Effects of chemical acidification and microbial fermentation on the rheological properties of meat products

The gelation patterns of meat batters acidified with lactic acid bacteria (LAB) fermentation, liquid lactic acid, encapsulated lactic, citric and gluconic acids were studied. LAB provided slow (overnight) acidification that resulted in a significantly higher pre-cooking modulus of rigidity (G') value compared to all treatments, including a non-acidified control. The LAB heat-gelation pattern was also different from all other treatments. Liquid lactic acid caused an immediate pH reduction (from 5.6 to 4.6), crumbly texture, moisture release, and an initial higher G' value compared to the control, but lower than the LAB. The hydrogenated oil encapsulated acids, designed to release acid at 51-55 degrees C, did not produce crumbly texture or moisture release. Encapsulated lactic acid showed an increase in the initial G', probably because of limited pre-cooking acid release. However, citric and gluconic acids showed no such effect. During cooling, LAB treatment showed the lowest G' value curve, followed by the control, liquid lactic acid, and the encapsulated acids. (C) 2005 Elsevier Ltd. All rights reserved.