This study was conducted to determine antioxidant activities in acetone, ethanol, methanol, and water extracts from the seeds of 4 persimmon cultivars. Antioxidant activities were evaluated on the basis of DPPH (1,1-diphenyl-2-picrylhydrazyl) radical-scavenging activity (RSA), ABTS (2,2-azino-bis [3-ethylbenzothiazoline-6-sulfonic acid]) RSA, and reducing power. Cheongdobansi seed extracts showed significantly higher antioxidant activities and phenolic contents than did Bongok, Fuyu, and Nishimurawase seed extracts. Ethanol was more effective for the extraction of antioxidant compounds from persimmons than other solvents. Palmitic acid, oleic acid, and linoleic acid were the main fatty acids found in persimmon seeds. Fuyu seeds contained the highest levels of fatty acids, and the unsaturated fatty acid contents of persimmon seeds range from 70.4% to 78.3%. All persimmon seed extracts, with the exception of the water extract of Nishimurawase seeds, inhibited DNA damage induced by H 2 O 2 .

The aim of this study was to develop a new natural preservative system making up for the weak points of chitosan as a preservative. As reported in a previous manuscript (20th IFSCC Congress, Cannes, France, 1998), the minimum inhibitory concentrations (MICs) of water-soluble chitosan against bacteria and yeast were 0.9-3.0 mg mL(-1), whereas MICs of chitosan against Aspergillus niger were over 5.0 mg mL(-1). However, the result of recent study showed that the MICs of Inula helenium L. extract against A. niger were below 1.0 mg mL(-1). Thus, we could develop a new preservative system containing both chitosan and I. helenium L. extract named CI-mixture. MICs of CI-mixture against bacteria and fungi (yeast and mould) were 2.0-4.0 mg mL(-1). When 10.0% of the mixture (the ratio of chitosan to I. helenium L. extract = 7.5% : 2.5%) was applied to cosmetic formulae such as skin lotion, milk lotion, cream and pack, it revealed appropriate preservative efficacy. Our result of the patch test also showed that this preservative system reduced skin irritation by about 30-50%, as compared to the organic preservative system. Therefore, the good natural preservative system including chitosan and Inula helenium L. extract could be incorporated in cosmetic formulations.

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Persimmon (Diospyros kaki Thunb.), which is a climacteric fruit, softens in 3–5 weeks after harvest. However, little is known regarding the transcriptional changes that underlie persimmon ripening. In this study, high-throughput de novo RNA sequencing was performed to examine differential expression between freshly harvested (FH) and softened (ST) persimmon fruit peels. Using the Illumina HiSeq platform, we obtained 259,483,704 high quality reads and 94,856 transcripts. After the removal of redundant sequences, a total of 31,258 unigenes were predicted, 1,790 of which were differentially expressed between FH and ST persimmon (1,284 up-regulated and 506 down-regulated in ST compared with FH). The differentially expressed genes (DEGs) were further subjected to KEGG pathway analysis. Several pathways were found to be up-regulated in ST persimmon, including “amino sugar and nucleotide sugar metabolism.” Pathways down-regulated in ST persimmon included “photosynthesis” and “carbon fixation in photosynthetic organisms.” Expression patterns of genes in these pathways were further confirmed using quantitative real-time RT-PCR. Ethylene gas production during persimmon softening was monitored with gas chromatography and found to be correlated with the fruit softening. Transcription involved in ethylene biosynthesis, perception and signaling was up-regulated. On the whole, this study investigated the key genes involved in metabolic pathways of persimmon fruit softening, especially implicated in increased sugar metabolism, decreased photosynthetic capability, and increased ethylene production and other ethylene-related functions. This transcriptome analysis provides baseline information on the identity and modulation of genes involved in softening of persimmon fruits and can underpin the future development of technologies to delay softening in persimmon.

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