Effect of different thawing methods on quality of frozen blueberries

The effects of various thawing methods including low temperature thawing, thawing at room temperature, water bath thawing, microwave thawing, and ultrasonic thawing on quality of frozen blueberries were studied by measuring thawing time and changes of physical properties and nutritional contents.Significant differences ( p < 0.05) in thawing time were found among the five thawing methods, the order of the thawing time was microwave thawing < ultrasonic thawing < water bath thawing < room temperature thawing < low temperature thawing.Fruit treated with microwave thawing retained the most soluble solids, titratable acids, firmness, and the least juice loss. Microwave thawing retained the better anthocyanins, VCand total phenolics in the thawed blueberries, indicating that this method rendered the less damage to the blueberry constituents.Overall, it was concluded that microwave thawing was the most effective method for the defrosting process of frozen blueberries.