The effect of processing duration and pressure on the physicochemical characteristics and development of puffed rice

This study investigates how processing parameters, specifically roasting duration, steam pressure, and steam impregnation time, affect the proximate composition and physical properties of rice during the puffing gun expansion process. Experimental conditions varied Factor A (roasting duration: 12–16 min), Factor B (steam pressure: 10–14 atm), and Factor C (steam impregnation: 3–5 min) across eight treatment combinations, with controls set at A = 14 min, B = 12 atm, and C = 4 min. Results show that higher pressure and longer durations significantly increased crude fiber and protein levels compared to raw rice, while also altering moisture and ash contents. Optimal expansion ratios and desirable texture were achieved with prolonged roasting, lower steam pressure, and shorter impregnation times. Additionally, the redness value (a*) was notably sensitive to processing changes, demonstrating substantial shifts in product appearance. These findings provide practical insights for improving both the quality and nutritional characteristics of puffed rice, as well as informing process efficiency for food manufacturers.