Soy Isolate Research Articles

Cardioprotective Effect of Soy Protein on a High-Salt Diet in Cynomolgus Monkeys

Excessive salt intake is accompanied by the development of cardiovascular disorders, not always associated with an increase in blood pressure (BP). Given the cardioprotective effect of soy proteins in chronic kidney disease, the question arose of the possibility of leveling dietary interventions, in particular soy proteins, the damaging effect of a high-salt diet on the cardiovascular system. The aim of this work is to study the effect of long-term use of a diet high in NaCl and soy protein on myocardial remodeling and skin histomorphology in monkeys. The study was performed on male Javan macaques (Macaca fascicularis). The control group received a standard diet (2 g NaCl/kg feed). The second was a high-salt diet (8 g NaCl/kg feed), the third was a high-salt diet and SUPRO760 soy protein (200 g/kg feed). Echocardiography, registration of BP and heart rate were performed at baseline, after 4 and 12 months. After 12 months, a histological examination of the musculocutaneous flap was performed. In all animals, BP and heart rate did not change significantly during 12 months. In macaques on a high-salt diet, by the end of the study, deterioration in systolic and diastolic functions of the left ventricle (LV) was noted. In animals receiving additional soy protein, these changes leveled out. After 12 months, macaques fed soy protein had LV myocardial mass smaller and higher LV contractility than animals fed excess salt without soy protein. In monkeys on a high-salt diet, accumulation of collagen fibers in the hypodermis, hyalinization of the cytoplasm of capillary smooth muscle cells, perivascular and perineural edema of the reticular dermis were revealed. In animals treated with soy protein, skin capillary remodeling was less pronounced. Thus, high salt intake leads to adverse structural and functional disorders of the heart and blood vessels in cynomolgus monkeys, not associated with an increase in blood pressure. The inclusion of soy isolate in the diet reduces the negative effects of a high-salt diet on the cardiovascular system.

Deciphering the origin of total estrogenic activity of complex mixtures.

Identifying compounds with endocrine properties in food is getting increasingly important. Current chemical analysis methodology is mainly focused on the identification of known substances without bringing insight for biological activity. Recently, the application of bioassays has been promoted for their potential to detect unknown bioactive substances and to provide information on possible interactions between molecules. From the toxicological perspective, measuring endocrine activity cannot inform on endocrine disruption and/or health risks without sufficient knowledge on the nature of the responsible factors. The present study addresses a promising approach using High Performance Thin-Layer Chromatography (HPTLC) coupled to bioassays were analyzed using the Liquid Chromatography Mass-Spectrometry (LC-MS). The estrogen receptor activation was assessed using the transcription activation Estrogen Receptor Alpha Chemical Activated LUciferase gene eXpression assay (ERα- CALUX) and the HPTLC coupled to the Estrogen Screen Yeast assay (p-YES). Seven isoflavones were identified in the soy isolates. Estrogen receptor activation was assessed for both, the identified isoflavones and the soy isolates with ERα-CALUX test. Correlation between the soy isolates extracts and the identified isoflavones was shown. Moreover, p-YES revealed the presence of an estrogenic bioactive zone. Analysis of the bioactive zone through LCHRMS highlighted signals corresponding to several isoflavones already detected in the isolates as well as two additional ones. For all detected isoflavones, an estrogenic activity dose-response was established in both bioassays. Finally, genistein, daidzein, and naringenin were found as the most active substances. A concordance analysis integrating the analytical and bioassay data indicated that genistein and daidzein were the drivers of the estrogenic activity of these soy protein isolates. Altogether, these data suggest that the integration of HPTLC-bioassay together with chemical analysis is a powerful approach to characterize the endocrine activity of complex mixtures.

Sulfur-Containing Amino Acid Requirements of Growing Dogs

Three experiments were undertaken to establish the total sulfur-containing amino acid requirement of growing dogs. In experiment 1, six Labradors failed to grow normally when fed a soy isolate diet of 0.28% methionine with 0.18% cystine but grew well when the food was supplemented to either 0.57% or 0.74% methionine. In the next experiment, 12 Labradors and 21 beagles were fed the soy isolate diet containing either 0.39%, 0.57% or 0.74% methionine in the presence of 0.15% cystine for 12 weeks. Dogs fed 0.39% methionine had significantly lower body weights, nitrogen retentions, food intakes and feed efficiencies than their littermates fed the two higher levels. This diet provided 468 kcal metabolizable energy (ME) per 100 g, therefore a level of 116 mg total sulfur-containing amino acids (TSAA)/100 kcal ME was not adequate for growth. The lowest level found to be adequate was 0.57% methionine, or 154 mg TSAA/100 kcal ME, which is similar to the requirement of other young omnivores. A final experiment with a free amino acid diet indicated that a level of 117 mg TSAA/100 kcal ME while inadequate for Laboradors, may be sufficient for some beagles, highlighting differences between intact protein and free amino acid diets and suggesting possible breed differences.sulfur-containing amino acids methionine cystine growing dogs

The Development of Cookies from Modified Cassava Flour with Soy Isolate Protein (ISP) Substitution as an Alternative Supplementary Food for Pregnant Women with CED

Chronic Energy Deficiency (CED) in pregnant women can be caused by direct and indirect factors. The lack of energy and protein intake during pregnancy has been proven to increase the risk of CED in pregnant women. The purpose of this study was to analyze the differences in the acceptability and organoleptic properties of panelists, as well as the nutritional content of cookies based on Modified Cassava Flour with soy protein isolate substitution. The study was conducted as experimental research and a Completely Randomized Design was used. The research was conducted from June to December 2022. This study, which involved the production of Modified Cassava Flour cookies with the substitution of isolated soy protein flour and hedonic testing, was conducted at the Culinary Laboratory of Universitas Esa Unggul. The statistical test used to see the difference in nutrient content between the treatment levels of Cookies was Anova test and Ducan’s advanced test. The research results showed that there was a significant difference in hedonic quality in terms of taste and texture (p<0.05). There was a significant difference in hedonic among formulas in terms of taste, color, aroma, and texture (p<0.05). There was a significant difference in the content of carbohydrates, fats, and proteins among formulas (p<0.05). The conclusion of this study was that the best formula is F3, which can contribute to the energy and protein needed by pregnant women with CED.

The Development of Cookies from Modified Cassava Flour with Soy Isolate Protein (ISP) Substitution as an Alternative Supplementary Food for Pregnant Women with CED

The Development of Cookies from Modified Cassava Flour with Soy Isolate Protein (ISP) Substitution as an Alternative Supplementary Food for Pregnant Women with CED

Functional Properties of Brewer's Spent Grain Protein Isolate: The Missing Piece in the Plant Protein Portfolio.

Plant protein sources, as a part of developing sustainable food systems, are currently of interest globally. Brewer's spent grain (BSG) is the most plentiful by-product of the brewing industry, representing ~85% of the total side streams produced. Although nutritionally dense, there are very few methods of upcycling these materials. High in protein, BSG can serve as an ideal raw material for protein isolate production. This study details the nutritional and functional characteristics of BSG protein isolate, EverPro, and compares these with the technological performance of the current gold standard plant protein isolates, pea and soy. The compositional characteristics are determined, including amino acid analysis, protein solubility, and protein profile among others. Related physical properties are determined, including foaming characteristics, emulsifying properties, zeta potential, surface hydrophobicity, and rheological properties. Regarding nutrition, EverPro meets or exceeds the requirement of each essential amino acid per g protein, with the exception of lysine, while pea and soy are deficient in methionine and cysteine. EverPro has a similar protein content to the pea and soy isolates, but far exceeds them in terms of protein solubility, with a protein solubility of ~100% compared to 22% and 52% for pea and soy isolates, respectively. This increased solubility, in turn, affects other functional properties; EverPro displays the highest foaming capacity and exhibits low sedimentation activity, while also possessing minimal gelation properties and low emulsion stabilising activity when compared to pea and soy isolates. This study outlines the functional and nutritional properties of EverPro, a brewer's spent grain protein, in comparison to commercial plant protein isolates, indicating the potential for the inclusion of new, sustainable plant-based protein sources in human nutrition, in particular dairy alternative applications.

Effects of rice protein, soy isolate protein, and whey concentrate protein on the digestibility and physicochemical properties of extruded rice starch.

Protein, as the second major component in starchy foods, is crucial for its influence on the physicochemical properties and digestibility of starch. However, the effect of different sources of protein on starch digestibility is still unclear. In this paper, the effects of different sources of proteins (rice protein: RP, soybean isolate protein: SPI, and whey concentrate protein: WPC) on structural features, digestibility, and enzyme activity of extruded rice starch were investigated. The addition of all three proteins reduced the starch digestibility of extrudates. Native SPI and WPC suppressed amyloglucosidase activity, and all three proteins exhibited stronger amyloglucosidase inhibition when hydrolyzed. The rheological properties and Fourier transform infrared spectroscopy results revealed the exogenous proteins and starch interacted through non-covalent bonds and improved the ordered structures in the extrudates. The extrusion process also facilitated the formation of a V-type structure. The sum of SDS and RS content of extrudates was negatively correlated with the content of leached amylose and positively correlated with the ratio of 1047/1022cm-1 . These findings suggest that the inclusion of exogenous proteins during extrusion can affect starch digestibility through mechanisms such as the interaction with starch molecules, as well as the inhibition of amylase activity. PRACTICAL APPLICATION: This result indicated that the addition of protein during extrusion not only increased the nutritional value of the extrudate, but also decreased the starch digestibility. Extrusion technology can efficiently produce extruded products with protein, expanding further applications of protein in food and providing new healthy staple food options for special populations, such as diabetic and overweight people.

Adaptation of the rapid near-infrared (NIR) spectroscopy technique to determine the mass fraction of protein and moisture in gluten-free bakery products

Analysis of protein in food products is typically performed using a time-consuming and labor-intensive Kjeldahl method. The NIR method is allowed to determine the mass fraction of not only protein, but also moisture, fat, and sugar in one sample within 2 min. The NIR method is indirect; therefore, appropriate calibration models should be developed for each group of analyzed products. We performed a series of laboratory baking tests for gluten-free bakery products; the protein content in the products varied and depended on the ingredients included into the formula: rice, buckwheat and corn flour, starch and soy isolate. Continuous spectra were recorded using a NIR analyzer that operates in the wavelength range from 1400 to 2500 nm. It was shown that after validation for a specific device, the developed calibration models yield the root-mean-square deviation of 0.29 when determining the protein mass fraction and that of 0.46 when determining the moisture mass fraction.

Characterization, stability and antioxidant activity of curcumin nanocomplexes with soy protein isolate and pectin

Curcumin (Cur) has antioxidant, anti-inflammatory and other biological activities, but its poor stability, low water solubility and other defects limit the application. Herein, Cur was nanocomposited with soy isolate protein (SPI) and pectin (PE) for the first time and its characterization, bioavailability and antioxidant activity were discussed. The optimal encapsulation process of SPI-Cur-PE was as follow: the addition amount of PE was 4 mg, Cur was 0.6 mg and at pH of 7. It was observed by SEM that SPI-Cur-PE were partially aggregated. The average particle size of SPI-Cur-PE was 210.1 nm and the zeta potential was −31.99 mV. Through XRD, FT-IR and DSC analysis, the SPI-Cur-PE was formed through hydrophobic interaction and electrostatic interaction. The SPI-Cur-PE released more slowly in simulated gastrointestinal treatment and displayed higher photostability and thermal stability. SPI-Cur-PE, SPI-Cur and free Cur had scavenging activities for 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radicals.

The use of protein and other biologically active substances in feeding honey bees

In the presented work, the issue of the use of protein feeds with biologically active additives to increase the nutritional value of artificial feeds is considered. This approach makes it possible to introduce various sources of protein, amino acids, vitamins into the bee feed, as well as enzymes to relieve the load on the bee's body for digesting substances, growth-stimulating drugs based on organic acids, etc. Experiments conducted in 2018 on feeding candi bees to the composition, which included isolated soy protein, apple cider vinegar, showed the following results. In the control group, bees actively ate top dressing, however, in some bee families, the presence of yellowish-brown liquid excrement was noted, which indicated the presence of nosematosis. Bees from the experimental groups also actively consumed candi, but with the addition of soy isolate and apple cider vinegar, while the frames were clean, there were no spots of diarrhea and podmore. The Federal Scientific Center of Beekeeping is conducting research on the development of various formulations of feedings for honey bees. For the approbation of carbohydrate feeds with the inclusion of enzyme compositions in them, appropriate studies were conducted. 3 experimental groups were formed on the principle of pairs of analogues. The control group received sugar syrup, the first – inverted syrup, and the second group - inverted syrup enriched with flower pollen fermentolysate. Feeding of the presented feedings had an impact on the flight activity of bee colonies. Thus, the control group had the lowest flight activity. In the experimental groups, the flight activity of bee colonies was higher. In addition to the flight activity of bee colonies, the average daily egg production of queens was studied. In the control group, the average daily egg production of the uterus was at the level of 550 eggs. In the first experimental group, the uterine egg production was 9.10% higher compared to the control, and in the second group by 20.0%.

Amino acid and fatty acid compositions of texturized vegetable proteins

Texturized proteins are the main ingredients of meat analogues. This paper evaluated the amino acid and the fatty acid compositions of texturized proteins produced by pea isolates, soy isolates, or dry-fractionated pea proteins, all combined with oat proteins. The nutritional composition was significantly affected by the protein sources. All the texturized proteins had a balanced amino acid profile, complying with the recommendations by FAO/WHO, except for the sulfur amino acids. The fatty acid profile showed the predominance of the polyunsaturated fraction, which was the highest in the dry-fractionated pea mixes. The trans-isomers’ content was lower than 0.5%.

Pemanfaatan Tepung Pisang-Singkong Sebagai Alternatif Pengganti Tepung Terigu Pada Pembuatan Mie Dengan Penambahan Putih Telur atau Isolat Kedelai

In general, wheat flour noodles have a chewy and elastic texture, due to the presence of amylose, amylopectin and gluten proteins. People with celiac disease are gluten intolerant, so to enjoy noodles like people in general, an alternative gluten-free flour is needed to replace wheat flour, one of which is banana-cassava flour. To increase the nutritional value and texture of noodles, such as using wheat flour, egg white protein or soybean isolate and xanthan gum or ash water are added. This study aims to determine the effect of adding egg white protein or soybean isolate and the effect of xanthan gum or water ash on banana-cassava flour noodles on the physicochemical and sensory profiles. The research stages are the production of banana-cassava flour noodles, physicochemical profile analysis includes chemical profiles (moisture content, ash content and protein content), physical profile (optimum cooking time, swelling index, cooking loss and water absorption) and gluten content and sensory testing. The results of the analysis showed that the chemical profile of banana-cassava flour noodles met the wet noodle quality standard set by SNI 2987-2015, while the ash content was higher than the quality standard. Some good formulas, the water and ash content in the addition of egg white and xanthan gum (PTX) were around 4.95% and 1.80%, respectively, while the protein content in the addition of soybean isolate and water ash (PKA) was 12.89%. . Physical profiles for cooking time and swelling index on the addition of soybean isolate and water ash (PKA) were 2.50 minutes and 186.10%, respectively, cooking loss on the addition of egg white and xanthan gum (PTX) was 5.85%, while the water absorption in the addition of egg white and water ash (PTA) was 73.95%. Gluten levels in the addition of soybean isolates and water ash (PKA) ranged from 1.10%. The physicochemical profile of banana-cassava flour noodles was influenced by the type of protein and the best formula for gluten-free noodles was the addition of soy isolate. While the ash content, swelling index, water absorption, and gluten content are influenced by the type of agglomerate, and the best formulation for gluten-free noodles is the addition of ash water. The results of the organoleptic test obtained an average score of 4 (out of a scale of 5) on the attributes of color, aroma, taste, texture, and overall preference for the banana-cassava flour noodle sample.

Effects of different proteins and maltodextrin combinations as wall material on the characteristics of Cornus officinalis flavonoids microcapsules.

The flavonoids in Cornus officinalis (CO) have various pharmacological activities, however, the flavonoid instability limits its application in food and pharmaceutical industries. In this study, Cornus officinalis flavonoid (COF) microcapsules were prepared by using a combination of whey isolate protein (WPI), soy isolate protein (SPI), gelatin (GE), and maltodextrin (MD) as wall materials, respectively. Meanwhile, the encapsulation efficiency, solubility, color, particle size, thermal stability and microstructure as well as the antioxidant capacity of microcapsules were assessed. When the protein/MD ratio was 3:7, three kinds of combined wall materials realized high encapsulation efficiency (96.32–98.24%) and water solubility index (89.20–90.10%). Compared with other wall material combinations, the microcapsules with WPI-MD wall ratio at 3:7 had lower particle size (7.17 μm), lower moisture content (6.13%), higher encapsulation efficiency (98.24%), better water solubility index (90.1%), higher thermal stability (86.00°C), brightness L* (67.84) and higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging capacity (6.98 mgVc/g), and better flowability. Results suggested that WPI and MD could be better wall materials applied in encapsulating COF.

Effects of different combinations of probiotics on rheology, microstructure, and moisture distribution of soy materials-based yogurt.

The effects of different probiotics on the texture, rheological properties, microstructure, and water distribution of yogurt fermented with soy powder, soy isolate protein powder, soy umbilical powder, and soy whey as the main raw materials were studied. The soy materials-based yogurt fermented by Danisco mixed probiotic reached the end of fermentation after 4 h, which significantly shortened the fermentation time compared with other probiotic combinations. The fermentation with Danisco mixed probiotic and Kefir mixed probiotic respectively resulted in good texture and a denser and more homogeneous microstructure, which was consistent with the sensory evaluation results. Both fermentations had a high water holding capacity of 90.92% and 78.30%, respectively, in agreement with the results of moisture distribution tests. However, the elastic and viscous behaviors were weaker at certain shear frequency. This study achieved a high value-added utilization of soy whey and the development of a new soy materials-based yogurt that met the consumption needs of people with lactose intolerance and high cholesterol. PRACTICAL APPLICATION: In this study, high value-added utilization of soy whey was realized, which solved the problems of resource waste and environmental pollution. Meanwhile, the research and development of soy materials-based yogurt provided another nutritional and healthy consumption demand for lactose intolerant people.

Efficient production and biochemical characterization of a thermostable carboxypeptidase from Bacillus megaterium and its application on flavor improvement of soy isolate protein hydrolysates

Efficient production and biochemical characterization of a thermostable carboxypeptidase from Bacillus megaterium and its application on flavor improvement of soy isolate protein hydrolysates

Dietary Soy Prevents Alcohol-Mediated Neurocognitive Dysfunction and Associated Impairments in Brain Insulin Pathway Signaling in an Adolescent Rat Model.

Background: Alcohol-related brain degeneration is linked to cognitive-motor deficits and impaired signaling through insulin/insulin-like growth factor type 1 (IGF-1)-Akt pathways that regulate cell survival, plasticity, metabolism, and homeostasis. In addition, ethanol inhibits Aspartyl-asparaginyl-β-hydroxylase (ASPH), a downstream target of insulin/IGF-1-Akt signaling and an activator of Notch networks. Previous studies have suggested that early treatment with insulin sensitizers or dietary soy could reduce or prevent the long-term adverse effects of chronic ethanol feeding. Objective: The goal of this study was to assess the effects of substituting soy isolate for casein to prevent or reduce ethanol’s adverse effects on brain structure and function. Methods: Young adolescent male and female Long Evans were used in a 4-way model as follows: Control + Casein; Ethanol + Casein; Control + Soy; Ethanol + Soy; Control = 0% ethanol; Ethanol = 26% ethanol (caloric). Rats were fed isocaloric diets from 4 to 11 weeks of age. During the final experimental week, the Morris Water maze test was used to assess spatial learning (4 consecutive days), after which the brains were harvested to measure the temporal lobe expression of the total phospho-Akt pathway and downstream target proteins using multiplex bead-based enzyme-linked immunosorbent assays (ELISAs) and duplex ELISAs. Results: Ethanol inhibited spatial learning and reduced brain weight, insulin signaling through Akt, and the expression of ASPH when standard casein was provided as the protein source. The substitution of soy isolate for casein largely abrogated the adverse effects of chronic ethanol feeding. In contrast, Notch signaling protein expression was minimally altered by ethanol or soy isolate. Conclusions: These novel findings suggest that the insulin sensitizer properties of soy isolate may prevent some of the adverse effects that chronic ethanol exposure has on neurobehavioral function and insulin-regulated metabolic pathways in adolescent brains.

The impact of the protein-carbohydrate ratio in animal feed and the initial insect population density on the development of the red flour beetle, Tribolium castaneum

Progeny numbers and life parameters of Tribolium castaneum reared on a range of different animal feeds which varied in their protein-carbohydrate ratios (corn starch; corn feed flour; wheat bran; soybean meal; corn gluten; soy protein concentrate and soy protein isolate), four initial (population) densities (1, 2, 5 and 10 insect pairs) were evaluated. Adult insects were kept for seven days on a range of different diets to feed and oviposit before they were removed. After removing the adults, the emerging progeny were examined. The study found T. castaneum offspring could not develop on a carbohydrate-rich diet (corn starch) and on protein-rich diets (corn gluten, soy protein concentrate and soy protein isolate). Soy isolate showed a high, possibly insecticidal effect on parents. The fastest total development (egg to adult) (23.25–23.88 days, depending on the initial density), the highest offspring number (111.63–324.13) and the highest offspring body mass (1.38–1.73 mg) were recorded in wheat bran, while the slowest egg to adult development (35.13–37.88 days), the lowest offspring number (25–29) and the lowest offspring mass (1.04–1.48 mg) were recorded in soybean meal. The higher initial densities caused the eclosion period to be prolonged, reductions in female productivity and in offspring body mass on all diets. Initial density interacted differently with diet type in terms of offspring number, so as the density rose, the number of offspring in wheat bran and corn feed flour increased, while in soybean meal it remained low at all initial densities. This research gives us a better insight into the development of T. castaneum in animal feed that can help us to improve existing pest management in a way of finding a better solution to store products based on their susceptibility to this storage pest.

Serum cobalamin in children with moderate acute malnutrition in Burkina Faso: Secondary analysis of a randomized trial.

Among children with moderate acute malnutrition (MAM) the level of serum cobalamin (SC) and effect of food supplements are unknown. We aimed to assess prevalence and correlates of low SC in children with MAM, associations with hemoglobin and development, and effects of food supplements on SC. A randomized 2 × 2 × 3 factorial trial was conducted in Burkina Faso. Children aged 6 to 23 months with MAM received 500 kcal/d as lipid-based nutrient supplement (LNS) or corn-soy blend (CSB), containing dehulled soy (DS) or soy isolate (SI) and 0%, 20%, or 50% of total protein from milk for 3 months. Randomization resulted in baseline equivalence between intervention groups. Data on hemoglobin and development were available at baseline. SC was available at baseline and after 3 and 6 months. SC was available from 1,192 (74.1%) of 1,609 children at baseline. The mean (±SD) age was 12.6 (±5.0) months, and 54% were females. Low mid-upper arm circumference (MUAC; <125 mm) was found in 80.4% (958) of the children and low weight-for-length z-score (WLZ; <-2) in 70.6% (841). Stunting was seen in 38.2% (456). Only 5.9% were not breastfed. Median (IQR) SC was 188 (137; 259) pmol/L. Two-thirds had SC ≤222 pmol/L, which was associated with lower hemoglobin. After age and sex adjustments, very low SC (<112 pmol/L) was associated with 0.21 (95% CI: 0.01; 0.41, p = 0.04) and 0.24 (95% CI: 0.06; 0.42, p = 0.01) z-score lower fine and gross motor development, respectively. SC data were available from 1,330 (85.9%) of 1,548 children followed up after 3 months and 398 (26.5%) of the 1,503 children after 6 months. Based on tobit regression, accounting for left censored data, and adjustments for correlates of missing data, the mean (95% CI) increments in SC from baseline to the 3- and 6-month follow-up were 72 (65; 79, p < 0.001) and 26 (16; 37, p < 0.001) pmol/L, respectively. The changes were similar among the 310 children with SC data at all 3 time points. Yet, the increase was 39 (20; 57, p < 0.001) pmol/L larger in children given LNS compared to CSB if based on SI (interaction, p < 0.001). No effect of milk was found. Four children died, and no child developed an allergic reaction to supplements. The main limitation of this study was that only SC was available as a marker of status and was missing from a quarter of the children. Low SC is prevalent among children with MAM and may contribute to impaired erythropoiesis and child development. The SC increase during supplementation was inadequate. The bioavailability and adequacy of cobalamin in food supplements should be reconsidered. ISRCTN Registry ISRCTN42569496.

Preparation and characterization of phytosterol-loaded microcapsules based on the complex coacervation

The study developed the microcapsules by complex coacervation with soybean protein isolate (SPI) and pectin to be used for phytosterol (PS) encapsulation. Fluorescence analysis suggested the formation of SPI/pectin complex coacervates. Fourier-transform infrared further confirmed the electrostatic attraction between SPI and pectin. X-ray diffraction and differential scanning calorimetry analysis revealed that pectin molecule chains were closely absorbed by SPI molecules during coacervation. PS was dispersed into conjugated linoleic acid and used as the core materials of the microcapsules. The microcapsules that were made at pH 2.5 with SPI/pectin mixing ratio of 5:1 exhibited the highest encapsulation efficiency of PS. Confocal laser scanning microscopy image presented that the oil droplets were encapsulated by SPI/pectin coacervates. Scanning electron microscopy images showed the microcapsules with a rough and irregular shape and no obvious cracks or slits on the surface. Meanwhile, core materials showed favorable oxidation stability and gastric stability after encapsulation. However, after 7 h digestion in simulated intestinal fluid, about 70% of the encapsulated PS was released in sustained release mode. These results could be useful for designing an ideal carrier to deliver PS by complex coacervation using protein and polysaccharides. • Pectin was capable of absorbing onto the surface of soy isolate protein via electrostatic interaction to form microcapsule. • The microcapsule exhibited a favorable encapsulation efficiency of PS. • The microcapsules showed a sustained release of phytosterol in stimulated intestinal fluid.

A novel ELISA test to detect soy in highly processed foods

Soy allergens detection is challenging when they are in trace amounts in foods, especially when foods are subjected to heat treatment, after which the target allergen maybe modified. Two ELISA formats, sandwich and indirect competitive, were developed using rabbit polyclonal antibodies against heat-denatured glycinin as the target protein. Sandwich format showed less cross-reactions and better sensitivity than the competitive format. The performance of both formats was tested using three model foods incurred with soy proteins. Results showed that the recovery decreased with the increase of heat treatment intensity applied to foods. Sandwich format could detect amounts of added soy isolate of 10 μg/g in sausage (pasteurized), 100 μg/g in bread (baked) and 1000 μg/g in pâté (sterilized); whereas competitive format only detected 2500 μg/g in sausage and 10000 μg/g in bread, and no glycinin was detected in pâté samples. A prototype of the sandwich ELISA was in-house validated giving acceptable results of precision and robustness. Recovery of model foods spiked with heat-denatured glycinin after processing ranged between 88 % and 149 %. In a survey of retail foods, the sandwich ELISA could differentiate most of the commercial foods with soy or derivatives declared or not in the ingredient list and could detect soy in highly processed foods.