Han Miao-Miao, Yi Yang, Wang Hong-Xun, Huang Fei
College of Food Science & Engineering, Wuhan Polytechnic University, Wuhan 430023, China.
Sericultural & Agri-food Research Institute, Guangdong Academy of Agricultural Sciences, Key Laboratory of Functional Foods, Ministry of Agriculture, Guangdong Key Laboratory of Agricultural Products Processing, Guangzhou 510610, China.
Molecules. 2017 Jun 5;22(6):938. doi: 10.3390/molecules22060938.
The purpose of this study was to investigate the Maillard reaction between polysaccharides and proteins from longan pulp and the effects of reaction on their in vitro activities. The polysaccharide-protein mixtures of fresh longan pulp (LPPMs) were co-prepared by an alkali extraction-acid precipitation method. They were then dry-heated under controlled conditions for monitoring the characterization of the Maillard reaction by the measurement of the free amino group content, ultraviolet-visible spectrum, Fourier transform infrared spectrum and molecular weight distribution. All the physicochemical analyses indicated the development of the Maillard reaction between polysaccharides and proteins. The in vitro activity evaluation indicated that the Maillard reaction could effectively enhance the antioxidant, antitumor and immunostimulating activities of LPPMs. The enhancement of 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and ferric reducing antioxidant power displayed both a positive correlation with the reaction time ( < 0.05). LPPMs dry-heated for three days obtained relatively strong inhibitory activity against HepG2 cells and SGC7901 cells, as well as strong immunostimulating effects on the nitric oxide production and tumor necrosis factor α secretion of macrophages. Maillard-type intermacromolecular interaction is suggested to be an effective and controllable method for improving the functional activities of polysaccharides and proteins from longan pulp.
本研究旨在探究龙眼果肉多糖与蛋白质之间的美拉德反应及其对体外活性的影响。采用碱提取-酸沉淀法共制备新鲜龙眼果肉的多糖-蛋白质混合物（LPPMs）。然后在可控条件下对其进行干热处理，通过测定游离氨基含量、紫外可见光谱、傅里叶变换红外光谱和分子量分布来监测美拉德反应的特征。所有理化分析均表明多糖与蛋白质之间发生了美拉德反应。体外活性评估表明，美拉德反应可有效增强LPPMs的抗氧化、抗肿瘤和免疫刺激活性。1,1-二苯基-2-苦基肼自由基清除活性和铁还原抗氧化能力的增强均与反应时间呈正相关（P<0.05）。干热三天的LPPMs对HepG2细胞和SGC7901细胞具有较强的抑制活性，对巨噬细胞一氧化氮产生和肿瘤坏死因子α分泌具有较强的免疫刺激作用。美拉德型大分子间相互作用被认为是提高龙眼果肉多糖和蛋白质功能活性的一种有效且可控的方法。
