Use of physical processes to maximize goat milk cream hydrolysis: Impact on structure and enzymatic hydrolysis

Abstract

This study evaluated the use of ultrasound (US), high-shear dispersion (HSD), stirring (ST), and low or high pressure homogenization (LPH or HPH) technologies to modify the goat milk cream (GMC) structure, focusing on improving the enzymatic hydrolysis of its lipids. The GMC structure was evaluated, as well as its creaming and emulsion stability index (ESI). The processed GMC was hydrolyzed by lipase at 50 °C for 300 min, and the fatty acids concentration (FAC) was evaluated over the reaction. ST, HPH, and HSD showed ∼ 90% lower emulsion destabilization, 10 times higher ESI, and smaller fat globule size than unprocessed GMC. The pretreatments increased the hydrolysis rate up to 2.4 times and the final FAC up to 8.7 times. ST (4 min), HPH (40 MPa) and HSD (5 min/ 25,000 rpm) showed the best results, which were correlated with the changes in the GMC structure. The results suggest that the physical treatments impacted the substrate structure, favoring enzyme activity and accelerating the hydrolysis degree. Therefore, the application of physical processes can be an interesting strategy to enhance the hydrolysis of GMC, aiming to produce compounds of industrial interest.

Keywords: Emulsion stability; Enzymatic hydrolysis; Fatty acid; Goat milk fat; Lipase; Physical process.