Highlights•Hot oil alone is not suf

Highlights
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Hot oil alone is not sufficient to remove Salmonella on processing equipment.
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Hot oil may be a viable first step in a two part cleaning-sanitization process.
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Hot oil followed by 60% isopropanol removes Salmonella on processing equipment.
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Hot oil followed by isopropanol + QACs removes Salmonella on processing equipment.
Abstract
Microbial contamination of peanut butter by Salmonella poses a significant health risk as Salmonella may remain viable throughout the product shelf life. Effective cleaning and sanitation of processing lines are essential for preventing cross-contamination. The objective of this study was to evaluate the efficacy of a cleaning and sanitation procedure involving hot oil and 60% isopropanol, ± quaternary ammonium compounds, to decontaminate pilot-scale processing equipment harboring Salmonella. Peanut butter inoculated with a cocktail of four Salmonella serovars (∼7 log CFU/g) was used to contaminate the equipment (∼75 L). The system was then emptied of peanut butter and treated with hot oil (90 °C) for 2 h followed by sanitizer for 1 h. Microbial analysis of food-contact surfaces (7 locations), peanut butter, and oil were conducted. Oil contained ∼3.2 log CFU/mL on both trypticase soy agar with yeast extract (TSAYE) and xylose lysine deoxycholate (XLD), indicating hot oil alone was not sufficient to inactivate Salmonella. Environmental sampling found 0.25–1.12 log CFU/cm2 remaining on processing equipment. After the isopropanol sanitation (±quaternary ammonium compounds), no Salmonella was detected in environmental samples on XLD (

ผลลัพธ์ (ไทย) 1:

ไฮไลท์•น้ำมันร้อนเพียงอย่างเดียวไม่เพียงพอที่จะเอาสายในอุปกรณ์การประมวลผล•น้ำมันร้อนอาจจะทำงานได้ขั้นตอนแรกในกระบวนการ sanitization ซักสองส่วน•น้ำมันร้อนตาม isopropanol 60% เอาสายในอุปกรณ์การประมวลผล•น้ำมันร้อนตาม isopropanol + QACs เอาสายในอุปกรณ์การประมวลผลบทคัดย่อปนเปื้อนจุลินทรีย์ของเนยถั่วลิสงโดยสายซึ่งทำให้เกิดความเสี่ยงทางสุขภาพอย่างมีนัยสำคัญเป็นสายอาจยังคงทำงานได้ตลอดอายุการเก็บรักษาผลิตภัณฑ์ ประสิทธิภาพทำความสะอาดและสุขาภิบาลของการประมวลผลรายการจำเป็นสำหรับการป้องกันการปนเปื้อนข้าม วัตถุประสงค์ของการศึกษานี้คือการ ประเมินประสิทธิภาพของกระบวนการทำความสะอาดและการสุขาภิบาลที่เกี่ยวข้องกับน้ำมันร้อนและ isopropanol 60%, ±ควอเทอร์นารีแอมโมเนียสารประกอบ การ decontaminate harboring สายอุปกรณ์ประมวลผลระดับนำร่อง เนยถั่วลิสง inoculated กับค็อกเทล serovars สายสี่ (∼7 ล็อก CFU/g) ใช้ปนเปื้อนอุปกรณ์ (∼75 L) ระบบแล้วอบเนยถั่วลิสง และรับการรักษา ด้วยน้ำมันร้อน (90 ° C) ตาม ด้วยน้ำยาฆ่าเชื้อสำหรับ h. 1 วิเคราะห์จุลินทรีย์อาหารติดต่อพื้นผิว (7 ตำแหน่ง), เนยถั่วลิสง h 2 และน้ำมันได้ดำเนิน น้ำมันที่ประกอบด้วย ∼3.2 ล็อก CFU/mL ในทั้ง trypticase ถั่วเหลือง agar xylose ไลซีน deoxycholate (XLD), และสารสกัดจากยีสต์ (TSAYE) แสดงว่า น้ำมันร้อนเพียงอย่างเดียวไม่เพียงพอที่จะยกระดับ สิ่งแวดล้อมสุ่มพบ 0.25 – 1.12 ระบบ CFU/cm2 เหลืออุปกรณ์การประมวลผล หลังจากสุขาภิบาล isopropanol (สารประกอบแอมโมเนีย ±quaternary), ซัลไม่พบในตัวอย่างสิ่งแวดล้อมบน XLD (< 0.16 ล็อก CFU/cm2) ข้อมูลเหล่านี้แนะนำว่า ทำความสะอาดน้ำมันร้อนสองขั้นตอนและ isopropanol sanitization รักษาอาจกำจัด pathogenic สายอุปกรณ์ปนเปื้อนคำสำคัญButterSalmonellaSanitation ถั่วลิสงบทนำ 1Low-moisture foods, including nut butters, were once thought to be relatively safe with respect to foodborne illness risk since low water activities do not permit the growth of foodborne microorganisms. Research has shown that while pathogenic foodborne microorganisms are unable to grow in these foods, they are able to persist in the products at both refrigerated and ambient conditions for a long period of time (Burnett et al., 2000, Grasso et al., 2010, Keller et al., 2012 and Park et al., 2008). Furthermore, low-moisture foods such as peanuts, almonds, hazelnuts, sesame seeds, pine nuts, walnuts, and pistachios have all been implicated in outbreaks or recalled due to contamination with bacterial pathogens (Centers for Disease Control and Prevention, 2011, U.S. Food and Drug Administration, 2004, U.S. Food and Drug Administration, 2009a and U.S. Food and Drug Administration, 2010). Nuts may become contaminated with pathogens, such as Salmonella, at any point from growth to processing (Schaffner et al., 2013). Since the mid 1990's there have been five recorded Salmonella outbreaks associated with commercial peanut butter, peanut-based products, and peanut flavored savory snacks (Centers for Disease Control and Prevention, 2007, Centers for Disease Control and Prevention, 2009, Centers for Disease Control and Prevention, 2012, Killalea et al., 1996 and Scheil et al., 2008). More than 1150 people became ill consuming Salmonella-contaminated peanut butter products during two particularly high-profile U.S. outbreaks in 2007 and 2009 (Centers for Disease Control and Prevention, 2011), which highlighted the vulnerability of such products to contamination by pathogenic microorganisms. The 2012 outbreak, involving a variety of nut butter products processed at the same facility, was likely the result of poor equipment sanitation (U. S. Food and Drug Administration, 2012).Typical grinding and packaging of roasted peanuts occurs at 48 °C (Woodroof, 1983) yet inactivation of microorganisms in peanut butter and peanut butter products is minimal at this temperature (Mattick et al., 2001). Keller et al. (2012), found a 6 log CFU/g reduction in Salmonella over 50 min at 85 °C. Ma et al. (2009) and Shachar and Yaron (2006) found similar results. These findings indicate thermal processing of peanut butter is not a practical intervention step. Consequently, to reduce the risk of foodborne illness in such products, prevention of contamination rather than processing is essential.Effective cleaning and sanitation of nut butter lines are essential for preventing both initial and cross-contamination with microbial hazards such as Salmonella (U.S. Food and Drug Administration, 2009b, Grocery Manufacturers Association, 2009a, Grocery Manufacturers Association, 2009b, Grocery Manufacturers Association, 2010, International Life Science Institute Europe, 2011, Podolak et al., 2010 and Scott et al., 2009). In a May 2007 survey of Grocery Manufacturers Association (GMA) members, 53% of respondents (n = 17 respondents) had manufacturing periods for low-moisture areas of processing that extended 7 days or longer prior to shutting down for sanitation (Scott et al., 2009). Several companies reported production periods as long as 28–35 days prior to shutting down for sanitation (Scott et al., 2009). Environmental investigations of consecutive Salmonella outbreaks originating from a single bakery found that inadequately cleaned piping nozzles may have been responsible for a continual cross-contamination problem (Evans et al., 1996). Traditional wet-cleaning methods are generally not used in such a setting, as the introduction of moisture may increase the risk of equipment contamination (Beuchat et al., 2013 and Codex Alimentarius, 1979). Traditional dry-cleaning methods are not suitable for all dry cleaning situations, such as nut butters (International Life Science Institute Europe, 2011). Currently there are no validated sanitation programs for use in high fat emulsified processing plants. As this type of product was considered to be of minimal risk, good manufacturing practices have not been implemented and collectively used throughout the nut butter manufacturing industry. Non-aqueous based chemical sanitation methods are needed to ensure the killing/removal of pathogenic microorganisms from nut butter processing equipment. However, the efficacy of such treatments needs further investigation. Potential non-aqueous chemical sanitation products, such as quaternary ammonium compounds or isopropyl alcohol containing quaternary ammonium compounds, have shown promising effects against Salmonella in low-moisture environments (Du et al., 2007, Du et al., 2010 and Kamineni et al., 2011). A range of products are commercially available for disinfection of low-moisture food production areas. Isopropanol has the added benefit of evaporating quickly and leaving no residue on food production surfaces. The objective of this research was to evaluate the efficacy of a model cleaning and sanitation method involving 60% isopropanol with and without the addition of quaternary ammonium compounds on Salmonella removal from pilot-scale peanut butter processing equipment.2 Methods and methods2.1 Organisms and growth conditionsSalmonella Tennessee K4643 and Salmonella Anatum 5802 were obtained as a gift from Dr. L. Beuchat, University of Georgia (Athens, GA). S. Tennessee K4643 was originally isolated from the 2006 United States peanut butter outbreak (Centers for Disease Control and Prevention, 2007). S. Anatum 5802 was isolated from a raw pecan sample. Salmonella Typhimurium 09-0001-E5 and Salmonella Typhimurium 09-0001-A1 cultures were obtained as a gift from the Minnesota Department of Agriculture (St. Paul, MN) and originally isolated from peanut butter involved in a 2008 multi-state outbreak in the United States. Stock cultures were maintained frozen at −20 °C.Overnight cultures of the four Salmonella serovars were transferred from TSAYE to test tubes containing 10 mL trypticase soy broth (TSB; Becton, Dickinson, and Co.). After 24 h incubation (37 °C), 0.1 mL was spread on the surface of TSAYE plates and incubated for 24 h at 37 °C to obtain lawn cultures. After incubation, cells were harvested from plates by adding 1 mL TSB and mixed using a sterile L-shaped plate spreader (Fisher Scientific, Pittsburgh, PA). The suspension was removed from the plate using a 1-mL pipette and collected in a 50 mL conical centrifuge tube (Becton Dickinson, and Co., Franklin Lake, NJ). Approximately 0.5 mL cell suspension was recovered from each plate. Ten plates of each serovar were harvested separately for each experiment. Approximately 20 mL of cell suspension was recovered from 40 plates. Five mL of each serovar cell suspension was pipetted together to form the Salmonella cocktail used in this study. The concentration of harvested cells was 11.6 ± 0.6 log CFU/mL. This cell suspension was then mixed 1:1 with peanut oil and approximately 1 mL of Tween 80 (Fisher Chemical, Whippany, NJ).The cell:oil:Tween 80 mixture was thoroughly mixed with a vortex mixer. The mixture, ∼41 mL total, was equally divided between two 400 g lots of commercial creamy peanut butter in separate Whirl-Pak bags (24 oz, Nasco, Fisher Scientific, Pittsburgh, PA) and mixed by alternating hand mixing and stomaching (Stomacher™ 400, Seward Ltd, West Sussex, UK) at 30 s intervals at 250 rpm three times each. These two contaminated lots were subsequently used to contaminate peanut butter used in pilot plant processing experiments.
2.2 Peanut butter processing equipment
A peanut butter pumping machine consisting of two steam-jacketed vessels and two pumps, with stainless steel piping (inner diameter 1.5″) to circulate molten peanut butter (donated by North Carolina State University and funded through a FDA Centers of Excellence grant awarded to Western Center for Food Safety, University of California at Davis) was installed into the IFSH Bio-Containment Pilot Plant (BCPP) to allow safe experimentation with large quantities of pathogen (Fig. 1). Biohazard suits with breathing air were used