Microbial safety control of compost material with cow dung by heat treatment

Various kinds of pathogenic bacteria derived from the intestinal tract of animals exist in compost material like cow dung. In order to sterilize the pathogenic bacteria completely in compost material, the cow dung was put into a heat treatment machine in pilot plan, and harmless condition in short time was examined. The results indicated, pathogenic indicator bacteria such as coliform bacteria, fecal coliform, Escherichia coli and salmonella were all 106 cfu/g dw at the beginning, died rapidly when cow dung temperature rose to above 50~C, and not detected at 54-68~C for 6-24 h heat treatment. Coliform bacteria and salmonella in heated cow dung were not detected by re-growth culture and enrichment culture examination. Moreover, it was hardly influenced on the fermentation ability of composting microbe, organic decomposition bacteria. During heat treatment, the mesophile decreased rapidly and the thermophile stabilized or increased, and the most of composting microbe were bacillus in cow dung by fluorescence microscope, this indicated that bacillus was dominator and composting microbe in composting process.

Development of a mixed fruit beverage and pulsed light treatment thereof to obtain a microbially safe and enzymatically stable product

A mixed fruit beverage was formulated according to D-optimal mixture design using apple ber juice(X_(1),45-59%v/v)-an underexplored fruit,carambola juice(X_(2),1-20%v/v),and black table grape juice(X3,35-40%v/v).The crisp overall acceptability(COA)from 16 semi-trained panelists and overall hedonic score(OSH)from consumers were estimated.The best formulation was apple ber:carambola:black table grape juices=59.0:3.5:37.5 v/v with COA and OSH values of 3.23(on a scale of 5)and 7.55(on a scale of 9),respectively.Further,the efficacy of pulsed light(PL)(18-30 W cm^(-2) for 33-167 s;total fluence 600-5000 J cm^(-2))and thermal treatments(90℃ for 1-5 min)were studied on various attributes of the mixed beverage.The beverages processed at 90℃ for 5 min(thermal treatment)and 5000 J cm^(-2)(PL treatment at 30 W cm^(-2) for 167 s)showed no microbial count with a complete enzyme inactivation.The thermally pasteurized sample(90℃/5 min)was more brown(browning index=70.15)than the PL pasteurized beverage(browning index=65.98).Interestingly,the PL pasteurized(5000 J cm^(-2))beverage showed 25%,27%,and 19% more vitamin C,antioxidants,and phenolic compounds,respectively,than the thermally pasteurized(90℃/5 min)beverage.The PL-treated beverage had a greater sensory appeal than the thermally treated beverage.PL-treatment can be an efficient non-thermal pasteurization treatment for ensuring complete microbial and enzymatic inactivation with maximal retention of nutritional and sensory attributes of the blended beverage.

Investigation of drinking water bacterial community through high-throughput sequencing

Delivery of safe and pathogen-free drinking water is crucial to public health.However,there exist challenges to the maintenance of the sterility of drinking water throughout the drinking water distribution systems（DWDS）.Microbial growth in DWDS,such as growth of opportunistic pathogenic microorganisms,can lead to severe health problems in consumers（Berry et al.,2006;Brettar and Hofle,2006;Lu et al.,2014;Zhang et al.,2015）.