Production, Vitality And Application Of Microencapsulated Bifidobacteria

Bifidobacterium is an important and well known sort of probiotics. They have various of physiological and beneficial effects to our health. However, they have poor viability even extinction because their environmental sensitivities. How to protect the physiological activity of Bifidobacteria effectively became the research focus. Microencapsulation is one of the effective methods to protect probiotics from adverse conditions. The materials used for microencapsulation are typically natural polysaccharides and proteins because they often lack cytotoxicity and have safe biodegradation products. The present work was therefore undertaken to explore the reaction between protein and Bifidobacteria, the protection ability of polysaccharides to Bifidobacteria. Three technology conditions:layer by layer (LBL), complex coacervation (CC) and embedded in Maillard reaction products (MRPs) have effect on the viability of Bifidobacteria during food product processing, storage and gastrointestinal passages were discussed.Four kinds of Bifidobacteria’s surface hydrophobicities were decreased in the following order:B. breve (39.52±1.3%)> B. longum (29.60±1.7%)> B. bifidum (17.11±0.58%)> B. infantis (5.4±0.26%). Isothermal titration calorimetry (1TC), in combination with particle size measurements and lsaer scanning confocal microscope, provided new insights into the interaction between Bifidobacterium and proteins. The results revealed that soy protein isolate (SPI) and B. longum might form complexes in a certain way and showed the location of B. longum in SPI pockets. The main interaction was generated from the hydrophobicity force between SPI and B. longum, which comfirmed by ITC.The zeta potencial, UV-visible spectroscopy and morphology characters of before and after microencapsulation were studied and rheological behaviors and survival viability were measured. It could deduced that the physical and chemical properties of polysaccharides particular rheological behaviors plaied an important role in protecting Bifidobacterium rather than charge characteristics and hydrophilic property of polysaccharides. In addition, L-carrageenan (LC) was acid labile while I-carrageenan (IC) did not show very sensitive to acid.The research discussed the feasibility of LBL and complex coacervation according to the zeta potencial change of SPI, IC and B. longum. The morphology was characterized by transmission electron microscope (TEM) and scanning electron microscope (SEM). The influence to the complex coacervation yield of pH, IC amount and curing condition were inspected. The optimal conditions of complex coacervation reaction were established:pH3, the ratio of protein and IC was15:1, storage at4℃for12h. The viabilities of LBL and complex coacervation during storage were surveyed.The protection of MRPs which prepared by the combination of spray-dry and heating incubation was studied. Degree of graft of the MRPs in different ratios between SPI and IC was rapidly increased during the spray-dry process, but slowly under subsequent heating incubation. MRPs exhibited optimistic protective effect on survival number during food product processing, storage and GI passage. It was the first time that MRPs used in microencapsulated probiotics. MRPs would be new wall materials and the novel prebiotics in protecting probiotics in the future Producting fermenting beverage by microencapsulated B. longum we made, the result show that the microencapsulated B. longum in beverage could tolerant pasteurization (85℃and5min).