Influence of Mangosteen Peel Extract on Oxidative Stability, Nutritional Values, Physicochemical Properties and Sensory Preference of Soy-Based Burgers.

Research background: Despite being a substantial and expanding market segment, there remain challenges concerning the shelf life of plant-based meat alternatives when synthetic preservatives are not used. Consequently, it is necessary to investigate the integration of natural extracts into these products to extend their shelf life.

Experimental approach: The total phenolic content, flavonoid content and antioxidant capacity of the powder of dried mangosteen peel extract was characterised. The fresh soy-based burgers were then formulated for six treatments including control (no antioxidant added), 10 mg butylated hydroxytoluene (BHT, a synthetic antioxidant), 10, 7.5, 5 and 2.5 mg dried extract and their proximate composition, physicochemical characteristics, protein and lipid oxidation, texture profile and sensory parameters during 10 days of storage were evaluated.

Results and conclusions: The addition of the extract reduced the moisture content and cooking loss. In addition, the burgers with the extract (5-10 mg/100 g) had remarkably lower values of peroxides, thiobarbituric acid reactive substances and carbonyls, indicating their higher stability against lipid and protein oxidation. These effects of the extract proved to be better than those of BHT. The burgers containing the extract also had improved texture in terms of springiness, chewiness and cohesiveness, resulting in higher texture scores. All treatments were accepted by consumers, with the average score of approx. 7 to 9 points. Therefore, the extract from mangosteen peels could be used as an excellent natural antioxidant substitution for synthetic ones currently used in food preservation.

Novelty and scientific contribution: The study fulfils a need for the growing plant-based meat alternatives with an extended shelf life of a healthier version by using a natural antioxidant extract from mangosteen peels instead of synthetic butylated hydroxytoluene. In addition, the study provides an assessment of product quality during storage and presents findings that could drive innovation in the use of natural preservatives in the food industry.