Department of Food Science, University of Arkansas, Fayetteville, AR, USA.
Food Sci Technol Int. 2012 Jun;18(3):291-8. doi: 10.1177/1082013211428001.
Due to the environmental concerns and expense associated with the disposal of wastewater after industrial cooking of rice, the purpose of this study was to evaluate the extent of leaching, water uptake and volumetric expansion of rice during cooking at various milling durations and water-to-rice ratios. Two cultivars of Arkansas rice, a long grain (Francis) and a medium grain (Jupiter), were milled for 10, 20, and 30 s with a laboratory mill. Samples were cooked in aluminum foil covered beakers at water-to-rice ratios of 10:1, 15:1, and 20:1. After 20 min, rice was weighed for water uptake and measured for volumetric expansion using hexane displacement. The excess cooking water was evaluated for total solids, amylose, and protein to determine the extent of leaching. Water uptake and volumetric expansion significantly increased with milling duration in both cultivars. Leached solids increased as the water-to-rice ratio increased in Francis and increased with milling duration in Jupiter; however, the amylose content of leached solids was unaffected by the water-to-rice ratio in both cultivars. Thus, shorter milling durations may limit the extent of leaching during cooking, as observed with Jupiter, while a lower water-to-rice ratio may reduce wastewater contamination for cultivars similar to Francis.
由于工业煮饭前处理废水所带来的环境问题和费用，本研究旨在评估在不同碾磨时间和米水比下煮饭前大米的浸出程度、吸水率和体积膨胀率。将阿肯色州的两种大米品种（弗朗西斯长粒米和朱庇特中粒米）用实验室碾米机碾磨 10、20 和 30 秒。将样品用铝箔覆盖的烧杯在米水比为 10:1、15:1 和 20:1 的条件下煮 20 分钟。煮完后，大米称重以测量吸水率，并使用正己烷置换法测量体积膨胀率。评估多余的煮米水的总固体、直链淀粉和蛋白质含量，以确定浸出物的程度。在两个品种中，吸水率和体积膨胀率均随碾磨时间的延长而显著增加。在弗朗西斯品种中，浸出物中的固体含量随米水比的增加而增加，在朱庇特品种中则随碾磨时间的增加而增加；然而，在两个品种中，浸出物中的直链淀粉含量均不受米水比的影响。因此，如朱庇特品种所示，较短的碾磨时间可能会限制煮饭过程中的浸出程度，而对于类似于弗朗西斯品种的较低米水比可能会减少废水污染。
