Refreezing Freeze Chilled Products
Many foods 'suitable for freezing the seal on the packaging and consumer freeze them for convenience and to prolong the shelf life. However, with freeze-chilled products home freezing and refreezing means the second frosts, which may raise issues of product safety and quality. Test address is required to freeze chilled mashed potatoes, steamed sliced carrots and commercially produced lasagna, ready-made meals. Frozen samples from three products were prepared (Redmond et al., 2004a, 2004b), held in -25C for 7 days, unfreeze the night of the 4th ofC, at a temperature of 4C for 7 days with subsequent testing (to determine the basic amount, i.e. thaw 1 tests).
Freezing, cooling of the samples were then quickly freeze (shock freezing at temperature from -30C for up to 2.5 hours (air speed of 3,75 m s-1) or slowly (Cabinet; stationary air -25C) procedures and held at -25C for 7 days. They were thawed at 4C overnight and re-test (i.e.. thaw 2 tests). The color shift of values, centrifugal drip loss and vitamin C (only potatoes) contents freeze chilled mashed potatoes, steamed sliced carrots and heated lasagna were not affected by refreezing (both ways) or defrosting.
However, refreezing/thaw did reduce the stickiness of freeze-cooled mashed potatoes, but the effect was small, from a practical point of view. The microbiological status freeze chilled (without heating), lasagna was not affected by the refreezing/thawing and TVC values were below the upper limit of logio some 5 g1 of the Food Safety Authority of Ireland for ready-to-eat products at the point of sale. These data suggest that stop chilled mashed, boiled carrot, or lasagna can be freezing/thawing, without compromising quality and safety. However, it is important to remember that there are temperature violence occurs during chill phase of freezing-chill process.
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Food refrigeration and freezing