Abstract
The present study evaluated the combined effects of low-methoxyl pectin (LMP) extracted from durian (Durio zibethinus) peel and inulin on the physicochemical, textural, and stability properties of low-fat yogurt. LMP was prepared in solution with concentrations of varying 0.05–0.60 % w/v and added to skim milk (1.5 wt% fat) while inulin was varied from 0.5 to 3.0 % w/v, with each formulation fermented at 40 °C for 9-15 h. Key parameters—pH, total soluble solids (°Brix), firmness (texture analyzer), and syneresis—were measured, and sensory attributes (texture and flavor) were assessed. Results showed that using pectin at 0.10 % combined with 2.0 % inulin restored firmness (0.62 N) to levels comparable to full-fat yogurt (0.65 N), while reducing whey separation by 25 % relative to the low-fat control (28.5 % vs. 38.1 %, p < 0.05). The inclusion of these hydrocolloids had no significant impact on the final pH (3.80–3.84) or total soluble solids (°Brix: 9.8–10.1). Extending fermentation from 9 to 15 h further enhanced gel strength and minimized syneresis (down to 29.1 %). This work demonstrates that the judicious use of durian rind-derived pectin and inulin can effectively compensate for the textural and stability deficits of low-fat yogurt, offering a sustainable valorization route for durian rind and a formulation strategy for health-oriented dairy products.
