Browsing by Author "Ojala, Birita"

The american cranberry (Vaccinium macrocarpon) is a woody perennial plant. Cranberry fruit has been studied for its many different health benefits due to the high level of human health-promoting compounds such as flavonoids and anthocyanins. The growing season is too short in Finland, and the fruits must be harvested before frost. Studies have shown that post-harvest lighting can affect the quality of fruits. Light treatment increases the anthocyanins content and red color in fruits. Lighting during storage might improve also shelf life. The aim was to find out how different light treatments affect different quality characteristics of fruits. In this thesis, the effect of three different light treatments on the accumulation of anthocyanins and phenols during 14 days following harvest in american cranberry fruits was investigated. The light treatment was APL (multispectrum), blue and red light. The control was dark treatment. In addition, the color of the fruits, the sugar content and titratable acids were measured. Light treatments increased anthocyanin content in all varieties compared to dark control. The most effective was APL treatment. The phenol content first (7 days) increased in all varieties, after which the increase continued only in Early Black and Howes varieties. There were statistically significant differences between the light treatments only for these varieties, but only 14 days after the treatments. The treatment did not have significant effect on sugar content or the titratable acids. The berries turned red in light treatments and the color intensity increased. The treatments differed significantly from the dark, but not with each other. The results of this thesis indicate that it would be possible to ripen cranberry fruits during storage. The berries could be harvested half ripe and ripened during storage using lights. There would also be a demand for domestic cranberries in the food industry, allowing imported cranberries to be replaced by a domestic alternative.