Efficacy of cold plasma-activated water as an environmentally friendly sanitizer in egg washing

Eggs in the United States are typically washed using chemical sanitizers such as quaternary ammonia (QA) or chlorine. Such treatments generate wash water, which could be potentially hazardous to the environment. A novel, nonthermal sanitization technique for washing shell eggs using cold plasma-activated water (PAW) was investigated in this study. The inactivation efficacy of PAW on Klebsiella michiganensis and the impact of PAW on the cuticle of the eggshell and shell strength were tested in comparison to QA. Washing inoculated eggs with PAW and QA achieved a similar microbial reduction (>5.28 log CFU/egg). Colorimetric analysis showed that ∆E-value for PAW-treated eggs was significantly lower than QA-treated eggs, suggesting higher cuticle coverage in eggs treated with PAW. The texture analysis to test for shell egg strength indicated that washing eggs with PAW did not affect the structural integrity of the eggshell when compared to eggs washed with QA. According to this study, PAW has the potential as an alternative to commercial sanitizers like QA in the egg-washing industry. PAW does not detrimentally impact shell strength or cuticle coverage and provides similar microbial reduction efficacy.

Chargeability study of disinfectants and the optimization of design parameters of a handheld electrostatic disinfection device for small scale applications

Apart from aerosols, contaminated surfaces with SARS-CoV-2 virus are the significant carriers of virus transmission. The disinfection and sanitization of the indoor and outdoor places are one among the powerful and effective strategies to avoid the surface-to-human transmission of SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) through frequent touch and physical contact. Electrostatic spraying is one of the effective and efficient methods to apply the liquid-based sprays on surfaces to be disinfected or sanitized. This technique covers the directly exposed and obscured surfaces uniformly and reaches to hidden areas of the target. In this paper, the design and performance parameters of a motorized pressure-nozzle based handheld electrostatic disinfection device were optimized and the chargeability of ethanol (C2H5OH), formaldehyde (CH2O), glutaraldehyde (C5H8O2), hydrogen peroxide (H2O2), phenol (C6H5OH) and sodium hypochlorite (NaClO) has been critically investigated. The chargeability indicator for disinfectants was presented in terms of the charge-to-mass ratio. The significant value of the charge-to-mass ratio of 1.82 mC/kg was achieved at an applied voltage of 2.0 kV, the liquid flow rate and pressure of 28 ml/min and 5 MPa, respectively. The experimental results are well aligned to the proposed theoretical context.

Effects of Peroxyacetic Acid on Postharvest Diseases and Quality of Blueberries

Postharvest diseases are a limiting factor in the storage of fresh blueberries. Gray mold caused by Botrytis cinerea and Alternaria rot caused by Alternaria spp. are important postharvest diseases in blueberries grown in California. Control of these fungal pathogens is generally dependent on preharvest sprays of synthetic fungicides, but in California multiple fungicide resistance has already developed in those pathogens, leading to the failure of disease control. Therefore, alternatives to synthetic fungicides are needed for the control of postharvest diseases. Peroxyacetic acid (PAA) is a disinfectant agent that poses low risk to human health. In this study, we evaluated the effects of postharvest use of PAA at 24 µl liter^-1 and 85 µl liter^-1 on fruit decay caused by fungal pathogens and quality of stored blueberry fruit. PAA treatment was applied to four cultivars over three seasons using two methods, dipping or spraying. Dipping blueberries compared with spraying them with PAA and its application at 85 µl liter^-1 were the most effective treatments. For example, when applied to 'Snowchaser' blueberries, this combination reduced naturally occurring decay after 4 weeks of storage at 0 to 1°C from 14.3% among water-treated controls to 2.7% in 2018, and from 25.7% among water-treated controls to 8.6% in 2020. In general, PAA did not adversely affect fruit quality or sensory quality of blueberries. Postharvest use of PAA appears to be a promising means to reduce postharvest decay of blueberries. To reliably obtain an acceptable level of disease control, the best use of PAA may be in combination with other practices rather than using it alone.

Comparison of the Efficacy of Electrostatic versus Conventional Sprayer with Commercial Antimicrobials To Inactivate Salmonella, Listeria monocytogenes, and Campylobacter jejuni for Eggs and Economic Feasibility Analysis

This study was conducted to compare the efficacy of antimicrobials sprayed by electrostatic versus conventional sprayer for inactivation of Salmonella, Listeria monocytogenes, and Campylobacter jejuni on eggs and to determine the economic feasibility of these treatments. Eggs were dip inoculated with overnight cultures (18 h) of Salmonella Typhimurium, Salmonella Tennessee, a two-strain mixture of L. monocytogenes, and a three-strain mixture of C. jejuni (microaerophilic condition). Inoculated eggs were then not sprayed or subjected to electrostatic and conventional spraying with peroxyacetic acid (PAA; 0.1%), lactic acid (5.0%), lactic and citric acid blend (2.5%), sodium hypochlorite (SH; 50 ppm), and SaniDate-5.0 (SD [a mixture of PAA and H₂O₂]; 0.25%) for 30 s (15 s each side). Surviving bacteria on eggshells were recovered on xylose lysine Tergitol 4 agar ( Salmonella), modified Oxford agar ( L. monocytogenes), or Brucella agar ( C. jejuni). Compared with conventional spraying, electrostatic spraying of PAA, SD, and SH achieved significant additional reductions ( P < 0.05) of Salmonella, L. monocytogenes, and C. jejuni of 0.96 to 3.18, 1.19 to 3.05, and 0.96 to 1.62 log CFU per egg, respectively. A simple cost comparison suggests that regardless of the antimicrobial agent used, the cost of using an electrostatic sprayer is 20 to 40% lower than that of a conventional sprayer for a small poultry farm that produces 1,500 eggs per day. Among the five antimicrobials, the total sanitizing cost was lowest for SH, followed by PAA and SD. The results indicated that electrostatic spraying of commercial antimicrobials can be considered an effective and economical approach to enhancing the microbial safety of eggs, especially for small poultry processors.

Use of an Electrostatic Spraying System or the Sprayed Lethality in Container Method To Deliver Antimicrobial Agents onto the Surface of Beef Subprimals To Control Shiga Toxin-Producing Escherichia coli

The efficacy of an electrostatic spraying system (ESS) and/or the sprayed lethality in container (SLIC) method to deliver antimicrobial agents onto the surface of beef subprimals to reduce levels of Shiga toxin-producing Escherichia coli (STEC) was evaluated. Beef subprimals were surface inoculated (lean side; ca. 5.8 log CFU per subprimal) with 2 mL of an eight-strain cocktail comprising single strains of rifampin-resistant (100 μg/mL) STEC (O26:H11, O45:H2, O103:H2, O104:H4, O111:H^-, O121:H19, O145:NM, and O157:H7). Next, inoculated subprimals were surface treated with lauric arginate (LAE; 1%), peroxyacetic acid (PAA; 0.025%), or cetylpyridinium chloride (CPC; 0.4%) by passing each subprimal, with the inoculated lean side facing upward, through an ESS cabinet or via SLIC. Subprimals were then vacuum packaged and stored at 4°C. One set of subprimals was sampled after an additional 2 h, 3 days, or 7 days of refrigerated storage, whereas another set was retreated via SLIC after 3 days of storage with a different one of the three antimicrobial agents (e.g., a subprimal treated with LAE on day 0 was then treated with PAA or CPE on day 3). Retreated subprimals were sampled after 2 h or 4 days of additional storage at 4°C. A single initial application of LAE, PAA, or CPC via ESS or SLIC resulted in STEC reductions of ca. 0.3 to 1.3 log CFU per subprimal after 7 days of storage. However, when subprimals were initially treated with LAE, PAA, or CPC via ESS or SLIC and then separately retreated with a different one of these antimicrobial agents via SLIC on day 3, additional STEC reductions of 0.4 to 1.0 log CFU per subprimal were observed after an additional 4 days of storage. Application of LAE, PAA, or CPC, either alone or in combination, via ESS or SLIC is effective for reducing low levels (ca. 0.3 to 1.6 log CFU) of STEC that may be naturally present on the surface of beef subprimals.

Preharvest Food Safety in Broiler Chicken Production

Preharvest food safety in broiler production is a systematic approach to control the introduction, propagation, and dissemination of Salmonella and Campylobacter from breeder flocks to the end of their progeny (broilers) life cycle. New and revised more stringent performance standards for these pathogens at the processing plant level require continuous evaluation of the preharvest management practices and intervention strategies used by the poultry industry. The implementation of stricter biosecurity plans, vaccination of breeder flocks for Salmonella , and usage of feed that is free of animal by-products are some of the measures recommended to control the pathogens. Interventions shown to be effective in experimental settings need to be assessed for their cost-effectiveness and efficiency when applied at the farm level.