CHANGES IN LIPIDS OF WHOLE AND MINCED RAYFISH (RAJA-CLAVATA) MUSCLE DURING FROZEN STORAGE

The effects of the storage temperature (-18 degrees C and -40 degrees C) and the addition of butylhydroxytoluene (BHT) on the different clas ses of lipids (phospholipids, triacylglycerides, free fatty acids, ste rols and sterol esters plus waxes) and the fatty acid composition of m inced (8 and 12 mm) and whole rayfish wing muscle stored for I year in the frozen state were studied. The phospholipid content decreased sig nificantly and the free fatty acid content increased significantly at both storage temperatures, but more pronounced, at -18 degrees C. Sign ificant differences were found between phospholipid and free fatty aci d contents of the minced and the whole samples, which again were more pronounced at -18 degrees C. A significant increase of the major fatty acids (22:6n-3 and 16:0) was observed after 1 year in the frozen stat e. Significant differences were also obtained between the samples stor ed at -18 degrees C and at -40 degrees C; the lower the storage temper ature, the higher their content. The polyunsaturated fatty acid (PUFA) content increased significantly in all the samples. Significant diffe rences were found between the samples stored at -18 degrees C and at - 40 degrees C. The lower the temperature, the higher the PUFA content. Nonsignificant differences were observed between the 8-mm and the 12-m m minced samples. Non-significant differences were found between the s amples stored in the presence and in the absence of BHT. Mincing haste ned hydrolytic and oxidative processes, which were slowed down at the lower storage temperature. Nonetheless, nonsignificant differences wer e found between both particle sizes.