Effect of ultrasound‐assisted osmotic dehydration (<scp>UAOD</scp>) pretreatment on <i>Mangifera pajang</i> Kosterm. fruit pulp: Drying kinetics, chemical qualities, and color measurement

Abstract Mangifera pajang Kosterm., or 'Bambangan,' a fruit known for its rich phytochemical content, was investigated for the effects of ultrasound‐assisted osmotic dehydration (UAOD) on pretreated M. pajang fruit pulp (PMPF) and drying at different temperatures (40, 50, 60, 70, and 80°C). Thin‐layer drying kinetics were analyzed using six models, with the Midilli and Kucuk model being the most suitable, showing optimal effective moisture diffusivity and activation energy. PMPF dried at 50°C, using natural deep eutectic solvents (NADES) as the extraction solvent, exhibited the highest extraction yield (64.13 ± 1.08%), mangiferin content (0.5818 ± 0.00164 mg/g), total phenolic content (146.2081 ± 1.33 mg GAE/g DW), total flavonoid content (2.4737 ± 0.06 mg RE/g DW), and DPPH inhibition activity (95.87 ± 0.16%), along with the best color retention compared to untreated M. pajang fruit pulp. This highlights its potential for nutraceutical and functional food applications, with UAOD as pretreatment effectively preserving food quality and color. Practical Applications This article provides new insights into the drying and pretreatment of Mangifera pajang fruits. Rich in phytochemicals, M. pajang offers numerous health benefits. Pretreatment methods such as ultrasound‐assisted osmotic dehydration (UAOD) and oven drying at different temperatures significantly enhance the retention of bioactive compounds like phenolics and flavonoids, as well as antioxidant activity and color stability. The study identified optimal drying temperatures, conditions, drying rates, and activation energy to maximize these qualities. Using mathematical models for drying kinetics, this research offers practical guidance for the food processing industry. It provides an operational tool for manufacturers to optimize the drying process, reduce operational costs, and ensure the preservation of chemical qualities while extending the shelf life of M. pajang fruits. This work supports the development of high‐quality nutraceutical and functional food ingredients, promoting their commercialisation and use in health‐focused markets.