Five soymilk quality-related characteristics were investigated as affected by different grinding, heating, extraction methods and varieties. The five characteristics are (1) protein and solid recovery, (2) trypsin inhibitor activity, (3) antioxidant compounds and antioxidant capacity, (4) soy odor, and (5) isoflavone content and profile. The two varieties were Prosoy and black soybeans. The results show that significant differences existed among the three grinding methods (ambient grinding, cold grinding, and hot grinding). Ambient grinding gave the best protein and solid recoveries. Hot grinding showed the best results for the other four parameters. Cold grinding gave the poorest performance, with the exception of the odor profile. The three heating methods (traditional stove cooking, one-phase UHT, two-phase UHT) also resulted in significant differences in the chemical compounds and properties of the soymilk. In many cases, the effects of heating methods were closely related to grinding methods and varieties. Our results clearly demonstrated that a UHT processor equipped with a vacuum chamber was a very efficient way to reduce or eliminate some undesirable soy odors, especially in conjunction with hot grinding. Our results also demonstrated that many complex reactions occurred during thermal treatment. Because of different seed characteristics, the two different varieties behaved differently during processing. For both varieties, extraction with okara washing water from last batch (Method #2) gave the highest solid and protein recoveries.

No description available.

M. Tech. Food Technology. / Aims to develop a standardised procedure for the production of soymilk that could be used to evaluate the food technological potential of the 30 different locally grown soybean cultivars. Such a procedure should have standardised soaking and cooking times and temperatures that could ensure the inactivation of lipoxygenase enzymes and other anti-nutritional factors that negatively affect the flavour or nutritional quality of the soymilk. A filtration technique would be needed to quantitatively and reproducibly separate the soymilk and okara fractions. The soymilk produced should have sensory properties that conform to the requirements of a soymilk that is acceptable to the consumer.

Call number: LD2668 .T4 1986 M57 / Master of Science / Human Nutrition

The physico-chemical characteristics of soymilk particles and the gelation properties of soymilk were investigated as a function of soymilk protein concentration, by preparing soymilk samples from different water-to-bean ratios. Particles from different soymilk protein concentrations showed similar protein composition and surface hydrophobicity, but different -potential, size and protein content. The particle voluminosity was derived using a relation between the effective refractive index of soymilk and the turbidity parameter determined experimentally. For the first time, experimental data was compared to theoretical models, drawing general conclusions about colloidal properties of soymilk particles. Protein concentration and the rate of acidification did not have a significant effect on the acid-induced gelation of soymilk. Results demonstrated that decreased charge is a prerequisite for particle aggregation, which is driven by hydrogen bridging. This thesis provides soymilk processors with general principles on the colloidal behaviour of soymilk, valuable information for new product development and better process design. / Soybean Growers of Ontario, Natural Sciences and Engineering Research Council of Canada

This work was done with the purpose of evaluating different forms of soybean milk processing, the product acceptance by the public, and to do a study on the feasibility for the production of milk at a small scale to be used as a nutritional supplement in school breakfasts. The soybean milk was prepared with 2 varieties "(Cristalina and Doko)" and two periods of enzymatic inactivation (Before and After) of the grain mush. The "organoleptic" quality was evaluated through surveys and its posterior statistical analysis. Parameter quality was also considered just as did the microbiologic analysis and the conservation tests. The surveys showed that the products obtained were of regular acceptance. The statistical results indicate that the best treatment was that of the variety "doko" with its enzymatic inactivation previous to the trituration. The degree of microbiologic contamination is moderate, it is within the ranges permitted by human consumption. The conservation tests showed that soybean milk without conservatives can have, if refrigerated, a duration similar to that of cow's milk. The financial economic analysis showed that it is possible for the installation of small rural soybean milk processing plants (VAN=2058.68, TIR=34.8). Finally, it is concluded that soybean milk can be constituted as part of a fundamental basic food to lighten the high malnutrition present in the rural and urban areas of our country.

The primary goal of this research was to evaluate the effects of light on soymilk, including the oil component. Soybean oil with added chlorophyll a (0, 1, and 2μg/ml), a photosensitizer, was exposed to light (no light [control], broad-spectrum light) and narrow-band wavelengths (430nm, 450nm, and 660nm] for 4h. Chlorophyll completely degraded under broad-spectrum light and 430nm treatments; 64% degradation occurred at 660nm. Oil with chlorophyll addition resulted in significantly higher peroxide values and malondialdehyde concentrations with light exposure to broad spectrum and 430nm wavelengths. Light at 430 and 660 nm degraded chlorophyll and increased risk of oxidation in soybean oil. Soymilk contains low concentrations of chlorophyll, the photosensitizer riboflavin, as well as highly susceptible oxidizable substrates from the soy oil. Soymilk (1% fat from soybean oil) was packaged under a positive flow hood into 5 high density polyethylene (HDPE) packages and stored for 36 days at 4°C under fluorescent lighting (1122 lux ± 439 lux). Control packaging had no light protective additive (LPA; positive (foil-wrapped) and negative control) and the experimental packaging treatments had three levels of LPA (low, medium, high). Chemical and sensory analyses to measure oxidation changes were completed on the product at days, 1, 4, 8, 15, 22, 29, and 36. HDPE packages with high LPA protected the sensory quality of the product as well as the positive control (foil-wrapped) packages for a minimum of 15 days. High-LPA HDPE protected soymilk for 29 days from degradation of riboflavin and limited development of aldehyde end-products associated with photooxidation. Soymilk was treated with food grade TiO2 at levels of 0, 0.5, and 1.0% by weight. TiO2 significantly whitened the product as demonstrated by L* values. TiO2-treated soymilks resulted in significantly improved hedonic scores for appearance, smell, taste, mouthfeel, and aftertaste compared to control soymilk. However, in a second experiment, overall acceptability of TiO2-treated soymilk, at additions of 0.1%, 0.3%, and 0.5% TiO2, was not higher than control soy milk. / Ph. D.

Alimentos funcionais são alimentos que contêm uma ou mais substâncias capazes de atuar no metabolismo ou na fisiologia do ser humano, promovendo benefícios à saúde. A soja é uma excelente matéria-prima para o desenvolvimento de alimentos funcionais, pois proporciona benefícios ao hospedeiro que apresenta intolerância ou alergia associada ao consumo de produtos lácteos. As bactérias láticas probióticas vêm sendo aplicadas na fermentação de alimentos devido aos benefícios que as mesmas propiciam a saúde, como na manutenção do equilibrio da microbiota intestinal, em distúrbios do metabolismo gastrointestinal e como adjuvante na absorção de determinados nutrientes. Nesse contexto, o presente trabalho tem por objetivo desenvolver um fermentado a base de soja utilizando bactérias probióticas. A fermentação da bebida à base soja foi realizada pelos micro-organismos Streptococcus thermophilus (St), Lactobacillus delbrueckii subsp. bulgaricus (Lb) e Lactobacillus paracasei (Lp) Lpc-37 realizada à 37ºC e também em diferentes condições de resfriamento aplicadas nas amostras ao fim da fermentação e durante os 28 dias de armazenamento refrigerado (4ºC). Os resultados demonstraram que em média o tempo de fermentação foi menor na presença de St, Lb e Lp quando comparada a fermentação realizada apenas por Lp. A exposição das amostras a uma temperatura intermediária de resfriamento (25ºC) durante 8 horas aumentou cerca de 2,1% a viabilidade das co-culturas ternárias, apresentando pós acidificação em média de 0,2 unidades de pH a partir do pH final da fermentação (4,5) até d1. O resfriamento intermediário promoveu uma modificação no perfil de ácidos graxos, demonstrando aumento de 14,5% do ácido linoleico após 28 dias de armazenamento a 4ºC assim, como também, promoveu aumento de 14,6% na produção de ácido lático. Outro resultado relevante e bastante expressivo foi o consumo de sacarose (94,9%). Desta forma, o resfriamento intermediário demonstrou ser um procedimento capaz de aumentar a viabilidade das bactérias em modelo in vitro de estresse gastroinstestinal. De acordo com esses resultados, é possível concluir que o uso do resfriamento intermediário promove maiores benefícios em relação ao perfil microbiológico e de ácidos graxos. / Functional foods are foods that contain one or more substances capable of acting on the metabolism or physiology of the human being, promoting health benefits. Soy is an excellent raw material for the development of functional foods, providing benefits to the intolerant and allergic people to the dairy products consumption. The use of probiotic lactic acid bacteria in food fermentation has become quite common due to the beneficial effects provided by these bacteria to the individuals\' health, maintaining the balance of intestinal microflora, in the gastrointestinal metabolic disorders and as an adjunct in the absorption of certain nutrients. In this context, this study aimed to develop a fermented soy base using probiotic bacteria. Fermentation of soy beverage was made by the microorganisms Streptococcus thermophilus (St), Lactobacillus delbrueckii subsp. bulgaricus (LB) and Lactobacillus paracasei (Lp) Lpc-37 at 37°C and evaluated at the end of the fermentation process and during 28 days of storage at 4°C. The results showed that the fermentation time was less on average in the presence of St, Lb and Lp when compared to the fermentation performed only by Lp. The exposure of samples to a cooling intermediate temperature (25°C) for 8 hours increased about 2.1% the viability of ternary cocultures, with post acidification on average of 0.2 pH units from the final pH of the fermentation (4.5) to d1. The intermediate cooling promoted a change in fatty acid profile, showing a 14.5% increase of linoleic acid after 28 days of storage at 4°C as well as also promoted an increase of 14.6% of lactic acid. Another important and very significant result was the sucrose consumption (94.9%). In this way, the intermediate cooling procedure demonstrated to be able of increase bacteria viability in the in vitro model of gastroinstestinal stress. According to these results, it is possible to conclude that the use of the intermediate cooling promotes greater benefits in relation to the microbiological profile and fatty acids.

Alimentos funcionais são alimentos que contêm uma ou mais substâncias capazes de atuar no metabolismo ou na fisiologia do ser humano, promovendo benefícios à saúde. A soja é uma excelente matéria-prima para o desenvolvimento de alimentos funcionais, pois proporciona benefícios ao hospedeiro que apresenta intolerância ou alergia associada ao consumo de produtos lácteos. As bactérias láticas probióticas vêm sendo aplicadas na fermentação de alimentos devido aos benefícios que as mesmas propiciam a saúde, como na manutenção do equilibrio da microbiota intestinal, em distúrbios do metabolismo gastrointestinal e como adjuvante na absorção de determinados nutrientes. Nesse contexto, o presente trabalho tem por objetivo desenvolver um fermentado a base de soja utilizando bactérias probióticas. A fermentação da bebida à base soja foi realizada pelos micro-organismos Streptococcus thermophilus (St), Lactobacillus delbrueckii subsp. bulgaricus (Lb) e Lactobacillus paracasei (Lp) Lpc-37 realizada à 37ºC e também em diferentes condições de resfriamento aplicadas nas amostras ao fim da fermentação e durante os 28 dias de armazenamento refrigerado (4ºC). Os resultados demonstraram que em média o tempo de fermentação foi menor na presença de St, Lb e Lp quando comparada a fermentação realizada apenas por Lp. A exposição das amostras a uma temperatura intermediária de resfriamento (25ºC) durante 8 horas aumentou cerca de 2,1% a viabilidade das co-culturas ternárias, apresentando pós acidificação em média de 0,2 unidades de pH a partir do pH final da fermentação (4,5) até d1. O resfriamento intermediário promoveu uma modificação no perfil de ácidos graxos, demonstrando aumento de 14,5% do ácido linoleico após 28 dias de armazenamento a 4ºC assim, como também, promoveu aumento de 14,6% na produção de ácido lático. Outro resultado relevante e bastante expressivo foi o consumo de sacarose (94,9%). Desta forma, o resfriamento intermediário demonstrou ser um procedimento capaz de aumentar a viabilidade das bactérias em modelo in vitro de estresse gastroinstestinal. De acordo com esses resultados, é possível concluir que o uso do resfriamento intermediário promove maiores benefícios em relação ao perfil microbiológico e de ácidos graxos. / Functional foods are foods that contain one or more substances capable of acting on the metabolism or physiology of the human being, promoting health benefits. Soy is an excellent raw material for the development of functional foods, providing benefits to the intolerant and allergic people to the dairy products consumption. The use of probiotic lactic acid bacteria in food fermentation has become quite common due to the beneficial effects provided by these bacteria to the individuals\' health, maintaining the balance of intestinal microflora, in the gastrointestinal metabolic disorders and as an adjunct in the absorption of certain nutrients. In this context, this study aimed to develop a fermented soy base using probiotic bacteria. Fermentation of soy beverage was made by the microorganisms Streptococcus thermophilus (St), Lactobacillus delbrueckii subsp. bulgaricus (LB) and Lactobacillus paracasei (Lp) Lpc-37 at 37°C and evaluated at the end of the fermentation process and during 28 days of storage at 4°C. The results showed that the fermentation time was less on average in the presence of St, Lb and Lp when compared to the fermentation performed only by Lp. The exposure of samples to a cooling intermediate temperature (25°C) for 8 hours increased about 2.1% the viability of ternary cocultures, with post acidification on average of 0.2 pH units from the final pH of the fermentation (4.5) to d1. The intermediate cooling promoted a change in fatty acid profile, showing a 14.5% increase of linoleic acid after 28 days of storage at 4°C as well as also promoted an increase of 14.6% of lactic acid. Another important and very significant result was the sucrose consumption (94.9%). In this way, the intermediate cooling procedure demonstrated to be able of increase bacteria viability in the in vitro model of gastroinstestinal stress. According to these results, it is possible to conclude that the use of the intermediate cooling promotes greater benefits in relation to the microbiological profile and fatty acids.

Fortified and unfortified soymilk were produced from the same production batches for comparative evaluation. Fortification included a comprehensive array of micronutrients of interest to community and humanitarian nutrition programs. The effects of time after fortification prior to cooling, cooling method, and light or dark refrigerated storage on the stability of 5 vitamins (vitamin A, vitamin C, thiamine, riboflavin, and folate) were investigated for both fortified and unfortified soymilk. Significant vitamin C loss (6%) and mild vitamin A isomerization occurred while soymilk was hot immediately following fortification. Cooling bottled soymilk in an ambient water bath or ice water bath made no difference in the levels of any of the vitamins measured. Significant loss of riboflavin (18%) and significant vitamin A isomerization to cis isomers other than 13-cis, resulting in loss of bioactivity, occurred during 12 days of light-exposed refrigerated storage. An increase of 13-cis isomer was observed in dark refrigerated storage but with no significant loss of vitamin A bioactivity. No significant degradation of any other vitamins occurred during 12 days of dark refrigerated storage. Sensory evaluation by a panel of youth and children revealed no significant preferences between fortified and unfortified soymilk excepting colour, for which property there was a slight preference for unfortified soymilk. Acceptable vitamin stability and sensory characteristics can be achieved in comprehensively fortified soymilk produced in small-scale batch processes with appropriate management of production and storage conditions.