Effect of Various Pretreatment and Thawing Methods on Quality Characteristic of Frozen Carrot and Potato

다국어 초록 (Multilingual Abstract)

This study investigated the effect of various blanching and thawing methods on frozen carrots and potatoes by individual quick freezing (-35°C). Carrots and potatoes were cut into 1×1×1 cm cubes and then blanched by using steam blanching (SB) and hot water blanching (HB). Frozen samples were thawed by room temperature thawing (RT), running water thawing (WT), and microwave thawing (MT). Sample qualities such as drip loss, pH, color, vitamin C, hardness, DPPH radical scavenging activity, and total polyphenol content were evaluated. Freezing and thawing time had no difference according to blanching method. In the freezing process, carrots and potatoes took 37 min and 40 min to reach -35°C, respectively. In the thawing process, MT was the most rapid thawing time, and RT took more than twice as long as WT. Overall, SB and HB had lower drip loss and higher moisture content than control (nontreatment). It was proved that the samples quality were maintained by blanching and when carrots or potatoes were thawed by RT or WT method, respectively, they showed the optimal quality in drip loss, moisture content, DPPH radical scavenging activity, and vitamin C.