This study was aimed to lead high income using defect strawberry fruits of domestic cultivated cultivar for forcing culture from December to early March, and low priced fruits harvested after March, and to develop strawberry jam containing phytochemicals such as anthocyanin, ascorbic acid and ellagic acid similar level to the fresh fruits. Processing of strawberry jam was established using freeze-dried powdered fruit for constant contents of anthocyanin and ascorbic acid in fruits and ellagic acid in seeds.
Quality of market and defect fruits were compared. Sugar content of market fruits showed 3˚ brix higher than that of defect fruits. Acidity of market and defect fruits was 0.43% and 0.79%, respectively, and saccharinity-acidity ratio of market and defect fruits was 28.65 and 11.37, respectively. Width and height of the market fruits were longer than 1 cm compared to those of defect fruits. Color of market fruit was dark red, but defect fruit was light red colored. Anthocyanin content of powdered fruit was 75% of fresh fruit. Ascorbic acid content in the fresh fruits and powdered fruits were not different. Ellagic acid content of powdered fruit was 5 times higher than that of fresh fruit. For strawberry jam processing, 7.5 and 10.0% of the powder was good for optimal jam quality, but 10% powder was suggested to be added for economic feasibility. Anthocyanin content at 100 ℃ was drastically decreased, and it was further significantly reduced at 75℃ compared to that at 50 ℃. Ascorbic acid and ellagic acid were significantly decreased above 75 ℃, whereas they remained still high at 25-50 ℃. It was thought that 50-60 ℃ would be the best temperature for high contents of anthocyanin, ascorbic acid and ellagic acid not degraded during heat processing