• Food Science and Preservation
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• v.14 no.5
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• pp.511-515
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• 2007

'Ooishiwase' plum (Prunus salicina L.) fruits were harvested at three pre-climacteric stages of ripeness (stages 1, 2, and 3) and treated with 1-methylcyclopropene (1-MCP, $1\;{\mu}L/L$) for 24 hours at $10^{\circ}C$ before storage to evaluate the effectiveness of 1-MCP in extending shelf-life at $10^{\circ}C$. Ethylene production and respiration rates were significantly lower after 1-MCP treatment compared to those of control fruit, throughout the entire storage period. Also 1-MCP delayed plum softening and color changes. However the chemical 1-MCP had no effect on fruit soluble solid content changes, the preservative 1-MCP is an effective tool for quality improvement in plums, and extension of shelf life of the fruit and plums can safely be harvested at stage 3 of ripening, at which time the most desirable organoleptic attributes have been developed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.2
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• pp.110-117
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• 1987

Polyphenol oxidase in Prunus salicina(Red) was extracted, some properties and its partially purification were investigated as follows; Polyphenol oxidase was purified about 15 folds after ammonium sulfate saturation and about 64 folds after Sephadex G-100 column chromatography. Polyphenol oxidase showed optimum pH for activity at 6.5 and optimum temperature at at $35^{\circ}C$ and high affinity to catechol in o-diphenol compounds. Thermal stability were about 85% and 75% of initial polyphenol oxidase activity remained after heating at $50^{\circ}C$ for 5 minutes and 30 minutes respectively. The Michaelis constant of the enzyme was 2.58mM. L-cysteine, glutathione, ascorbic acid and potassium cyanide appeared to be most effective inhibitors. EDTA showed a slight inhibition.

• Journal of Applied Biological Chemistry
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• v.56 no.1
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• pp.19-22
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• 2013

Plum (Prunus salicina L.) slices were dehydrated with red algae extract (RAE) at a concentration of 30% (w/w), and the dried samples were compared with maltodextrin (MD)-treated and hot-air dried samples in terms of physicochemical properties such as rehydration ratio, ascorbic acid, microstructure, and color. The rehydration ratios and colors of RAE-treated plum slices were better than those of MD-treated and hot-air dried samples. The ascorbic acid contents of RAE-treated samples were higher and their microstructures were finer than those of MD-treated or hot-air dried samples. These results suggest that plum slices can be dehydrated with RAE without loss of quality.

• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.221-227
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• 2005

Apoptosis of Prunus salicina Lindl. cv. Soldam, which possesses hematopoiesis, osteoporosis prevention, and antimutagenic effects, at different growth stages was evaluated. Cytotoxic effect of acetone extracts of immature fruits against various tumor cell lines was higher than that of mature fruits, particularly in hormone-independent human breast cancer, MDA-MB-231 cell line. Immature fruit extract increased expression level of pro-apoptotic protein Bax and reduced that of anti-apoptotic protein Bcl-2, and stimulated caspase-3 activity in MDA-MB-231 cells. Results suggest immature fruit of P. salicina Lindl. cv. soldam to be natural source for development of functional food and medical agents to prevent human breast cancer.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2007.11a
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• pp.167.1-167.1
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• 2007

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.4 no.2
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• pp.45-57
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• 1998

Immature and mature plums(Prunus salicina L.) were coated with calcium-added methylcellulose(CaMC) and hydroxypropylmethyl-cellulose-15(CaHPMC-15). Physicochemical, nutritional and sensory characteristics were compared during the 8-day storage period at $30^{\circ}C$. Irrespective of maturity, pH of plums increased and the titratable acidity decreased during storage. Free sugars such as glucose, fructose, sucrose and sorbitol were eventually decreased during storage, but Ca-added cellulose coatings influenced on the prevention of free sugars from decreasing especially in mature plums. Vitamin C contents in immature and mature plums became decreased during storage, but the coatings took effective on its retention. Changes of malic acid, the major organic acid in plums were appeared the same tendency as vitamin C during storage. Results of sensory evaluation showed the development of red color in peel and the softening of plum tissue, and also showed that the overall eating quality and appearance generally decreased during storage. However, the coated plums either CaMC or CaHPMC-15 exhibited the better sensory characteristics. As though the significant difference in postharvest storage quality were not found between the two coatings, CaMC and CaHPMC-15 coatings significantly contributed to the improvement of overall storage quality, especially the retention of vitamin C and organic acids only on the mature plums.

• Food Science and Preservation
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• v.11 no.3
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• pp.358-363
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• 2004

This study was performed to evaluate the antioxidant effect of Prunus salicina Lindl. cv. Soldam at different growth stages (sample 1-8). Previous studies shows that this fruits possess hematopoiesis effect, osteoporosis prevention, and antimutagenic effects. Prunus salicina Lindl. cv. soldam was picked in every 5 days from the 40th day before harvesting date for marketing in Gimcheon, Gyeongbuk. The fruits at different growth stages (sample 1-8) were extracted with 60$\%$ acetone and chlorophyll in the extracts was removed. In proximate compositions, the contents of moisture of sample 1, 5, 8 were 88.52, 87.01, 83.56$\%$ ; crude ash were 7.12, 3.35, 3.57$\%$ ; crude protein were 7.52, 5.55, 3.85$\%$ ; crude fat contents were 3.20, 0.99, 5.15$\%$, respectively. The contents of total polyphenols and condensed tannin in the acetone extracts from sample 1, 5, 8 were 10.67, 4.05, 2.57$\%$, and 8.36, 3.11, 1.88$\%$, respectively. The antioxidantive effect of acetone extracts from immature fruits showed strong scavenging effect on DPPH free radicals. The RC$_{50}$ values of the extracts from sample 1, 2 were 2.23, 9.70 $\mu$g/mL, respectively while those of butylated hydroxyanisole (BRA) was 5.25 $\mu$g/mL. The extracts from immature fruits showed over 85$\%$ inhibition on peroxidation of linoleic acid at 100 $\mu$g/mL as determined by both the ferric thiocyanate (FTC) and the thiobarbituric acid (TBA) method.

• The Korean Journal of Ecology
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• v.13 no.4
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• pp.251-266
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• 1990

Extrafloral nectaries have been shown in many studies to promote mutualistic interactions between plants and insects(usually ants) that visit the glands. The insects gain sugars, water and amino acids secreted by the extrafloral nectaries and benefit the plants by reducing the damage caused by plant's inseet herbivores. Little is known about the occurrence of extrafloral nectaries in plants growing in Asia. To learn about the occurrence of extrafloral nectary bearing plants in Korea, living plants and herbarium material were examined for the glands. In addition, the cover of plants with extrafloral nectaries and the proportion of woody plants with extrafloral nectaries were measured in three forest communities on Kangwha Island. 131 species of plants belonging to 53 genera and 30 families were found to have extrafloral nectaries. These 131 species comprise about 4.0% of Korea's flora, a highet percentage of extrafloral nectary bearing plants than occurs in the studied areas of North America. Extrafloral nectary bearing plants occupied 7, 23 and 55% of the covers and comprised 15, 21 and 15% of the woody plants in the three different forests, a significant level of occurrence. Many important Korean crop plants were found to have extrafloral nectaries including : sesame (Sesamum indicum L.), squash (Cucurbita moschata Duchesne), sweet potato (Ipomoea batatas Lam), persimmon (Diospyros kaki Thunb.) cotton (Gossypium indicum Lam.), mung bean (Phaseolus radiatus L.), red bean (Phaseolus angularis W.F.), peach (Prunus persica (L) Batsch.), plum (Prunus salicina Lindl.). Many of these cultivated and wild plants may receive protection by ants and other beneficial insects that visit their extrafloral nectaries.

• Horticultural Science & Technology
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• v.29 no.6
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• pp.592-599
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• 2011

Plum is a climacteric fruit and softening is a serious problem for storage and transportation. Thus $1{\mu}L{\cdot}L^{-1}$ of 1-methylcyclopropene (1-MCP) was applied to plums to prolong their shelf life and maintain quality. Japanese plums (Prunus salicina cv. Formosa) were stored at $20^{\circ}C$ and $0^{\circ}C$ for 14 days and 46 days respectively, with or without 1-MCP treatment. Fruits were treated with $1{\mu}L{\cdot}L^{-1}$ 1-MCP at $10^{\circ}C$ for 24 h. Ethylene production and respiration rate were strongly inhibited in 1-MCP-treated fruits at $20^{\circ}C$. It was also observed that there was less ethanol and acetaldehyde evaporation in 1-MCP-treated fruits stored at $20^{\circ}C$ compared to those in control fruits not treated with 1-MCP. Fruit qualities, such as firmness, titratable acidity (TA), skin color, and decay, changed more slowly in 1-MCP-treated fruits stored at $20^{\circ}C$ than in untreated fruits. There were no differences in the ethylene production or respiration rate between the groups of fruits stored at $0^{\circ}C$ throughout the experiment. Chilling injury was also inhibited by the application of 1-MCP during storage at $0^{\circ}C$. When the fruits stored at $0^{\circ}C$ with or without 1-MCP were transferred to $20^{\circ}C$ after 25 days, the differences in ethylene production and respiration rate, firmness, TA, TSS, and acetaldehyde and ethanol evaporation between the initial (after being stored at $0^{\circ}C$ for 25 days) and the final measurements (after being stored at $0^{\circ}C$ for 25 days and then transferred to $20^{\circ}C$ for three days) were lower in 1-MCP treated fruits than in non-treated fruits. The postharvest application of 1-MCP in Formosa plums showed positive effects at both $0^{\circ}C$ and $20^{\circ}C$ storage conditions with regard to quality, such as low ethylene production and low respiration rates, firmness, TA, ethanol, and acetaldehyde evaporation, chilling injury, and decay.

• Food Science and Preservation
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• v.15 no.6
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• pp.891-896
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• 2008

Total phenolics and flavonoids, and the antioxidant capacity of plum cultivar wines (Prunus salicina L. cv. Soldam and P. salicina L. cv. Formosa) were determined using spectrophotometric methods. The total phenolic and flavanoid contents of Soldam wine were $478.4\;{\pm}\;5.6\;mg$ GAE and $202.4\;{\pm}\;7.5\;mg$ CE per L,respectively, and in Formosa wine were $200.6\;{\pm}\;7.5\;mg$ GAE and $64.4\;{\pm}\;6.8\;mg$ CE per L, respectively. Neutral and acidic phenolics in Soldam wine were extracted with ethyl acetate and 0.01 N HCl, respectively. In the 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging assay, neutral phenolics (64.5 EDA%) had $3{\sim}4$ times higher antioxidant activity than acidic phenolics (21.5 EDA%) and other related phenolic compounds such as chlorogenic acid (15.5 EDA%) and quercetin (24.6 EDA%) at a concentration of $100\;{\mu}g/mL$. The antiviral activities of neutral and acidic phenolics in Soldam wine were investigated in vitro using a virus-induced cytopathic effect (CPE) inhibition assay. Results showed that neutral and acidic phenolics at concentrations of $100\;{\mu}g/mL$ inhibited porcine epidemic diarrhea virus (PEDV) replication at rates of 78.12% and 58.37%, respectively. The inhibition rate of 10 g/mL neutral phenolics (69.42%) was higher than that of ribavirin as an antiviral reagent (57.86%). At concentrations of $100\;{\mu}g/mL$ or less, neutral and acidic phenolics of Soldam wine had no cytotoxic effect against vero cells.