Abstract
It is difficult to heat tapioca (cassava starch) pearls which are liable to get out of shape or be undercooked upon heating. The object of this study is to establish a convenient heating method, compared with conventional ones, for the preparation of tapioca pearls which are transparent, have a good texture and scarcely get out of shape nor be undercooked.
Tapioca pearls heated by two methods, namely, water-bath method and thermos bottle method, were compared with each other through microscopic observation, determination of physical properties and sensory evaluation to thereby examine the dipping effects and heating processes. The following results were obtained.
1) Dipping exerted no effect on the heating of tapioca pearls. It was found that tapioca pearls, which had not been dipped in water but directly heated, less got out of shape than dipped ones did.
2) Tapioca pearls heated by using a thermos bottle were preferred to those heated on a water-bath in both the physical properties and the sensory evaluation. That is to say, the former ones less got out of shape and were more elastic and hardly undercooked than the latter ones. It is ascertained that the thermos bottle method, which requires neither stirring nor supplying hot water during the heating and gives well-cooked tapioca pearls, is convenient and effective.
3) Tapioca pearls which had been added to cold water and then cooked (cold water-bath method) could be cooked within a shorter period of time than those which had been directly added to hot water (hot water-bath method). In particular, the former ones gave transparent products having a good texture when cooked for 2 hr.
