Enzyme-Assisted Extraction of Ambarella Juice : Process Optimization and Pasteurization-Based Storage Evaluation

Lee, Jie Yin (2026) Enzyme-Assisted Extraction of Ambarella Juice : Process Optimization and Pasteurization-Based Storage Evaluation. Final Year Project (Bachelor), Tunku Abdul Rahman University of Management and Technology.

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Abstract

Ambarella (Spondias dulcis) is a tropical fruit rich in bioactive compounds, vitamins, and antioxidants, making it a promising raw material for functional juice production. However, conventional juice extraction methods often result in low yield and nutrient loss due to limited release of cell-wall-bound components. This study aims to investigate the enzyme-assisted extraction conditions of Ambarella juice using response surface methodology, and to evaluate the storage stability of the optimized juice after pasteurization. A Box-Behnken design was performed to investigate the effects of pectinase concentration (0, 1, and 2%, w/w), cellulase concentration (0, 1, and 2%, w/w), and extraction time (1, 3, and 5 hours) on the juice yield, color, physicochemical, chemical, and antioxidant properties of enzyme-assisted extracted Ambarella juice, while the optimum extraction condition was identified. The storage stability of the pasteurized and unpasteurized Ambarella juice was evaluated over 14 storage days at 4 °C. Results showed that the enzyme concentration and extraction time significantly affected (P < 0.05) all the responses except L* and hue. The optimum condition was determined as 1.2727% pectinase, 0.0202% cellulase, and 5 hours of extraction time, with a composite desirability of 0.7297, which contributed to 70.44 ± 0.01% of yield, 52.00 ± 0.10 of color L*, 5.10 ± 0.10 of color a*, 20.20 ± 0.10 of color b*, 15.48 ± 0.05 of color change, 20.83 ± 0.09 of chroma, 75.83 ± 0.31 of hue, 5.53 ± 0.06 °Brix of total soluble solids content, 6.14 ± 0.27 of brix-acid ratio, 54.03 ± 0.31% of clarity, 1.05 ± 0.17 mg/100 mL of ascorbic acid content, 26.13 ± 0.15 mg GAE/100 mL of total phenolic content, 30.26 ± 0.22 mg QE/100 mL of total flavonoid content, 17.40 ± 0.08 mg TE/100 mL of ABTS, 8.39 ± 0.05 mg AAE/100 mL of DPPH, and 55.15 ± 0.55 mg FeSO4E/100 mL of FRAP. Compared with non-enzymatic control juice, enzyme-assisted extracted Ambarella juice showed significantly higher yield and clarity, better color stability, and greater antioxidant activity. Pasteurization enhanced nutrient stability significantly (P < 0.05), with retention of ascorbic acid (87.50–100.00%), ABTS (99.22–99.39%), DPPH (58.00–79.62%), and FRAP (82.19–98.52%), while also demonstrating better microbiological stability than unpasteurized juice. This study demonstrates that enzyme-assisted extraction effectively improves Ambarella juice recovery and quality, while pasteurization combined with cold storage ensures nutritional retention and microbial safety, offering a practical strategy for developing value-added functional beverages.