EFFECT OF GAC FRUIT PULP POWDER SUPPLEMENTATION ON THE QUALITY OF THAI CUSTARD DESSERT

Abstract

This study aimed to investigate the chemical and physical properties, as well as the antioxidant activity, of gac fruit pulp powder—a by-product obtained from the processing of food and health-related products. Furthermore, the effects of gac fruit pulp powder supplementation into a Thai custard dessert (Khanom Mo Kaeng) were evaluated in terms of consumer acceptability and product safety. The gac fruit pulp powder exhibited a reddish-yellow color, with carbohydrates as the predominant chemical component. It contained a total phenolic content of 3,307.17 mg gallic acid equivalents (GAE) per 1,000 g sample (DW) and demonstrated DPPH radical scavenging activity of 36.77 mg Trolox equivalent antioxidant capacity (TEAC) per 1,000 g sample (DW). The supplementation of gac fruit pulp powder in Thai custard dessert at concentrations of 2, 4, and 6% resulted in decreased lightness (L*) values, while redness (a*) and yellowness (b*) values increased. In parallel, both total phenolic content and DPPH antioxidant activity showed a significant increasing trend (p ≤ 0.05). The sample containing 4% gac fruit pulp powder received sensory evaluation scores ranging from 7.27 to 7.63 across all attributes, indicating a moderate level of consumer acceptability. The chemical composition of this formulation consisted of 49.85% moisture, 14.11% protein, 9.33% fat, 2.43% ash, 3.72% dietary fiber, and 20.56% carbohydrates. In addition, the microbiological quality of the product met the standards specified in the Thai Community Product Standards for traditional Thai desserts. All tested parameters—including total viable count, yeast and mold, Salmonella spp., Staphylococcus aureus, Bacillus cereus, and Escherichia coli—were within acceptable safety limits.