Wang Wan, Cui Chunli, Wang Qiuling, Sun Changbao, Jiang Lianzhou, Hou Juncai
College of Food Science, Northeast Agricultural University, No. 600 Changjiang Rd., Xiangfang Dist, Harbin, 150030 China.
J Food Sci Technol. 2019 Jan;56(1):49-58. doi: 10.1007/s13197-018-3453-y. Epub 2018 Nov 27.
The objective of this study was to determine the effects of pH on the physicochemical properties of soybean oil bodies (SBOBs), peanut oil bodies (PNOBs) and sunflower oil bodies (SFOBs). The mean particle diameter (D) of oil bodies (OBs) changed to a stationary trend with increased pH. The surface hydrophobicity (H) of SBOBs, PNOBs and SFOBs significantly decreased with increasing pH 2-12. The emulsifying activity index of SBOBs, PNOBs and SFOBs decreased with increased pH from 2 to 10. The viscosity modulus (G″) value of SBOBs at pH 4 was significantly higher than at pH 7 and pH 9. The initial elastic modulus (G') and G″ values of PNOBs at pH 9 were significantly higher than at pH 4 and pH 7. The G″ values of SFOBs at pH 4 and pH 9 were significantly lower than at pH 7. The steroleosin protein bands of SBOBs significantly decreased at pH 12. The protein bands of PNOBs were reduced at pH 2-4 and pH 10-12, and protein bands decreased most obviously at pH 2. The enthalpy of denaturation (ΔH) values of the oil body (OB) protein at pH 9 were significantly higher than at pH 4 and pH 7. The results showed that the ζ-potential, D, emulsifying property and H of SBOBs, PNOBs and SFOBs were similar to the change of pH value. The three types of OBs have better stability away from the isoelectric point.
本研究的目的是确定pH对大豆油体（SBOB）、花生油体（PNOB）和向日葵油体（SFOB）理化性质的影响。随着pH升高，油体（OB）的平均粒径（D）呈现出稳定趋势。在pH值从2升高到12的过程中，SBOB、PNOB和SFOB的表面疏水性（H）显著降低。SBOB、PNOB和SFOB的乳化活性指数随着pH从2升高到10而降低。pH为4时SBOB的粘性模量（G″）值显著高于pH为7和9时的值。pH为9时PNOB的初始弹性模量（G'）和G″值显著高于pH为4和7时的值。pH为4和9时SFOB的G″值显著低于pH为7时的值。pH为12时SBOB的固醇油体蛋白条带显著减少。pH为2 - 4和10 - 12时PNOB的蛋白条带减少，在pH为2时蛋白条带减少最为明显。pH为9时油体（OB）蛋白的变性焓（ΔH）值显著高于pH为4和7时的值。结果表明，SBOB、PNOB和SFOB的ζ电位、D、乳化性能和H与pH值的变化相似。这三种类型的OB在远离等电点时具有更好的稳定性。
