INFLUENCE OF WEAK ORGANIC ACIDS AND SODIUM CHLORIDE MARINATION ON CHARACTERISTICS OF CONNECTIVE TISSUE COLLAGEN AND TEXTURAL PROPERTIES OF BEEF SEMITENDINOSUS MUSCLE

Beef semitendinosus (ST) muscle was marinated for 24 h in 2% NaCl solution, and 1.5% lactic, acetic and citric acid solutions individually and in mixed marinades for the combination of NaCl and three kinds of weak organic acids, respectively. The effectiveness of marinades on beef ST muscle was investigated. Changes in denaturation characteristics of connective tissue collagen were examined using differential scanning calorimetry; microstructural changes of collagenous fibers were observed with scanning electron microscopy; and textural properties of meat were studied by texture profile analysis. The results showed that: marinating with organic acids and NaCl increased filtering residue contents of connective tissue significantly, especially for the presence of NaCl in organic acids compared with marinating in acids alone. Meat marinated in 2% NaCl and the presence of NaCl in citric acid significantly increased the mechanical strength (MS) of connective tissue, and other marinating treatments had a significant reduction on MS. Marinating resulted in denaturation of the intramuscular heat-insoluble collagen as exhibited by the lower onset (To) and peak (Tp) temperature compared with the control samples. After marinating, fiber diameter and perimysial thickness were decreased and arrangements of collagenous fibers were disordered. These changes of collagen characteristics contributed to the significant effects on meat quality and textural properties. PRACTICAL APPLICATIONS Characteristics of connective tissue and collagen are related to meat quality, especially for meat tenderness and texture. While marinating is recognized as a means of improving palatability by enhancing or complementing the flavor of meat, despite numerous recipes for meat marination, there are limited data concerning the effectiveness of weak organic acids and NaCl solutions on the texture of beef meat. Marinations in acidic solutions, e.g., lactic, acetic, citric acid, have been traditionally used as a means of softening and flavoring meats. These treatments decrease the mechanical resistance of meats, including those of high connective tissue content. Based on those responses, we reported the textural properties affected by characteristics changes of connective tissue and collagen by marinating with weak organic acids and NaCl. Results reported in this article would be useful either for the scientific community or for the beef processing industry.