Use of Aspergillus repens in the moulding process of dried fish stick made from little tuna (Euthynnus affinis)

Dried fish stick is a popular product in Japan and called as Arabushi. The product which has undergone moulding process is known as Katsuobushi. So far, Indonesia, particularly North Sulawesi Province, exports dried fish stick to Japan. Dried fish stick used in this study was made from little tuna (Euthynnus affinis) through smoking process. Prior to moulding process, the products were divided into two lots. The first lot was irradiated using ultraviolet rays for sterilization purpose and the second lot was without irradiation treatment. For moulding process, starter culture solution of Aspergillus rep ens was sprayed over the surface of each dried fish stick lot. The dried fish stick was kept in glass boxes having 85 to 95% relative humidity level for 4 weeks. The samples were withdrawn every week and analyzed chemically and organoleptically. Chemical analyses included pH, moisture, a sub(w) protein, fat, and phenol contents. Organoleptic acceptability of the dried fish stick extract was evaluated in terms of odour and taste. Results indicated that dried fish stick without irradiation treatment was more acceptable than the product with irradiation. The most acceptable product was the one without irradiation treatment and undergoing 4 weeks moulding process.