본 연구는 도살후 air spray chilling 방법에 의하여 냉각시킨 도체중량 1.6(±0.1)㎏ 내외의 계육을 흉근부위와 대퇴부위로 발골하여 진공포장과 함기포장을 하여 -45℃의 급속동결실에서 35분간 급속동결을 시킨 후 -20℃의 동결온도에서 1, 4, 8, 12 및 16주 저장하면서 조사한 이화학적인 변화의 결과는 다음과 같다.
1) pH의 변화를 보면 저장 1주째 흉근함기, 흉근진공, 대톼함기, 대퇴진공이 각각 5.77, 5.77, 6.35, 6.36으로 대퇴부위가 높게 나타났으며, 저장기간이 경과함에 따라 약간 상승하였다. 진공과 함기포장 방법에 따른 차이는 없었다.
2) 함유수분은 저장 1주째 흉근함기, 흉근진공, 대퇴함기, 대퇴진공이 각각 74.41, 74.76, 76.98, 76.98로 대퇴부위가 높게 나타났으며, 저장기간이 경과함에 따라 전처리구가 약간씩 감소하였으며, 진공과 함기포장 방법에 따른 차이는 없었다.
3) 전단가는 대퇴부위가 흉근부위에 비하여 높게 나타났으며, 포장방법과 부위간에 상관없이 저장기간이 경과함에 따라 감소하였다.
4) 수용성 단백질의 추출성은 대퇴부위가 흉근부위에 비하여 높게 나타났으며, 전처리구가 저장 8주까지 감소하다가 약간 증가하는 경향을 보였다. 포장방법에 따른 차이는 진공포장이 높은 수치를 나타내었다.
5) 염용성단백질의 추출성은 흉근부위가 대퇴부위에 비하여 높게 나타났고 저장기간이 경과함에 따라 전저리구가 감소하는 경향이었다. 포장방법에 따른 차이는 저장 8주까지는 진공포장이 함기포장에 비하여 약간 높은 추출성을 보였다.
6) 총지질 함량은 저장 1주째 흉근함기, 흉근진공, 대퇴함기, 대퇴진공이 각각 0.38, 0.36, 1.30, 1.33으로 대퇴부위가 흉근부위에 비하여 높은 함량을 나타내었고 저장기간이 경과함에 따라 약간씩 감소하였으며, 포장방법에 따른 차이는 없었다.
7) 지방산의 조성은 oleic acid(33.5~42.4)가 가장 높은 함량을 나타내었으며, 다음으로 palmitic acid(19.7~30.8), linoleic acid(10.8~17.4) 순으로 높게 나타났다.
This experiment was carried out to find out the effect of packing methods on physico-chemical properties of breast and thigh meats in chicken, which was dried by air spray chilling method. The chicken carcass was cut into breast and thigh muscles, which were either vacuum packed or atmosphere packed, and stored at -20℃ for 1, 4, 8, 12 and 16 wk after quick freezing at -45℃ for 35 min. The pH values of atmosphere-packed breast meat and vacuum-packed breast meat after one wk of storage were higher than those of atmosphere-packed thigh meat and vacuum-packed thigh meat(P<.05). The pH values increased as storage period extended, but no significant difference was detected between two packing method(vacuum vs. atmosphere). Total moisture contents of breast meats after one wk of storage were higher than those of thigh meats. The total moisture contents decreased slowly as storage period extended, but no significant difference was detected between two packing method(vacuum vs. atmosphere). The shear force value of thigh meat was higher than that of breast meat. The shear force values of both meats decreased as storage period extended, regardless of packing method. The water soluble protein extractability of thigh meats was higher than that of breast meat, and the water soluble protein extractability of all treatments decreased until 8 wk after storage, but increased gradually after 8 wk of storage period. The salt soluble protein extractability of breast meat was higher than that of thigh meat, and the salt soluble protein extractability of all treatments decreased as storage period extended. With regard to the packing method, the vacuum packing showed higher value than that of atmosphere packing method until 8 wk of storage. Total lipid contents of atmosphere- and vacuum-packed thigh meats at 1 wk of storage were higher than those of breast meats, and the total lipid contents of all of treatments decreased as storage period extended. However, no significant difference was detected between two packing methods. The fatty acid contents of breast and thigh meats were in order of oleic(33.5~42.4), palmitic(19.7~30.8) and linoleic acid(10.8~17.4).