Host: The Japan Society Cookery Science
Name : 2021Annual Meeting of The Japan Society Cookery Science 2021
Location : [in Japanese]
Date : September 07, 2021 - September 08, 2021
[Purpose]
Since “Silk sweet” is a relatively new sweet potato variety, there are few scientific reports on its composition. I reported that the amount of maltose in “Silk sweet” was higher than that in “Beniazuma” and about the same as that in “Beniharuka”, and that the difference in maltose content was not related to the β-amylase activity of unheated samples and its optimum temperature, but “Silk sweet” had a higher percentage of β-amylase activity remaining in heated samples. In this study, I investigated the differences in starch gelatinization as a factor affecting the maltose content after heating among sweet potato varieties.
[Methods]
“Beniazuma”, “Beniharuka”, and “Silk sweet” grown in the same field in Niigata City were stored in a room air-conditioned at 20 degrees Celsius for 30 days. The center of sweet potatoes with a length of 12 cm or more was cut into 1.5 cm squares, and steamed at 65-95 degrees Celsius for 60 min. The maltose content was determined by HPLC method, and the degree of starch gelatinization was determined by glucoamylase method using starch extracted from heated sweet potatoes.
[Results]
“Beniazuma” contained little maltose up to 75 degrees Celsius and increased rapidly at 85 degrees Celsius, while “Beniharuka” and “Silk sweet” increased rapidly at 75 degrees Celsius. In the samples heated at 75-95 degrees Celsius, the maltose content of “Beniharuka” and “Silk sweet” was higher than that of “Beniazuma”. The results for the degree of starch gelatinization showed a similar trend to that of the maltose content. “Beniazuma” was barely glued until 75 degrees Celsius, while Benihana and Silk Sweet gradually increased their degree of gluing from 70 degrees Celsius. The degree of starch gelatinization in the sample heated at 75 degrees Celsius was highest for “Beniharuka”, followed by “Silk sweet” and “Beniazuma”.
