Submitted to: Journal of Horticultural Science and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/28/2002
Publication Date: 5/28/2002
Citation: Ledbetter, C.A., Aung, L.A., Palmquist, D.E. The effect of fruit maturity on quality and colour shift of dried 'Patterson' apricot during eight months of cold storage. Journal of Horticultural Science and Biotechnology. 2002. v.77(5). p 526-533. Interpretive Summary: California produces 86,000 tons of apricots during 2001 and over 25% of the tonnage was processed into dried fruit. These dry apricots must be stored for many months after being processed during the summer, since the Christmas holiday season is traditionally the largest market for dried apricots. Fruit quality at harvest influences product quality after the dry apricots are brought out of storage. It was demonstrated that dried apricots darken during the storage period. Furthermore, the rate of darkening in storage was related to fruit maturity. Fruit darkening was found to be least in apricots harvested at the optimum. This information enables the production of dry apricots of the high quality for consumer use.
Technical Abstract: Fresh 'Patterson' apricot was harvested at three levels of fruit maturity and characterized with measurements of flesh color (luminosity, chroma, and hue), Brix, titratible acidity, and levels of specific sugars. Fruit from the three maturity classes were halved, fumigated with sulfur dioxide, and sun-dried before packaging and cold storage at 3C. Stored fruit were sampled periodically for shifting of color coordinates luminosity, chroma, and hue during an eight month period. The experiment was repeated for two harvest seasons. In each of the harvest seasons, significant differences (p </= 0.05) were observed between the three fruit maturity classes for Brix, titratible acidity, chroma, and hue. Levels of specific reducing sugars varied significantly (p </= 0.05) in fresh 'Patterson' apricot with regard to fruit maturity class and tissue type (flesh vs. peel). Regression analysis of color coordinate changes during the storage period indicated significant (p </= 0.05) differences in rate of color shift of luminosity, chroma, and hue relative to fruit maturity class. While dried fruit of the immature class was of substandard quality after the storage period, both medium and most mature dry fruit were of sufficient quality to warrant marketing even after eight months of cold storage.