Extraction conditions and properties of Durio zibethinus Murr. seed gum and its application as a stabilizer in mung bean milk

Abstract

Importance of the work: Seeds of Durio zibethinus Murr. represent an abundant by-product of the processing industry in Southeast Asia but remain underutilized. Their recovery as functional hydrocolloids could enhance agricultural value addition and support sustainable food applications. Objectives: To evaluate aqueous extraction variables affecting the gum yield from durian seeds, to assess the influence of ultrasound pretreatment on extraction yield and functional properties and to examine the gum’s applicability as a stabilizer in mung bean milk. Materials and Methods: Gum was extracted from durian seed flour using a one-factor-at-a-time approach to investigate the effect on gum yield of the water-to-flour ratio (20:1–60:1, volume per weight, v/w), extraction temperature (30−70°C), pH (5−13) and extraction time (0.5−2.5 hr). Ultrasound pretreatment (20 kHz, 100−500 W, 1−5 min) was applied prior to extraction under selected conventional conditions. The extracted gum was characterized for physicochemical, functional and structural properties and evaluated as a stabilizer in mung bean milk. Results: The highest conventional yield (16.80%, dry basis) was obtained at a 40:1 (v/w) water-toflour ratio, 70°C, pH 11 and 2 hr extraction. Ultrasound pretreatment at 300 W for 3 min significantly (p < 0.05) increased yield to 19.93%, representing an approximately 19% increase over the conventional conditions. The gum had a near-neutral pH (6.91), low moisture content (5.44%), high water- (210 g/100 g) and oil-holding (123 g/100 g) capacities and a concentration-dependent viscosity. Fourier-transform infrared spectrometry and X-ray diffraction analyses indicated a carbohydrate-rich, predominantly amorphous heteropolysaccharide. In mung bean milk, 0.06% (weight per weight) gum improved the viscosity and reduced phase separation, while maintaining acceptable pourability. Main finding: Ultrasound-assisted extraction improved durian seed gum recovery and enhanced its potential application as a clean-label, plant-derived stabilizer for beverage systems.