Miso was prepared from winged bean, being substituted for soybean. Microstructural changes of winged bean miso at various stages of the manufacturing processes were studied by means of light and transmission electron microscopies. Soybean was also studied for comparison.
After steaming , winged bean and soybean cells were shrunken and intracellular spaces enlarged and cell wall structure was degraded, showing layered structures and aggregated lumps in intraspaces between cell walls during fermentation into misc . At the end of the fermentation , the PAS reaction with cell walls almost disappeared. Surprisingly the thick cel l walls of winged bean degraded as completely as those of soybean . However , seed coat tissues were not digested . Lipid bodies were broken and fused into oil drops located inside and outside of cells and then degraded, showing wavy and scaly patterns during fermentation.
Protein bodies lost their membranes and coagulated after steaming , and then were degraded as aging progressed . Generally, degradation of the gross cellular structures seemed to be faster in soybean miso than in winged bean misc. Partly degraded gross structures of raw beans remained in the miso after two months of aging.
Saio, K.; Suzuki, H.; Kobayashi, T.; and Namikawa, M.
"Microstructural Changes in Winged Bean and Soybean During Fermentation into Miso,"
Food Structure: Vol. 3
, Article 9.
Available at: https://digitalcommons.usu.edu/foodmicrostructure/vol3/iss1/9