Blanching and freezing of beef are important techniques used in developing frozen home meal replacement (HMR) products. These pre-thermal treatments minimize the deterioration of beef during storage. Beefs are washed, defatted, sliced (5.0×0.5×0.5 cm, fiber direction), and blanched by immersion in hot water for 2 min. Thereafter, the blanched beefs are spin-dried and frozen by individual quick freezing (IQF) method. Finally, the frozen beefs are packed using two methods: vacuum packages and air-containing packages. Packed beefs are stored at -12oC, -18oC, and -24oC for nine months. One in every three months, they are thawed in a microwave (400W). While thawing, vacuum-packed samples possess lower thawing loss than air-containing-packed ones. Compared to raw beef, blanched beef have a higher L* and lower a* value. However, less changes are observed after blanching the beefs as the enzymes get inactivated in the blanching process. Shear force of beef also increase through blanching. Moreover, vacuum-packed samples have maintained their hardness to a greater extent than the air-containing-packed samples. All the samples have met microbial safety standards. Thus, it is inferred that vacuum-packaging and -18oC storage temperatures are the best condition for maintaining beef that is later developed into HMR product.
In this study the effect of rice type and cooking methods on the quality of cooked rice during cold storage wereinvestigated to develop home meal replacement (HMR) products. The chemical and physical properties and sensoryquality of rice were studied by rice type (Oh-dae-mi, Baek-jin-ju S., and Indica) and cooking methods (electric ricecooker and super heated steamer). Cooked rice was stored at 5oC for 3 days and the moisture content, color, reduc-ing sugar content, texture profile, and sensory evaluation were analyzed. The results show that rice type Baek-jin-ju S. has the highest moisture content and that color and textural properties are maintained during storage. Ricecooked with an electric rice cooker has higher moisture content and better color properties; however, rice cookedwith a super heated steamer shows higher reduced sugar content with a softer texture. The selection of Baek-jin-juS. and cooking with a super heated steamer have a positive effect on the quality of rice during cold storage.
본 연구에서는 단백질 함량이 높은 들깨박을 기능성 식품소재로서의 활용가능성을 확인하기 위하여 단백질분해효소 및 한외여과를 이용하여 가수분해물과 펩타이드 분획을 제조하고 이들의 항산화 활성을 측정하였다. 먼저 들깨박단백질의 가수분해물 생산을 위한 최적 효소를 선정하기 위해 단백질분해효소 7종을 이용하여 효소 반응 후 가수분해도를 측정한 결과, flavourzyme이 가장 높은 가수분해율을 나타내었다. Flavourzyme에 의한 들깨박단백질 가수분해물을 얻기 위한 최적 조건은 pH 7.0, 50℃, 효소농도 10 unit, 가수분해시간은 4시간으로 결정되었다. 들깨박단백질 가수분해물을 한외여과 후 얻은 각 분획의 수율은 1 kDa 이하가 45.65%로 유의적으로 가장 높았으며, 그 다음으로5-10 kDa(16.45%), 10 kDa 이상(16.37%), 1-3 kDa(10.86%), 3-5 kDa(10.67%) 순으로 높았다. DPPH 라디칼 소거능은 효소가수분해물이, 환원력은 3-5 kDa 분획물이, superoxide dismutase 유사활성은 1 kDa 이하의 분획물이 가장 높은 활성을 나타내었다. 따라서 들깨박단백질로부터 생산된 가수분해물 및 펩타이드 분획은 각기 다른 항산화 활성 특성을 보여 기능성 식품 소재의 목적에 맞게 선택하여 활용할 수 있을 것으로 판단된다. 또한 향후 식품학적 기능성 평가가 이루어진다면 식품산업에서 다양한 식품재료로의 활용성이 확대될 수 있을 것으로 판단된다.