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Kim H.J.,Kyungnam University | An D.S.,Kyungnam University | Ahn G.-H.,Sweet Persimmon Research Institute | Lee D.S.,Kyungnam University
Journal of Food, Agriculture and Environment | Year: 2010

Non-astringent sweet persimmon fruits are stored for extended periods and distributed in modified-atmosphere packaging in eastern Asia. Differences in cultivar, harvest time and storage temperature affect the respiration rate of sweet persimmon, which should be taken into consideration when decisions are made regarding storage conditions and packaging materials. The respiration rate of two cultivars of non-astringent sweet persimmon (Nishimurawase and Fuyu) was measured at 0, 5, 10 and 15°C for consideration as storability index and package design variable. The effect of various harvest times on respiration rate was also assessed for the Fuyu cultivar. The early-harvest Nishimurawase cultivar had a higher respiration rate than the late-harvest Fuyu cultivar. Respiration of both cultivars exhibited similar temperature dependence, with Arrhenius equation activation energies of 67-89 kJ mol-1. Fruits of the Fuyu cultivar that were harvested at the interim stage weighed about 211 g and had a lower respiration rate than those picked at the early or late stages.

Jo Y.-H.,Kyungnam University | Park J.-W.,Kyungnam University | Lee J.-M.,Kyungnam University | Ahn G.-H.,Sweet Persimmon Research Institute | And 2 more authors.
Journal of the Korean Society of Food Science and Nutrition | Year: 2010

The antioxidant activity of methanol extracts from five different parts (flesh, peel, core, seed, calyx) of Jangseong Daebong persimmon (Diospyros kaki cv. Hachiya) were evaluated by determining total phenol content (TPC), DPPH radical scavenging activity (RSA), ABTS RSA, and reducing power (RP). The flesh extract gave the highest yield (92.93%) while the lowest yield was obtained from the seed (5.17%). The seed extract showed the highest total phenolic content (76.47±0.009 mg GAE/g extract), DPPH RSA (IC50=52.05±1.61 μg/mL), ABTS RSA (IC50=30.94±0.41 μg/mL) and RP (IC50=87.94±0.37 μg/mL). In addition, the calyx extract also showed high antioxidant activity. On the other hand, the core extract gave the lowest TPC and all antioxidant assays. In particular, HT-29 cells showed extensive cell death when treated with 500 μg/mL of calyx extracts. Thus, these results suggest that methanolic extracts of Jangseong Daebong persimmon seed and calyx may serve as a potential source of natural antioxidant for food and nutraceutical application.

Jang I.-C.,Kyungnam University | Oh W.-G.,Kyungnam University | Lee S.-C.,Kyungnam University | Ahn G.-H.,Sweet Persimmon Research Institute | Lee J.-H.,Andong National University
Food Science and Biotechnology | Year: 2011

In this study, the antioxidant activity of persimmon fruit of 4 different persimmon cultivars cultured at Korea was evaluated. There were 3 astringent persimmon cultivars ['Bongok' (BO), Japanese Hatchiya; 'Cheongdobansi' (CB); and 'Dogeunjosaeng' (DJ), Japanese Tonewase] and 1 non-astringent persimmon cultivar ['Seochonjosaeng' (SJ), Japanese Nishimurawase] fruits. After preparing extracts of fruits according to parts (calyx, pulp, and peel) with 4 different solvents (acetone, ethanol, methanol, and water), total phenolic contents (TPC) and antioxidant activity were determined. The extracts of calyx showed significantly higher TPC and antioxidant properties than those of the other persimmon parts. The highest 1,1- diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (IC50=43.36±1.78 μg/mL) and reducing power (IC50=81.93±1.18 μg/mL) were found at acetone extract of SJ calyx, while SJ pulp extracts showed relatively lower antioxidant activities. Astringent persimmons showed relatively higher antioxidant activity than non-astringent persimmons in peel and pulp parts. These results indicated that persimmons have different antioxidant activity depending on cultivars and parts. © KoSFoST and Springer 2011.

Kim H.J.,Kyungnam University | An D.S.,Kyungnam University | Ahn G.-H.,Sweet Persimmon Research Institute | Lee D.S.,Kyungnam University
Journal of Food, Agriculture and Environment | Year: 2011

A 60 μm-thick low density polyethylene (LDPE) and 50 μm thick polypropylene/low density polyethylene laminated (PP/LDPE) films were used to pack 5 persimmons in either heat-sealed or tie-banded bags. A perforated package was used as the control. Tie-banding of the plastic film bags led to increased gas permeability of the package and a different CO 2/O 2 permeability ratio when compared to heat-sealed plastic film bags. Among the packages stored at 0°C, LDPE heat-sealed packages were best in maintaining the atmosphere of the package (0.4-3.6% O 2 and 4.2-4.9% CO 2) at optimal MA condition (1-3% O 2 and 4-7% CO 2), whereas heat-sealing led to an anoxic atmosphere in the bag with the lowest permeability (PP/ LDPE). Both tied packages of LDPE and PP/LDPE had overly high O 2 concentrations but optimal CO 2 levels. All packages were suitable for preserving the fruit for 55 days at 0°C, although the fruit did suffer from browning discoloration or skin blackening after extended storage. Transfer of the packages to 20°C led to drastic changes in internal atmosphere and fruit quality even after 1 day and maintenance of lower temperature condition is suggested in the distribution after long-term storage at low temperature.

Choi S.-T.,Sweet Persimmon Research Institute | Park D.-S.,Sweet Persimmon Research Institute | Kang S.-M.,Gyeongsang National University | Park S.-J.,Gyeongsang National University
HortScience | Year: 2011

A possible relationship between leaf SPAD readings and nitrogen (N) concentrations was evaluated at different growing stages of 'Fuyu' persimmon trees under different N regimes in pots and in the field. When 5-year-old trees grown in pots received 0 to 40 g N over the growing season, leaf SPAD reading, N concentration, and specific leaf weight tended to increase with increasing N rate. The correlation between leaf SPAD reading and N concentration was statistically significant from late April to early November (R2 = 0.72 to 0.97). It was noted that the slope of regression line decreased as the season progressed. Similar significant correlations were found from pot-grown 4- to 7-year-old trees grown under various nutrient regimes (R2 = 0.67 to 0.96). Significant correlations were also confirmed with the leaves collected from 31 commercial orchards at different locations. The highest coefficient of determination was observed from the leaves collected at harvest time in both the pot and field experiments. Although the regression equations differed depending on the growing stage of trees, SPAD readings were found useful in estimating leaf N status at a specific time and in quickly judging the need for N application at that time. Seasonal changes of leaf SPAD readings from five well-managed orchards are presented as a reference guide for practical use.

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