卡拉胶对莲子果冻凝胶特性及储藏品质的影响

Effects of carrageenan on the gel properties and storage quality of lotus seed jelly

中文关键词:  卡拉胶  莲子果冻  凝胶  储藏

英文关键词:carrageenan  lotus seed jelly  gel  storage

中文摘要:

      目的 优化莲子果冻的制备工艺, 并探究卡拉胶对莲子果冻凝胶特性及储藏品质的影响。方法 在单因素实验的基础上, 通过感官评价、质构分析、低场核磁、傅里叶红外光谱和微生物平板计数法, 对莲子果冻的理化指标和微生物指标进行测定。结果 当莲子泥、黄冰糖和白凉粉的添加量分别为16%、4%和14%时, 莲子果冻的感官评分最高。卡拉胶的添加可以提高果冻凝胶的强度和保水性。当卡拉胶的添加量为0.6%时, 莲子果冻的硬度最好、弹性最佳。卡拉胶有序的双螺旋结构可以增强凝胶网络对水分子的束缚, 降低果冻的横向弛豫时间, 减少体系中的自由水分布。傅里叶红外光谱证明, 卡拉胶通过氢键相互作用与蛋白质分子发生交联。莲子蛋白的二级结构随着卡拉胶的添加而发生改变, 蛋白质的α-螺旋向β-折叠和β-转角转化, 有利于促进凝胶网络的形成。适量的添加卡拉胶有助于提高果冻的持水能力, 延长产品的货架期。莲子果冻经过20 d的储藏, 其微生物指标均符合国家标准。结论 卡拉胶的添加有助于改善以莲子泥、黄冰糖和白凉粉为主要原料的果冻产品的品质, 研究结果对于莲子产业发展和新型功能食品的开发具有一定的指导意义。

英文摘要:

      Objective To optimize the preparation technology of lotus seed jelly and to investigate the effects of carrageenan on the gel properties and storage quality of lotus seed jelly. Methods On the basis of single factor experiment, the physical and chemical indexes and microbial indexes of lotus seed jelly were determined by sensory evaluation, texture analysis, low-field nuclear magnetic resonance, Fourier infrared spectroscopy and microbial plate counting method. Results The sensory score of lotus seed jelly was the highest when the addition of lotus seed puree, brown rock candy and white jelly powder was 16%, 4% and 14%, respectively. The addition of carrageenan could improve the strength and water retention of jelly gel. When the addition of carrageenan was 0.6%, the hardness and springiness of lotus seed jelly were the best. The ordered double helix structure of carrageenan could enhance the water retention of the gel network, reduce the transverse relaxation time of the jelly, and reduce the free water distribution in the system. Fourier transform infrared spectroscopy proved that carrageenan cross-linked with protein molecules through hydrogen bond interaction. The secondary structure of lotus seed protein was changed with the addition of carrageenan, and the α-helix to β-folding and β-turning of protein were conducive to the formation of gel network. Appropriate addition of carrageenan could improve the water holding capacity of jelly and extend the shelf life of the product. After 20 days of storage, the microbial indexes of lotus seed jelly were in line with national standards. Conclusion The addition of carrageenan can improve the quality of jelly products with lotus seed puree, brown rock candy and white jelly powder as the main raw materials. The research results have certain guiding significance for the development of lotus seed industry and new functional foods.