• Korean Journal of Food Science and Technology
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• v.16 no.1
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• pp.59-65
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• 1984

Effect of ripening methods and harvesting time on vitamin content of 5 tomato varieties was investigated in 1978 and 1979. Ascorbic acid content in the breaker ripened tomatoes was significantly higher than that in the vine ripened tomatoes, and the result was consistent for two consecutive years. Ascorbic acid content in the vine ripened tomatoes markedly increased as the season progressed, early harvested tomatoes containing significantly less ascorbic acid. Carotene content was not significantly affected by the ripening method. Higher carotene content, however, was observed for tomatoes harvested in the late season. This result could indicate the effect of temperature for carotenogenesis around the harvest time. Thiamin and riboflavin contents in the vine ripened tomatoes were significantly higher than those in the breaker ripened tomatoes in the 1978 season, but these differences were not observed in the 1979 season. Thiamin and riboflavin contents in the vine ripened tomatoes decreased considerably as the season progressed. Thiamin and riboflavin contents in tomatoes harvested in the early season were significantly higher than those in the mid and late seasons.

• Journal of Plant Biotechnology
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• v.37 no.4
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• pp.388-393
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• 2010

Recently, a number of successful research reports are accumulated to increase the carotenoid level in potato tuber such as $\beta$-carotene, precursor of vitamin A and keto-carotenoid like astaxanthin in which is not synthesized in most plants tissue since it does not contain a specific enzyme to add keto-ring in carotenoid molecule. In particular, keto-carotenoids are more interested due to their strong antioxidant activity. Currently, the content of $\beta$-carotene was increased up to 3,600-fold ($47\;{\mu}g/g$ dry weight) when compared to the control potato tuber, parental cultivar for genetic modification. In addition, astaxanthin, one of the major keto-carotenoid was accumulated up to $14\;{\mu}g/g$ dry weight in potato tuber with red color by over expressing the gene encoding $\beta$-carotene ketolase isolated from marine microorganisms. In this article, we summarized carotenogenesis-related genes that have been used for metabolic engineering of carotenoid biosynthetic pathway in potato. Furthermore, strategies for the accumulation of carotenoids and ketocarotenoids in specific potato tuber, bottle necks, and future works are discussed.