Laboratory of Pharmaceutics, Faculty of Medicine and Pharmacy, Mohammed V University, Rabat, Morocco.
Laboratory of Medical Biotechnology, Faculty of Medicine and Pharmacy, Mohammed the Vth University in Rabat, Rabat, Morocco.
BMC Biotechnol. 2019 Aug 2;19(1):57. doi: 10.1186/s12896-019-0539-1.
The textural characteristics of fermented dairy products are important quality parameters that play a major role in their stability and consumer's acceptance. The aim of this study was to investigate the influence of sodium caseinate, starch, lactose and lactic acid bacteria as ferment on the syneresis in a mixed model system, and to evaluate their impact on the acid gel formation throughout pH and zeta potential monitoring. Accordingly, a protocol was designed to perform an experimental design by using a mixture of the selected factors.
A significant decrease of syneresis was detected in all mixtures at 8% of sodium caseinate, ranging between a minimum of 1.8% and a maximum of 20.6% compared to the mixtures at 3% of sodium caseinate in which the syneresis decrease had ranged between a minimum of 22.2% and a maximum of 47.8%. The addition of starch had a significant impact on the acidification profile and on the syneresis of the fermented mixed model. Moreover, the monitoring of pH and zeta potential during the lacto-fermentation process has also led to a better understanding of the acid gelation and the syneresis variations.
Syneresis varies very closely with sodium caseinate concentration, starch concentration and also with their association, regardless of the concentrations of lactose and ferment. In fact syneresis could be reduced to an optimum level if a sodium caseinate-starch mixed system is employed: Less syneresis gels could be obtained at a sodium caseinate concentration above 5% if starch is used above 1%.
发酵乳制品的质构特性是重要的质量参数，对其稳定性和消费者接受度起着重要作用。本研究旨在研究酪蛋白酸钠、淀粉、乳糖和乳酸菌作为发酵剂对混合模型体系中分离的影响，并通过 pH 和zeta 电位监测评估它们对酸凝胶形成的影响。因此，设计了一个方案来通过使用选定因素的混合物来执行实验设计。
在所有混合物中，在 8%的酪蛋白酸钠下，分离率显著降低，与在 3%的酪蛋白酸钠下的混合物相比，分离率降低幅度在 1.8%到 20.6%之间。淀粉的添加对酸化曲线和发酵混合模型的分离有显著影响。此外，在乳酸发酵过程中监测 pH 和 zeta 电位也有助于更好地理解酸凝胶化和分离变化。
分离率与酪蛋白酸钠浓度、淀粉浓度及其组合密切相关，而与乳糖和发酵剂的浓度无关。事实上，如果使用酪蛋白酸钠-淀粉混合系统，分离率可以降低到最佳水平：如果使用高于 1%的淀粉，则可以在高于 5%的酪蛋白酸钠浓度下获得更少的分离凝胶。
