Evaluating different levels of papain as texture modifying agent in bovine meat loaf containing transglutaminase

In this study, bovine meat loaves were produced with different levels of papain (0.00125%, 0.0025%, 0.00375%, and 0.005%) combined with transglutaminase (1%). The effect of this reformulation on pH, instrumental color, water activity, proximate composition, texture, yield, and scanning electron microscopy (SEM) of meat loaves was investigated. In addition, the enzymatic activity of papain was also analyzed. The papain addition increased the pH and the yield of the samples. The hardness was progressively reduced with the increase of papain level. Such changes could be seen through the images recorded by SEM, where an extremely fragmented structure was observed in treatments with higher papain concentration. Papain showed an optimum temperature of 80 °C. This study allowed to observe an intense proteolytic effect in all treatments, despite the papain concentration. Therefore, lower levels should be applied so that the product does not alter its sensory characteristics, such as soft and crumbly texture. •Meat loaves were treated with different levels of the enzyme papain, associated with transglutaminase.•Increasing the concentration of papain, a further reduction of hardness was observed.•An extremely fragmented structure was observed at higher levels of papain.•Addition of the enzymes papain and transglutaminase increased the yield of the meat loaf.•At lower levels, the papain promoted the softening of the meat loaf.