Spray Washing Research Articles

Microbiological evaluation of bovine carcasses decontaminated with lactic acid solution

Bovine meat is a nutritious food product that is highly susceptible to bacterial degradation. Organic acid spray washing can be used to reduce microbial populations in carcasses. This study aimed to examine the efficacy of lactic acid in reducing total coliforms and Escherichia coli and assess the effects of different lactic acid concentrations on meat. For this, bovine carcasses were classified into cleanliness categories and subjected to swab sampling before and after manual and automated washing with lactic acid solution at different concentrations (0, 0.5%, 1%, 2%, 3%, and 4%). Colorimetric analysis and lactic acid quantification of carcasses were performed at 0 and 24 h post mortem. The experiment followed a factorial design. Lactic acid inhibited microbial growth, particularly automated application of 3% lactic acid. Although minor changes in color were observed, lactic acid washing was beneficial from a microbial standpoint, effectively decontaminating bovine carcasses and leaving only minimum amounts of residual acid in meat.

Integrating meta-analysis with a quantitative microbial risk assessment model to investigate Campylobacter contamination of broiler carcasses

This study investigated the prevalence and associated risk factors of Campylobacter in South Korean broilers using a random-effects meta-analysis. Subsequently, to facilitate the design of preventive measures, the prevalence estimate from the meta-analysis was incorporated into a stochastic risk assessment model to quantify the Campylobacter contamination levels on broiler carcasses. The baseline model was developed based on the most common practices along the South Korean broiler processing line, with no interventions. Meta-analysis results revealed Campylobacter prevalence across the chicken supply chain in the following order: farms (60.6 % [57.3–63.4]), retail markets (43.90 % [24.81–64.99]), slaughterhouses (27.71 % [18.56–39.21]), and processing plants (14.50 % [3.96–41.09]). The model estimated a 52 % (36.1–70.8) Campylobacter prevalence at the end of chilling, with an average contamination level of 4.62 (2.50–6.74) log CFU/carcass. Sensitivity analysis indicated that Campylobacter fecal shedding (r = 0.95) and the amount of feces on bird exteriors (r = 0.17) at pre-harvest were the main factors for carcass contamination, while soft scalding (r = -0.22) and air chilling (r = -0.12) can serve as critical control points (CCPs) at harvest. Scenario analysis indicated that a combination of hard scalding, inside-outside bird washing, spray washing, and chlorinated water immersion chilling can offer a 30.9 % reduction in prevalence and a reduction of 2.23 log CFU/carcass in contamination levels compared to the baseline model. Apart from disinfection and sanitation interventions carried out during meat processing, the implementation of robust control measures is indispensable to mitigate Campylobacter prevalence and concentration at broiler farms, thereby enhancing meat safety and public health. Furthermore, given the high Campylobacter prevalence in the retail markets, future studies should explore the potential risk of cross-contamination at post-harvest stage.

Aqueous Ozone Efficacy for Inactivation of Foodborne Pathogens on Vegetables Used in Raw Meat-Based Diets for Companion Animals

The present study evaluates the efficacy of a batch wash ozone sanitation system (BWOSS) and spray wash ozone sanitation system (SWOSS) against Listeria monocytogenes (two strains) and Salmonella enterica subsp. enterica (three serovars) inoculated on the surface of carrots, sweet potatoes, and butternut squash, commonly used in raw meat-based diets (RMBDs) marketed for companion animals such as dogs and cats. Produce either remained at room temperature for 2 h or were frozen at −20°C and then tempered overnight at 4°C to mimic the preprocessing steps of a raw pet food processing operation (‘freeze-temper’) prior to ozone treatment. Two ozone concentrations (0 and 5 ppm) were applied for either 20 s or 60 s for BWOSS and 20 s for SWOSS. Based on an ANOVA, BWOSS data showed no significant difference (P > 0.05) in microbial reduction between 0 and 5 ppm ozone concentration across all treatment durations for each produce type. BWOSS resulted in mean microbial reductions of up to 1.56 log CFU/mL depending on the treatment time and produce type. SWOSS data were analyzed using a generalized linear model with Quasipoisson errors. Freeze-tempered produce treated with SWOSS had a higher bacterial log reduction at 5 ppm ozone compared to 0 ppm ozone (P = 0.0013) whereas room temperature produce treated with SWOSS did not show any significant difference in microbial reduction between ozone concentrations. The potential to mitigate microbial cross-contamination was also investigated during SWOSS treatment. The results indicate that 5 ppm ozone decreased pathogens in the rinsate and proximal surfaces by 0.63–1.66 log CFU/mL greater than no ozone depending on the pathogen and sample. Overall, data from this study indicate that SWOSS would be more effective compared to BWOSS in reducing the microbial load present on the surface of root tubers and squash subjected to freezing and thawing and has the potential to mitigate cross-contamination within RMDB manufacturing environments.

Enhancing the efficacy of peracetic acid against Listeria monocytogenes and Listeria innocua on fresh apples using commercial acidic and alkaline cleaners

Peracetic acid (PAA) is a commonly used antimicrobial in brush-bed spray bar interventions during apple packing. Prior to sanitizer application on the brush-bed, specific fruit cleaners, such as Acidex Duo (AD), EpiClean (EC), Nature's Shield 220-ACL (NS 220), or Nature's Shield 330-ALK (NS 330), are used to remove of soil, debris, and natural wax from the surfaces of apples. This study evaluated the effectiveness of commonly used cleaners in the apple industry to improve the antimicrobial efficacy of PAA against Listeria monocytogenes on apple surfaces during brush-bed spray bar interventions. Granny Smith apples, 48 h post-inoculation, underwent submersion treatment with different cleaners, as well as PAA alone or in combination with the cleaners. A 30-sec treatment of 5.0% AD, 4.2% EC, 10.0% NS 220, and 10.0% NS 330 resulted in 0.65, 0.50, 0.68, and 0.51 log10 CFU/apple reduction of L. monocytogenes on apples, respectively. Incorporating AD, NS 220, and EC significantly enhanced the antimicrobial efficacy of an 80 ppm PAA intervention. The enhancing effects were not impacted whether the cleaner was applied consecutively with PAA (sequentially) or in combination with PAA (simultaneously), nor were they impacted by a post-treatment water rinse. A 30–120 s wash of 80 ppm PAA with AD, EC, and NS 220 at their suggested concentration resulted in 2.46–2.55, 1.87–2.03, and 2.34–2.48 log10 CFU/apple reduction of L. monocytogenes, respectively, compared to 1.39–1.64 log10 CFU/apple in PAA treatment alone. The inclusion of AD or NS 220 in 80 ppm PAA solution resulted in a reduction of 1.51–1.63 log10 CFU/apple of Listeria after 30–60 s brush-bed spray wash. This enhancement in efficacy was significant compared to the treatment with 80 ppm PAA alone, which resulted in a reduction of 0.94–1.03 log10 CFU/apple. This study demonstrated that using certain commercially available cleaners along with PAA can enhance the effectiveness of PAA in reducing L. monocytogenes on fresh apples.

Efficacy of Antimicrobial Interventions Used in Meat Processing Plants against Antimicrobial Tolerant Non–Antibiotic-Resistant and Antibiotic-Resistant Salmonella on Fresh Beef

Salmonella is a common cause of foodborne illness in the United States, and several strains of Salmonella have been identified as resistant to antibiotics. It is not known whether strains that are antibiotic resistant (ABR) and that have some tolerance to antimicrobial compounds are also able to resist the inactivation effects of antimicrobial interventions used in fresh meat processing. Sixty-eight Salmonella isolates (non-ABR and ABR strains) were treated with half concentrations of lactic acid (LA), peracetic acid (PAA), and cetylpyridinium chloride (CPC), which are used in beef processing plants to screen for tolerant strains. Six strains each from non-ABR and ABR Salmonella that were most tolerant of LA (2%), PAA (200 ppm), and CPC (0.4%) were selected. Selected strains were inoculated on surfaces of fresh beef and subjected to spray wash treatment with 4% LA, 400 ppm PAA, or 0.8% CPC for the challenge study. Tissue samples were collected before and after each antimicrobial treatment for enumeration of survivors. Spray treatment with LA, PAA, or CPC significantly reduced non-ABR Salmonella and ABR Salmonella on surfaces of fresh beef by 1.95, 1.22, and 1.33 log CFU/cm2, and 2.14, 1.45, and 1.43 log CFU/cm2, respectively. The order of effectiveness was LA > PAA = CPC. The findings also indicated that LA, PAA, and CPC were equally (P ≤ 0.05) effective against non-ABR and ABR Salmonella on surfaces of fresh beef. These data contribute to the body of work that indicates that foodborne pathogens that have acquired both antibiotic resistance and antimicrobial tolerance are still equally susceptible to meat processing antimicrobial intervention treatments.

Preharvest Management and Postharvest Intervention Strategies to Reduce Escherichia coli Contamination in Goat Meat: A Review.

Simple SummaryGoat farms and processing facilities worldwide are primarily small-scale, limited resource operations. Cost-effectiveness and practicality are critical factors to be considered before adopting any pre- and/or post-harvest strategies for pathogen reduction in goat meat. Preharvest management methods in goats that can reduce Escherichia coli in meat include minimizing animal stress, selecting diets and feed deprivation times that can reduce fecal shedding of bacteria, and adding tannin-rich feed supplements. In addition, use of appropriate postharvest nonthermal intervention technologies that can reduce microbial loads in carcasses and meat can extend the shelf-life and marketability of goat meat products. Reducing stress prior to slaughter and using nonthermal intervention methods can result in better meat quality and economic returns for producers. Goat meat is the main source of animal protein in developing countries, particularly in Asia and Africa. Goat meat consumption has also increased in the US in the recent years due to the growing ethnic population. The digestive tract of goat is a natural habitat for Escherichia coli organisms. While researchers have long focused on postharvest intervention strategies to control E. coli outbreaks, recent works have also included preharvest methodologies. In goats, these include minimizing animal stress, manipulating diet a few weeks prior to processing, feeding diets high in tannins, controlling feed deprivation times while preparing for processing, and spray washing goats prior to slaughter. Postharvest intervention methods studied in small ruminant meats have included spray washing using water, organic acids, ozonated water, and electrolyzed water, and the use of ultraviolet (UV) light, pulsed UV-light, sonication, low-voltage electricity, organic oils, and hurdle technologies. These intervention methods show a strong antimicrobial activity and are considered environmentally friendly. However, cost-effectiveness, ease of application, and possible negative effects on meat quality characteristics must be carefully considered before adopting any intervention strategy for a given meat processing operation. As discussed in this review paper, novel pre- and post-harvest intervention methods show significant potential for future applications in goat farms and processing plants.

Synergistic Effects of Lauric Arginate and Peracetic Acid in Reducing Listeria monocytogenes on Fresh Apples.

Apples are naturally coated with a water-repelling hydrophobic wax layer, which may limit the antimicrobial efficacies of surface sanitizer solutions. Lauric arginate (LAE) is a cationic surfactant with antimicrobial efficacy against Listeria monocytogenes. In this study, we investigated the antimicrobial and the wettability effects of LAE in enhancing anti-L. monocytogenes efficacy of peracetic acid (PAA) and further verified the optimized treatment combinations in a pilot spray-bar brush bed system. Apples after 48 h of inoculation were treated with PAA surface sanitation in combination with different concentrations of LAE at 22 or 46°C. The effectiveness of PAA with LAE solutions in decontaminating L. monocytogenes significantly increased with the increased concentration of PAA (60–80 ppm) or LAE (0.01–0.05%) or the treatment temperature (from 22 to 46°C). A 30–120-sec wash by 80 ppm PAA with 0.01 and 0.05% LAE at 22°C reduced L. monocytogenes on apples by 2.10–2.25 and 2.48–2.58 log10 CFU/apple, respectively. Including LAE in the PAA solution decreased contact angles on apple surfaces. However, the increased wettability of the sanitizer solution may not be the main contributor to the enhanced antimicrobial efficacy of the PAA solution, given that the addition of Tween 80 or Tween 85 only slightly boosted the anti-L. monocytogenes efficacy of PAA solutions though both increased the wettability of the PAA solutions. The synergistic effects of PAA and LAE were further validated in a pilot spray-bar brush bed packing system, where a 30-sec spray wash with 80 ppm PAA and 0.05% LAE at 22 and 46°C caused 1.68 and 2.08 log reduction of Listeria on fresh apples, respectively. This study provides an improved PAA process/preventive strategy for ensuring microbial food safety of fresh apples that is applicable to commercial apple packing lines.

Sustainability Issues of Various Denim Washing Methods

Denim washing is increasingly joining the list of indispensable processes of meeting the demands of the world’s shifting fashion industry. Other than this, there is a rising trend in the sustainability perception among both producers and customers in the modern world. However, denim washing is considered to have direct impacts on the environment because of its chemical discharge and many other pollutants emitted during the process which affect water supplies. In the process, the denim industry encounters challenges at every level. Therefore, there is need for studying sustainable problems associated with denim washing. The unseen soul of the denim industry is technology, as nothing can be transformed without technological advancement. Sustainability problems of conventional washing have been addressed in this paper (i.e. pp spray washing, bleaching washing, stone washing, sand blasting etc.). Furthermore, the paper describes how sustainability can be achieved through the most recent washing techniques, such as laser, waterjet, nanobubble, ozone, NoStone, potassium permanganate alternatives etc. The introduction of new technologies has triggered a dramatic shift in the denim washing industry in terms of water usage, electricity and chemicals as well as improved quality. Consequently, it is undoubtful that the recent technologies in denim washing are crucial in making the industry sustainable. Moreover, the paper describes the idea of digitally printed denim and the available software for measuring sustainability in the process of denim washing.

Efficacy of commercial overhead washing and waxing systems on the microbiological quality of fresh peaches

Overhead spray washing and waxing systems (WWS) are used commercially to reduce the risk of microbial contamination and improve the quality of fresh produce during packing. This study evaluated the microbiological quality of overhead spray water and spent peach wash water, as well as fresh peaches before and after they pass the WWS. Pre- and post-washed/waxed peach samples (n = 192) and overhead spray water and spent peach wash water samples (n = 54) were collected several times over the course of a processing day in three packing facilities located in the state of Georgia. Populations of total aerobes (TA), yeasts and molds (YM), and coliforms (TC) and the presence of thermotolerant coliforms (TTC) and enterococci (EC) were measured in collected samples. The average TA and TC counts and the incidences of TTC and EC were significantly higher (P < 0.05) on peach samples collected after the WWS compared to those collected before the WWS. Counts and incidences of TA, YM, and TC in spent peach wash water were significantly higher than in the overhead spray water where neither TTC nor EC was detected. Results suggest that the commercial washing and waxing systems had little effect in improving the microbiological quality of fresh peaches.

Efficiency of some organic acids as decontaminants in sheep carcasses

Abstract Potent and food-safe antibacterial chemicals capable of decontaminating carcass surfaces have been researched for a long time due to their great value for the quality and shelf life of the meat. The aim of current study is to test the antibacterial effect of lactic acid (LA) and acetic acid (AA) spray treatments using three concentrations (1, 1.5 and 2 %) on the aerobic plate count, Enterobacteriacae count, coliform count, and Staphylococcus count of fresh sheep carcasses surface after 20 minutes of spraying. Results of the investigated bacteriological parameters showed significant reductions after being exposed to organic acids, especially Gram negative bacteria (Enterobacteriacae) which showed greater sensitivity to the used organic acids than Gram positive bacteria (Staphylococcus), where greater concentration gave greater reduction in the bacterial counts. Moreover, spray wash of lactic acid resulted in higher reduction of bacterial counts on meat surface than acetic acid. From the obtained results, organic acids showed safe, simple, efficient, cheap, and highly effective modality of meat decontamination, on addition, application of lactic acid 2.0% spray showed higher anti-bacterial effect, therefore, it is recommended to improve safety of sheep carcasses for industrial scales.

Validation of Enterococcus faecium NRRL B-2354 as a surrogate for Listeria monocytogenes on fresh apples during pilot spray-bar peroxyacetic acid intervention

Antimicrobial sanitizers applied through a manifold spray-bar brush bed system is a main intervention strategy to prevent cross-contamination of foodborne pathogens on fresh apples. To date, information about antimicrobial efficacy of sanitizers including peroxyacetic acid (PAA) intervention is mainly based on laboratory submerging testing which cannot be directly applied into spray-bar system in apple processing facility due to differences in processing parameters. Previously, we examined anti-Listeria efficacies of PAA in laboratory testing. The studies herein further verified the effectiveness of the selected PAA treatments in a pilot apple spray processing line against Listeria monocytogenes surrogate strains, Enterococcus faecium NRRL B-2354 and Listeria innocua, on apples of the selected varieties. The quality attributes of apples after the selected treatments were further evaluated. A 2-min, 80 ppm PAA treatment at 43 °C and 46 °C resulted in 2.4 and 2.4–2.7 Log10 CFU/apple reduction of E. faecium on different apple varieties, respectively, which had similar reductions compared to L. monocytogenes (2.3–2.5 and 2.5–2.8 Log10 CFU/apple reduction), indicating that E. faecium NRRL B-2354 is a suitable surrogate of L. monocytogenes for evaluating PAA efficacy at test temperatures (22–46 °C). Using this pilot spray-bar system, we further showed that a 30-sec spray wash of 80 ppm PAA at 22 °C and 44–46 °C resulted in 0.8–1.1 and 1.5–1.6 Log10 CFU/apple reduction of E. faecium on apple of the selected varieties, respectively, which were comparable to those of L. innocua. In addition, PAA applied at 44–46 °C did not affect the firmness, total soluble solids content and titratable acidity of apple fruits of tested varieties compared to its application at ambient temperature over 3-week of commercial storage. This study showed that E. faecium NRRL B-2354 is a suitable surrogate strain of L. monocytogenes during the pilot fresh apple processing and provides valuable practical data of PAA spray-bar intervention to the apple industry, facilitating compliance with the Preventive Controls for Human Food Rule.

Water rinse and flowing steam to kill Campylobacter on broiler transport coop flooring

Broilers can carry Campylobacter in their intestine during live haul transport to the slaughter plant; feces from positive birds will contaminate the floor surface of transport containers. Such contamination can be transferred to previously negative broilers when transported in unwashed cages. We tested the use of a water rinse and 15 s steam heat to lessen the numbers of coliforms, Escherichia coli and Campylobacter within broiler intestinal contents spread on 5 × 5 cm squares of broiler transport cage flooring. Floor squares were covered with 1 g of fresh broiler intestinal contents and subjected to either no treatment, 15 s water rinse, 15 s steam heat or a combination of water rinse followed by steam treatment. All squares were sampled by a sponge wipe method; sponges were used to prepare serial dilutions, which were plated for numbers of coliforms, E. coli and Campylobacter. Four replications were conducted with four samples of each treatment (n = 16). Spray washing alone was ineffective to lessen the numbers of bacteria detected on floor squares. Steam treatment resulted in a significant (P < 0.05) reduction of approximately 2 log CFU per floor square. Water rinse followed by steam heat was significantly more effective than steam alone (P < 0.05) lowering the numbers of all bacteria cultured by approximately 4 log CFU per floor square representing a 99.99% reduction. Although bacterial contamination was not eliminated by the two-step rinse and steam method it does show potential as an approach to lessen Campylobacter contamination in broiler transport containers.

Water-spray washing technique as a purification process in the production of biodiesel

In order to meet the standards set for biodiesel after biodiesel production via transesterification, a purification process is necessary. For the purification process, the wet washing method is mostly recommended because it is well-known for its easy application and high efficiency. However, this method requires a large volume of water and takes a long time. Consequently, this study focuses on designing a washing machine that reduces the amount of water used and shortens the application time for the washing method. The spray washing technique, a type of the wet washing method, was used for this study with a focus on the following parameters: the volume of water to crude biodiesel, flow rate, and time. All conditions investigated in the basic standards of biodiesel. The pH value, density, and velocity were considered as the criteria to select the optimum conditions for the washing machine. The results indicated that a volume ratio of 0.8:1 (water:crude biodiesel) and a flow rate of 4 L/min for 0.5 min was the optimum condition of the water washing machine for biodiesel purification that meets the international biodiesel specifications.

Research and design of a new type of spray washing machine

Considering the universality of washing machines today, washing machines consume a lot of water. In order to reduce the water consumption in the washing process and at the same time achieve the effect of cleaning clothes, a new spray type washing machine is designed. It mainly consists of transportation system, cleaning system and control system. The washing system is designed to perform different tasks for washing machines, washing, rinsing and dewatering, respectively. The new washing machine washes clothes with water spray, washing liquid spray washing, high pressure water mist rinsing residue, sponge roller squeezing dehydration and warm air drying, so that the stains of the clothes are washed and the initial dehumidification is completed. The spray-type new washing machine is completely cleaned by spraying droplets and spraying water mist, which can greatly reduce the water consumption.

Randomized Trial of Irrigation and Curetting for Cerumen Removal in Young Children.

Objectives: To gather preliminary data on the effectiveness and feasibility of cerumen removal using three irrigation methods and a metal curette in young children.Study design: Pilot study conducted as a randomized clinical trial of well and ill children age 6 months to 6 years with ≥25% cerumen occlusion in at least one ear. Children were stratified by age and randomized to one of four methods of cerumen removal: syringe with attached angiocath tubing, Elephant Ear Washer Bottle System®, OtoClear® Spray Wash Kit, or metal curette. Clinicians, blinded from treatment assignment, assessed the degree of cerumen occlusion before and after the procedure. Outcomes included reduction in cerumen occlusion, successful removal, time until completion and parental satisfaction. Rules for stopping procedures were established a priori.Results: Thirty-eight children underwent procedures (59 ears). There were no significant differences in reduction in cerumen and successful removal among the methods. Overall, 36 (61%) of 59 of procedures were successful. The syringe with angiocath tubing took the most time (P = 0.04) and resulted in the most stopped procedures (P < 0.01). Parental satisfaction scores were not significantly different.Conclusions: Irrigation methods performed comparably to cerumen removal with curette; the SA method had drawbacks. Irrigation can be performed by non-clinicians, which is potentially a significant advantage. (Clinical trial registration: http://www.isrctn.com/ISRCTN74402562).

Cinnamaldehyde/Lactic Acid Spray Wash Treatment for Meat Safety and Byproduct Quality Assurance

This study evaluated the effectiveness of spray washing with aqueous based solution of cinnamaldehyde (CA) and CA plus lactic acid (LA) in reducing aerobic bacteria, Enterobacteriaceae, E.coli and Salmonella from the grain surface of bovine hide so that the developed solutions can potentially be used to decontaminate the cattle carcasses to ensure meat safety. This study also examined the application impacts of the developed formulations on leather produced from the treated hides recognizing the value of cattle byproducts. Two concentrations (0.5% and 0.75%) of CA and LA were used to develop the formulations for 2 to 5 minutes treatment. Research data revealed the fresh cattle hides washed with water alone (control) resulted in recovery of aerobic bacteria of 7.39 and 9.30; Enterobacteriaceae of 5.43 and 5.42; E.coli of 4.88 and 5.50 and Salmonella of 3.81 and 4.65 log CFU per leather panel at 2 and 5 minutes of treatment respectively. Comparing to control, hides treated with CA solution alone resulted in the highest reduction of aerobic bacteria, Enterobacteriaceae, E.coli and Salmonella up to 2.22, 0.42, 0.72 and 1.61 Log CFU respectively for 2 to 5 minutes treatment. The treatment with the formulations of CA plus LA resulted in the highest reduction of aerobic bacteria, Enterobacteriaceae, E.coli and Salmonella up to 2.12, 3.12, 2.33 and 2.28 log CFU respectively for 2-5 minutes of treatments. From microscopic analysis, mechanical and subjective examinations, it was revealed that the leather produced from the formulation treated hides were comparable to the control in terms of structural integrity.

Spray Washing Disinfection with Peracetic Acid in the Processing of Fresh-Cut Strawberries: An Alternative for Dipping Techniques

ABSTRACTThe effect of spray washing disinfection with peracetic acid (PAA) on quality attributes of fresh-cut strawberries was studied. The effectiveness on native microflora and experimentally inoculated Escherichia coli was also investigated. The responses were evaluated at 0 day and after 7 days of storage (2 °C). PAA concentration (1–240 mg L−1) and spraying time (11–138 seconds) did not affect the retentions of quality attributes. Optimizing the process at days 0 and 7 allowed to obtain significant reductions for total mesophilic microorganism, molds, and yeasts; furthermore, E. coli reduction was 3.4 log (day 0). All these results suggest that spraying with PAA could be a good disinfection method.

Purification characteristics of fine particulate matter treated by a self-flushing wet electrostatic precipitator equipped with a flexible electrode

ABSTRACTA self-flushing wet electrostatic precipitator was developed to investigate the removal performance for fine particles. Flexible material (polypropylene, 840A) and carbon steel in the form of a spiked band were adopted as the collection plate and discharge electrode, respectively. The particle concentration, morphology, and trace-element content were measured by electric low-pressure impactor, scanning electron microscope, and energy-dispersive x-ray spectroscopy, respectively, before and after the electrostatic precipitator. With increasing gas velocity, the collection efficiency of fine particles (up to 0.8 μm in diameter) increased, while it decreased for particles with diameters larger than 0.8 μm. Increasing the dust inlet concentration increased the collection efficiency up to a point, from which it then declined gradually with further increases in the inlet concentration. The particulate matter after the wet electrostatic precipitator showed different degrees of agglomeration. The collection efficiency of trace elements within PM10 was less than that of the PM10 itself. Notably, the water consumption in the current setup was significantly lower than for other treatment processes of comparable collection efficiencies.Implications: Wet electrostatic precipitators, as fine filtration equipment, were generally applicable to coal-fired plants to reduce PM2.5 emissions in China. However, high energy consumption and unstable operation, such as water usage and spray washing directly in the electric field, seriously restricted the further development. The utilization of self-flushing wet electrostatic precipitator can solve these problems to some extent.

Evaluation of Novel Pre-Slaughter Cattle Wash Formulations for Meat and Byproduct Safety and Quality

The aim of this study is to ensure safety and quality of meat and leather, innovative new carcass washing formulations need to be developed and tested. This study investigated six novel spray wash solutions for their effectiveness on reducing microbial concentrations from the carcass while concurrently examining their effects on leather quality produced subsequent to treatment. The combination of surfactants and anti-bacterial agents was the basis of developing effective carcass wash formulations. Cleansing with water or only surfactant dissolved aqueous solution was found to be ineffective in reducing bacterial concentration including aerobic, Enterobacter iaceae, Salmonella and E. coli. In comparison to spray water treatment, the effective formulations had average reductions of 4.19 to 5.59 log CFU of aerobic bacteria and up to 7 log CFU of Enterobacter iaceae, Salmonella and E. coli concentrations per selected area. Microscopic analysis of the leather produced from treated hides revealed insignificant/no adverse impact from some of the developed formulations on finishing byproduct. Additionally, mechanical properties of finished leather produced from the hides treated with the formulations and water were found comparable. From this research, several effective spray wash formulations were developed for carcass decontamination keeping the integrity of hide to produce quality leather, a valuable byproduct.

Efficacy of Citrilow and Cecure spray wash on prevalence of aerobic and Enterobacteriaceae bacteria/gram‐negative enteric bacilli and cattle hide quality

AbstractThis study investigated spray wash treatments independently with Citrilow or Cecure for their effects on microbial concentrations and leather quality. Spray washing with Citrilow reduced aerobic mesophilic recovery by 2.42–2.78 log cycles 2.78–2.95 log cycles, and 3.32–3.72 log cycles on the belly, belly, and butt regions, respectively. After washing with Citrilow, Enterobacteriaceae/related gram‐negative enteric bacilli (ENT/gnEB) recovery counts reduced by, 2.14–2.57 log cycles, 3.06–4.08 log cycles, and 4.65–4.99 log cycles on the belly, head, and butt regions, respectively. Cecure significantly lowered aerobic bacterial levels on the belly, head, and butt regions by 6.00–6.12 log cycles, 1.40–1.65 log cycles, and 4.26–3.60 log cycles, respectively. Washing with Cecure significantly lowered ENT/gnEB counts by 3.65–3.01 log cycles and 2.17–3.17 log cycles on belly and butt regions. Subjective testing, grain structure analyses, and mechanical properties of leather made from fresh hides after Citrilow or Cecure treatments revealed no difference between the treatment and their corresponding controls.Practical applicationsThe purpose of this study is to investigate the ability of two antibiotics (Citrilow and Cecure) to reduce bacteria on the outer haired surface of cattle hides which serves as a potential source of cross‐contamination of pathogens to beef. In addition, while reducing probability of cross‐contamination during cattle processing, the quality of the byproducts need to be insured. In the cattle industry, antimicrobials and surfactants applied must be food safe and limit damage to the animal byproducts, in the case of this study hides which are used to produce leather. The results from this study may be beneficial for meat processing plants, hide preparers and leather manufacturers to identify antimicrobials that may limit bacterial cross‐contamination which can lead to food related illnesses while insuring the quality of one of the cattle industries main byproducts.