Wu Dan, Lin Quanquan, Singh Harjinder, Ye Aiqian
Riddet Institute, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand.
Riddet Institute, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand; School of Food Science and Bioengineering, Zhejiang Gongshang University, Hangzhou, Zhejiang 310018, China.
Food Res Int. 2020 Oct;136:109350. doi: 10.1016/j.foodres.2020.109350. Epub 2020 May 24.
Mixed systems of protein and polysaccharide are widely used in the food industry. It is important for food manufacturers to understand their interactions. In this study, the formation of complexes between whey protein isolate (WPI) and octenyl succinic anhydride (OSA)-modified starch was investigated as a function of pH and protein: starch ratio. OSA-modified starch tended to interact with heated WPI (HWPI) rather than non-heated WPI (NWPI), and the optimum conditions for their complexation were a protein: starch ratio of 1:10 and pH 4.5, probably driven by both electrostatic and hydrophobic interactions. The effects of the degree of substitution (DS) and molecular weight (Mw) of OSA-modified starch on the properties of the complexes formed under the optimum conditions were investigated using absorbance measurements (at 515 nm). Soluble complexes (HWPI-OSA SC) between 0.5% (w/v) HWPI and 5% (w/v) OSA-modified starch with a Mw of 19.24 ± 0.07 × 10 g/mol and a DS of 4.29 ± 0.11% could be formed at pH 4.5. The structure of HWPI-OSA SC was examined using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Characterization of the HWPI-OSA SC revealed that the intermolecular interactions between HWPI and OSA-modified starch led to their different characteristics from HWPI and OSA-modified starch alone.
蛋白质和多糖的混合体系在食品工业中广泛应用。对于食品制造商而言，了解它们之间的相互作用非常重要。在本研究中，研究了乳清分离蛋白（WPI）与辛烯基琥珀酸酐（OSA）改性淀粉之间复合物的形成与pH值和蛋白质：淀粉比例的关系。OSA改性淀粉倾向于与加热的WPI（HWPI）相互作用，而非未加热的WPI（NWPI），其复合的最佳条件是蛋白质：淀粉比例为1:10且pH值为4.5，这可能是由静电和疏水相互作用共同驱动的。使用吸光度测量（在515nm处）研究了OSA改性淀粉的取代度（DS）和分子量（Mw）对在最佳条件下形成的复合物性质的影响。在pH值为4.5时，可形成0.5%（w/v）HWPI与5%（w/v）Mw为19.24±0.07×10 g/mol且DS为4.29±0.11%的OSA改性淀粉之间的可溶性复合物（HWPI-OSA SC）。使用透射电子显微镜（TEM）、扫描电子显微镜（SEM）和傅里叶变换红外光谱（FTIR）对HWPI-OSA SC的结构进行了研究。HWPI-OSA SC的表征表明，HWPI与OSA改性淀粉之间的分子间相互作用导致它们具有与单独的HWPI和OSA改性淀粉不同的特性。
