This study examined the survival of Listeria monocytogenes in 18 commercially available cold-brewed coffees with and without added ingredients that had been under refrigeration at 4 degrees C. The pH of the cold-brewed coffees ranged from 4.97 to 6.14. Each sample was inoculated with a 5-strain mixture of L. monocytogenes and incubated at 4 degrees C for 60 days. No growth in the L. monocytogenes population was observed; in contrast, a decrease in L. monocytogenes counts was seen in all the cold-brewed coffees evaluated. L. monocytogenes counts reached <1 CFU/ml in 10 of the 18 cold-brewed coffee samples within the 60 days of incubation. Among the 8 samples where L. monocytogenes survived after 60 days, 3 demonstrated >4-log reduction in final counts. The remaining 5 samples did not achieve a 4-log reduction, with the total reduction observed ranging from 1.69 to 3.28 log CFU/ml. The decrease of L. monocytogenes counts regardless of the concentration and pH of the samples suggests a lack of nutrients for metabolism or possible antimicrobial activity originating from the coffee itself. The comparable reduction in L. monocytogenes counts between cold-brewed coffee with and without added ingredients also suggests the possible antimicrobial activity of the coffee components even in the presence of added dairy or nondairy ingredients. Although there were significant decreases in L. monocytogenes counts, the survival of L. monocytogenes for up to 60 days at 4 degrees C in some of the cold-brewed coffees we evaluated necessitates the need for good manufacturing practices and hazard analysis critical control point (HACCP) method consideration.

Some bars and restaurants have begun displaying alcoholic fruit and vegetable cocktail mixes at ambient temperature. Operators often believe that ethanol makes this practice safe, and conversely, some regulators question the safety. It has been reported that ethanol may inhibit the growth of some bacteria at concentrations starting at 8–10% and may be biocidal at concentrations ≥30%. In this study, Escherichia coli O157, Salmonella,and Listeria monocytogenes did not grow in bananapuree, pear puree, orange juice, and apple juice cocktailmixtures prepared with ethanol concentrations from 10to 50% at 25°C. Inoculated pathogens were not detectedin juice plus ethanol at 40 or 50% after 48 h. Juices withethanol concentrations of 10–30% exhibited different logreductions over time for each of the pathogens introduced.This study has implications for how regulators assess therisk of ethanol juice mixtures held at ambient temperatureunder the U.S. Food and Drug Administration (FDA) FoodCode. Operators that desire to display ethanol and fruitjuice mixtures at room temperature need to ensure a pH< 4.2 or a combination of pH and water activity values based on Table B of the FDA Food Code, or they must keep the product under refrigeration at a temperature ≤ 41°F.

This study examined the survival of acid-adapted E. coli O157 in kombucha during fermentation and refrigerated kombucha mixed with fruit juices. Acidic and non-acidic kombucha mixes were fermented at 25°C using a commercially available starter culture and inoculated with a 5-strain mixture of acid-adapted E. coli O157. There was >5-log reduction in the pathogen count for both starter mixes within 7 days of fermentation. For the kombucha-juice blends at refrigerated temperature, 14 ml of lemon, apple, orange, and mango juices were mixed with 186 ml kombucha separately. The treatments were inoculated with a 5-strain mixture of acid-adapted E. coli O157 and incubated at 5°C for 14 days. >5-log reduction in the pathogen count was observed in lemon, control, and mango juice blend after 1, 3, and 14 days, respectively. The total reduction in pathogen count in the apple and orange juice blend after 14 days was 4.43 and 4.12 log CFU/ml, respectively. The inability of the kombucha fruit blend to cause a 5-log reduction of E. coli O157 suggests the need for following strict hygienic and good sanitation practices during blending and bottling for home fermenters and an approved HACCP plan for foodservice operators to ensure product safety.

Fermented foods have become a part of our cultural heritage and chefs and retailers seek to offer these tasty foods to their customers. Fermenting foods at the retail food service level, however, is considered a special process under the Food and Drug Administration model Food Code and requires a food safety plan. This special report was developed to assist both operators and regulators in preparing or reviewing a food safety plan for vegetable fermentation, including pickles, sauerkraut, kimchi, and fermented vegetable juices.

The interest in fermenting foods at retail and food service levels is increasing. Foodborne pathogens such as E. coli O157:H7 and Listeria monocytogenes, however, have been implicated in foodborne illness in several fermented and acidic foods. This study evaluated and validated the lethality of potentially acid-tolerant pathogens E. coli O157 and L. monocytogenes in sauerkraut that was made using traditional fermentation techniques. Fresh cabbage juice prepared with 2.5% salt was inoculated separately with a 5-strain mixture of E. coli O157 and a 5-strain mixture of L. monocytogenes and then was allowed to ferment at 25 degrees C. The pH decreased at a steady rate for the first 7 days and remained relatively stable thereafter. There was a significant decrease in E. coli O157 from Day 1 to Day 7 (p < .05) and a significant decrease in L. monocytogenes count from Day 2 to Day 7 (p < .05) with a 5-log reduction for both pathogens at Day 7 and no pathogens detected after Day 9. The data indicate that fermentation of cabbage at ambient temperature is lethal to the survival of E. coli O157 and L. monocytogenes. This study can be used to support the safety of sauerkraut fermentations in retail and food service operations.

Carbohydrate fatty acid esters have been shown to inhibit the growth of bacteria in growth media.In this study, the antilisterial activities of the carbohydrate esters lactose monodecanoate (LMD) and lactose monolaurate (LML) were tested in milk samples with variable fat content (up to 10%) and at different temperatures (37˚C, 24˚C and 5˚C) after inoculation with a 5-strain Listeria monocytogenes cocktail.Both LMD and LML demonstrated antilisterial properties against L. monocytogenes in milk, with the observed log reductions in the LMD milk samples being higher than those in the LML samples at all tested temperatures.LMD in 1% and 2% fat milk was found to be bactericidal with no Listeria growth by day 6.LMD showed significant antilisterial activity in milk samples containing up to 9% fat at 37˚ and in samples with up to 3.5% fat at 24˚C and in milk samples with up to 2% fat at 5˚C.LML showed significant Listeria log reductions at 37˚C with milk containing up to 9% fat but showed no microbial inhibition in milk in any samples at 24˚C and 5˚C.Although carbohydrate fatty acid esters have proven microbial bactericidal/bacteriostatic properties in growth media, their antimicrobial properties are reduced in a food system containing fat and at temperatures lower than 37˚C.The significance of this research is identifying food constituents and storage temperatures that limit the microbial inhibitory properties of lactose esters to ensure appropriate use as potential food grade antilisterial agents.

Dry flavor ingredients such as black pepper and hydrolyzed vegetable protein (HVP) have been frequently recalled from the supply chain due to contamination with Salmonella. These spices are commonly used in preparation of savory meat flavor bases. This study evaluated the effect of various salt levels on the survival of Salmonella spp. in chicken bases formulated with pepper and HVP, in either paste or powder form. The salt content (% w/w), a(w) and pH for regular-salt, 45% reduced-salt and 90% reduced-salt paste formulations were 33.0, 0.686, 5.75; 18.2, 0.691, 5.85; and 3.5, 0.751, 5.96, respectively, and powder formulations were 34.0, 0.254, 6.15; 18.5, 0.290, 6.28; and 3.1, 0.301, 6.50, respectively. To mimic natural contamination, a dry sand inoculation technique was used to prepare the samples. A five serovar cocktail of Salmonella was used and the final inoculation level in the samples was 7.5 +/- 0.2 log CFU/g. Inoculated paste samples were stored at 21 degrees C for up to 12 weeks, and up to 42 weeks for powder formulations. Salmonella counts did not increase in either treatment during storage. The effect of salt levels on Salmonella survival was insignificant. There was a 5.2 +/- 0.4 log reduction in paste formulations by 3 week. However, low Salmonella counts (<1.0 log CFU/g) were detected in samples from 6 to 12 weeks. In powder formulations, minimal log reductions of 1.3 +/- 0.1 were observed over 42 weeks. When preparing a food product that does not undergo a kill step, it is necessary to ensure the absence of Salmonella in the ingredients, as well as practicing strict adherence to good manufacturing practices including proper environmental monitoring and sanitation in food processing. Furthermore, adequate consumer cooking instructions are important to ensure proper Salmonella lethality during preparation of reconstituted dry products. (C) 2015 Elsevier Ltd. All rights reserved.

Lactose monolaurate (LML) was previously found to be an antimicrobial against Listeria monocytogenes in culture medium at concentrations between 3 and 5 mg ml(-1). In this study, the microbial inhibitory activity of LML in dairy products inoculated with a 5-strain cocktail of clinical isolates of L.monocytogenes was investigated. Addition of LML at a concentration of 5 mg ml(-1) resulted in 4.4, 4.0 and 4.2 log reductions in 0.5% fat, 1% fat and 3.25% fat milks, respectively; 4.1, 4.4, and 3.5 log reductions in nonfat, 1% fat, and 1.5% fat yogurts, respectively; and 4.0 log reductions in both nonfat and 2% fat cottage cheese. The inhibitory effect of LML was only observed at 37 degrees C and not 5 degrees C. Experiments suggest that both the lauric acid and the esterified lactose moiety of LML play roles in the growth inhibition.

The purpose of this study was to quantify the presence of minor open-wound hand injuries in addition to Salmonella, Staphylococcus aureus, coliforms, and Escherichia coli on the hands of farm workers who hand-harvest fruit crops in Utah. Data collection was conducted on four farms without USDA Good Agricultural Practices (GAP) certification and on two farms with GAP certification. This study identified essential safety issues that need to be addressed for improving the effectiveness of safety training for migrant farm workers. Farms that have a food safety audit program in place are less likely to have farm workers exposed to pathogenic bacteria and open-wound injuries to their hands. High frequency of S. aureus may indicate a potentially higher risk for wound infection within this worker population. This could lead to infections that are resistant to the antibiotics commonly used to treat ordinary staph infections, resulting in greater work loss time and medical expenses for these workers. Higher frequencies of bacterial presence on workers' hands on non-certified farms indicate a need to identify essential practices to improve worker hygiene habits and on-farm management practices to promote healthy hygiene. Open-wound injuries to migrant farm workers during hand-harvesting could create additional health problems with the possibility of infection and the spread of diseases. Continued research is needed to understand workers' acceptance of these injuries and barriers to personal protection.

Kombucha is a fermented beverage made from brewed tea and sugar. The taste is slightly sweet and acidic and it may have residual carbon dioxide. Kombucha is consumed in many countries as a health beverage and it is gaining in popularity in the U.S. Consequently, many retailers and food service operators are seeking to brew this beverage on site. As a fermented beverage, kombucha would be categorized in the Food and Drug Administration model Food Code as a specialized process and would require a variance with submission of a food safety plan. This special report was created to assist both operators and regulators in preparing or reviewing a kombucha food safety plan.

The objective of this study was to identify minor open-wound hand injuries of farm workers who hand harvest fresh fruits in Utah. During on-site data collection during harvesting of fruit, farm workers were asked to have their hands examined for minor open-wounds. Data collection was conducted on four farms. There were 33 workers that participated. The majority (57.6%) of farm workers were male. Most farm workers (81.8%) identified themselves as Latino or Hispanic. There were six (18%) individual who identified themselves as Thai. There were eight (24%) farm workers who had cuts to the dorsal portion of their hands. Only two (6%) individuals had cuts to the palm potion of their hands. There were four (12%) workers with dorsal abrasions located near the base of the hand near the wrist, while only one (3%) individual was identified with a palm abrasion. Only two (6%) farm workers were found with small puncture wounds to one of their fingers. There were two (6%) individuals that were noted with fingernail loss. This study has identified essential safety issues that need to be addressed for improving the effectiveness of safety training for migrant farm laborers. These open wound injuries to Migrant Hispanic farm workers during hand harvesting could create additional health problems with the possibility of infection and the spread of diseases such as hepatitis A. Continued research is need to understand workers acceptance of these injuries and barriers to personal protection.

The microbiological stability of low-salt cheese has not been well documented. This study examined the survival of Salmonella in low-salt compared to regular salt Cheddar cheese with 2 pH levels. Cheddar cheeses were formulated at 0.7% and 1.8% NaCl (wt/wt) with both low and high-pH and aged for 12 wk resulting in four treatments: 0.7% NaCl and pH 5.1 (low-salt and low-pH); 0.7% NaCl and pH 5.5 (low-salt and high-pH); 1.8% NaCl and pH 5.7 (standard-salt and high-pH); and 1.8% NaCl and pH 5.3 (standard-salt and low-pH). Each treatment was comminuted and inoculated with a 5-serovar cocktail of Salmonella at a target level of 4 log CFU/g, then divided and incubated at 4, 10 and 21 degrees C for up to 90, 90, and 30 d, respectively. Salmonella counts decreased by 2.8 to 3.9 log CFU/g in all treatments. In the initial period of survival study, standard-salt treatments exhibited significantly lower Salmonella counts compared to low-salt treatments. The pH levels did not exhibit obvious significant effect in the Salmonella survival in low-salt treatments. Salmonella counts declined gradually regardless of a continuous increase in pH (end pH of 5.3 to 5.9) of low-salt treatments at all study temperatures. Salmonella counts were reduced faster at 21 degrees C storage. Although there were significant reductions in Salmonella counts, the treatments demonstrated survival of Salmonella for up to 90 d when stored at 4 or 10 degrees C and for up to 30 d at 21 degrees C, the need for good sanitation practices to prevent postmanufacturing cross contamination remains.

Traditional aged Cheddar cheese does not support Listeria monocytogenes growth and, in fact, gradual inactivation of the organism occurs during storage due to intrinsic characteristics of Cheddar cheese, such as presence of starter cultures, salt content, and acidity. However, consuming high-salt (sodium) levels is a health concern and the dairy industry is responding by creating reduced-salt cheeses. The microbiological stability of low-salt cheese has not been well documented. This study examined the survival of L. monocytogenes in low-salt compared with regular-salt Cheddar cheese at 2 pH levels stored at 4, 10, and 21°C. Cheddar cheeses were formulated at 0.7% and 1.8% NaCl (wt/wt) with both low and high pH and aged for 10 wk, resulting in 4 treatments: 0.7% NaCl and pH 5.1 (low salt and low pH); 0.7% NaCl and pH 5.5 (low salt and high pH); 1.8% NaCl and pH 5.8 (standard salt and high pH); and 1.8% NaCl and pH 5.3 (standard salt and low pH). Each treatment was comminuted and inoculated with a 5-strain cocktail of L. monocytogenes at a target level of 3.5 log cfu/g, then divided and incubated at 4, 10, and 21°C. Survival or growth of L. monocytogenes was monitored for up to 90, 90, and 30 d, respectively. Listeria monocytogenes decreased by 0.14 to 1.48 log cfu/g in all treatments. At the end of incubation at a given temperature, no significant difference existed in L. monocytogenes survival between the low and standard salt treatments at either low or high pH. Listeria monocytogenes counts decreased gradually regardless of a continuous increase in pH (end pH of 5.3 to 6.9) of low-salt treatments at all study temperatures. This study demonstrated that post-aging inoculation of L. monocytogenes into low-salt (0.7%, wt/wt) Cheddar cheeses at an initial pH of 5.1 to 5.5 does not support growth at 4, 10, and 21°C up to 90, 90, and 30 d, respectively. As none of the treatments demonstrated more than a 1.5 log reduction in L. monocytogenes counts, the need for good sanitation practices to prevent post-manufacturing cross contamination remains.

Consumer interest in storing vegetables or herbs in oil or infusing oils with these products has grown over recent decades. Vegetables and herbs stored in oil provide several conditions necessary for botulinum toxin production, including an anaerobic environment. Studies of documented outbreaks of botulism have identified vegetables and herbs in oil as the food source, with most outbreaks traced to home-prepared versions. Implicated foods include peppers, garlic, mushrooms, and eggplant. Visual or other organoleptic clues do not provide adequate information to prevent botulism. Most Cooperative Extension resources have communicated the risks and hazards of storing these foods at room temperature and suggest refrigeration, freezing, drying, and acidifying as alternatives. The safest recommendation is to freeze vegetables or herbs stored in oil. If the product is not frozen, it should be refrigerated and then either consumed within four days or discarded. Future research is required to clarify the potential of additional hurdles to preparing and storing these foods safely. Possible research areas include the use of boiling water canning, acidification, and drying followed by an acid dip.

This study examined the survival of a two strain mixture of Salmonella serovar Typhimurium in peanut butter flavored candy fondant during ingredient mixing and after storage up to 7 weeks. The sample was further tested for the presence or absence of Salmonella after six and twelve months of storage. Fondant ingredients mixed with inoculated peanut butter at a starting temperature of 70 degrees C led to 2.2 and 2.9 log cfu reduction in level of surviving Salmonella after 10 and 20 min of mixing respectively. A lower mixing temperature (65 degrees C) resulted in 1.2 log cfu reduction at both 10 and 20 min. Flavored fondant from both mixing temperatures were then stored at room temperature. During storage for up to 7 weeks, there was reduction in the level of surviving salmonellae by an average of 0.58 log cfu/week. The combination of heated mixing and storage for 5 weeks resulted in a 5-log reduction in the colony counts of salmonellae. In comparison, the average reduction of the inoculum in peanut butter was 0.45 log cfu per week totaling 3.16 log cfu after 7 weeks of storage. This study suggests that common candy industry mixing temperatures will not lead to a significant lethality of Salmonella in this product. Although the heated mixing followed by storage of flavored fondant for five weeks at room temperature provided a Slog reduction in Salmonella survival, there was a presence of Salmonella in samples for up to twelve months of room temperature storage. Therefore, the need for good sanitation practices exists. (C) 2011 Elsevier Ltd. All rights reserved.