针对米饭的体外口腔消化方法优化及压力烹饪米饭甜味比较

Optimization of An in Vitro Oral Digestion Method for Rice and Comparative Analysis of Sweetness in Pressure-cooked Rice

摘要:

米饭甜味是品尝米饭的重要感官指标之一，其甜味感知主要发生在口腔消化过程中。但现有米饭体外口腔消化方法不统一，导致不同实验结果之间缺乏可比性。为改善体外口腔消化方法之间的可比性并提升米饭甜味，该研究参考“INFOGEST”消化体系利用A/MEC咀嚼装置进行体外口腔消化方法的优化。在该优化方法的基础上，探究了电饭煲不同烹饪条件（浸泡时间和烹饪压力）对米饭质构特性及甜味感知的影响。结果表明，体外口腔消化最优参数为米饭加样量15 g，双向挤压循环25周期。不同条件烹饪米饭的还原糖含量（≤0.45 mg/g）均未达到甜味感知的阈值。10 min中温浸泡和50 kPa压力烹饪处理降低了米饭的口腔破碎难度，导致米饭的体外口腔消化第一次破碎硬度由7 572.41 g降低至6 151.23 g，挤压限制值由17.00降低至7.00，并促进了淀粉的酶解过程，使其体外口腔消化产物的麦芽糖含量由6.43 mg/g提升至10.85 mg/g。综上，合适的浸泡时间和烹饪压力有利于提高米饭的甜味感知。该研究为甜味米饭的烹饪工艺优化提供了理论依据。

Abstract:

Sweetness is a key sensory attribute of rice, primarily perceived during oral digestion. However, the lack of standardized in vitro oral digestion methods for rice has limited comparability between experimental results. To address this, an in vitro oral digestion method was optimized using the A/MEC chewing device and the “INFOGEST” digestion framework to enhance methodological consistency and assess rice sweetness more reliably. The effects of different cooking conditions (soak time and cooking pressure) on the textural properties and sweetness perception of rice were investigated using this optimized method. The optimal in vitro oral digestion parameters consisted of a rice sample weight of 15 g and 25 bidirectional extrusion cycles. The reducing sugar content (≤0.45 mg/g) across all cooking conditions did not reach the threshold for sweetness perception. Soaking rice at a medium-temperature for 10 min and a cooking pressure of 50 kPa reduced the difficulty of oral fragmentation. The first extrusion hardness decreased from 7 572.41 to 6 151.23 g, and extrusion restriction decreased from 17.00 to 7.00, thereby facilitating starch enzymatic hydrolysis. Consequently, the maltose content in in vitro oral digestion products increased from 6.43 mg/g to 10.85 mg/g. The findings of this study indicate that appropriate soak time and cooking pressure can enhance the perceived sweetness of rice, thereby providing a theoretical basis for optimizing the cooking process.