University of Bologna, Department of Agricultural and Food Scinces, p.zza Goidanich 60, 47521 Cesena, Italy.
University of Bologna, Department of Agricultural and Food Scinces, p.zza Goidanich 60, 47521 Cesena, Italy.
Food Res Int. 2017 Jul;97:250-257. doi: 10.1016/j.foodres.2017.04.020. Epub 2017 Apr 18.
This study was aimed to evaluate the potential of high pressure homogenization for the microencapsulation of two probiotic lactic acid bacteria, Lactobacillus paracasei A13 and Lactobacillus salivarius subsp. salivarius CET 4063 to produce functional fermented milks. Microcapsules of the considered functional microorganisms were obtained by HPH treatments at 50MPa in the presence of sodium alginate and vegetable oil. The microencapsulated microorganisms were then inoculated as adjuncts to produce fermented milks. As controls were used fermented milks in which the two probiotic lactobacilli were inoculated without encapsulation. The viability of the strains was monitored during almost 2months of refrigerated storage. The survival of lactic acid bacteria after the gastric-duodenal simulated test was determined. Fermented milk texture parameters, the presence of exo-polysaccharides and the production of volatile molecules were also evaluated over storage. The microcapsules, for both the considered probiotic strains, were homogeneous and with a size<100μM and therefore did not adversely affect the sensory properties of the fermented milks. The encapsulation decreased the hyperacidity phenomena generally related to the inclusion of probiotic microorganisms in fermented milks. The lower acidity of the products due to the microencapsulation was fundamental for the improvement of the viability of the starter culture and the sensory characteristics of the products. The microencapsulation conditions increased the resistance to the simulated digestion processes, although the strain Lb. paracasei A13 generally showed a higher resistance to the gastric barrier respect to Lb. salivarius CECT 4063. By contrast, the data obtained showed a reduction of EPS production by the microencapsulation. The volatile profiles showed specific profiles in relation to the probiotic strain used and microencapsulation process. In conclusion, the results of this study underlined the applicative potential of HPH microencapsulation of probiotic microorganisms to produce fermented milk with improved functionality and with enhanced sensory properties.
本研究旨在评估高压均质（HPH）处理在微胶囊化两种益生菌乳杆菌（副干酪乳杆菌 A13 和唾液乳杆菌唾液亚种 CET 4063）中的潜力，以生产功能性发酵乳。通过在 50MPa 下使用海藻酸钠和植物油进行 HPH 处理，获得了考虑的功能微生物的微胶囊。然后，将微囊化的微生物作为添加剂接种以生产发酵乳。对照品为不进行包埋而接种两种益生菌乳杆菌的发酵乳。在冷藏储存期间监测了菌株的存活率。测定了胃-十二指肠模拟试验后乳酸菌的存活率。还评估了发酵乳的质地参数、外多糖的存在和挥发性分子的产生。两种考虑的益生菌菌株的微胶囊均为均匀的，粒径<100μm，因此不会对发酵乳的感官特性产生不利影响。包埋降低了通常与将益生菌微生物包含在发酵乳中相关的高酸度现象。由于微胶囊化而导致的产品酸度降低对于改善起始培养物的存活率和产品的感官特性至关重要。微胶囊化条件增加了对模拟消化过程的抵抗力，尽管与唾液乳杆菌 CECT 4063 相比，副干酪乳杆菌 A13 通常对胃屏障具有更高的抵抗力。相比之下，所得数据表明，微胶囊化会降低 EPS 的产生。挥发性图谱显示出与使用的益生菌菌株和微胶囊化过程相关的特定图谱。总之，本研究的结果强调了高压均质（HPH）微胶囊化益生菌微生物在生产具有改善功能和增强感官特性的发酵乳方面的应用潜力。
