Process optimization and characterization of physicochemical properties of freeze-dried pineapple snacks enriched with propolis

Abstract

The propolis (PP) and linseed oil (LO) were encapsulated into the gum Arabic (GA) matrix along with whey protein concentrate (WPC) using the freeze-drying technique to form a hydrophilic matrix for production of functional pineapple snacks. The concentrations of the components in the matrix were optimized using response surface methodology (RSM) to maximize the protein content and encapsulation efficiency (EE). The encapsulation efficiency, protein content, color parameters (L*, a*, b* values), microstructure and texture properties of the snack containing optimum component concentrations were investigated. The glass transition temperature for the snack prepared with optimized ingredient concentration and components, oxidation temperature for linseed oil were estimated using a differential scanning calorimeter (DSC). The results revealed an encapsulation efficiency of 83.15% and a protein ratio of 31.53% for the developed matrix. Gum Arabic did not increase the encapsulation efficiency. The use of WPC has increased the encapsulation efficiency and protein content. Linolenic acid (50.804%), oleic acid (22.443%), and linoleic acid (14.012%) were the major fatty acids in the snack, owing to the highly encapsulated linseed oil and propolis. These result data support the freeze-dried pineapple snacks, which may be optimized for their component ratios and then used as a functional product suitable for consumption owing to its high nutritional value.