Optimization of Hot Water Treatment in Red Dragon Fruit Using Response Surface Methodology

Yuniarsih Yuniarsih (Department of Mechanical and Biosystem Engineering, Faculty of Agricultural Engineering and Technology, IPB University, IPB Darmaga Campus, Bogor 16680, Indonesia)
Emmy Darmawati (Research Organization for Agriculture and Food, National Research and Innovation Agency, Jalan Raya Jakarta-Bogor KM 46, Kec. Cibinong, Bogor 16911, Indonesia)
Siti Mariana Widayanti (Laboratory of Ecology and Crop Production, Department of Agriculture, Faculty of Animal Husbandry and Agriculture, Universitas Diponegoro, Semarang City 50275, Indonesia)

Jurnal Ilmu Pertanian Indonesia
Vol. 31 No. 3 (2026): Jurnal Ilmu Pertanian Indonesia

Red-fleshed dragon fruit is recognized as a superfruit because of its betacyanin content, a natural pigment with antioxidant properties. However, the fruit is highly perishable after harvest, requiring effective postharvest handling, such as Hot Water Treatment (HWT). This study aimed to determine the optimum combination of temperature, immersion time, and maturity index using Response Surface Methodology (RSM) with a Box-Behnken Design. The optimized quality parameters included lightness value (L*), total soluble solids (TSS), betacyanin content, and vitamin C content. The optimum conditions were found to be 50°C for 15 min at maturity index IV, achieving a desirability of 0.885. The predicted model values were 28.40 (L*), 13.5 °Brix (TSS), 56.44 mg/L (betacyanin), and 3.53 mg/100 g (vitamin C). Validation of the optimal treatment revealed that only the quality attributes of total soluble solids (13.1 °Brix) and vitamin C (3.36 mg/100 g) were in close agreement with the predicted model values. In contrast, the model demonstrated lower predictive accuracy for lightness (L*) and betacyanin content. Keywords: Box-Behnken Design, dragon fruit, hot water treatment, response surface methodology