本研究成功的利用黃豆分離蛋白（SPI）來製造高蛋白質之豆腐，並探討黃豆分離蛋白、油和水分含量對高蛋白質豆腐質感和顏色之影響。高蛋白質豆腐膠強度會隨著水份的增加而減少，隨著油含量的增加而減少，而白度則隨著油含量的增加而增加，其中以SPI：水：油=1:4.5:2時，其膠強度值為725g，L值為81.90，此時產品的性質最接近市售盒裝之中華豆腐（膠強度值為700g，L值為81.29）。當以澱粉(0-40%)取代黃豆分離蛋白時，其膠強度值從750g降至85g。當探討PH值和離子強度對膠強度之影響時，發現離子強度愈高，其膠強度愈差，但加工流動性好;而PH值在6-8時，其膠強度最好。比較不同種類之黃豆分離蛋白，發現Pro-Fam 974比Supro620有更好的成膠特性，由近紅外線反射光譜偵測結果，發現其光譜結構有明顯差異。 The objectives of this research are to develop the high protein content tofu by using the soybean protein isolate (SPI) as the starting material and to investigate the effect of SPI type, oil and water content on the quality of SPI-tofu. The gel strength of SPI-tofu decreased as the water content increased. It also decreased with increasing the oil content. The whiteness (L values) increased as the oil content increased. The SPI-tofu has the similar properties (gel strength=725g, L=81.90) as the commercial one with gel strength=700g and L=81.29 when the ratio of SPI:water:oil is equal to 1:4.5:2. The gel strength decreased from 750g to 85g as the starch content increased from 0 to 40%. The gel strength also decreased as the ionic concentration increased. The SPI-tofu made by Pro-Fam 974 has better gel strength than the one made by Supro 620. The spectra of Near Infra Reflectance of these two SPIs indicate that there exists the obviously difference between these spectra.
