The effect of short- and long-term freeze-chilling on the quality of cooked green beans and carrots

摘要

Freeze-chilling of food involves freezing and frozen storage followed by thawing and chilled storage. In this study, the effect of freeze-chilling on the quality of cooked green beans and carrots was examined, as was the effect of long and short-termfrozen storage prior to thawing. Three process treatments were used in the short-term trial; chill, freeze-chill and freeze and the products were tested for firmness, colour, centrifugal drip loss, total viable count (TVC) and taste panel acceptability.Results showed that freeze-chilling and freezing led to softer cooked carrots (P<0.001) than chilling. However, freeze-chilling and freezing had no effect on the texture of cooked green beans (P>0.05) but led to significantly higher drip losses than chilling (P<0.001). Freeze-chilling and chilling led to paler green beans but this was not reflected in the taste panel acceptability scores No difference in TVC was found between any of the process treatments for cooked carrots or green beans. In general, frozen storage (-- 25 deg C) for up to 12 months had no effect on firmness, drip loss, colour, total viable count or sensory acceptability of freeze-cbilled cooked carrots and green beans compared to freezing. kw:Freeze-chilling; Cooked carrots; Cooked green beans; Quality; Long-term frozen storage