This study investigated the changes in fruit quality characteristics and how they correlated with the storage conditions and storage period. The firmness of peaches stored in cold storage decreased rapidly after 14 days (13.0 N), but the firmness of peaches stored in CA storage remained high for 28 days (20.9 N). The titratable acidity of peaches stored in cold storage decreased rapidly from 0.23 to 0.26% after 21 days, but there was no change until 7 days for peaches stored in CA storage, and then it decreased to 0.23% after 28 days. The soluble solid content increased significantly as the storage period elapsed under cold storage, but there was no notable difference for CA storage. After 28 days of storage, the weight loss rate of peaches stored in CA storage(8%) was lower than peaches stored in cold storage( 23%). The was significant background color for peaches stored in cold storage after 7 days, and changed to a completely different color after 28 days of storage. As for the correlation between the quality characteristics of peach fruits stored at low temperatures, weight loss rate, sunny side ΔE value, background color lightness, background color redness, and ΔE value showed high correlations, and CA storage showed high correlations with weight loss rate and coloration. In conclusion, according to our study results, 'Kunika' peaches can be stored for 14 days in low-temperature storage and up to 28 days in CA storage, and it is thought that the weight loss rate, firmness, and coloration during storage can be used as factors for quality prediction.

To predict the quality of Fuji apples, this study investigated the characteristics and correlations of their fruit quality according to storage method and storage period. Fuji apples were stored in cold storage at 0oC for 250 days with no treatment, with 1-MCP treatment, and under controlled atmosphere (CA) storage. According to the storage method, the weight loss was the lowest in the CA-treated group (3.43%) until 250 days, and the change in fruit firmness was the least in the 1-MCP group. The titratable acidity remained above 0.2% for 1-MCP and CA storage until 250 days and decreased to 0.1% for cold storage. The principal component analysis showed a difference in quality between the 1-MCP group, CA group, and cold storage group after 200 days of storage. Six types of volatile components were commonly detected in all storage methods, while three types of independent components with a low threshold were detected in 1-MCP. Weight loss, titrable acidity, and firmness were highly correlated with physicochemical quality, and CA storage was judged to be a long-term storage technology that satisfies consumers’ tastes by maintaining excellent flavor and quality.

소고기의 건식 숙성 기간을 단축하고자 연육과 관련된 효소 활성이 높은 15-36oC 온도범위에서 저습도로 숙성할 수 있는 라디오파 숙성장치를 개발하였다. 이 장치는 평행 판 전극 사이에 소고기를 넣고 라디오파를 가하여 유전가열이 되는 현상으로 고기의 온도를 높였고, 냉풍을 이용하여 습도를 낮춰서 고기표면이 건조되게 하였다. 이 장치를 이용하여 2등급 소고기 채끝 부위를 숙성시킨 결과 40 W/ kg로 가열하여 고기 품온이 30oC를 초과하는 온도 범위 24 h 숙성할 경우 12.3%, 10-30oC 온도 범위에서 숙성시킬 경우 55.2% 연육효과가 나타났다. 라디오파 숙성 중 제상 과정 없이 냉풍을 계속 가할 경우 미생물 증식에 의한 문제가 발생하지 않았으며, 이러한 연육 효과는 기존 건식숙 성 21일간 절단강도 17% 감소하는 것에 비해 매우 단시간 나타난 것으로 숙성기간을 크게 단축할 수 있음을 확인 하였다. 닭고기와 돼지고기는 육질의 차이로 라디오파 숙성에 의한 연육 효과가 나타나지 않았다.

When kimchi is frozen and thawed, the amount of lactic acid bacteria (LAB) and yeast is usually reduced by more than 2 logs, and its texture including its crispness and hardness are changed significantly. As a possible means to minimize these problems, various freezing (direct freezer with -25, -40, and -60oC and plate freezer with -40oC) and thawing methods (radio frequency (RF) thawing, plate thawing, and room temperature thawing) were investigated in terms of the amount of LAB and texture of kimchi. From the use of plate freezing and plate thawing, the amount of LAB of white cabbage kimchi could be maintained by more than 10% of its initial amount while that for red cabbage kimchi could be maintained by more than the initial amount. Pretreatment with trehalose (19 oBrix soluble solid content) to salted Chinese cabbage could maintain kimchi’s hardness and crispness. In order to maintain the texture and the amount of LAB in kimchi, the use of the plate freezer (-40oC) and the plate thawing (20oC) seemed to be effective with the assistance of trehalose.

This study was conducted to investigate the quality of kimchi cabbages stored under a pallet unit-controlled atmosphere (PUCA), containing 2% O2 and 5% CO2, and to develop quality prediction models for cabbages stored under such conditions. Summer and winter cabbage samples were divided into PUCA-exposed groups and atmospheric airexposed control groups (in a cold storage). The control summer cabbages lost up to 8.31% of their weight, whereas the PUCA-exposed summer cabbages lost only 1.23% of their weight. Additionally, PUCA storage effectively delayed the reduction in cabbage moisture content compared with the control storage. After storage for 60 and 120 days of the summer and winter samples, respectively, the reducing sugar contents were higher in the PUCA groups than in the control groups. The linear regression analysis-derived equations for predicting the storage period, weight loss, and moisture content in the control groups, as well as those for predicting the storage period and weight loss in the PUCA groups, were appropriate according to the adjusted coefficient of determination, root mean square error, accuracy factor, and bias factor values. Therefore, this PUCA system would be useful for improving the shelf life of the postharvest summer and winter cabbages used in the commercial kimchi industry.