Evaluation of electrolyzed water as cleaning and disinfection agent on stainless steel as a model surface in the dairy industry

In the dairy industry, cleaning and disinfection of surfaces are important issues and development of innovative strategies may improve food safety. This study was aimed to optimize the combined effect of alkaline electrolyzed water (AEW) and neutral electrolyzed water (NEW) as alternative cleaning and disinfection procedure on stainless steel plates (SSP) with and without electropolishing. NEW at 10 ppm total available chlorine (TAC), achieved a ˃5 log CFU/mL reduction of milk spoilage bacterial suspension, grown in trypticase soy broth (8.7 log CFU/mL of each bacterial strain: Pseudomonas aeruginosa, Enterococcus faecalis and Micrococcus luteus) contacted for 30 s. An optimal design of experiments was used to assess the combined effect of cleaning with AEW, followed by disinfection with NEW (40 ppm TAC, contact time 3 min). Tested factors were contact time (10, 20 and 30 min), concentration of AEW (100, 200 and 300 mg NaOH/L), temperature (30, 40 and 50 °C), and surface type (304-2B SSP with or without electropolishing), using sixteen treatments with two replicates. The response variable was bacterial cells removal (log CFU/cm²). All main effects, two factors interactions and a quadratic term significantly influenced cells removal, and were modeled using a second order polynomial. Best cleaning procedures were significantly affected by surface roughness; electropolished SSP required 10 min, 100 mg/L AEW at 30 °C, whereas SSP without modification required 30 min, 300 mg/L AEW at 30 °C. From confirmatory tests cells removed were 3.90 ± 0.25 log CFU/cm² for electropolished SSP, and 3.20 ± 0.20 log CFU/cm² for SSP without modification. NEW is non-corrosive, and can be advantageously used for environmentally friendly cleaning and disinfection processes.     

Effect of blanching followed by refrigerated storage or industrial microwave drying on the microbial load of yellow mealworm larvae (Tenebrio molitor)

Yellow mealworm larvae (Tenebrio molitor) are being introduced into Western food products. The effect of blanching, followed by either chilled storage or industrial microwave drying, on microbial counts of the larvae was investigated. Whatever time applied (10, 20 or 40 s), considerable log reductions were obtained after blanching (total viable count, Enterobacteriaceae, lactic acid bacteria, yeasts and molds and psychrotrophs), except for aerobic endospores. No major growth was observed during subsequent chilled storage for 6 days. Total viable counts were below 3.5 ± 0.3 log cfu/g for all samples. When blanching for 40 s was followed by industrial microwave drying, drying for 8, 10 or 13 min did not yield larvae with a water activity below 0.60, which is necessary to eliminate all microbial growth. Drying times of 16 or 20 min yielded average water activities of 0.16 and 0.23, respectively. The number of vegetative cells was reduced to a large extent by blanching plus drying, but the number of bacterial endospores only slightly. Total viable counts were maximally 3.4 ± 0.8 log cfu/g for all samples. Bacterial endospores were the most resistant to the processing technologies investigated.     

油基钻屑常温清洗—微生物联合处理技术

油基钻井液因具有抑制性强、润滑性好、抗高温、抗污染、安全和钻速快等优点而被广泛应用在对非常规油气资源的勘探开发工作中,而其钻屑矿物油含量高、乳化严重、不易回收等缺点也成为环保治理的难点。为此,针对不同类型油基钻屑的物性特点,将高效清洗剂破乳清洗处理、油—水—固三相分离和石油微生物消除等3种工艺有机集成,试制出一套油基钻屑现场处理装置,形成了油基钻屑常温清洗—微生物联合处理技术。经过对4口井的油基钻屑进行放大试验,结果表明:油相回收率超过85%,清洗后废渣总石油烃含量小于2%,再经生物深度处理30天后,废渣中总石油烃含量降至0.3%以下,均达到相关标准的要求。结论认为:该联合处理技术实现了油相的回收再利用以及废渣的无害化处理,不仅有效解决了油基钻屑环保治理难题,而且还节约了钻井工程综合成本,具有良好的推广应用前景。     

Factors affecting the status of food safety management systems in the global fresh produce chain

Increase in global trade raised questions regarding status of food safety management systems in fresh produce companies, especially from developing and emerging countries. The aim of this study was to investigate the status of food safety management systems (FSMSs) implemented at primary production companies of fresh produce, to examine the potential differences between companies operating in European Union (EU) and non-EU (developing and emerging) countries, and to explore the underlying factors. Primary production companies (n = 118), located in the EU and in international cooperation partner countries exporting to the EU, were assessed by using a diagnostic tool. The results from the study indicated that several factors have a dominating effect on the status of FSMSs in the global fresh produce chain. International export supply chains promote capacity building within companies in the chain, to answer the stringent requirements of private brand standards. This was shown to be an important factor in emerging and developing countries, where local institutional environments often fail to support companies in setting and implementing their FSMSs. Moreover, the legislative framework in these countries still requires improvements in the establishment and enforcement. All this has negative consequences for the FSMSs in companies supplying the local markets. In companies located in the EU, sector and other produce organisations facilitate the sampling for pesticide residues and collaboration in the sector. Overall, farmers showed less knowledge and overall awareness regarding microbiological hazards, which is related to the less attention paid to these in the current legislation and standards. Furthermore, standards are an important tool to trigger the maturation of the systems as companies that were lacking any pressure to comply to standards operated at a very basic level - with only few activities implemented. The insights from this study indicate the need of stratified measures and policies to support companies in the fresh produce chain in designing and operating their FSMSs according to the institutional environment in which they operate.