Response surface methodology study on the effects of salt,microbial transglutaminase and heating temperature on pork batter gel properties

Response surface methodology was used to investigate the main effects and interactions of sodium chloride (0–2%), microbial transglutaminase preparate (MTG, 0–0.6%) and heating temperature (HT, 70–100°C) on water binding, textural and colour characteristics of pork batter gels cooked to an internal temperature of 70 °C. Lower salt gels showed decreases in hardness, chewiness and elastic properties, as well as significant reduction in the cooking yield and increase of expressible moisture. Salt levels also affected gel colour parameters, with Hunterlab a* and b* values being inversely correlated with salt concentration. MTG addition favourably reduced the cooking loss and increased hardness and chewiness of gels, but was not able to improve these parameters in low-salt products to the same levels as the high-salt products. Heating temperature was found to have relatively minor effect, primarily through its interaction with salt level and in a quadratic term affecting the elasticity and springiness of the gels.