Soybean variety and storage effects on soymilk flavour and quality

Abstract

Soymilk prepared from five soybean cultivars, grown in Ontario, were analysed for protein, oil, mineral composition, viscosity, colour, lipoxygenase (LOX) activities and flavour profile. Among the five soybean cultivars, the Vinton 81 variety contained the highest protein and the lowest fat. The yield of soymilk from all five cultivars was similar. Major differences were observed in viscosity and in the composition of both the soymilk and the okara. Higher protein and fat extractability was found in soymilk made from S08-80 and Vinton 81 varieties. Their okara protein contents were also among the highest. Minimum extractability was observed with S03W4 cultivar. Soymilk made from S 03W4 and Vinton 81 cultivars had the whitest colour (lowest DE values). Viscosity values were the highest for S08-80, FG1 and S20-20 varieties. Headspace solidphase microextraction gas chromatography was used to analyse volatile compounds in soymilk. A total of fourteen volatiles were identified, among which aldehydes and their corresponding alcohols were the major compounds. Similar volatile compounds were identified in all the samples analysed but at different concentrations. The highest LOX activity was observed in the Vinton 81 and S20-20 soybean cultivars, which had the highest total volatile and hexanal contents. A positive correlation (correlation coefficient ¼ 0.82) between enzymatic activity and the total volatiles was observed. Vinton 81 cultivar was subjected to storage (at 18°C and 50% relative humidity) for a period of 10 months. Soymilk was prepared at different times during storage. The results showed that the soymilk colour, LOX and total volatiles were significantly (P < 0.05) affected by the storage of the soybeans over time.

Effect of sprouting of soybean on the chemical composition and quality of soymilk and tofu

“…Viscosity ranged from 2.7 (DSb1-sprouted) to 3.2 (JS335 Ranchi raw). The results are similar to earlier studies (Achouri et al 2008) and the decrease could be due to increased solubility of proteins, decrease in fat content on sprouting (Agrahar Murugkar and Jha 2009).…”

“…These observations could be explained considering the fact that during sprouting, there is a breakdown of reserve protein to give NH 3 , which accumulates, in the form of amide such as glutamic acid and aspartic acid (Hsu et al 1980) while depletion of the fat stored is due to the catabolic activities of the seeds during sprouting Mostafa et al (1987) which agrees with our results. Fat content value in soymilk prepared be raw seeds were similar a reported by Achouri et al (2008). Sprouting can degrade both Kunitz soybean trypsin inhibitor and the major Bowman-Birk soybean trypsin inhibitor (Collins and Sand 1976) due to the proteolytic activity of enzymes, which are activated during sprouting (Chauhan and Chauhan 2007).…”

“…The Soymilk yield (ml g-l) ranged from 6.2 (MAUS47 raw) to 6.6 (MAUS47 sprouted), which are close to the yields found by Achouri et al (2008). Though not significantly different, the yields of soymilk from sprouted samples were higher than milk from raw samples by about 3%.…”

Caracterização Físico-Química E Sensorial De Extrato Hidrossolúvel De Soja Obtido Por Diferentes Métodos De Processamento.

“…Por ser uma bebida sem lactose e com ácidos graxos poli-insaturados é ideal para portadores de intolerância à lactose ou indivíduos com índice de colesterol alto (GUERREIRO, 2006;MAIA et al, 2006). Segundo Achouri et al (2008) e Axerold et al (1981), a população ocidental não tem o hábito de consumir produtos à base de soja, os quais são descritos como amargos e adstringentes (beany flavor). A soja e seus derivados apresentam sabor e odor característico em consequência da ação das lipoxigenases, enzimas capazes de oxidar os ácidos graxos poli-insaturados, os quais são metabolizados em substâncias voláteis.…”

Storage of Soybeans and Its Effects on Quality of Soybean Sub-Products

“…SAIO et al (1980) For grains stored at 30 ºC and relative humidity of 84.0%, the authors observed a reduction in yield (512g/100g of grains at time zero to 71g/100 g of grains after 7 months of storage) and alterations in texture with increasing hardness and color (Table 10). ACHOURI et al (2008) evaluated the quality of the soymilk obtained from soybeans stored for 10 months at 18 ºC and 50% relative humidity. Under these storage conditions the authors observed no significant change in the water uptake factor and pH of the soymilk, but there was significant variation in color and total volatiles.…”