Acetic Acid Fermentation of Soybean Molasses and Characterisation of the Produced Vinegar.

Soybean molasses is a by-product from the production of protein concentrate from soybean meal that predominantly contains sugars, with sucrose as the major component. In Brazil, soybean molasses is used for animal feed or it is discarded, although some industries use it to produce ethanol. This study aims to evaluate the parameters required for the acetic acid fermentation of soybean molasses, and characterise the resultant vinegar. To study the most suitable parameters for the acetic acid fermentation, vinegar was produced from the alcohol fermentation of soybean molasses through eight fermentation cycles: five for adaptation and three for production. The average acidity of the acetic acid fermentation product was 50.60 g/L, with an acetic acid fermentation yield, total yield of acetic acid in broth and productivity 65.01%, 92.76% and 0.033 g/(L·h), respectively. The vinegar produced from soybean molasses has an acidity of 5.07% (m/V), residual ethanol content 0.17% (m/V), sugars 7.86% (m/V), dry extract 14.67% (m/V), ash 2.27% (m/V) and a density of 1.023 g/cm3. The contents of total phenolics and isoflavones decreased after the alcohol and acetic acid fermentations. Moreover, the isoflavones profile of the fermented product comprised only three forms: daidzein, glycitin and genistin. According to our results, 3460 L of vinegar can be produced for every tonne of soy molasses, with an acetic acid concentration of 40 g/L, the minimum required by the legislation on vinegar production. Thus, these findings demonstrate that soy molasses represents a useful raw material for the production of vinegar.

Protein, lipid and isoflavone contents of food-type soybean lines at two sowing dates / Teores de proteína, óleo e isoflavonas de linhagens de soja tipo alimento em duas épocas de semeadura

Few works have reported the relationship among genotype, temperature, rainfall and the chemical compounds of soybean. Therefore, the aim of this study was to investigate the interaction effect between soybean food-type inbred lines sowed in two different dates and the contents of protein, oil and isoflavones. Eight lines with null lipoxygenase seeds classified as food-type soybean were sowed in October 7 (early sowing) and October 29 (late sowing) at 2013/2014 crop year. The oil, protein and isoflavones contents were determined and the data were analyzed by variance analysis (ANOVA), principal component analysis (PCA) and UPGMA hierarchical. The genetic variability, sowing date and interactions between inbred lines and sowing date showed differences for all characteristics, except for oil content that did not showed a significant effect to the interaction. The greater participation of complex interaction was attributed to protein content with 87.82 %. According to PCA and UPGMA results, the food-type soybean lines were separated into three groups and were consistent in both sowing dates. The UEL 131 and UEL 153 lines showed the highest isoflavones content for the two sowing dates, indicating these genotypes as promising for breeding programs.

Poucos trabalhos relataram a relação entre genótipo, temperatura, precipitação e os compostos químicos de grãos de soja. Portanto, o objetivo deste estudo foi investigar o efeito da interação entre linhagens de soja tipo alimento semeadas em duas épocas nos teores de proteína, óleo e isoflavonas nos grãos. Oito linhagens de soja ausentes das enzimas lipoxigenases e classificadas como tipo alimento foram semeadas em 7 de outubro (semeadura precoce) e 29 de outubro (semeadura tardia) no ano agrícola 2013/2014. Os conteúdos de óleo, proteína e isoflavonas foram determinados e os dados foram submetidos a análise de variância (ANAVA), análise de componentes principais (PCA) e UPGMA hierárquica. A variabilidade genética, a época de semeadura e as interações entre linhagens e a época de semeadura mostraram diferenças para todas as características, com exceção do teor de óleo que não apresentou efeito significativo na interação. A maior participação da interação complexa foi atribuída ao teor de proteína com 87,82%. De acordo com os resultados da PCA e UPGMA, as linhagens de soja tipo alimento foram separadas em três grupos que se mantiveram com a mudança da época de semeadura. As linhagens UEL 131 e UEL 153 mostraram o maior teor de isoflavonas em ambas as épocas de semeadura, indicando que esses genótipos são promissores para programas de melhoramento.

Application of self-organising maps towards segmentation of soybean samples by determination of amino acids concentration.

Soybeans are widely used both for human nutrition and animal feed, since they are an important source of protein, and they also provide components such as phytosterols, isoflavones, and amino acids. In this study, were determined the concentrations of the amino acids lysine, histidine, arginine, asparagine, glutamic acid, glycine, alanine, valine, isoleucine, leucine, tyrosine, phenylalanine present in 14 samples of conventional soybeans and 6 transgenic, cultivated in two cities of the state of Paraná, Londrina and Ponta Grossa. The results were tabulated and presented to a self-organising map for segmentation according planting regions and conventional or transgenic varieties. A network with 7000 training epochs and a 10 × 10 topology was used, and it proved appropriate in the segmentation of the samples using the data analysed. The weight maps provided by the network, showed that all the amino acids were important in targeting the samples, especially isoleucine. Three clusters were formed, one with only Ponta Grossa samples (including transgenic (PGT) and common (PGC)), a second group with Londrina transgenic (LT) samples and the third with Londrina common (LC) samples.

Soybean β-Glucosidase immobilisated on chitosan beads and its application in soy drink increase the aglycones

The objective of this study was to investigate the immobilisation efficiency of soybean β-glucosidase (181.6 U/mL; 23.8 mg protein/mL) on activated chitosan beads. Central Composite Rotational Design (CCDR) 23 was used and the application of immobilised enzyme in commercial soy drink was evaluated. The activation of chitosan beads was achieved with established 2.5% glutaraldehyde, pH 7.5, 8 h incubation time (6 h with agitation and 2 h without agitation) at 37ºC. The highest immobilisation efficiency (%) of soybean β-glucosidase on chitosan beads obtained was 37.74 U/mL and 18.84 mg protein/4 chitosan beads at pH 7.5 and 20 h coupling time of enzyme-matrix (7 h with agitation and 13 h without agitation) at 4ºC. The immobilised enzyme incubated at 50ºC, pH 5.5 resulted in 24% increase in the aglycones content in commercial soy drink after 60 min.

Cassava starch as a stabilizer of soy-based beverages.

Soy-based beverages are presented as healthy food alternatives for human nutrition. Cassava (Manihot esculenta, Crantz) starch is relatively inexpensive, widely available in Brazil and is broadly used by the food industry due to its desired properties that result from pasting. The objective of this study was to develop soy-based beverages with good sensory quality using native cassava starch as a stabilizer and maintaining the nutritional value that makes this product a functional food. The developed formulations featured a range of cassava starch and soybean extract concentrations, which were tested in a 2² experimental design with three central points. The results of sensory analysis showed that the studied variables (cassava starch and soybean extract concentrations) did not have a significant effect with respect to a 5% probability level. When considering the apparent viscosity, on the other hand, the variables had a significant effect: the increase in soybean extract and cassava starch concentrations caused an increase in the viscosity of the final product. The profile of isoflavones in the tested formulations was similar to the profiles reported in other papers, with a predominance of the conjugated glycosides over the aglycone forms.

Evaluation of the shelf-life of vegetable-type soybean pods

The shelf-life of the vegetable-type soybean pods stored under different conditions was evaluated by chemical characteristics and color. The pods were harvested in the R6 stage and stored either at 30 or 7ºC for 9 d. After the storage period, the pods were blanched and threshed, and the immature green grains were used for the analysis. The protein content decreased after 6 d of storage at 7ºC. There was no difference in the lipid content after the storage at 30 and 7ºC for 9 d. The starch and sucrose contents decreased after the first day of storage at 30ºC. There was no difference in trypsin inhibitor activity until 6 d of storage at 30 and 7ºC. The green color of the pods that was an indication of the quality that was maintained when stored at 7ºC during 3 d. To preserve the quality of vegetable-type soybean, pods should be stored at 30ºC and consumed within 24 h or stored at 7ºC for up to 3 d of storage.

Antioxidant characterization of soy derived products in vitro and the effect of a soy diet on peripheral markers of oxidative stress in a heart disease model.

This study analyzed and compared the content of isoflavones in 2 soy products, the effectiveness of isoflavones as antioxidants, in vitro, and demonstrated the antioxidant effect of a soy diet in rats with myocardial infarction (MI). Isoflavone content was analyzed in soybean hypocotyl (SH) and isolated soy protein (ISP). The quality (TAR) and quantity (TRAP) of antioxidants present in the samples was quantified. The amount of daidzin was higher in SH (9 times) and genistein in ISP (5 times). SH presented a 3-fold increase in TAR, while both products exhibited same TRAP. The rats were fed an ISP diet for 9 weeks. Animals were distributed among 6 treatment groups: (i) Sham Casein; (ii) Infarct Casein < 25%; (iii) Infarct Casein > 25%; (iv) Sham Soy; (v) Infarct Soy < 25%; and (vi) Infarct Soy > 25%. MI was induced 5 weeks after the commencement of the diets. Lipid peroxidation (LPO), antioxidant enzyme activity, and levels of nitrites/nitrates were determined in blood. Rats receiving the ISP diet demonstrated increased activity of antioxidant enzyme activity and nitrite/nitrate content. In addition, the increase in LPO seen in rats subjected to MI was significantly mitigated when the ISP diet was given. These findings suggest a nutritional approach of using a soy-based diet for the prevention of oxidative-stress-related diseases such as heart failure.

Snack bars with high soy protein and isoflavone content for use in diets to control dyslipidaemia.

The objective was to develop a cereal bar product rich in isoflavones and soy protein to be used in diets for controlling dyslipidaemia. A soy snack bar with 39.88 g/100 g dietary fibre, 34.25 g/100 g protein, 100.39 mg/100 g isoflavones and 245.47 kcal/100 g was produced. The shelf life of the product was tested over a period of 6 months. The hardness, water activity and darkness of the snack bars increased with storage time. Clinical trial was carried out to evaluate the effectiveness of the soy snack bar on the lipid profiles of 22 dyslipidaemic subjects for a period of 45 days. There was a decrease in levels of triglycerides (TGs) (- 20%) and an increase in high-density lipoprotein cholesterol (HDL-c) (+8%) comparing with baseline values. Therefore, relatively high intakes of soy protein and isoflavones in moderately hypercholesterolaemic subjects (>200 mg/dl) may have a moderately beneficial effect on plasma lipid profiles, as TG and HDL-c levels, without additional diet restrictions.

Evaluation of soybean methanol fraction on acute inflammation.

Soybeans have been of interest of researchers because of the presence of isoflavones, a subclass of flavonoids, which have demonstrated anti-inflammatory activity. The aim of this study was investigate the anti-inflammatory activity of the methanol fraction from soybean, which contains mainly isoflavone glucosides and malonylglucosides. The anti-inflammatory activity of the methanol fraction from soybean was studied using croton oil-induced mouse ear edema and carrageenan-induced pleurisy models. The methanol fraction inhibited the ear edema in a dose-dependent manner: 0.625 mg/kg by 44.23% (P<.05), 1.25 mg/kg by 60.68% (P<.01), and 2.5 mg/kg by 65.68% (P<.01). Myeloperoxidase enzyme activity was reduced at the dose of 2.5 mg/kg (64.79%, P<.05). No effects were seen on carrageenan-induced pleurisy at different doses of the methanol fraction (100 or 400 mg/kg). These results demonstrated that the methanol fraction containing conjugated isoflavones showed topical anti-inflammatory activity. There was no acute toxicity in Swiss mice after oral administration of the fraction, at doses of 1,000, 2,000, 3,000, and 4,000 mg/kg.