While it is preferred that flavour improves during the beer maturation process, formation of undesirable flavours inevitably occurs during beer storage. Beer ageing problems occur during beer storage and can damage the beer style, especially for lager beer of a more delicate style. In this research, the impact of pasteurising intensity on beer ageing and flavour stability was studied. Through process adjustments, three types of bottled beer were obtained from one fermenter and classified by their PU values as 2 PU, 8 PU and 14 PU. The dynamic changes of related indices (taken every month) characterizing the ageing and flavour of the beer under different pasteurising intensities were investigated during a 6-month room temperature storage period. The key factors of colour, the thiobarbituric acid (TBA) index, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, bitterness and total polyphenol composition, the concentration of beer volatile compounds (BVCs), and 5-hydroxymethyl furfural (5-HMF) were examined . Statistically, the 14 PU sample showed the highest degree of damage, with the greatest flavour change compared to the other samples.

BackgroundThe aim of the project is to retrospectively study the changes in bacterial pathogens in acute neonatal bacterial conjunctivitis from 2002 to 2016 in Southern China. The results may provide the guidance for drug choice for acute neonatal bacterial conjunctivitis.MethodsSecretion specimens for bacterial culture were taken from 485 cases with clinically diagnosed acute bacterial neonatal conjunctivitis. Bacterial pathogens were detected by Gram staining and subsequent bacterial culture.ResultsFrom the analysis of the bacterial pathogens in 485 cases of acute neonatal conjunctivitis patients from 2002 to 2016 in Southern China, there is an overall trend of decreasing detection of Gram-positive bacteria and increasing detection of Gram-negative bacteria from the conjunctival sac secretions. Gram-positive bacteria in the bacteria-positive samples dropped year by year from 82.6% in 2002 to 72.4% in 2016. Accordingly, the ratio of Gram-negative bacteria increased from 17.4% in 2002 to 27.6% in 2016. Of note, despite the overall trend, there was a significant increase in detection of Gram-positive bacteria and decrease in detection of Gram-negative bacteria from 2011 to 2012. Among the Gram-positive bacteria, there is a trend of increasing percentage of the opportunistic pathogens (an ~60% increase in Staphylococcus epidermidis and Staphylococcus saprophytic) and decreasing percentage of Staphylococcus aureus (~30% decrease) and hemolytic streptococcus (~20% decrease) in the last 15 years. The main Gram-negative bacterium is Neisseria gonorrhoeae. Overall, there is a change in the pattern of bacterial species in acute neonatal bacterial conjunctivitis in Southern China in the last 15 years.ConclusionOur study provides a trend analysis of the bacterial pathogens in the conjunctival sac secretions of the acute neonatal bacterial conjunctivitis patients in Southern China in recent years. This data could provide useful information regarding the treatment options for neonatal bacterial conjunctivitis.

In order to explore the applicability of waste engine oil and waste cooking oil used in aged asphalt, the effect of waste engine oil and waste cooking oil on aged asphalt recycling was studied through the analysis of the improvement of its physical, chemical, and rheological properties. Six aged asphalt binders with different aging times were obtained by indoor test simulation using the Thin Film Oven Test at 163 °C. Then, waste engine oil and waste cooking oil with five different dosages were added to investigate improvement performances. The results clearly demonstrated that waste engine oil and waste cooking oil could soften and recover the work ability of aged asphalt effectively. Furthermore, the physical, chemical, and rheological performances of six aged asphalts could be improved to normal level of virgin asphalt if the content of waste engine oil or waste cooking oil was suitable. The rheological properties of aged asphalt with waste cooking oil had better improvement than that with waste engine oil. Overall, the good applicability would provide waste oil a much wider service range in asphalt pavement recycling field. It also provided a method of developing new rejuvenating agent with the two waste oils to achieve complex synergism effect. Moreover, it realized the waste cyclic utilization and environmental protection.

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