Characteristics and Flavor Retention of Structured Emulsion from Pomelo (Citrus maxima) Residue

Abstract

A growing awareness of consumer health has currently led to the increasing demand for healthy foods. To address this trend, food recipes have moved to products with lower fat content. According to our previous work, pomelo (Citrus maxima) fiber gel showed a promising property as a fat replacer. However, its retention of hydrophobic flavors like ethyl butanoate and ethyl hexanoate is still relatively low, compared to whipping cream which is composed of 35% fat. To overcome such a drawback, structured emulsions based on this fiber gel were designed and their characteristics, in particular flavor retention, were investigated in this study. The results revealed that the pomelo fiber is a rich source of dietary fiber comprising pectin and phenolic compounds that are able to claim an added health benefit. Moreover, the presence of pomelo fiber in the structured emulsions altered viscosity of the system from liquid-like to that of a gel with a storage modulus (G¢) of 600 Pa, and an altered microstructure. Furthermore, the structured emulsions containing low of oil significantly decreased the volatility of the flavor compounds and affected their retention profiles, such that, the retention of hydrophobic flavors in the structured emulsions with 2.5% oil was found to be comparable to that of whipping cream. Such phenomena should thus be useful when formulating low-fat food products.