Submitted to: Journal of Shanghai Normal University (Natural Science)
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/20/2014
Publication Date: 12/1/2014
Citation: Zhuang, H., Bowker, B.C. 2014. Effects of freezing-thawing on sensory descriptive profiles of cooked poultry breast meat. Journal of Shanghai Normal University (Natural Science). 43(6):558-565.
Interpretive Summary: The practice of freezing fresh meat in a -20oC freezer for later use has been widely adapted for shelf life extension by consumers and sample preparation by researchers. Although the effects of freezing on sensory quality of cooked red meat have been well documented in literature, there was limited information about effects of freezing and subsequently thawing on sensory quality of poultry breast meat. The objective of this study was to evaluate effects of freezing-thawing on sensory quality profiles of cooked poultry breast meat using chicken breast fillets as a model. Frozen chicken fillets were thawed with three different methods, thawing during cooking (or cooked directly from a frozen state), thawing at 20oC tap water for 2 h prior to cooking, or thawing at a 4oC refrigerator for 24 h prior to cooking. The fillets that were directly cooked from a fresh state were used for a comparison. Our results show that there were no differences in flavor of cooked chicken fillets regardless of freezing treatment and thawing method. However, there were significant differences for sensory texture quality among the four meat preparation methods. The texture of cooked frozen fillets was more consistent and perceived more tender than that of cooked fresh fillets regardless of thawing method. These results indicate that storage of poultry breast fillets at -20oC freezer before use does not affect flavor of cooked meat. However, it may cause changes in texture of cooked products. Freezing results in more tender and consistent texture of cooked poultry breast meat compared with fresh meat.
Technical Abstract: Freezing is a common method used by consumers to extend meat shelf life and by researchers to allow for subsequent meat quality assessments and processing. However, the effects of freezing on the sensory quality of cooked poultry breast meat are not well documented. The objective of this study was to compare sensory quality profiles of fresh and frozen/thawed chicken breast fillets (pectoralis major). Breast fillets were removed from carcasses within 24 h postmortem and either cooked from a fresh state or placed in a -20oC freezer. Frozen samples were thawed by three different methods: thawing during cooking directly from a frozen state (0h), thawing in 20oC water for 2 h prior to cooking (2h), or thawing at 4oC for 24 h prior to cooking (24h). A control treatment with fillets cooked directly from a fresh state was used. Fillets were cooked to an endpoint temperature of 78oC and sensory quality was evaluated by trained descriptive panelists using 0-15 universal intensity scales. Results show that there were not treatment differences (P > 0.05) in the average intensity scores for any of the descriptive flavor attributes or for 5 of the descriptive texture attributes (cohesiveness, hardness, juiciness, wad size, and wetness of wad). However, the intensity scores for cohesiveness of mass, rate of breakdown, and chewiness were significantly different among the treatments (P < 0.05). Cohesiveness of mass intensity scores for 0h and 24h fillets were significantly higher than 2h samples. Fillets cooked directly from a frozen state (0h) had significantly higher intensity scores for rate of breakdown and chewiness than fresh controls and 2h samples, respectively. These results indicate that freezing-thawing does not affect sensory flavor quality; however, it may change the texture attributes of cooked chicken breast meat products. The effects on meat texture depend on thawing methods prior to cooking.