抄録
Parboiling process consists of soaking, steaming and drying. The properties of parboiled rice may be formed by many kinds of processing conditions which are concerned with one another.
This investigation was carried out to determine a practical and rationalized method for producing parboiled rice, considering these processing conditions.
This paper is based upon laboratory tests conducted to find out the rate of gelatinization of parboiled rice starch.
The results obtained are as follows.
(1) The rate of gelatinization of parboiled rice starch increased with increase of water absorbed during soaking.
(2) Under special soaking condition with some various steaming conditions, the rate of gelatinization increased with rising of steaming temperature and prolonging of steaming time. From these results it was recognized that gelatinization was considered as an endothermal reaction and the rate of gelatinization depended upon amount of heat supplied by steaming.
(3) The rate of gelatinization on products was profoundly influenced by not only moisture in soaking and heat quantity in steaming, but also drying conditions.
(4) As the rate of gelatinization is intimately related to over-all conditions of soaking, steaming and drying, it may be considered as a good indication to determine the effectiveness of parboiling treatment.
(5) The dimensions of parboiled kernels which were thoroughly subjected to moisture-heat treatment decreased by contraction with comparing to untreated kernels.
(6) The parboiling system in Fig. 8 will be considered as feasible system for both dried paddy and raw paddy because it is designed so as to be also available and raw paddy for high moisture paddy newly harvested.
