疏水改性藜麦淀粉的制备及其Pickering乳液乳化性研究

Preparation of Hydrophobic Modified Quinoa Starch Granules and Study on Emulsifying Properties of Pickering Emulsion

本文用碱提法从藜麦种子中提取藜麦淀粉,并用辛烯基琥珀酸酐(Octenyl Succnic Anhydride,OSA)对提取的藜麦淀粉进行疏水改性,得到了辛烯基琥珀酸淀粉酯(OSA淀粉)。通过傅里叶红外光谱、扫描电子显微镜对比原淀粉和OSA淀粉颗粒的结构和形态,发现OSA基团成功接到淀粉表面,在形态上表现为颗粒表面轻度破坏。通过测定乳液微观结构,乳滴粒径及乳化指数(EI),分析了OSA淀粉取代度、颗粒浓度和油相比例等因素对Pickering乳液乳化性的影响。结果表明,乳滴粒径随OSA淀粉取代度或淀粉颗粒浓度的增加而减小、EI值随OSA淀粉取代度或淀粉颗粒浓度的增加而提高,乳液乳化性增强。当油相比例的增加时,乳滴粒径增大,且在食品添加剂允许OSA添加量的范围内,取代度为1.43%的OSA淀粉颗粒的EI值达到最大值75.48%,乳化性最好。研究表明OSA改性藜麦淀粉作为Pickering乳液的稳定颗粒在食品领域有极大的应用潜力。

In this study, quinoa starch was extracted from quinoa seeds by alkali method, and the extracted starch was modified by octenyl succnic anhydride(OSA), then the starch octenylsuccinate(OSA starch) was obtained. The structure and morphology of the native starch and OSA starch granules were compared by Fourier transform infrared spectroscope and scanning electron microscope. It was found that the OSA group was successfully attached to the surface of the starch, and the Particle surface was slightly damaged. And the effects of starch substitution degree, particle concentration and oil fraction on emulsion emulsification were analyzed by emulsion microstructure, droplet size and emulsifying index(EI). The results showed that the droplet size decreases with the increase of OSA starch substitution or starch granule concentration, and the EI value increases with the increase of OSA starch substitution degree or starch granule concentration, and the emulsion emulsifying properties is enhanced. As the oil fraction raise, the droplet size appears to increase, and within the range of the amount of OSA added by the food additive, the EI value of the OSA starch granule with substitution degree of 1.43% reaches a maximum of 75.48%, emulsifying properties were the best. These findings demonstrated that OSA modified quinoa starch can be used as a particle to stable Pickering emulsions and have great potential applications in food.