Some Quality Changes of Dried Loach (Misgurnus-mizolepis) by Microwave (2,450 MHz) Heating

Micro파(波) 처리(處理)에 따른 건(乾)미꾸라지의 품질변화(品質變化)

This study was attemtped to improve the conventional processing method and to establish the basic data for evaluating the product suitabilities of dried loach. The semidressed raw material were salted in 15% NaCl solution for 15 minutes and dried to contain about 44% of water, and then heated about 10 minutes at $80^{\circ}C$ controlled by microwave (2,450 MHz). The moisture content of monolayer value for the product showed 5.34% and its water activity was 0.28. The optimum relative humidity for the storage was recognized to be from 32% to 44%. The average shelf life around the year of the Nylon-PVC-PE $(40\;{\mu})$ packed product in domestic circulation market was estimated as 207.4 days. In comparison with raw material, the contents of the major amino acids, glutamic acid, alanine and valine in the product were shown to be slightly increased, while the level of lysine, aspartic acid and methionine were slightly decreased. The contents of saturated fatty acids and oleic acid were shown to be slightly increased, while the other fatty acids tended to be slightly decreased.

Micro파(波) 처리에 의한 건(乾)미꾸라지 제품의 품질변화를 조사하기 위하여 semidressed로 처리한 원료를 15%염수$(9^{\circ}C)$중 15분 침지후 44%정도의 수분량이 되도록 건조하였을때 어체 내부온도, $80^{\circ}C$로의 가열시간은 10분 정도가 적합하였고 제품의 단분자층 수분량은 Aw:0.28 일때 건물(乾物)로 5.34%였다. 저장 최적습도는 상대습도(相對濕度) 32-44%로 보아지며 국내 유통, 저장환경에서의 Nylon-PVC.PE film$(40{\mu})$ 포장제품의 년평균 shelf-life는 207.4일로 추청되였다. 가열에 따른 일반성분의 감소는 거의 없었으나 주요 아미노산인 glutamic acid, alanine, valine은 각각 0.74g/16gN, 0.96g/16gN, 0.97g/16gN이 증가되었으며 Iysine, aspartic acid 등은 각각 소량 아미노산인 serine, histidine, methionine 및 tyrosine의 감소가 비교적 크게 나타났다. 제품중 필수아미노산 함량은 Iysine등 7종이 총아미노산의 40.8%(16,697.8mg%)로 27.28g/16gN을 차지하였다. 지방산조성 역시 큰변화는 없었으나 C14 : 0산, C16 : 0산, C18 : 0산등 포파지방산은 0.8% 증가된 반면, C14 : 1산, Cl6 : 1산, C18 : 2산, C2O 1산등 불포화지방산은 1.5% 감소되었고, 특히, C18 : 3산과 C20 : 4산은 각각 1.8%, 0.2%의 현저한 감소를 보였으나 C18 : 1산은 오히려 1.8%가 증가되었다.