Abstract Four rice cultivars (Ayutthaya 1, Khao Bahn Nah 432, Plai Ngahm Prachin Buri, and Prachin Buri 2) that usually have a major problem with chalkiness were processed by applying superheated-steam drying and conventional parboiling methods. The main objectives were: (1) to determine the possibility of applying superheated-steam drying to solve the chalkiness and low head rice yield problems and (2) to compare the properties of rice produced using superheated-steam drying and the conventional parboiling process. Both the initial moisture content and superheated-steam drying temperature significantly affected head rice yield. The higher moisture helped to increase starch gelatinization leading to a stronger rice structure and subsequently an increased head rice yield. The rice samples dried in the superheated-steam dryer using an initial moisture content of paddy at 32% w.b. for 6 h under a steam pressure of 1.2 bar and at three drying temperatures (120, 140, 160 °C) had higher milling quality than the conventionally parboiled rice samples. The darker color of the superheated-steam-dried samples was their main drawback. Both parboiling and superheated-steam drying could clearly lessen the percentage of chalky rice kernels compared to the raw paddy. The parboiled rice and superheated-steam-dried rice had more nutrients than normal white rice.

中文翻译：

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过热蒸汽干燥与传统预煮相比对白垩米粒的垩白、精米产量和品质的影响

摘要 采用过热蒸汽干燥和常规蒸煮方法对通常存在主要白垩问题的四个水稻品种（Ayutthaya 1、Khao Bahn Nah 432、Plai Ngahm Prachin Buri 和 Prachin Buri 2）进行了加工。主要目标是：(1) 确定应用过热蒸汽干燥解决垩白和低单米产量问题的可能性，以及 (2) 比较使用过热蒸汽干燥和传统预煮工艺生产的大米的特性。初始含水量和过热蒸汽干燥温度均显着影响整粒稻产量。较高的水分有助于增加淀粉糊化，从而形成更强的大米结构，从而提高整粒稻米的产量。在过热蒸汽干燥机中使用 32% wb 的稻谷初始水分在 1.2 bar 的蒸汽压力和三个干燥温度（120、140、160 °C）下干燥 6 小时的大米样品的碾磨质量高于常规蒸煮的大米样品。过热蒸汽干燥样品的颜色较深是它们的主要缺点。与生稻谷相比，预煮和过热蒸汽干燥都可以明显降低白垩米粒的百分比。蒸谷米和过热蒸干米比普通白米含有更多的营养。过热蒸汽干燥样品的颜色较深是它们的主要缺点。与生稻谷相比，预煮和过热蒸汽干燥都可以明显降低白垩米粒的百分比。蒸谷米和过热蒸干米比普通白米含有更多的营养。过热蒸汽干燥样品的颜色较深是它们的主要缺点。与生稻谷相比，预煮和过热蒸汽干燥都可以明显降低白垩米粒的百分比。蒸谷米和过热蒸干米比普通白米含有更多的营养。