Characterization of the quality of imbibed soybean at an early stage of pre-germination for the development of a new protein food item

Abstract

This was a pilot study carried out to develop a new protein food item from imbibed soybean before germination. It identified the significance of a short stage after imbibition and before germination, and that vitamin C production was activated in as little as 16 h from the start of imbibition, without any influence on the soy protein quality or sensory acceptability, while longer imbibition caused the imbibed soybean to activate its phytophysiological metabolism for germination. DNA microarray analysis indicated that the genes for carbohydrate metabolism were up-regulated prior to 16 h, and that the expression rates of genes responsible for environmental factors were down-regulated. Thereafter, the expression rates of the genes associated with lipid metabolism and secondary metabolite production were changed. This information should contribute to a better understanding of how to develop a new soy protein item in pre-germination before active physiological processes begin.

Gene Expression Profiling in Short‐Term Imbibition of Wheat: Tools for Dissecting of Pasting Properties of Imbibed Wheat Seeds

“…It showed there was a greater difference in gene expression profiles between seeds imbibed for 16 compared with 24 hr than between pre‐ and postimbibition (that is, 0 and 16 hr) (Figure ). This result is consistent with our previous observation that soybean seeds imbibed for 16 hr formed a cluster that was separate from that comprising dry seeds and seeds imbibed for 8 hr (Tamura et al., ). Imbibition starts with physical absorption of ambient moisture, after which proteins are synthesized (Bewley, ).…”

“…Imbibition starts with physical absorption of ambient moisture, after which proteins are synthesized (Bewley, ). Our results indicate that this second phase had not begun in the 16‐hr imbibed wheat, as in the case of 8‐hr imbibed soybean seeds (Tamura et al., ).…”

“…Total RNA (200 ng) of 0‐, 16‐, and 24‐hr imbibed samples were amplified and transcribed into fluorescent cRNA using the Low Input Quick Amp Labeling kit (One‐color) (Agilent Technologies). After washing, fragmentation, hybridization, and scanning were performed as previously described (Tamura et al., ).…”

“…Sprouted foods provide novel texture and taste and can be rich in nutrients (Baranzelli et al., ; Cartea & Velasco, ; Gan et al., ; Hung, Maeda, & Morita, ; Komatsuzaki et al., ; Tamura, Kamei, Ueda, Arai, & Mura, ). For instance, soybean, rice, and broccoli germinated for 12 to 72 hr produce vitamin C, γ‐aminobutyric acid, and isothioyanate (Cartea & Velasco, ; Komatsuzaki et al., ; Tamura et al., ), which promote health. In wheat, germination maximizes phytochemical content and antioxidant activity (Hung et al., ) and alters the chemical composition, gluten content, and pasting properties (Baranzelli et al., ).…”

“…We previously carried out a transcriptome analysis of short‐term imbibition in soybean and noted marked changes in gene expression before germination before the radicle had grown from a seed (Tamura et al., ). In this study, wheat seeds were imbibed over a short term and DNA microarray analysis was performed to identify genes related to wheat flour processing traits.…”