豌豆及綠豆蛋白之擠壓加工特性

Abstract

在此研究中，利用豌豆和綠豆蛋白開發組織化植物蛋白 (texturized vegetable protein, TVP) 產品並分析其原料與擠壓設定條件對擠出物 (extrudate) 特性的影響。本研究分為四個部分，第一部分，評估不同原料經低水分含量擠壓處理之影響。將豌豆分離蛋白 (pea protein isolate, PPI)、綠豆分離蛋白 (mung bean protein isolate, MBPI)、大豆分離蛋白 (soy protein isolate, SPI) 和馬鈴薯澱粉 (potato starch, PS) 混合製備樣品，並分析其色澤變化、物理特性和微觀結構。結果顯示，MBPI色澤變化較少，且有較低的假密度(bulk density, BD)及較高的吸水指數(water absorption index, WAI)，因此具有良好的加工性質。從SEM圖中觀察到，含有 MBPI 和 PS 的樣品具多孔結構，提高孔隙率。添加SPI和PS的樣品則增強以PPI為主原料之擠出物的物理性質。第二部分，評估不同擠壓設定條件在低水分擠壓操作之影響，包括在 PPI 加工過程中改變螺桿轉速和水分含量以製備樣品。結果顯示，提高螺桿轉速和降低水分含量有利於產品膨發並增強其物理性質。不同的擠壓條件會影響擠出物的WAI，但不會影響保油率 (oil holding capacity, OHC)。第三部分，評估經擠壓後之 TVP 的烹煮性質。經烹煮後的TVP具較有利保存的低水分含量和低水活性，儲存穩定性佳。在感官品評中，MBPI 與對照組 (non-fat soybean, NFS) 有相同的可接受性，但PPI組則有較低的數值。第四部分，評估不同原料經高水分擠壓處理之影響。結果顯示，經擠壓後的產品 (high moisture meat analogue, HMMA) 在特定方向有纖維狀結構，且富含蛋白質的組別具有較高硬度和切斷力，添加 PS的組別顯著降低其硬度和切斷力，經油煎的HMMA可提高其硬度和切斷力。經由一系列的擠壓和烹煮試驗，顯示PPI 和 MBPI 的加工性質適合作為取代蛋白質之原料。相信這項研究將會為開發 PPI 和 MBPI 的新產品提供參考。

In this study, the characteristics of the extrusion process were analyzed for the development of new products using pea and mung bean proteins. This research was carried out in four parts. In the first part, the impact of different raw materials on low-moisture extrusion process was evaluated. Pea protein isolate (PPI) and mung bean protein isolate (MBPI) were mixed with soy protein isolate (SPI) and potato starch (PS) to prepare samples and analyzed for color change, physical properties, and microstructure. MBPI showed good processing properties such as less color deterioration, low bulk density (BD), high water absorption index (WAI) of the products. In SEM image, porous structures were observed in the product containing MBPI and PS, which increased the porosity. The addition of SPI and PS improved the physical properties of PPI. In the second part, the effect of different extruder operating conditions on low-moisture extrusion process was evaluated. The screw speed and moisture content were varied in the processing of PPI and the samples were prepared. Increasing screw speed and decreasing moisture content facilitated the product expansion and improved the physical properties. Changing conditions affected water holding capacity (WAI), but not oil holding capacity (OHC). In the third part, cooking properties of the product (texturized vegetable protein, TVP) obtained by extrusion processing were evaluated. The cooked TVP showed reasonable moisture content and water activity, and showed high storability. In sensory evaluation, MBPI showed a high level of acceptability similar to the control (non-fat soybean, NFS), while PPI showed low sensory properties. In the fourth part, the impact of different raw materials on high moisture extrusion process was evaluated. The product after extrusion process (high moisture meat analogue, HMMA) formed a fibrous structure in a certain direction, and high hardness and cutting force were measured for the protein-rich sample. The addition of PS significantly decreased hardness and cutting force. Frying process of HMMA increased hardness and cutting force. A series of extrusion processing and cooking revealed the processing properties of PPI and MBPI, indicating their suitability as alternative proteins. It was believed that this research will serve as fundamental data for the development of new protein foods using PPI and MBPI.