Authors:G.W. Shu, D.L. Ma, H. Chen, J.P. Meng, Y. Wang, and N. Xin
The present study was to evaluate the survival rate of free and encapsulated Bifidobacterium bifidum BB28 under simulated gastrointestinal conditions and its stability during storage. Results showed that non-microencapsulated Bifidobacterium bifidum BB28 was more susceptible to simulated gastrointestinal conditions than microencapsulated bacteria. Microencapsulated Bifidobacterium BB28 exhibited a lower population reduction than free cells during exposure to simulated gastrointestinal conditions, the viable count of monolayer microcapsules, double layer microcapsules, and triple layer microcapsules decreased by nine magnitudes, four magnitudes, and one magnitude after 2 h, respectively. The enteric test showed that the microorganism cells were released from the monolayer, double layer, and triple layer microcapsules completely in 40 min. Moreover, the optimum storage times of free Bifidobacterium BB28, monolayer microcapsules, double layer microcapsules, and triple layer microcapsules were 21 days, 21 days, 28 days, and more than 35 days in orange juice, pure milk, and nutrition Express (a commercially available milk based drink), and the viable counts were maintained at 1×106 CFU g−1 or more, which means that the double layer and triple layer of microcapsules of B. bifidum BB28 have great potential in food application.
Two lines, L-19-613 and L-19-626, were produced from the common wheat cultivar Longmai 19 (L-19) by six consecutive backcrosses using biochemical marker-assisted selection. L-19 (Glu-D1a, Glu-A3c/Gli-A1?; Gli-A1? is a gene coding for unnamed gliadin) and L-19-613 (Glu-D1d, Glu-A3c/Gli-A1?) formed a set of near-isogenic lines (NILs) for HMW-GS, while L-19-613 and L-19-626 (Glu-D1d, Glu-A3e/Gli-A1m) constituted another set of NILs for the LMW-GS/gliadins. The three L-19 NILs were grown in the wheat breeding nursery in 2007 and 2008. The field experiments were designed using the three-column contrast arrangement method with four replicates. The three lines were ranked as follows for measurements of gluten strength, which was determined by the gluten index, Zeleny sedimentation, the stability and breakdown time of the farinogram, the maximum resistance and area of the extensogram, and the P andWvalues of the alveogram: L-19-613 > L-19-626 > L-19. The parameters listed above were significantly different between lines at the 0.05 or 0.01 level. The Glu-D1 and Glu-A3/Gli-A1 loci had additive effects on the gluten index, Zeleny sedimentation, stability, breakdown time, maximum resistance, area, P and W values. Although genetic variation at the Glu-A3/Gli-A1 locus had a great influence on wheat quality, the genetic difference between Glu-D1d and Glu-D1a at the Glu-D1 locus was much larger than that of Glu-A3c/Gli-A1? and Glu-A3e/Gli-A1m at the Glu-A3/Gli-A1 locus. Glu-D1d had negative effects on the extensibility and the L value compared with Glu-D1a. In contrast, Glu-A3c/Gli-A1? had a positive effect on these traits compared with Glu-A3e/Gli-A1m.