Effects of starch addition on the activity and specificity of food‐grade lipases

Abstract

Lipases are surface-active enzymes, acting on their substrates at the polar/nonpolar interface in emulsions. This study was aimed to test whether their activity, specificity, and the rates of formation/degradation of the various hydrolysis intermediates (i.e., mono-and diglycerides of interest as surface-active agents) could be modulated by adhesion of the triglyceride substrates as a thin layer on the surface of solids. These hypotheses were tested by using an array of food-grade lipases used in bakery, testing various types of starch as the "solid" phase. Starch-dependent increase in the hydrolysis rate was tested by pH-stat techniques on pure triglycerides and on food-grade oils in diluted emulsions. Starch-related improvements in the rate of fatty acids release were most evident at temperatures above 40 • C, and when using maize starch instead of wheat starch. Starch-dependent changes in the nature of the hydrolysis products were tested by chromatographic profiling of ethyl ether extracts from aqueous slurries containing up to 33% fat and 33% starch.

Comparative characterization of baking lipase substrate specificities using emulsions and the p-nitrophenyl assay

“…An emulsion of both phases is therefore needed for the reaction to take place, but there is no standard procedure for emulsion preparation to analyze lipase reactions. Ultrasonic treatment has been used (Carpen et al, 2019), as well as stirring (Avelar et al, 2013), shaking (Omar et al, 2016) or homogenization (Bourlieu et al, 2012;Byun et al, 2007). The resulting droplet size of the emulsion directly affects lipase activity with increasing interfacial areas leading to higher lipase activities (Saktaweewong et al, 2004).…”

Improving the quality of the chicken fillet using chitosan, gelatin, and starch coatings incorporated with bitter orange peel extract during refrigeration

“…Lipases are known as surface‐active enzymes and act on their substrates at the polar/nonpolar interface. The protective effect of coatings against lipolysis may be due to prevent the moisture and oxygen penetration into the fillets tissue, slowing down the accessibility of enzymes to the substrate and thus inhibiting lipase activity (Carpen et al, 2019).…”

Microbial lipases and their industrial applications: a comprehensive review

“…The molecular weight of lipases is in the range of 19–60 kDa and reported to be monomeric protein. The position of the fatty acid in the glycerol backbone, chain length of the fatty acid, and its degree of unsaturation are the factors and the physical properties of lipases depend on it [ 51 , 52 ]. The sensory and nutritive values of given triglyceride also affected by these features.…”