본 연구는 감마선 및 전자선 조사에 의한 닭고기 원료 사료 내에 존재하는 주요 위해 미생물을 비열처리 살균 효과를 검증하기 위하여 진행되었다. 일반세균, E. coli 및 Salmonella의 위해 미생물을 분쇄 닭고기 원료사료에 접종 후 3, 5, 7, 10 kGy의 전자선과 감마선으로 조사하였다. 전자선과 감마선 모두 3 kGy의 조사 시 시험된 미생물을 검출 한계 이하로 사멸시켜 분쇄 육류 원료 사료의 경우 3 kGy의 흡수선량이 충분한 비열 살균 조건임을 보여주었다. 방사선 조사에 의한 원료 사료의 품질 지표 변화를 알아보기 위하여 분쇄 닭고기의 조사 처리 후 pH 변화, 색도 측정, 전자코 이취 분석을 수행하였다. pH와 색도의 경우 감마선 및 전자선 조사에 의해 유의미하게 변화하지 않는 것으로 나타났다. 전자코 이취 시험의 경우 감마선 조사의 경우 3 kGy의 저선량 조사부터 이취가 발생되기 시작하였으며 10 kGy 조사 시 급격하게 이취의 정도가 증가하는 것으로 나타났다. 전자선 조사 역시 3 kGy의 조사부터 이취가 발생하였으며 5 kGy의 선량 이후 흡수선량이 증가함에 따라 이취가 점진적으로 증가하였다. 본 연구 결과 3 kGy의 저선량에서도 닭고기를 원료로한 펫푸드의 비열 살균 효과를 충분하게 이루어짐을 확인하였고 품질 지표에도 부정적인 영향을 주지 않는 것으로 나타났다. 이러한 비열처리 펫푸드의 살균 기술 개발은 국내 펫푸드 시장의 활성화와 반려 동물의 복지 향상에 기여할 것으로 기대된다.

This study examined the physicochemical properties of radish pickle containing different natural preservatives (grapefruit seed extract, green tea extract, rosemary, or olive) stored for 0, 1, 2, 3, and 4 weeks. The hardness and color of the radish pickles with the grapefruit seed extract was higher than the other radish pickles during storage from week 0 to week 4. A 14.52% and 13.80% decrease in hardness and color were observed in the radish pickles with grapefruit seed extract (GFE), respectively. In addition, the total phenolic content was highest in the GFE in natural preservatives. Based on the results, GFE was selected as the optimal natural preservatives, and the growth of total viable bacteria and yeast were evaluated. The total viable bacteria and yeast showed similar patterns to the control. These results are expected to be useful in producing radish pickles with optimal quality and contribute to the development of various foods in the food industry.

The feasibility of infrared assisted freeze drying (IRAFD) was evaluated for shelf stable sea cucumber to improve the traditional drying methods such as freeze drying (FD), vacuum drying (VD) and hot air drying (AD, 60, 80, 100oC). Infrared (IR) radiant energy was provided to accelerate the drying rate of freeze drying (FD). IRAFD had the most rapid drying rate among IRAFD, FD and VD. IRAFD showed drying time of 13.7 h followed by VD (18.7 h) and FD (24.3 h). In the final moisture content of sea cucumber, it decreased down to 3.25% at IRAFD. However, FD and VD could not reduce down the moisture content of sea cucumber below 7%. Quality attributes of AD sea cucumber were not acceptable with very low restoration rate and excessive hardness. For example, AD 100 had very low weight restoration rate of 23% and hardness of 22 N. IRAFD showed quite high restoration rates (weight: 50%, width: 82%, length: 91%) and acceptable hardness of 3.1 N. IRAFD consumed the minimal electrical energy of 120 kJ as compared to 209 kJ of FD. This study showed the potential application of IRAFD to produce the shelf stable dried sea cucumber with microbial safety.

This study was conducted to investigate the potential of infrared assisted air drying (IRAD) to dry dorumuk (Arctoscopus japonicus). The IRAD system is composed of a far infrared lamp, convection fan, data loggable electronic balance, and proportional-integral-differential temperature controller. The infrared lamp provided radiative energy for temperature increase and substance moisture vaporization. The convection fan removed the moisture outside the drying chamber. Various IRAD conditions were tested at 40oC & 5 m/s, 40oC &11 m/s, 50oC & 5 m/s, 50oC & 11 m/ s, 60oC & 5 m/s, or 60oC & 11 m/s. The IRAD of 40oC & 5 m/s could reduce the moisture content by 42.2 %. The IRAD of 60oC and 11 m/s could further reduce the moisture content to 16.7% within 17 h. During the IRAD test, electrical energy consumption ranged from 1.16 to 1.38 kWh which is lower than that of hot air drying. IRAD resulted in dried dorumuk with yellow color and crispy texture. In this study, IRAD showed potential for the production of high-quality, dried dorumuk products.