Utilization of Star Fruit Pomace Powder as Antioxidants Source in Salad Dressing

Abstract

Salad dressing was fortified by dried star fruit pomace which is a good source of natural antioxidant. The purpose of this study was to determine an optimal condition of SFP drying as for maximum nutritional value. The research methodology has divided into 3 step 1) determining the physico-chemical properties star fruit at 4 ripening stages: dark green (DG), light green (LG), color break (CB), and ripe (R) 2) studying drying conditions (hot air, microwave, and sun drying) and 3) studying dried star fruit pomace powder adding in salad dressing (0-3% w/w). The CB-stages of star fruit showed the highest bioactive compounds: total phenolic content of
2985 mg Gallic acid/100 g FW, vitamin C of 21.6 mg/100 g, antioxidant activity of 126.00 mol AEAC/g FW. Hot air drying at 50 °C for 180 min showed the best drying condition. The SFP powder contained total phenolic content of 7239.56 mg Gallic acid/100 g FW, vitamin C of 6.2 mg/100 g, antioxidant activity of 136.21 mol AEAC/g FW and water activity of 0.42. Salad dressing added with star fruit pomace powder contained high levels of total phenolic content, vitamin C and antioxidant activity. An optimum concentration of star fruit pomace powder was equal to 3% which retard rancidity, inhibit microorganism growth and increase antioxidant activity of salad dressing. This study demonstrated that star fruit powder may be used as a functional food ingredient for promoting health.