• Food Science and Preservation
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• v.4 no.2
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• pp.131-137
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• 1997

Effect of storage on the tree and quality of early cultivar of Citrus unshiu Marc. produced in Cheju according to harvest time were investigated. Soluble solids, acid content, flesh ratio, firmness and specific cavity of the fruits harvested at 27th of November were 12.0, 1.03%, 79.98%, 0.774kg-force, 0.912, respectively. Soluble solids, total sugar and reducing sugar were increased gradually, but acid content was decreased slightly as delayed in harvest time. Otherwise specific gravity and firmness were not shown in great during harvest time, color index(a/b) was increased sharply till late November and then remained in stationary phase. On these result, we recommend that the harvest time of early cultivar of Citrus unshiu Marc. would be during December because of wilting partly. Fully ripened-fruits harvested late, compared to ordinary harvest time, with cold storage would be kept more quality and freshness of fruits for fresh consumption than the fruits harvested early and stored at room temperature.

• Food Science and Preservation
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• v.2 no.2
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• pp.293-301
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• 1995

Quality changes of Korean native-bee honey were investigated during processing and preseration at different temperature. There were no changes of HMF(Hydroxy methyl furfural) and proline contents, color and diastase activity in Korean native-bee honey, when the honey separated from honey combs at 20$^{\circ}C$ and 40$^{\circ}C$. However, at 50 and 80$^{\circ}C$, browning of Korean native-bee honey was shown, HMF content was increased rapidly and proline content and diastase activity were decreased. There were no changes of chemical composition in Korean native-bee honey during storage at 4$^{\circ}C$ for 6 months. But color was darken and HMF content was increased slowly in Korean native-bee honey during storage at 20$^{\circ}C$. During storage at 30$^{\circ}C$ and 40$^{\circ}C$, HMF content was increased highly, proline content, diastase activity and total acidity was decreased rapidly. It is recommended that Korean native-bee honey is separated from honey comb and purified at less than 40$^{\circ}C$ and stored at 4$^{\circ}C$ through 20$^{\circ}C$.

• Food Science and Preservation
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• v.4 no.2
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• pp.189-196
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• 1997

Blanching conditions for immatured soybeans were optimized by analyzing the effects of various time/temperature blanch treatment on the activities of peroxidase and lipoxygenase, the stability of vitamin C and color, and moisture content in immatured soybeans for the purpose of minimizing quality deterioration during frozen storage. Blanching at 96$^{\circ}C$ for 70 sec led to maximum inactivation of lipoxygenase in the immatured soybeans, while my blanching conditions tested in this study were not enough to inactivate peroxidase. Blanching at 82$^{\circ}C$ for 60 sec resulted in the highest amount of vitamin C remaining in the immatured soybeans after blanching. Hunter -a/b ratios of immatured soybeans blanched at 82$^{\circ}C$ for 60 sec and hue values (ΔE) of the immatured soybeans blanched at 76$^{\circ}C$ for 60 sec showed the closest values to those of fresh products. The changes in moisture content of immatures soybeans was not so significant after blanching. In conclusion, it was suggested that immatured soybeans be blanched at 96$^{\circ}C$ for 70 sec to minimize lipoxygenase activity and resulting quality deterioration, while blanching at 82$^{\circ}C$ for 60 sec was recommended to stabilize vitamin C and color.