The study was conducted to evaluate the effect of drying, curing and freezing on the quality of beef. Three types of dried (without salt = T1, with salt = T2 and salt + spices = T3); three types of cured (salt curing = T4, sugar curing = T5 and brine curing = T6) and three types of frozen beef (0℃ = T7, -10℃ = T8 and -20℃ = T9) were analyzed at different time intervals up to the period of 180 d. Parameters studied were protein, fat, ash, color and cooking loss of beef. All the chemical constituents (protein, fat and ash) were decreased gradually up to 120 d. The decreasing trend was observed rapid after 120 d up to 180 d of preservation. Highest protein loss was found in T7 (11.1%) and the lowest protein loss was found in T6 (3.85%) in 180 d preservation and significant (p < 0.01) differences were observed among the different preservation methods. Highest fat loss was observed in T6 (7.62%) and the lowest fat loss was observed in T2 (3.18%) and the differences were also significant (p < 0.05) among different methods during the experimental period. Spices dried beef showed a brighter color than others and cured beef showed brown color and the intensity of color was reduced gradually with the increasing of storage period. T9 showed the lowest cooking loss among 3 treatments of frozen beef and the differences also significant (p < 0.01) up to 180 d. It might be stated that sugar curing (T5) and spices drying (T3) would be the useful technique of meat preservation in rural areas and freezing (T9) would be used in large scale preservation at urban areas.

Beef marbling is known as one of the most important beef-quality traits in Korea. It is likely that marbling derived from fatty acids, mainly propionate, is mediated by rumen. Recently micro-agents were studied to enhance marbling, although many parts of that were digested in rumen. Therefore, this study was conducted to screen candidate materials to effect on beef quality with in vitro ruminal incubation. The materials such as saponin, chitosan, Zn compounds (4), vitamin C sources (2), Korean herb cocktail and garlic sources (2) were added to rumen fluid to 1.25% of substrate volume at 0 and 24 h incubation time. Total gas production in intact vitamin C source increased but that in all Zn compounds decreased (P＜0.05). Total gas production in Zn sulfate compound less decreased than in other Zn sources. Propionate in Zn sulfate increased than the other candidate compounds at all incubation time (P＜0.05). Experiment two was conducted to clarified effect of additives such as vitamin C sources (2), garlic lyophilized, Korea herb cocktail and Zn sulfate were supplemented with 2.5% volume at the 0, 3, 6, 12 and 24 h incubation time. Total gas in Zn sulfate was lower than any other treatments. Propionate in garlic, herb and Zn sulfate appeared to be lower than control and vitamin C sources at all incubation time, although significant difference was not observed in total VFA among control and all treatment. This study suggested that micro-agent might be used to improve beef quality with minute level.

Bacteriological quality of beef carcass and distributions of pathogens in beef processing environments were investigated to improve the hygienic quality of fresh beef. Total bacterial contamination of carcass surface in slaughtering process and cutting board in cut-meat process showed 10^5-10^6CFU/㎠ and l0^5CFU/㎠ in summer, respectively. The viable bacterial count of cotton glove was similar to that of cutting board during and entire period of year. Microbial contamination of carcass surface, cutting board, cotton glove and deboned meat showed the highest in summer and the lowest in winter during the year. Escherichia coli O157, Pseudomonas aeruginosa, Klebsiella. ornithinolytica, Staphylococcus aureus, E. coli, Tatumella. ptyseos, Serratia odorifera, Aeromonas sobria, Enterobacter cloacae and Flavimonas oryzihabitans were isolated from carcass surface during slaughter treatments. S. aureus, Listeria grayi and L. monocytogenes were isolated from cutting board and L. grayi, Erwinia spp. Salmonella spp. and S. aureus were isolated from cotton glove in cut-meat process environments. Citrobacter freundii, L. monocytogenes, and S. aureus were isolated from deboned meat.

본 연구에서는 열전소자와 플라즈마 장치를 삽입하여 제작된 컨테이너와 기존의 사용되고 있는 스티로폼(EPS)박스에 소고기를 저장하면서 저장 중 품질특성을 조사하였다. 온도변화 측정 결과 저장기간 동안 TCS-1 컨테이너가 2℃ 이하로 온도유지가 잘 되는 것으로 측정되었다. EPS박스는 저장 3일 이후 소고기가 부패되어 더 이상 실험이 불가능 하였다. 소고기의 신선도를 나타내는 휘발성염기질소(VBN)과 지방산패도(TBA)값의 측정 결과, 저장 7일째 TCS-1의 VBN은 7.72 mg%, TBA는 0.52 mgMA/kg, TCS-2의 VBN 값은 9.20 mg%, TBA는 0.91 mgMA/kg로 측정되어 TCS-1이 TCS-2 보다 유의적으로 적은 증가율을 나타내어 소고기의 신선도를 더 잘 유지하는 것으로 판단되었다. 미생물 변화는 저장 7일 TCS-1은 4.62 log CFU/g, TCS-2는 7.09 log CFU/g으로 측정되어 TCS-1이 유의적으로 미생물 증식 억제에 효과적인 것으로 나타났다. 기호도 조사 또한 저장 7일째 TEU-1은 모든 항목에서 6.5점 이상의 평가를 받았으나 TCS-2는 4.1 이하의 평가를 받아 소고기의 상품성이 상실된 것으로 판단되었다. 모든 분석항목에서 TCS-1이 TCS-2보다 소고기 신선도 유지에 효과적인 것으로 판단되었다.

The efficacy of an experimentally designed cold chain container and a currently used styrofoam container was investigated with respect to important factors affecting the quality of fresh beef during storage under different conditions. The temperature in the TEPP-1 container was maintained at 5℃ using a phase change material (PCM) during transport and delivery. During storage in the TEPP-1 container, no significant difference was observed in pH of beef, but color decreased slightly, which does not affect the desire to purchase. After storage for 7 days, the rate of VBN and TBA in the TEPP-1 container, was lower than that in the TEPP-2 container. Drip loss was lower in the TEPP-1 container (0.87%) than in the TEPP-2 container (1.78%). No significant changes were observed in microbal count until 4 days in either of the containers, but after storage for 7 days, the count increased significantly. Microbial count in TEPP-1 was 6.65 log CFU/mL and that in TEPP-2 was 7.62 log CFU/mL. The results of sensory evaluations indicated that the overall acceptability of beef after storage for 7 days was better in the TEPP-1 container than in the TEPP-2 container. The EPS container was inferior in comparison with TEPP-1 and TEPP-2. It was impossible to continue the experiment using the EPS container after 3 days. These results suggest that the experimentally designed TEPP-1 container can be used for beef transport and delivery for 7 days without significantly affecting the quality of beef.

돼지고기와 쇠고기의 부위별 저장 중 발생하는 품질 변화와 부패시점을 확인하고자 돼지고기의 등심, 삼겹살, 전지와 쇠고기의 안심, 등심, 양지 부위를 냉장 저장 하면서 pH, VBN, TBARS, 전자코 측정 및 관능검사를 수행하였다. 돼지고기의 경우 삼겹살 부위가 등심, 전지와 비교하여 pH, VBN, TBARS에서 전반적으로 높은 결과를 나타냈고, 부패취를 확인하기 위해 실시한 전자코 분석에서는 저장 초기와 저장 말기의 주성분 분석 값이 뚜렷이