Soursop fruits comprise many bioactive compounds that potentially support human health. The processing method dramatically affects the antioxidant activity found in the soursop fruit. This study aimed to explore the effects of preheating treatment approaches (steam blanching, hot water blanching, and microwave-assisted blanching) on the physiochemical properties of soursop fruit. The changes in colors, total ascorbic acid, and total phenolic content were based on the variations in surveyed parameters including treatment time 2–4–6–8 min, temperature 60–70–80–90°C (blanching hot water), and capacity 150–300–450–600 W (blanched by microwave). About 59.57% of total phenolic content and 64.07% of total ascorbic acid were retained after 8 min of blanching, 17.97% of total phenolic content and 31.42% of total ascorbic acid remained after blanching at 90°C, whereas the microwave-assisted blanching at 300 W was found to retain over 70% of total phenolic content and about 50% of total ascorbic acid. The evaluation results showed the total phenolic content loss was hindered by using microwave-assisted blanching at 150 W for 2 min. The color changes (darken conversion) were significantly affected by the prolonged processing time, increasing the total different color value compared to the control sample. These databases provide insight into the blanching processes, which are considered intermediate stages for many food products.