Effect of repeated freezing and thawing on the tenderness of beef

Abstract

The present study was conducted to find the effect of repeated freezing and thawing on beef tenderness. The Biceps femoris muscle from six adult crossbred female cattle were collected hygienically, portioned into a chunk size of 10×10×5 cm, and subjected to ageing for 72 hours at 4ºC. Meat samples were subjected to freezing at -18ºC for seven days and thawed under five different thawing methods, viz. ambient temperature (AT) at 31-34ºC, chiller temperature (CT) at 4ºC, microwave thawing (MT) at 2450 MHz, immersion thawing with water replacement (ITW), immersion thawing without water replacement(ITWO). Three freeze-thaw cycles were carried out. The unfrozen meat samples after ageing and meat samples after every freeze-thaw cycles were subjected to assessing myofibrillar fragmentation index (MFI), Warner-Bratzler shear force (WBSF), collagen content, collagen solubility and cooked sensory evaluation for assessing the tenderness. The results of the present study suggested that as the number of freeze-thaw cycles increased, a significant decrease (p≤0.05) was observed in the myofibrillar fragmentation index and WBSF. The collagen content and collagen solubility remained non-significant throughout the freeze-thaw cycles. The sensory scores for tenderness increased significantly (p≤0.05) with an increased freeze-thaw cycle. In conclusion, beef tenderness increased as the number of freezethaw cycles increased.