Effects on the Storage Life of Satsuma Mandarin by the Pretreatment at various Temperatures

저장전 온도처리가 온주밀감의 저장에 미치는 영향

The storage life of satsuma mandarin(Citrus unshiu Marc. var. miyagawa) by the various pretreatment of temperatures; non-treated, room temperature, $10,\;20^{\circ}C$ and $35^{\circ}C$ were investigated. The pretreated citrus fruits were stored at $4^{\circ}C$, 85% relative humidity. Weight loss of citrus fruits by the pretreatment at $35^{\circ}C$ for 24 hrs was the lowest among that of others. Decay ratio of $35^{\circ}C$ pretreated fruits was increased at initial stages of storage, but was maintained low level after that, compared to other treatments. After 115 days storage, firmness of fruits was lowered by the softening, and decayed fruits were occurred increasingly. Ethylene evolution was increased between $55{\sim}65$ days after storage, and the amount was increasing rapidly after 115 days. It seemed to be derived from decayed fruits and physiological activities. $CO_2$ content in fruit was decreased at initial stages of storage, but was increased between $55{\sim}100$ days during storage periods. Acid content, soluble solids, total sugar and vitamin C were reduced gradually during cold storage, but the difference among treatments was not so great. Pretreated fruits at $35^{\circ}C$ for 24 hrs before cold storage was effective on preventing from weight loss and respiration ratio. Optimum storage period of early variety of Satuma mandarin was regarded for 100 days on the basis of appeareance and taste.

제주산 온주밀감의 저장전 온도처리에 의한 저장효과를 검토하기 위하여 궁천조생을 각각 무처리, 상온처리, $10,\;20,\;35^{\circ}C$의 저장전 처리를 한 다음 $4^{\circ}C$, 85% 상대습도에서 저온저장하였다. $35^{\circ}C$ 고온처리한 감귤의 중량감소가 매우 적었으며 부패율은 저장 초기에 다소 많았으나 저장 후기에는 오히려 떨어졌다. 과육율과 가용성 고형물은 저장기간 중 큰 변화를 보이지 않았으나 경도는 저장 115일 후부터 심하게 감소하였다. 에틸렌 발생은 저장 $55{\sim}65$일 사이에 약간 증가하다가 115일 이후 급격히 증가하여 부패과의 발생 및 생리활성과 연관이 있는 것으로 보인다. 감귤내 $CO_2$ 함량은 초기에 약간 감소하다가 저장 $55{\sim}100$일 사이에 다소 증가하였으며, 저장 후기에는 감소하는 경향을 나타내었다. 산 및 비타민 C함량은 호흡작용에 의해 저장기간이 경과함에 따라 계속하여 감소하였다. 저장전 $35^{\circ}C$에서 24시간 고온처리는 중량감소와 호흡작용의 억제에 효과가 있었다. 외관 및 내용 성분을 기준한다면 품질 유지를 위해서는 수확후 100일 정도가 조생온주밀감의 최적저장기간으로 판단되었다.