Changes of Characteristics in Red Pepper by Various Freezing and Thawing Methods

The development of an effective long-term storage protocol for harvested fresh pepper is urgently required to increase the market for pepper products. The protocol must minimize quality loss, so that the product may be used either as a spice or as a raw material for processed pepper products, both in the home and in food processing plants. We investigated the optimum size of pepper fruits, freezing temperatures, storage periods, and thawing methods, to establish an optimum storage protocol. This study was conducted not only to develop freezing and thawing methods for long term storage of harvested red pepper, but also to develop processed pepper products utilizing the stored pepper. We aimed to expand the pepper products market and to increase the incomes of pepper growers. Whole red pepper, sliced red pepper, and crushed red pepper were frozen and stored at $-5^{\circ}C,\;-20^{\circ}C,\;or\;-40^{\circ}C$. The soluble solid content and the vitamin C level showed maximal stability at $-40^{\circ}C$, although total free sugars decreased on storage at all temperatures tested. Such Changes were more marked at $-5^{\circ}C$ than at the other(lower) temperature tested. The vitamin C content of whole red pepper was higher than that of sliced red pepper or crushed red pepper. Room-temperature thawing resulted in twice the drip loss seen on low temperature($5^{\circ}C$) thawing or microwave oven thawing. Brown discoloration was a serious problem with room temperature thawing. Total free sugars were higher in samples thawed at low temperature or in the microwave oven, compared to the level seen after room-temperature thawing. pepper samples thawed at low temperature scored higher in sensory tests than samples thawed at room temperature.

홍고추의 저장온도 및 해동조건에 따른 물리화학적 특성 변화

홍고추를 원료형태에 따라 원형, 세절, 분쇄로 제조하여 $-5^{\circ}C,\;-20^{\circ}C$ 및 $-40^{\circ}C$ 저장고에 보관하였다. 고추의 표면색도는 저장온도 조건에 따라 저장일수가 증가할수록 약간 감소하는 경향을 보였으며, 비타민 C 함량은 원형 홍고추가 세절고추나 분쇄고추보다 저장기간 동안 완만하게 감소하는 경향을 보였다. 저장온도별로는 $-40^{\circ}C$ 저장군에서 비타민 C 함량이 가장 높게 유지되었으며, $-5^{\circ}C$ 저장군에서 저장 2개월째 50% 이하로 급격히 감소하였다. 유리당 함량은 저장일수가 증가할수록 모든 처리구에서 저장 2개월까지 약간 증가하다가 점차적으로 감소하였으며 $-5^{\circ}C$ 저장온도 처리군에서의 감소변화가 $-20^{\circ}C,\;-40^{\circ}C$ 저장온도 처리군보다 심하게 나타났다. 냉동고추를 실온 해동시 드립로스의 양이 냉장 해동, microwave oven 해동시보다 약 2배 가까이 드립로스양이 발생하였으며, 표면색도는 고온 해동시 갈색화가 심하게 나타났다. 해동조건에 따른 냉동고추의 성분 변화는 냉장 해동과 microwave oven 해동시 가장 적게 나타났으며, 해동 시간을 고려한다면 microwave oven 해동이 가장 실용적인 방법이라고 여겨진다.