研究濕磨(膠體研磨機)結合鹼萃取去除蛋白質開發低蛋白米類似物

如今，有些人的腎臟出現了問題。因此，他們必須注意日常膳食中蛋白質的攝入。因此，如果他們想吃米，但不應該吃普通米，因為碾米後的米仍然含有 6-7% 的蛋白質。他們需要限制膳食中米飯的數量。因此，這項研究的想法就是試圖為這群人去除蛋白質。因此，他們的飲食不會受到大米中蛋白質的影響。本研究主要以物理方法（以膠體研磨方式進行濕磨）及化學方法（鹼萃取，0.2% NaOH）以將米顆粒製成米粉。以傳統進行處理需要較長時間，約24-48小時才能將雜質顆粒去除，不僅影響澱粉顆粒，且浪費時間。因此以物理方式處理能夠讓我們以更短時間接續化學方法處理的部分，並減少米中的蛋白質。本研究以普通米粉作為對照組，並與膠體研磨不同時間（5、10、15 min）的米粉進行比較，發現其粗蛋白含量依序7.50 %、6.25 %、5.33及5.18%。而經由物理方法處理後，鹼處理（0.2%NaOH；30、45、60 min）將其粗蛋白含量分別降低至4.58%、4.22%及3.01%。透過掃描式電子顯微鏡（SEM）觀察米澱粉之結構，發現膠體研磨使米粉的破損較少，且剩餘之澱粉顆粒與一般米粉相同，皆為半結晶。與此同時，鹼處理之米粉的結晶度及表面粗糙度較高。相較之下，以傳統方法處理之米澱粉通常需要更長的時間，且更加粗糙、更廣泛的凝膠化及更多澱粉顆粒之凝聚。接下來將減少蛋白質之米粉透過義大利麵擠壓機結合不同黏著劑（2% 卡拉膠及4% 三仙膠）進一步開發成低蛋白米粉（LP-R），發現以4%三仙膠結合的米粉其吸水性指標（WAI）及吸水率（WAR）皆明顯高於以2%卡拉膠結合之米粉，分別為2.59 %、2.95 % 及2.66 %、3.61 %）。另一方面，與2%卡拉膠結合之米粉其水溶性指標（WAI）及烹煮流失率皆較與4%三仙膠結合之米粉高，分別為2.48 %、1.76 %及11.51 %、10.38 %；而其色澤（L*、a*、b*及E）則無顯著性差異。最後，測量並比較LP-R和一般米的基本組成分，發現LP-R的蛋白質含量僅為一般米（7.22%）的一半（3.56%），而其他成分則無明顯差異。這兩種方式並非減少米中蛋白質含量的唯一方法，相反還有許多其他方法在未來能夠被修改及研究，例如使用其他方式與酶結合等。然而，根據此處呈現的結果，可以假設使用物理方法及化學方法結合也是一種可有效降低米中蛋白質含量的有趣方式。

關鍵字

低蛋白；米；蛋白質移除；濕磨法；鹼萃取；米類似物

並列摘要

Nowadays, some people have problems with their kidneys. So, they must watch out for the intake of protein in regular meals. Thus, if they would like to have rice but they should not have normal rice because rice after milling still has 6-7% protein. Then, they need to be limited the amount of rice in the meal. So, it became the idea of this study, which tried to remove the protein for this group of people. So, their diets won’t be influenced by the presence of protein in rice. This study focused on physical methods (Colloid mill) and chemical methods (Alkaline extraction, 0.2% NaOH) to turn rice grain into rice flour and measure their cooking characteristics, physical characteristics, and nutritional properties. The traditional method (without a colloid mill) takes a long time around 24-48 hours to soak rice in an alkaline solution to remove protein leading to wasting time and affecting starch particles after treatment, the molecules of rice starch dramatically lower their semi-crystallinity and become more agglomerate. But, terms of using a colloid mill under extremely high shear force could break down the particle size of rice, this process could break down the particle size of rice, making it more chance for its protein could be exposed and dissolved into the water. This procedure was followed before using an alkaline solution. Consequently, the starch molecules will be affected less. However, the structure still reduces the semi-crystallinity and increases agglomeration, but not as much as traditional methods. and this process allows us to investigate the shorter-time chemical part. The control protein in this study is normal rice flour compared with rice flour milling by a colloid mill at various times (5, 10, and 15 min), the crude protein content were 7.50, 6.25, 5.33, and 5.18, respectively. After physical extraction, alkali extraction (0.2% NaOH; for 30, 45, and 60 min) reduced the crude protein content to 4.58, 4.22, and 3.01, respectively. The structure of rice starch was observed by scanning electron microscopy (SEM), It was found that using a colloid mill resulted in less damaged rice flour, as indicated by the remaining starch grains being semi-crystalline as well as normal rice flour. Meanwhile, the rice flour treated with alkaline showed increased levels of crystallinity and surface roughness. In contrast, the traditional method of rice starch usually requires a long period of time and results in more roughness, more extensive gelation, and more condensation of starch granules. then, the protein-reduced rice flour was further developed into low-protein rice (LP-R) by a pasta extruder using different binding agents (2% of carrageenan and 4% of xanthan gum), the value of the water absorption index (WAI) and water absorption ratio (WAR) was significantly different which from the rice flour combined with 4% of xanthan gum were higher than 2% of carrageenan (2.59, 2.95 / 2.66, 3.61, respectively). On the other hand, the value of water solubility index (WSI) and cooking loss from the rice flour combined with 2% of carrageenan is higher than 4% of xanthan gum (2.48, 1.76 / 11.51, 10.38, respectively) but in terms of the value of color (L*, a*, b*, and delta E) were not significantly different. Lastly, LP-R will be measured to compare the chemical composition of LP-R to normal rice. Other values were not significantly different, but the protein content of LP-R was only half (3.56%) of normal rice (7.22%). These two methods are not the only methods that can be used to reduce protein in rice; rather, there are many other methods that can be modified and researched in the future such as using enzymes when combined with other methods. However, based on the results presented here, it is possible to assume that using a combination of physical and chemical methods was also an interesting method that was able to efficiently lower the protein content.