Storage of adzuki beans and other pulse grains causes biochemical and physical changes that affect the hydration properties of the beans. This affects the quality of products made from the beans such as the Japanese bean paste "ann." Storage, particularly under unfavourable conditions, leads to the "hard shell" phenomenon, where beans fail to imbibe water when soaked and remain hard, and the "hard-to-cook" phenomenon where the seeds hydrate normally, but the cotyledon fails to hydrate and soften during cooking. The hard shell phenomenon is attributable to impermeability of the seed coat to water, which is due to biochemical changes in the seed coat, such as the formation of protein-tannin complexes, and biophysical changes such as reduction in size or closure of the straphiole aperture in the hilum area - the main area for water entry into the adzuki bean. The hard-to-cook phenomenon is due to changes in the cotyledon tissue, which include formation of insoluble pectinates, lignification of the cell wall and middle lamella, interaction of condensed tannins with proteins and starch, and changes to the structure and functionality of the cellular proteins and starch.

Item Type:	Refereed Article
Keywords:	Adzuki, beans, seed structure, ann, storage, hard shell, hard-to-cook, hydration, lignification, starch gelatinisation, pectinates
Research Division:	Agricultural, Veterinary and Food Sciences
Research Group:	Crop and pasture production
Research Field:	Crop and pasture post harvest technologies (incl. transportation and storage)
Objective Division:	Manufacturing
Objective Group:	Processed food products and beverages (excl. dairy products)
Objective Field:	Non-dairy milk
UTAS Author:	Yousif, AM (Dr Adel Yousif)
ID Code:	136774
Year Published:	2007
Web of Science® Times Cited:	32
Deposited By:	Agriculture and Food Systems
Deposited On:	2020-01-17
Last Modified:	2020-03-26
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