Physicochemical properties of starches and proteins in alkali-treated mungbean and cassava starch granules.
This study explored the influences of envelope integrity of cooked starch granules on physicochemical and thermophysical properties of mungbean and cassava starches. Alkali treatment was used to selectively leach amylose from the amorphous region of both starches and partially fragmented starch molecules into lower-molecular-weight polymers. It was found that despite the loss of 40% of the original content of amylose, both mungbean and cassava starches retained similar crystallinities, gelatinization temperature ranges, and pasting profiles compared to the native starches. However, the loss of granule-bound starch synthases during alkali treatment and subsequent alkali cooking in excess water played significant roles in determining granular disintegration. The alterations in envelope integrity due to the negative charge repulsion among polymers within the envelope of swollen granules, and the fragmentation of starch molecules, were responsible for the alterations in thermophysical properties of mungbean and cassava starches cooked under alkaline conditions.
Department of Food Science and Technology, Faculty of Agro-Industry, Kasetsart University, 50 Ngam Wong Wan Road, Chatuchak, Bangkok 10900, Thailand.
Kamolwan
K
Israkarn
Department of Food Science and Nutrition, Faculty of Agricultural Product Innovation and Technology, Srinakharinwirot University, 114 Sukhumvit 23, Bangkok 10110, Thailand.
Nantarat
N
Na Nakornpanom
Department of Food Science and Technology, Faculty of Agro-Industry, Kasetsart University, 50 Ngam Wong Wan Road, Chatuchak, Bangkok 10900, Thailand. Electronic address: parichat.h@ku.ac.th.
Parichat
P
Hongsprabhas
D000468:Alkalies / Q000494:pharmacology*; D055598:Chemical Phenomena / Q000187:drug effects; D007887:Fabaceae; D002365:Manihot; D010940:Plant Proteins / Q000737:chemistry*; D013213:Starch / Q000737:chemistry*
D000468:Alkalies; D010940:Plant Proteins; D013213:Starch
Alkali; Cassava; Crystallinity; Mungbean; Starch