利用MiSeq技术研究调味面制食品中优势菌群及细菌多样性分析

为研究调味面制食品中微生物菌群分布的多样性与结构特点,以期把握其特定的致病菌提供理论依据,该试验采用高通量测序技术,研究分析调味面制食品中微生物的多样性,通过GB 4789.2-2016《食品安全国家标准食品微生物学检验菌落总数测定》中的均质拍击法提取调味面制食品中的微生物基因组,并选择Illumina MiSeq测序平台以及可变区域V3-V4进行测序。结果表明,3种调味面制食品中的细菌菌群多样性虽不高,但菌群结构具有一定的相似性,优势菌属为芽孢杆菌属(Bacillus),同时还有铜绿假单胞菌属(Pseudomonas)、明串珠菌属(Leuconostoc)、泛菌属(Pantoea)等。为后续加强食品生产工艺流程卫生,防控微生物污染,保证食品质量安全提供了新思路和新方法。

魔芋葡甘聚糖/纳米SiO_2复合涂膜配方及其对芒果贮藏品质的影响

以桂七芒果为材料,以魔芋葡甘聚糖、纳米二氧化硅为涂膜基质,采用3因素3水平正交试验,通过因子分析分析不同处理对芒果的色差、失重、硬度、可溶性固形物含量、pH和VC含量的影响,得出25℃条件下,对采后芒果保鲜效果良好的涂膜配方:魔芋葡甘聚糖8 g/L、纳米SiO_26 g/L、甘油4 g/L。该配方有效延迟了芒果的呼吸跃变,在一定程度上减少了芒果果皮色泽的变化,抑制了果皮褐变的发生,使失重率维持在10%以下,芒果果实硬度维持在0.05 MPa以上,可溶性固形物含量、pH和VC含量在贮藏后期仍然维持较高含量。

Preparation of tricalcium silicate and investigation of hydrated cement

Tricalcium silicate cement(TSC)has been widely used in dental materials because of its self-setting behavior,good bioactivity,biocompatibility,osteoinductivity,and antibacterial effect.Tricalcium silicate(C3S)powder was prepared by Pechini technique with a calcining temperature of 1300℃ for 3 h.The influence of liquid/powder(L/P)rate on the setting time and the mechanical property of TSC was studied.Characterization methods including XRD,FTIR,SEM-EDS,TEM,and ICP-AES were utilized to study the properties of C3S powder and its hydrated cement.The bioactivity and biocompatibility of the cement were investigated by soaking test and cell culture,respectively.The results show that the L/P rate plays an important role in the setting time and the compressive strength of TSC.The surface of TSC was covered by hydroxyapatite deposition during the immersion experiment and the cells attachment on the surface of TSC was well,which indicated that TSC has good bioactivity and biocompatibility.In addition,TSC has excellent antibacterial properties against Staphylococcus aureus.In conclusion,TSC is a promising candidate for root canal filling materials.

真空冷冻干燥技术在食品方面的应用

本文介绍了真空冷冻干燥技术的原理及其在食品加工中的应用,同时详细阐述了四个与其组合的冷冻干燥技术,并总结了冷冻干燥技术中的优点与需要改进的地方,最后,分析了国内外真空冷冻干燥技术在应用方面的状况与展望。