다당류 및 TGase를 처리한 동결 무지개송어육을 이용한 간편식 가공기술 개발

Abstract

The rainbow trout Oncorhynchus mykiss, which is in the spotlight as an import-dependent alternative to salmon, is a salmon species in the family Salmonidae. A significant portion of the total harvest of cultured rainbow trout remains unused or poorly used due to inherent problems related to unattractive color, smaller size, and mortality. In this study, the nutritional compositions compared rainbow trout with Atlantic salmon (USDA). Rainbow trout contained a high amount of polyunsaturated fatty acids, specially DHA (10.3%) and EPA (4.37%). According to the results of amino acids, minerals and vitamins, significant components of rainbow trout were aspartic acid, glutamic acid, leucine, and lysine in amino acids, Mg, K, Cu, Se in minerals, and vitamin D and E. Astaxanthin was contained 9.36 mg/kg in rainbow trout. There was a significant difference in lipid between rainbow trout and Atlantic salmon. It was concluded that the lipid in rainbow trout and Atlantic salmon was influenced by characteristics of individuals, species, and environment. Rainbow trout changes take place rapidly in textural alterations, undesired color, flavor, and odor. In this study, the effect of TGase and polysaccharide kappa carrageenan on the texture, chemical, and microbiological quality of frozen unmarketable fishes was investigated. There was no statistical difference between the treated group and control samples on the 10th day in pH. The VBN increased in all samples during storage at 4℃ for 10 days, but the samples adding 0.5% and 1% carrageenan had the lowest VBN. The viable cell count increased in all samples treated with TGase and carrageenan, but an increase in TGase enzyme and carrageenan concentration met successful results in hindering the growth of total bacteria. As a result of the texture properties, viscosity and gel strength highly increased in TGase-treated samples, and there was no significant difference with the addition of carrageenan. SDS-PAGE results confirmed that the myosin heavy chain (MHC) band with a molecular weight of 205~250 kDa was weakened in trout meat added with 1% TGase, which led to cross-linking reactions between proteins. The best results were obtained with the addition of 1% TGase and 1% carrageenan. Overall, utilizaing of TGase and carrageenan can be a useful tool for seafood processing technology to achieve products with improved texture and extended shelf life. To expand the use of frozen unmarketable rainbow trout, the rainbow trout roll was manufactured in the optimal conditions and the chemical composition of the trout roll was studied. Result of response surface methodology, optimum condition of galic-pepper mixure for masking was 21 g and starch for texture was 23g. The major free amino acids of rainbow trout roll were anserine (41.93%), arginine (11.27%), glycine (7.13%), and taurine (7.01%). With regard to fatty acid composition, rainbow trout roll contained a lot of unsaturated fatty acids (73.3%) and the major fatty acids were 18:1n-9c(34.54%), 16:0(15.9%), 18:2n-6c(14.35%), DHA (10.33%), and EPA (2.5%). The mineral contents were 99.38 mg/100 g P, 17.75 μg/100 g Cr, 8.89 μg/100 g Se. The content of vitamin E was 1,010.91 μg/100 g. The contents of allyl mercaptan, allyl methyl disulfide, diallyl disulfide, and trans-caryophyllene in rainbow trout roll contained 80% of the total flavor compounds. It was concluded that garlic-pepper mixture was effective to mask for hexanal and 1-octen-3-ol of off flavor in frozen rainbow trout. This study suggests that rainbow trout roll has high nutritional value and may be accepted by consumers.