Studies on the Constituents and Processing Methods of Japanese Chestnut

Part VIII. A trial for removing both inner peel and the most outside layer in the edible portion of chestnut with chemical reagents

Abstract

The edible part of chestnut was divided into three parts, i.e. outer part, intermediate part and inner part by hand shaving method for analysis. The outer part was less in the content of moisture and higher in the content of the other constituents, especially starch, total nitrogen and minerals than the inner part.
Perchloric acid, hydrochloric acid and nitric acid were effective to remove both the inner peel and the outside layer of chestnut. The heat treatment should be proceeded below 53°C, in order to avoid hardening the surface layer over 53°C. The best condition was obtained by the treatment with 2% mineral acid at 50°C for 30min.
The yield of the edible portion to the whole chestnut will be necessary to kept under 60% in order to keep the shape of the peeled one well when the mineral acid is employed.
The hardening of the edible portion of the chestnut when mineral acid is used for peeling was accompanied by the lowering of pH value suggesting the relationship of water-soluble protein.