Effect of structure forming agent inclusion on color, physicochemical, and textural characteristics of pet treats derived from upcycled broiler chicken wing tips

Abstract

Pet food industry's demand for animal-based protein presents an opportunity for the broiler industry to repurpose undervalued co-products, which could yield higher profits compared to rendering processes. Two experiments were carried out to assess the physicochemical characteristics and instrumental color changes over time of raw, pressure-cooked, and dehydrated pet treats made with broiler chicken wing tips (WT) and varying concentrations of hydrocolloids as a structure-forming component. Impacts of hydrocolloid concentrations differed among the 3 types of pet treats, with raw treats becoming harder and more adhesive, and pressure-cooked treats becoming softer. However, cohesiveness, springiness, and chewiness improved in both raw and dehydrated treats. In dehydrated treats, firmness increased with increased hydrocolloid concentration, but in pressure-cooked treats, stiffness decreased, and flexibility increased. Although hydrocolloids did not affect the pH or water activity of raw and pressure-cooked treats, it did increase water activity in dehydrated treats. Moisture content was variably influenced by hydrocolloids, decreasing in raw and pressure-cooked treats, but increasing in dehydrated ones. Expressible moisture increased in pressure-cooked treats and decreased in raw. Hydrocolloids and time only impacted the lightness (L*) values of raw treats, while redness (a*) increased with the addition of hydrocolloids in raw and pressure-cooked treats. Yellowness (b*) increased with hydrocolloids in raw and pressure-cooked treats but decreased over time in raw treats. Delta-E values were greatest between day 0 and any other day, indicating that color differences would be hardly noticeable if purchasers did not see the pet treat the same day it finished production Although hydrocolloids had varying effects on physicochemical characteristics and instrumental color, it aided in the bonding of the protein matrix of ground WT, making it a reliable protein source for the pet food industry, with the potential to develop a profitable product through upcycling.