Author
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Berry, Bradford |
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Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 4/15/1998 Publication Date: N/A Citation: N/A Interpretive Summary: Foodborne illnesses associated with the bacteria E. coli O157:H7 in inadequately cooked ground beef patties continue to be a major problem for processors, regulators and consumers. The growing occurrence of extreme color variation in patties cooked to 160 deg F recently caused the Food Safety Inspection Service to issue a recommendation to consumers to use a thermometer and not cooked color when cooking patties. Use of high pH beef often results in pink or red color when patties are cooked to 160 deg F, especially if the patties are cooked from the frozen state. Thawing patties prior to cooking or increasing the fat content has occasionally produced a brown color in the interior of patties cooked to temperatures lower than 160 deg F. This study was undertaken to determine if thawing prior to cooking and increasing the fat content would provide a more "brown" cooked color in patties made from high pH beef. Some pink color was observed in all cooked patties. While increasing the fat content resulted in some reduction in pink color as determined visually and instrumentally, it would appear that high pH (6.0 or higher) in beef muscle presents a very dominant influence on cooked patty color. More than 18 hours of refrigerated thawing may be necessary to completely eliminate pink color in high pH patties cooked to 160 deg F. Technical Abstract: Beef patties were processed from high pH (>6.0) beef to possess either 5, 10, 15, 20 or 25 percent fat. Patties were cooked to 71 deg C from either the frozen or thawed state before evaluating color properties. While neither fat content nor state of patties when cooked exerted major influence on color properties, linear effects (P<0.01) in association with increased fat content were higher L* values and hue angles and lower a* values. Higher values for L*, b* (but not for 5 percent fat patties), and hue angles were observed for patties cooked thawed rather than frozen. It appears that high pH beef negates much of the effects of fat and frozen vs. thawed cooking on color in cooked patties. |
