Soy Yogurt Research Articles

Comparative study of the synbiotic effect of inulin and fructooligosaccharide with probiotics with regard to the various properties of fermented soy milk

Numerous combinations of probiotics were explored to find the suitable starter culture for the development of synbiotic soy yoghurt which can give good product characteristics and may be acceptable among consumers. Prebiotics (fructooligosaccharide (FOS) and inulin) were supplemented in an attempt to reduce the after-taste of soymilk, improve acidification profile and growth of probiotics. The addition of prebiotics in soy milk significantly enhanced the acidification rate (10.82 to 23.00 × 10-3 pH units/min) and condensed the fermentation completion time. FOS-supplemented fermented soy milk showed better acidification and post-acidification profile as compared to inulin supplemented samples. The Streptococcus salivarius subsp. thermophilus (ST) - Lactobacillus acidophilus (LA) with FOS gave the better textural properties with firmer gel (350.10), lower adhesiveness (-93.10) and springiness (0.92), higher gumminess (164.50) and average cohesiveness (0.47). FOS-supplemented ST-LA-fermented samples showed good gel characteristics with higher elastic modulus (1672.39 Pa), viscous modulus (416.41 Pa), complex modulus (1723.53 Pa), lower tan δ (14) and higher overall acceptability scores (7.40) on a 9-point hedonic scale. Developed synbiotic soy fermented milk showed more than the 9 log cfu/ml count throughout storage which is required for probiotic functional food.

การพัฒนาโยเกิร์ตพร้อมดื่มจากนมถั่วเหลืองเสริมควินัวและไซเลียมฮัสค์

การพัฒนาโยเกิร์ตพร้อมดื่มจากนมถั่วเหลืองเสริมควินัวและไซเลียมฮัสค์

Assessment of Knowledge and Consumption Patterns of Soybean, Moringa Oleifera, Aloe Vera and Other Agro-Resources: The Case of the Elderly and Pregnant/Nursing Women in Lome, Togo

Purpose: To assess how soybean products and other agro-resources are known and consumed by some vulnerable populations in Lome (Togo). Methods: A cross sectional study was conducted from March to April 2015 among people aged 50 years and over attending two Pension Fund departments and pregnant and nursing women attending Bè Hospital in Lome. Data were collected using a pre-tested face-to-face questionnaire. Participants were surveyed about their knowledge and consumption habits of soybean, Moringa oleifera, Aloe vera products and other agro-resources. Results: A total of 847 respondents were included in the study with 426 pregnant/nursing women and 421 people aged 50 years and over. The majority of respondents were married (39.5%) and 45.3% of the elderly people were widowed. At least nine over ten respondents (96%) knew soybean products and 76.8% of them reported a lifetime consumption of soybean products. The available and most consumed agro-resources included tofu (82.7%), moringa leaves (87.2%) and soy flour (29.7%). The least consumed products were soymilk, soy yogurt and moringa juice. Respondents also reported using moringa tea and soap, as well as Aloe vera juice and toothpaste. Conclusion: Soybean products and other agricultural resources are well known and consumed by people living in Lome. Data on actual food intake is useful to public health professionals and food safety risk assessors. It is important to inform the public at large of the recognized benefits of some foods that will provide solutions to their health problems.

Steady and dynamic rheological behaviour of frozen soy yogurt mix affected by resistant starch and β-glucan

ABSTRACTThe present study investigated the effect of resistant starch (0, 1%, 2%) and β-glucan (0, 1%, 2%) on the steady and dynamic rheological properties of frozen soy yogurt mixes. The results showed that addition of fibres to the mix caused an enhancement of pseudoplasticity. The power law model was the best model to fit with data. The lowest and the highest of hysteresis loop area belonged to sample containing 1% β-glucan and 2% resistant starch, respectively. Dynamic rheology results showed that storage modulus (G’) and loss modulus (G”) increased within the frequency range of 0.01–100 Hz. The loss tangent (tan δ) of all samples was above 1, indicating liquid viscoelastic behaviour. Resistant starch at concentration of 2% as compared to β-glucan was a better choice to modify the rheological properties of frozen soy yogurt mixes.

Effect of Fruit Lemon Juice Addition to The Content of Protein, Fat, Lactose and Probiotic on Soy Yogurt

This research aimed to determine the effect of lemon juice to the content of protein, fat, lactose and probiotics, in beverages soy yogurt. Soy yogurt which produced was a multifunction yogurt drink high levels of antioxidants, contains probiotics and can be used by people with lactose intolerance. The research method includes the production of fortified soy yogurt with lemon juice, were made with the ratio between the lemon juice and soy yogurt were 0:10 (L0); 1:9 (L1); 2:8 (L2); and 3:7 (L3). Analysis of the results include the content of protein by Kjeldahl method, the content of fat by Soxhletasi method, lactose test by Luff Schoorls method and content of probiotics with total plate count enumeration techniques. The results showed fortified yogurt had a protein content greater than before fortification (L3 > L2 > L1 > L0); The fat content L0 > L1 > L2 > L3. Fortified yogurt lactose content is smaller than before fortification (L0 > L1 > L2 > L3). The content of probiotic yogurt fortified L1 > L3 > L2. From this research can be concluded that the yoghurt fortified (L3) is the best, with the highest protein content, low fat, low lactose than L1 and L2, and had probiotics content. It is advised to conduct further research on the expired time of fortified soy yogurt products

EFFECTS OF DIFFERENT METHODS OF DRYING ON ANTIOXIDANT AND MICROSCOPIC CHARACTERISTICS OF Spirullina platensis ENRICHED SOY YOGURT

Spirulina platensis was discussed as an active compound with regard to the combined effects with soy yogurt in dried food formulation. Drying influenced the microscopic, and antioxidant properties of soy yogurts, and could be used to create new functionalities. The present investigation aimed to convert Spirulina platensis enriched soy yogurts to powder form by different drying methodologies such as air, vacuum, freeze, and microwave drying and evaluate the microstructure and antioxidant activity of the powders obtained. Antioxidant activities were assayed by using polyphenol assay, estimation of carotenoid content, DPPH radical scavenging activity and FRAP assay. Structural changes were analyzed using a scanning electron microscope and an X-ray diffraction pattern. Freeze-drying was produced significantly high quality dried Spirulina platensis enriched soy yogurt, i.e. better functional and antioxidant properties (Polyphenol 0.211 Gallic acid equivalent. g-1, p

OPTIMIZATION OF INGREDIENT AND PROCESSING PARAMETER FOR THE PRODUCTION OF Spirulina platensis INCORPORATED SOY YOGURT USING RESPONSE SURFACE METHODOLOGY

In this study, response surface methodology (RSM) was employed to optimize the ingredient formulation and processing parameters of Spirulina platensis incorporated soy yogurt production such as temperature, time, and amount of Spirulina platensis on the sensory evaluation responses on 9 point Hedonic rating. Besides, the physico–chemical properties such as pH, titratable acidity, viscosity and penetration of the Spirulina platensis incorporated soy yogurt were also analysed. The analyses show that the Spirulina platensis incorporated soy yogurts have a pH from 3.43 to 5.55, acidity from 0.64 to 2.32 (%), Brookfield viscosity from 752 to 903 Centipoise and penetration from 362 to 432 1/10th mm at 25°C during the optimization process. From the analysis of variance, the R2 of all response variables is more than 0.77 that indicates that a high proportion of variability was explained by the model. Based on the response surface 3D plot of the sensory evaluation, the optimum acceptability of the Spirulina platensis incorporated soy yogurt processing parameter are at temperature of 40°C, 12 h of the fermentation duration and 0.80% (w/w) of the Spirulina platensis.

국내산 대두의 불용성 물질을 포함한 두유 요구르트의 발효 및 품질 특성

The objective of this research was to determine the fermentation and quality properties of soy yogurt incorporating insoluble components fermented with Streptococcus thermophilus (S. thermophilus) and Lactobacillus bulgaricus (L. bulgaricus) for 24h. Boiled soybeans were ground and reconstituted into equivalent total solids (18%). After soymilk was homogenized with sugar, it was pasteurized in a water bath at 90℃ for 30 min. Two kinds of lactic acid bacteria were inoculated into two types of soymilk after cooling down 40∼45℃ and fermentation at 37℃ for 24h. Titrable acidity, pH, viscosity, sugar content, and number of viable cells were determined in triplicate. Soy yogurt fermented with L. bulgaricus did not reach pH 4.5, where as S. thermophilus was considered good for achieving pH 4.08 and titratable acidity of 2.27% for 24 h. Soy yogurt fermented with S. thermophilus had a higher viscosity and lower sugar contents than that fermented with L. bulgaricusas incubation time increased. Total viable count was 1.80 × 1010 CFU/mL on S. thermophilus and 2.16 × 108 CFU/mL on L. bulgaricus after 24 h at 37℃. However, there was no significant difference in sensory intensities and preference between the two samples. As a result, S. thermophilus was identified as a better culture than L. bulgaricus for the manufacture of soy yogurt incorporating insoluble components.

Hypolipidemic effects of soy yogurt fortified with antioxidant rich vegetable oil on albino mice fed high cholesterol diet

Soy yogurt containing specific antioxidants such as oryzanol by adding rice bran oil and specific lignans such as sesamin and sesamolin from sesame oil that exhibited lipid peroxidation was developed with the use of mixtures of yogurt starter culture and edible soy flour (meal) instead of using whole soy bean seed. The aim of this study was to investigate the cholesterol-lowering properties of rice bran oil and sesame oil containing soy yogurt. In order to examine the effects on hypercholesterolemia in Swiss albino male mice with administration of 1.25% cholesterol, soy yogurt (control) and rice bran oil-sesame oil incorporated soy yogurt with doses of 3.0 and 2.5 g kg-1 body weight was given orally daily for 8 weeks respectively. Changes in the content of functional components (antioxidants, lipid profile and proximate composition) and microbiological characteristics (microbial cell counts) of soy yogurt (control) and rice bran oil-sesame oil incorporated soy yogurt were also examined. In hypercholesterolemia, mice fed with rice bran oil-sesame oil incorporated soy yogurt showed a favourable effect in reducing blood cholesterol, triglycerides and LDL-c cholesterol, caused a significant decrease in lowering the atherogenic index when compared with regular chow diet only. In hypercholesterolemia, consumption of bio-fortified soy yogurt significantly improved the HDL-c in serum, super oxide dismutase and catalase level in liver homogenate and significantly declined the serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, acid phosphatase and gamma glutamyl transferase activities. Treatment with rice bran oil-sesame oil incorporated soy yogurt with yogurt starter culture ameliorates lipid peroxidation in liver. The results indicated that the addition of oil(s) improved physicochemical and microbiological characteristics of soy yogurt and enabled a novel technological approach for making antioxidants and lignans fortified soy yogurt which had anti-atherogenic, hypolipidemic and improved liver function effects.

Production of Probiotic Soy Yoghurt–A Dairy Product for the Future

Probiotic soy yoghurt is a fermented product obtained from inoculation of probiotic yoghurt starter to soymilk. The aim of this study was to prepare probiotic soy yoghurt and plain soy yoghurt using a simple technique and compare the physico-chemical parameters of the products. It was observed that though there is not much difference observed in total ash, casein, total fat, copper, calcium, chloride and phosphorus level in both the samples, a significant difference was observed in the pH, protein, total solids, albumin and magnesium content. As far as physical properties are concerned, better whey drainage and water holding capacity were observed in probiotic samples than plain samples.

Quality characteristics of soy yogurt produced using proteases and mixed microbial consortia

In this study, we examined the quality characteristics of soy yogurts produced using two proteases(Flavourzyme® and Neutrase®) and the mixed microbial consortia of Lactobacillus bulgaricus and Streptococcus thermophilus (two-mixed) and Lactobacillus acidophilus, Bifidobacterium lactis, and S. thermophilus (three-mixed). The viscosity was the highest in the untreated yogurt. Among the proteolyzed samples, those treated with Flavourzyme® for 20 min showed the highest viscosity, whereas the samples treated with Neutrase® for 30 min and cultured with three-mixed microbial consortia showed the lowest viscosity. The numbers of viable bacteria in the Flavourzyme®-treated samples were slightly greater than those in the Neutrase®-treated samples. The number of viable bacteria increased as hydrolysis time increased. The organic acid content was higher in the three-mixed group than in the two-mixed group, and it was higher in the Flavourzyme®-treated samples than in the Neutrase®-treated samples. Among the Flavourzyme®-treated samples, the three-mixed group showed higher total free amino acid content than the two-mixed group. In contrast, among the Neutrase®-treated samples, those cultured with both mixed microbial consortia produced the similar amounts of free amino acids. The above results showed that proteolytic treatment promoted the growth of lactic acid-producing bacteria. Soy yogurts produced using Flavourzyme® and three-mixed microbial consortia were thought to be more desirable because of more organic acids and free amino acids than those produced using Neutrase® and two-mixed microbial consortia.

Effect of resistant starch and aging conditions on the physicochemical properties of frozen soy yogurt.

The present study investigated the effects of resistant starch concentration (0, 1, 2%), aging time (2, 13, 24h) and aging temperature (2, 4, 6°C) on the physicochemical properties of frozen soy yogurt. The results showed that resistant starch increased viscosity because of its water binding properties. Resistant starch also increased foam stability, fat destabilization, and hardness, but it decreased overrun and meltdown rate. Viscosity, hardness and fat destabilization increased as aging time increased. An increase in aging temperature decreased viscosity, overrun, hardness and fat destabilization of frozen yoghurt, but increased the meltdown rate.

Applications ofBacillus subtilisas an important bacterium in medical sciences and human life

Probiotics are a group of organisms without pathogenic effects. These organisms are known as creatures that have advantageous effects on the safety of their host. The most common kinds of microbes that are used as probiotics are Lactic acid bacteria (LAB) and bifidobacteria; but several yeasts and bacteria may also be used. In this study, we have reviewed the benefits of Bacillus subtilis as a probiotic bacterium. The journals published from 1989 to 2012, have been used in the study. At the start of the twentieth century, these organisms were thought to usefully affect their host by ameliorating the intestinal bacterial equilibrium, and therefore, injuncting the toxin-producing organisms and pathogens. Nowadays, particular health effects are being examined and documented, including the prohibition and remedy of pathogen-induced diarrhea, palliation of severe intestinal inflammatory diseases, urogenital infections, and atopic cases. Probiotics are generally used as a division of foods with particularly added active live cultures, including soy yogurt, yogurt or as dietary supplements. B. subtilis strains produce antibiotics and enzymes that are important in both medical and industrial sciences.

Characterization and Comparison of Soy Milk and Buffalo Milk Based Synbiotic Product

Today consumers prefer foods that not only provide basic nutrition but also contain compounds that confer health benefits. Among the functional food, synbiotic products are showing a promising future. Soy based synbiotic products using different probiotics: A1B and MgA (lactobacillus strains) and L.rhamanosus ATCC 9595 and prebiotics: lactulose, sunfibre and inulin were prepared and its antiradical activities along with other characteristics were studied. The study also aimed to determine the most suitable prebiotics and probiotics. Furthermore, the prebiotics and the organisms were also cultured in buffalo milk to compare its properties with synbiotic soy yoghurt. Synbiotic soy yoghurt showed highest anti-radical activity with % inhibition at the range of 41-45 % and the one with probiotic L.rhamnosus and prebiotic inulin was found to be the most suitable product. DOI: http://dx.doi.org/10.3126/jfstn.v8i0.11737 J. Food Sci. Technol. Nepal, Vol. 8 (23-29), 2013

Optimization of the prebiotic & probiotic concentration and incubation temperature for the preparation of synbiotic soy yoghurt using response surface methodology

This research work aimed to develop synbiotic soy yoghurt with improved product characteristics and consumer acceptability. Response surface methodology was employed to investigate the combined effects of FOS concentration (2–10 % w/v), ST-LA inoculum size (2–4% v/v), and fermentation temperature (37–42 °C) on fermentation time (h), hardness (g), whey separation (%) and overall acceptability on 9 point hedonic scale of synbiotic soy yoghurt. A second-order polynomial response surface equation and response surface graph revealed that the experimental variables significantly affected the studied responses. Determination coefficients (R2) were higher than 87% which showed that the developed models were well fitted to the experimental data. Synbiotic soy yoghurt was prepared using optimized FOS concentration (8.1% w/v), culture combination ST-LA with inoculum size 3.6% v/v, 1:1 ratio and incubated at temperature 41 °C for 5.25 h. The optimized product was well set with very less whey separation (1.14%). The developed product showed good nutritional, textual and sensory characteristics.

Optimization of Fermentation Conditions for Probiotic Soy Yoghurt Using Response Surface Methodology

Response surface methodology was adopted in order to optimize the fermentation process conditions for the development of probiotic soy yoghurt utilizing single probiotic culture i.e., Streptococcus faecalis, without using any additives. The experiments were designed following central composite rotatable design with three independent variables i.e., inoculation concentration (1–3% v/v), incubation temperature (37–43C) and incubation time (12–15 h). Lack-of-fit tests were insignificant and determination coefficients were high ranging from 79.59 to 95.11%, except in the case of syneresis (53.54%). The results revealed that inoculum concentration, incubation temperature and incubation time influence the physicochemical properties of soy yoghurt. The optimized conditions were as follows: inoculum concentration, 1.78%; incubation temperature, 40.53C (41C); and incubation time, 16 h, for the preparation of probiotic soy yoghurt with 80.7% desirability. Practical Applications The present paper describes the optimized process of soy yoghurt development. Single probiotic culture was used to develop probiotic soy yoghurt. As single culture is used, the product of consistent quality could be obtained. Response surface methodology has been utilized for process optimization; the obtained model could be used to find out the optimum parameters for any factor combination. The information provided could be useful for large-scale development of probiotic soy yoghurt.

Physico-chemical, sensory and microbiological characteristics of plain yoghurt from bambara groundnut (Vigna subterranea) and soybeans (Glycine max).

Physico-chemical, sensory and microbiological characteristics of plain yoghurt from bambara groundnut and soybean milks were studied. Milks were prepared from bambara and soybean and then fermented using Lactobacillus delbruieckii subspp. bulgaricus and Streptococcus salivarus subspp. thermophilus to produce yoghurt. The yoghurts were stored at 7°C and 27°C for 9days and their quality monitored. Results showed that pH of soy and bambara yoghurts decreased during the storage period for both storage temperatures. This decrease in pH was accompanied by simultaneous increase in titratable acidity. Total solids and apparent viscosities of soy and bambara yoghurts increased at 7°C, but decreased at 27°C during storage period. Bambara yoghurt received higher sensory acceptability than soy yoghurt. Predominant microorganisms in the stored yoghurts were lactic acid bacteria (LAB). The LAB count in the yoghurts stored at 7°C decreased but increased at 27°C during the storage period. Similar trends were followed by total aerobic bacteria, yeast and moulds counts. Pathogenic bacteria such as Salmonella, Coliform and E. coli were absent in all the yogurt samples. Yoghurts of acceptable quality and safety were produced from bambara groundnut and soybeans.

β-Glucosidase activity and bioconversion of isoflavones during fermentation of soymilk.

Lactobacillus rhamnosus C6 strain showed higher β-glucosidase activity as well as biotransformation of isoflavones from glycones (daidzin and genistin) to aglycones (daidzein and genistein) in soymilk. However, L. rhamnosus C2 and Lactobacillus casei NCDC297 also exhibited similar activity during soymilk fermentation. These three strains can be selected for the development of functional fermented soy foods enriched with aglycone forms of isoflavones, such as soy yoghurt, soy cheese, soy beverages and soy dahi. The study determined β-glucosidase activity of probiotic Lactobacillus cultures for bioconversion of isoflavones to aglycones in fermenting soymilk medium. Soymilk was fermented with six strains (L. rhamnosus C6 and C2, L. rhamnosus NCDC19 and NCDC24 and L. casei NCDC17 and NCDC297) at 37 °C for 12 h. The highest β-glucosidase activity and isoflavone bioconversion after 12 h occurred by L. rhamnosus C6 culture during fermentation in soymilk. Increased isoflavone aglycone content in fermented soymilk is likely to improve the biological functionality of soymilk (e.g. antioxidant activity, alleviation of hormonal disorders in postmenopausal women, etc.). Lactobacillus rhamnosus C6 culture can be used for the development of functional fermented soy-based products.

Texture characteristics of soymilk gels formed by lactic fermentation: A comparison of soymilk prepared by blanching soybeans under different temperatures

Soymilk can be used as a raw material to produce gel-like food with texture characteristics of yogurt through lactic fermentation. The removal of beany flavors and a soft yogurt-like texture are two fundamental criteria for evaluating the quality of soy yogurt. However, the effect of blanching treatment, which can eliminate beany flavors, on the texture of soy yogurt remains unclear. The objective of this study was to compare the texture of soy yogurt prepared by blanching soybeans under different blanching temperatures. Variations in texture and microstructure of soymilk gels were analyzed by texture profile analysis and scanning electron microscopy. A soft and weak soymilk gel was produced at a blanching temperature above 70 °C. The strength and rigidity of the soymilk gel produced at a blanching temperature of 80 °C decreased by approximately 50% compared to that obtained by traditional treatment. With the increase in blanching temperature, the microstructure of the soymilk gel transformed from a three-dimensional stranded network with dense crosslinks of “string of beads” protein polymers to a thick honeycomb, lamellar structure of stacked protein particles and clustered aggregated around the stranded networks. A yogurt-like soymilk gel with soft, tender, and smooth characteristics was obtained with ≥70 °C blanching treatment.

Viability and Resistance of Lactobacilli Isolated from Cocoa Fermentation to Simulated Gastrointestinal Digestive Steps in Soy Yogurt

To study the potential probiotic characteristics such as decrease of pH, microbial viability, and tolerance to simulated digestive steps of fermented soy beverage ("soy yogurt") produced with lactobacilli isolated from cocoa fermentation (Lactobacillus fermentum TcUESC01 and Lactobacillus plantarum TcUESC02) during fermentation and refrigerated storage. The sensory acceptance of the yogurts was also tested. Samples of soy yogurt produced with L. fermentum TcUESC01 or L. plantarum TcUESC02 were collected during fermentation (0, 4, 8, and 12 h) and refrigerated storage (1, 9, 18, and 27 d), and submitted to pH and bacterial viability determinations. Tolerance to simulated digestion steps was done with refrigerated storage samples at 9 °C. Simulated digestion was performed in 3 successive steps: exposure to pepsin-HCl solution, bile shock, and simulated small intestinal juice. During storage, a decrease in pH and lactobacillus viability was observed. L. fermentum TcUESC01 showed to be more resistant than L. plantarum TcUESC02 to simulated gastrointestinal digestion. All soy yogurts showed acceptable hedonic scores (greater than 5 in a 9-point hedonic scale ranging from "like extremely" to "dislike extremely") in sensory evaluation for flavor, aroma, color, consistency, and overall impression. L. plantarum TcUESC02 and, especially, L. fermentum TcUESC01 showed potential probiotic characteristics when considering pH, cell viability, and tolerance to simulated digestive steps and did not affect the sensory characteristics when supplemented to soy yogurt during storage.