This study was carried out to investigate the effects of various temperatures of electro-magnetic resonance and air blast freezing methods on the physicochemical quality of meat. Beef (loin and round), pork (belly and ham) and chicken (breast and leg) were purchased at a commercial market, and the meat was frozen using three methods: air blast freezing (-20 o C and -45 o C) and electro-magnetic resonance quick freezing. Changes in the physicochemical properties of meat were analyzed by drip loss, cooking loss, water holding capacity (WHC) and proximate compositions. In comparison, regardless of the animal species and cuts of meat, electro-magnetic resonance quick freezing (2 h) resulted in a completely frozen product in a much shorter time than -20 o C and -45 o C air blast freezing (24 h and 8 h, respectively). Drip loss of loin which had underwent electro-magnetic resonance quick freezing were significantly (p<0.05) lower than those of the other two treatments, but cooking loss and water holding capacity were the highest at 43.7% and 60.7%, respectively (p<0.05). Characteristics such as crude protein, crude fat and moisture compositions showed significant differences, depending on the cuts and freezing methods (p<0.05). The fat composition of electro-magnetic resonance quick frozen loin and round were significantly low (p<0.05). However, moisture content was the highest compared to other freezing methods, as 67.1% and 71.9%, respectively (p<0.05). Electro-magnetic resonance quick freezing was an appropriate way to reduce the deterioration of meat quality due to freezing, and the drip loss was least for the part with low moisture, low protein, and high fat. 서 론 식품 냉동은 식품에서 열을 빼앗아 식품 내의 수분을 액 체에서 고체로 상 변화시키는 방법으로 장기 보존을 위한 최선의 방법 중 하나이다. 식육은 냉동 시 드립 발생, 단백 질 변성 및 지방 산화 등이 일어나 품질을 저하시킨다 (Lagerstedt et al., 2008; Mancini and Hunt, 2005). 특히, 식육 의 변성과 연관된 생화학적 반응은 냉동 온도에서도 액상 으로 잔존하는 식육 내의 수분 때문에 일시적으로 정지되 지만 저장 기간의 경과에 따라 진행이 지속된다 (Akamittath et al., 1990; Grujic et al., 1993). 일반적인 식육의 냉동 방 법으로는 정지 공기 냉동법(sharp freezing), 송풍식 냉동법 (air blast freezing), 접촉식 냉동법(contact freezing) 및 침 지식 냉동법(immersion freezing)이 있다. 정지공기 냉동법 은 냉각된 실내에 설치된 선반에 식품을 얹어 놓거나 또는 매달아 놓고 동결시키는 방법으로 응용 범위가 가장 넓고 관리가 용이한 반면 열전도율이 접촉식, 침지식 및 액체 질 소 냉동법보다 낮아 냉동 시간이 상대적으로 긴 단점이 있 는데 이를 보완한 것이 송풍식 냉동법이다. 송풍식 냉동법 은 냉기에 유속을 주어 공기와 시료 간에 열 전달 계수를 크게 하여 빠르게 냉동시키는 방법으로 산업적으로 가장

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Acne vulgaris is a common chronic skin disorder that affects millions of people. The pathogenesis of acne has been known to be closely associated with the bacterium Propionibacterium acnes. Here we investigated the anti-acne activity of Lactobacillus plantarum K-1 BR by observing the expressions of proinflammatory cytokines, TNF-α, IFN-γ and IL-8, of human keratinocytes. When we applied heat-killed P. acnes to HaCaT cells, the inflammatory cytokines were induced by two-to four-fold compared to the normal control. When the bacteriocin, purified from L. plantarum K-1 BR, was pretreated to the HaCaT cells, the expression levels of TNF-α and IFN-γ stimulated by P. acnes significantly decreased to 25% and 30% of the induced levels, respectively. The IL-8 levels also significantly decreased with the concentration dependent manner of the bacteriocin. These results suggest that the bacteriocin from L. plantarum K-1 BR could reduce the expression levels of inflammatory cytokines and thus may relieve inflammations caused by acne.

Intercom System(ICS) of Korean Utility Helicopter(KUH) is an essential equipment for pilot to perform flight mission and it consists of communication system of KUH with VHF-FM radio set and U/VHF-AM radio set. It provides pilots and crews with internal communication, external communication and audible alarm. It has function of controlling volume and selecting two communication modes, normal mode and backup mode. This paper summarizes pilot comments in flight test which are classified by cause of occurrence and the troubleshooting process about each comment. It also describes design improvements which was derived from troubleshooting and suggests verification results of flight test.

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