% soy protein isolate (SPI) for 6 weeks (n = 8). Results: Body weight, weight gain, body mass index, and Lee index showed no significant differences between the WPI and SPI groups. Compared with the WPI group, serum concentrations of insulin and leptin and the homeostasis model assessment of IR (HOMA-IR) were significantly lower, and thymus wet weight, fetal total cholesterol level, and serum glucose-dependent insulinotropic polypeptide concentration were significantly higher in the SPI group. Compared with the WPI group, the protein levels of GLUT4 and p-PI3K/PI3K were significantly higher in the SPI group. Metabolomics analysis showed that hepatic phosphocholine levels were significantly higher in the SPI group than in the WPI group. Moreover, hepatic differentially abundant metabolites of SPI- and WPI-fed mice were primarily enriched in the glycerophospholipid metabolism pathway. Conclusions: Soy protein was more effective than whey protein in ameliorating IR in HFD-induced obese mice, probably by modulating the PI3K-GLUT4 pathway and glycerophospholipid metabolism. Moreover, soy protein and whey protein showed comparable anti-obesity efficacy.

Different types of instant porridges have become a popular choice for breakfast, and it is known that breakfast is an important meal for daily appetite control. On our market there is porridge of uniform composition based on cereals, primarily oats. However, high-protein porridge is not available, which is a significant deficiency in the assortment of these products. In addition, insufficient intake of quality protein remains a dietary problem, particularly among children and the elderly, where diets consist mainly of cereals. Plant proteins in combination with cereals could be used to produce high protein instant porridge. In this study, proteins from legumes such as soybean and pea, specifically soy protein concentrate, soy protein isolate, and pea protein isolate were applied. Protein preparations were added to the main mixture composed of the buckwheat and corn extrudate and other additional ingredients. The protein preparations were added at three different levels: soy protein concentrate at 0, 7.5 and 15% (w/w main mixture basis) and soy protein isolate and pea protein isolate at 0, 15 and 30% (w/w main mixture bases), with the objective of optimizing the composition of the high-protein instant porridge. The aim of optimization was to maximize the protein content and overall acceptability. The optimal doses of protein preparations were determined using the method of desirability function and it was found that the optimized dose for the soy protein concentrate was 1.43 g/100 g, soy protein isolate 21.07 g/100 g and pea protein isolate 14.83 g/100 g. The prediction value for protein content was 24.77 %/DM and overall acceptability 4.09. The obtained experimental values were close to the prediction values: 24.32 %/DM for protein content and 4.41 for overall acceptability. The protein content of the formulated porridge was 24.32 %/DM, which is more than twice as high as that in the oat porridge present on the market. Based on standard nutritional values, the newly formulated high-protein instant porridge could be recommended as appropriate breakfast meal for adults.

Lutein is a natural fat-soluble carotenoid with various physiological functions. However, its poor water solubility and stability restrict its application in functional foods. The present study sought to analyze the stability and interaction mechanism of the complex glycosylated soy protein isolate (SPI) prepared using SPI and inulin-type fructans and lutein. The results showed that glycosylation reduced the fluorescence intensity and surface hydrophobicity of SPI but improved the emulsification process and solubility. Fluorescence intensity and ultraviolet–visible (UV–Vis) absorption spectroscopy results showed that the fluorescence quenching of the glycosylated soybean protein isolate by lutein was static. Through thermodynamic parameter analysis, it was found that lutein and glycosylated SPI were bound spontaneously through hydrophobic interaction, and the binding stoichiometry was 1:1. The X-ray diffraction analysis results showed that lutein existed in the glycosylated soybean protein isolate in an amorphous form. The Fourier transform infrared spectroscopy analysis results revealed that lutein had no effect on the secondary structure of glycosylated soy protein isolate. Meanwhile, the combination of lutein and glycosylated SPI improved the water solubility of lutein and the stability of light and heat.

Soy protein isolate (SPI) and polyethylene oxide (PEO) were dissolved in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) and nonwoven nanofiber membranes were prepared from the solution by electrospinning. PEO functioned as a cospinning polymer in the process to improve the spinnability of SPI. The ratio of SPI to PEO was varied and the rest spinning conditions remained unchanged. The morphology of the nanofiber membranes, SPI and PEO distribution and phase structure in the fiber, crystallization and interaction between SPI and PEO, thermal properties and wettability of the membranes were studied. The results showed that the diameter of most of the nanofibers was in the range of 200-300 nm. SPI and PEO showed high compatibility in the fiber and SPI was homogeneously dispersed at nanoscale. Crystallization of SPI and PEO in the fiber was significantly different from that of their pure forms. All the nanofiber membranes showed superhydrophilicity. These nanofiber membranes can find importance in filtration and biomedical applications.

The purpose of this research was to investigate the characteristics of catfish meatball with addition of isolate soy protein, carrageenan and STPP. The Research used a Randomized Block Design (RDB) with five addition of food additives (carrageenan 2%, STPP 0.3% and isolate soy protein 7%). Each treatment was replicated two times. The attributes observed were physical analysis (expressible moisture content, gel strength and folding test), chemical analysis (moisture content, protein content and fat content) and sensory analysis (aroma, taste and colour). The result showed the average value of expressible moisture content was ranged from 0.52%-1.72%, gel strength was 79-172 gf, folding test was 2-4, moisture content was 70.14%-75.41%, protein content was 3.98%-7.13% and fat content was 1.4%-2.16%. Sensory analysis for colour of meat ball was ranged from 3.88-4.56, taste 3.8 - 4.56 and aroma 3.88-4.44. Addition of food additives into catfish meatballs significantly affect (p&lt;0.05) to expressible moisture content, gel strength, protein content, aroma, taste and folding test. But did not significant affect about moisture content, fat content and colours. The chemical analysis showed kind of food additive that can replace the STPP is isolate soy protein. And according to physical analysis the food additive than can repace STPP is combination isolate soy protein and carrageenan as well on the analysis of sensory analysis.

Athletes as well as elderly or hospitalized patients use dietary protein supplementation to maintain or grow skeletal muscle. It is recognized that high quality protein is needed for muscle accretion, and can be obtained from both animal and plant-based sources. There is interest to understand whether these sources differ in their ability to maintain or stimulate muscle growth and function. In this study, baseline muscle performance was assessed in 50 adult Sprague-Dawley rats after which they were assigned to one of five semi-purified “Western” diets (n = 10/group) differing only in protein source, namely 19 kcal% protein from either milk protein isolate (MPI), whey protein isolate (WPI), soy protein isolate (SPI), soy protein concentrate (SPC) or enzyme-treated soy protein (SPE). The diets were fed for 8 weeks at which point muscle performance testing was repeated and tissues were collected for analysis. There was no significant difference in food consumption or body weights over time between the diet groups nor were there differences in terminal organ and muscle weights or in serum lipids, creatinine or myostatin. Compared with MPI-fed rats, rats fed WPI and SPC displayed a greater maximum rate of contraction using the in vivo measure of muscle performance (p<0.05) with increases ranging from 13.3–27.5% and 22.8–29.5%, respectively at 60, 80, 100 and 150 Hz. When the maximum force was normalized to body weight, SPC-fed rats displayed increased force compared to MPI (p<0.05), whereas when normalized to gastrocnemius weight, WPI-fed rats displayed increased force compared to MPI (p<0.05). There was no difference between groups using in situ muscle performance. In conclusion, soy protein consumption, in high-fat diet, resulted in muscle function comparable to whey protein and improved compared to milk protein. The benefits seen with soy or whey protein were independent of changes in muscle mass or fiber cross-sectional area.