Studies on the Constituents and Processing Method of Japanese Chestnuts

Part X. Utilization of several natural color stuffs to syrupped chestnuts (Kanroni)

Abstract

The following color stuffs were used in this experiment: Food Yellow No.4, carthamine yellow (Tana color Y), crocin (crude extracts of Gardenia grandiflora), riboflavin and curcumin (Curcumin "Sanei"). Stability of them was examined with several food additives in transparent ampoules and the above color stuffs were tried to utilize to processing of the syrupped chestnuts.
1. Crocin was the most stable among the yellow natural color stuffs, as the results of model ampoule test of aqueous solutions. Stability of durcumine and carthamine yellow was promoted with ascorbic acid, but riboflavin was very unstable.
2. As the results of utilization of the colour stuffs to syrupped chestnuts, crocin and curcumin were the best among the tested stuffs in respect to residual ratio, permiability into peeled chestnuts, distributive ratio among syrup and peeled chestnuts, and the tone of the color. The above two natural color stuffs were expected to be superior to Food Yellow No.4 practical use.