The Influence of the Parameters of the Subcritical Water Extraction Process on the Efficiency of Isoflavones Elicitation from Soy Meal

Topicality. Incidental products of soy processing (okara, meal, millcake) contain a large amount of protein, and, additionally, other valuable biologically active substances. Among them, isoflavones are of particular researchers’ interest. Subcritical water extraction is a promising method for elicitation biologically active substances from plant raw material. However, such a method of extracting isoflavones, and its rational parameters for soy meal, remain insufficiently investigated. Aim and methods. The aim of this work is to study the influence of parameters (temperature: 120...160°С, duration of extraction: 5...15 min, hydromodule: 1:15...25) of the extracting process of soy meal with subcritical water on the isoflavones content in the dry material of the extract. The empirical research method is applied, using the second-order orthogonal compositional outline for a fractional factor experiment. The samples of soy meal extract are obtained using the experimental setup, based on the high-pressure reactor “RHP-2-500”. The total isoflavones content in the dry extract material is defined in terms of gallic acid with absorption spectrophotometry method. Results. Based on the obtained results, the quadratic interpolation model is constructed. This model links the total isoflavones content in the dry extract material with the extraction parameters. The analysis of the constructed model makes it possible to establish rational measures of extraction parameters. Conclusions and discussion. In this study, the intensive growth of soflavones content in the dry extract with highing the temperature process, and a relatively small influence of the process duration on this indicator, were defined. The influence of the hydromodule is ambiguous. The lowest yield of isoflavones is noted at hydromodule ≈1:21,41. Its increase or decrease lead to the growth of isoflavones content in the extract. In this paper, for the first time, the existence of rational measures of parameters in the process of extracting isoflavones with subcritical water from soy meal is studied and established. The obtained results can be used in the elaboration of the technology for producing isoflavones enriched soy protein concentrate.

Characteristics of Soy Protein Prepared Using an Aqueous Ethanol Washing Process

Currently, the predominant process for soy protein concentrate (SPC) production is aqueous ethanol washing of hexane-extracted soy meal. However, the use of hexane is less desired, which explains the increased interest in cold pressing for oil removal. In this study, cold-pressed soy meal was used as the starting material, and a range of water/ethanol ratios was applied for the washing process to produce SPCs. Washing enriched the protein content for the SPCs, regardless of the solvent used. However, we conclude that washing with water (0% ethanol) or solvents with a high water/ethanol ratio (60% and above) can be more advantageous. Washing with a high water/ethanol ratio resulted in the highest yield, and SPCs with the highest protein solubility and water holding capacity. The water-only washed SPC showed the highest viscosity, and formed gels with the highest gel strength and hardness among all the SPCs at a similar protein concentration. The variations in the functionality among the SPCs were attributed to protein changes, although the effects of non-protein constituents such as sugar and oil might also be important. Overall, the aqueous ethanol washing process combined with cold-pressed soy meal created SPCs comparable to commercial SPC in terms of composition, but with varied functionalities that are relevant for novel soy-food developments.

Food Grains and Jaggery-based Expanded Food: Optimization of Process Variables, Protein Efficiency Ratio and Consumer Acceptability

Extrusion parameters for nutritious expanded food with jaggery were optimized following box-benken design using Response Surface Methodology. Jaggery and feed moisture affected physical properties, while nutritional and sensory properties of products were influenced by jaggery only. Optimized level of extrusion parameters consisted of 100 C die head temperature, screw speed of 304 rpm, 14 % moisture and 4 g jaggery per 100 g of formulation with 80 % maize, 14 % defatted soy-meal, and 6 % sesame-based formulation having overall desirability of 0.807. This expanded food showed expansion ratio of 3.57, 173.76 kg.m-3 bulk density, 15.18 % protein with 72.55 % invitro protein digestibility and 2.63 protein efficiency ratio, 1.97 % total minerals, 2.9 mg.100 g-1 iron, 158 mg.100 g-1 calcium with acceptability score of 8.2 that also indicated the consumer acceptability ≥7 by 95.37 % using 9-point hedonic scale.

Prospects for sustainable intensification of soybean production in sub-Saharan Africa

There is a significant soybean yield gap in sub-Saharan African (SSA) countries. Sustainable intensification of the agricultural sector to reduce such a yield gap is important. Increasing soybean productivity can meet the growing demand for food and feed when complemented with higher soy meal demand by the local livestock industry. This study performs an ex-ante economic analysis to determine the effect of higher soybean production on trade and land use within SSA countries. We find that increasing soybean yield by 50% can increase the total returns from soybean production by 186 million LC (local currency) in Ethiopia and 36 billion LC in Nigeria. We show that soybean yield growth alone is enough to boost soy oil production, as the crushing of the beans produces 18% oil and 79% meal. While increasing productivity may lead to freeing land to produce high-valued cash crops, investors will be reluctant to invest in the crushing facilities in the absence of soy meal demand by the livestock industry. Therefore, policymakers need to establish collaboration between development organisations, private companies, farmers and researchers to achieve this transformation and thereby raise agricultural productivity.

Bioconversion of soy under the influence of Aspergillus oryzae strains producing hydrolytic enzymes

Introduction. The fungus Aspergillus oryzae is widely used in the production of fermented soy-based products. However, there is little data on how its genetic characteristics affect the biochemical and fractional composition of protein substances during fermentation and the quality of fermented products. This study aimed to investigate the conversion of soy meal under the influence of two A. oryzae strains with different morphological and cultural properties during the production of a fermented soy sauce. Study objects and methods. The study used two A. oryzae strains, RCAM 01133 and RCAM 01134, which were isolated from the industrial F-931 strain (Russian Collection of Industrial Microorganisms), a producer of hydrolytic enzymes. Micromycetes were cultivated by a solid-phase method on soy meal, followed by dry fermentation. The results were analyzed with regard to accumulation of amine nitrogen, bound and free amino acids, proteins and carbohydrates. Results and discussion. The cultivation of micromycetes resulted in a 35–38% increase in protein, a tenfold increase in free amino acids, and a 1.5–1.7 fold decrease in polysaccharides. The contents of essential amino acids in the fermented soy sauce were 1.7 and 1.2 times as high as in the initial medium (soy meal) and in the reference protein, respectively. Fermentation enhanced the biological value of proteins, increasing the amino acid scores of phenylalanine (7.3–7.7 times), phenylalanine (2 times), as well as valine, threonine, tryptophan, and lysine. The contents of protein and essential amino acids were slightly higher in the sauce with the RCAM 01133 strain. Conclusion. Fermenting soy materials with the RCAM 01133 strain of A. oryzae is an alternative way to produce food ingredients with good sensory properties containing carbohydrates and biologically complete protein in easily digestible forms.

Improving Mildew Resistance of Soy Meal by Nano-Ag/TiO2, Zinc Pyrithione and 4-Cumylphenol

As a byproduct from the soybean oil industry, soy meal can be reproduced into value-added products to replace formaldehyde as a plywood adhesive. However, the use of soy meal has been limited by its poor antifungal and antiseptic properties. In this work, three kinds of material, namely nano-Ag/TiO2, zinc pyrithione, and 4-cumylphenol were applied to enhance the mildew resistance of soy meal via breakdown of the cellular structure of mildew. The fungi and mold resistance, morphology, thermal properties, and mechanism of the modified soy meal were evaluated. The success of the antifungal and antiseptic properties was confirmed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy. The results indicated that all three kinds of material improved the fungi and mold resistance of soy meal, and sample B, which was modified with a compound of nano-Ag/TiO2 and zinc pyrithione, was the effective antifungal raw material for the soy-based adhesives. FTIR indicated that the great improvement of antifungal properties of soy meal modified with 4-cumylphenol might be caused by the reaction between COO– groups of soy protein. This research can help understand the effects of the chemical modification of nano-Ag/TiO2, zinc pyrithione, and 4-cumylphenol on soy meal, and the modified soy meal exhibits potential for utilization in the plywood adhesive industry.

Attitude Gaps with Respect to GM Non-Food Crops and GM Food Crops and Confidence in the Government’s Management of Biotechnology: Evidence from Beijing Consumers, Chinese Farmers, Journalists, and Government Officials

Most soybean oil consumed in China is made from imported genetically modified (GM) soybeans, while livestock are fed imported GM soy meal and GM corn. However, no GM food crops are allowed to be planted in China at present. That puts China in a confusing situation where GM foods can be eaten but cannot be grown. Many studies suggest that it is partially due to Chinese consumers’ and government officials’ opposition to GM technology. This is the first study that examines different stakeholders’ and journalists’ attitudes toward the commercialization of GM non-food crops and GM food crops and investigates the attitude gaps with respect to these crops. From 2015 to 2016, surveys were conducted face-to-face and by email with 1730 respondents, including 1460 consumers, 54 farmers, 70 journalists, and 146 agricultural officials. We find that nearly 60% of respondents are supportive of the commercialization of GM non-food crops, but less than 30% of respondents support the commercialization of GM food crops. Around 50% of respondents have no confidence in the government’s management of biotechnology, while only 17% have confidence in the government’s management. Those with lack of confidence in the government’s management are less likely to support the commercialization of GM crops.