Effect of Porcine Collagen Peptides on the Rheological and Sensory Properties of Ice Cream

The effects of low molecular-weight collagen peptides derived from porcine skin were investigated on the physicochemical and sensorial properties of chocolate ice cream. Collagen peptides less than 1 kDa in weight were obtained by sub-critical water hydrolysis at a temperature of 300 degrees C and a pressure of 80 bar. Ice cream was then prepared with gelatin powder and porcine skin hydrolysate (PSH) stabilizers mixed at seven different ratios (for a total of 0.5 wt%). There was no significant difference in color between the resulting ice cream mixtures. The increase in apparent viscosity and shear thinning of the ice cream was more moderate with PSH added than with gelatin. Moreover, the samples containing more than 0.2 wt% PSH had enhanced melting resistance, while the mixture with 0.2 wt% PSH had the lowest storage modulus at -20 degrees C and the second highest loss modulus at 10 degrees C, indicating that this combination of hydrocolloids leads to relatively softer and creamier chocolate ice cream. Among the seven types of ice creams tested, the mixture with 0.2 wt% PSH and 0.3 wt% gelatin had the best physicochemical properties. However, in sensory evaluations, the samples containing PSH had lower chocolate flavor scores and higher off-flavor scores than the sample prepared with just 0.5 wt% gelatin due to the strong off-flavor of PSH.