Pre-and post-harvest antimicrobial treatments of fresh produce (original) (raw)
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Methods to Reduce/Eliminate Pathogens from Fresh and Fresh-Cut Produce
Comprehensive Reviews in Food Science and Food Safety, 2003
In response to the current public health concerns with the microbiological safety of fresh and fresh-cut produce, researchers have investigated the efficiency of numerous physical, chemical, and biological methods for reducing the microbiological load of produce. This chapter focuses on this growing area of research with a particular emphasis on human pathogenic microorganisms; however, research related to mitigation treatment effects on nonpathogenic organisms is also included. There have been several reviews that address this topic and they are pointed out throughout the chapter; therefore, the focus here is on the latest and most significant research findings. A matrix (Table V-1) summarizing the characteristics of intervention methods is also included at the end of the chapter.
2016
Raw vegetables can sometimes be the source of outbreaks of human illness; however the potential for fresh vegetables to serve as a vehicle for antibiotic-resistant bacteria is poorly understood. Antibiotics and antibiotic-resistant bacteria have been shown to persist in manure of animals administered antibiotics, and in compost generated from this manure, where there is the potential for their transfer to produce. The purpose of this study was to determine the survival of antibiotic-resistant bacteria on raw, peeled, carrots after washing with commonly used chemical sanitizers. Multi-drug resistant E. coli O157:H7 and Pseudomonas aeruginosa were inoculated into a compost slurry of composted manure from dairy cattle, with and without prior administration of antibiotics, and used to inoculate carrot surfaces prior to the washing studies. This approach provided defined model antibiotic-resistant pathogens present within a background microbial community simulating potential carry over from manure-derived fertilizer. Carrots (n=3, 25g) were air-dried and stored at 4°C until washing with tap water, XY-12 (sodium hypochlorite, 50 ppm free chlorine) or Tsunami 100 (peroxyacetic acid/hydrogen peroxide, 40 ppm free paracetic acid), according to manufacturer's directions. A second batch of carrots representing each inoculation x wash condition (n=3) were individually packaged for storage at 2 C for 1,7, and 14 days, or 10 C for 7 days and enumerated on those day intervals to recover bacteria from the surfaces of washed carrots. The resulting previously washed and stored carrots were subject to serial dilution and plated onto corresponding agar to enumerate total aerobic bacteria (R2A), aerobic bacteria tolerant or resistant to antibiotics (antibiotic-supplemented R2A), E. coli (Eosin Methylene Blue), and Pseudomonas spp. (Pseudomonas Isolation Agar). In addition, the tetA gene was quantified from the carrot samples as a measure of the effect of sanitizers and storage on an antibiotic resistance gene known to be carried by the inoculated bacteria. Inclusion of sanitizer in the wash water significantly reduced the absolute numbers of inoculated bacteria (E.coli and Pseudomonas) as well as populations of bacteria capable of growth on the R2A media containing cefotaxime (10 g/mL), sulfamethoxazole (100 g/mL), or tetracycline (3 g/mL). Comparable reductions in the inoculated P. aeruginosa resistant to tetracycline (PIA T, 4 g/mL), bacteria resistant to cefotaxime (10 g/mL) and tetracycline (3 g/mL) occurred after washing with XY-12 or Tsunami 100. The sanitizer effectiveness may be bacterial dependent, as evident by larger absolute reductions of the inoculated E. coli (EMB) and bacteria grown on sulfamethoxazole (100 g/mL)-amended plates after washing with Tsunami 100 compared to washing with tap water or XY-12. Re-growth of both the inoculated and native compost-associated bacteria was inhibited by storage at 2 C, as there were no significant differences in the log CFU/g values on the various media (total aerobic bacteria, bacteria on antibiotic-amended plates, E. coli inoculum, P. aeruginosa inoculum) during the 14-day storage period. However, temperature abuse at 10 C resulted in significant re-growth of native Pseudomonas, compared to storage at 2 C. A sanitizer-associated interaction between re-growth and temperature was also observed for bacteria resistant to clindamycin (25 g/mL) and cefotaxime (10 g/mL), with substantial regrowth occurring only on carrots washed with Tsunami 100. There was no significant re-growth of the inoculated E. coli O157:H7 at either temperature. Results indicate that some bacterial populations are reduced by post-harvest washes and that temperature abuse of fresh produce may result in increases in antibiotic-resistant bacterial populations.
A Field Study of the Microbiological Quality of Fresh Produce
The Centers for Disease Control and Prevention has reported that foodborne disease outbreaks associated with fruits and vegetables increased during the past decade. This study was conducted to characterize the routes of microbial contamination in produce and to identify areas of potential contamination from production through postharvest handling. We report here the levels of bacterial indicator organisms and the prevalence of selected pathogens in produce samples collected from the southern United States. A total of 398 produce samples (leafy greens, herbs, and cantaloupe) were collected through production and the packing shed and assayed by enumerative tests for total aerobic bacteria, total coliforms, total Enterococcus, and Escherichia coli. These samples also were analyzed for Salmonella, Listeria monocytogenes, and E. coli O157:H7. Microbiological methods were based on methods recommended by the U.S. Food and Drug Administration. For all leafy greens and herbs, geometric mean indicator levels ranged from 4.5 to 6.2 log CFU/g (aerobic plate count); less than 1 to 4.3 log CFU/g (coliforms and Enterococcus); and less than 1 to 1.5 log CFU/g (E. coli). In many cases, indicator levels remained relatively constant throughout the packing shed, particularly for mustard greens. However, for cilantro and parsley, total coliform levels increased during the packing process. For cantaloupe, microbial levels significantly increased from field through packing, with ranges of 6.4 to 7.0 log CFU/g (aerobic plate count); 2.1 to 4.3 log CFU/g (coliforms); 3.5 to 5.2 log CFU/g (Enterococcus); and less than 1 to 2.5 log CFU/g (E. coli). The prevalence of pathogens for all samples was 0, 0, and 0.7% (3 of 398) for L. monocytogenes, E. coli O157:H7, and Salmonella, respectively. This study demonstrates that each step from production to consumption may affect the microbial load of produce and reinforces government recommendations for ensuring a high-quality product.
Review Novel disinfectants for fresh produce
Fresh produce such as fruit and vegetables are known carriers of pathogenic microorganisms that often lead to outbreaks of food borne illnesses and public health scares. During the processing of fresh produce strong sanitizers and disinfectants are often required to remove the microbiological load left behind by washing. While such sanitizers and disinfectants must be highly efficacious as an anti-microbial agent, at the same time they must be cost effective, environmentally friendly, non-hazardous to public health and have insignificant effect on the nutritional and organoleptic properties of the fresh produce. This paper reviews the efficacy of various disinfectants to reduce the microbial spoilage and to increase the shelf life of fresh produce without compromising the quality of the end product. Inactivation of microbes using various disinfectants and parameters governing for inactivation are detailed. This review identifies the safest disinfectants that inactive pathogens while maintaining the sensory quality of fresh produce. * Corresponding author. 0924-2244/$ -see front matter Ó
Novel disinfectants for fresh produce
Trends in Food Science & Technology, 2013
Fresh produce such as fruit and vegetables are known carriers of pathogenic microorganisms that often lead to outbreaks of food borne illnesses and public health scares. During the processing of fresh produce strong sanitisers and disinfectants are often required to remove the microbiological load left behind by washing. While such sanitizers and disinfectants must be highly efficacious as an antimicrobial agent, at the same time they must be cost effective, environmentally friendly, non-hazardous to public health and have insignificant effect on the nutritional and organoleptic properties of the fresh produce. This paper reviews the efficacy of various disinfectants to reduce the microbial spoilage and to increase the shelf life of fresh produce without compromising the quality of the end product. Inactivation of microbes using various disinfectants and parameters governing for inactivation are detailed. This review identifies the safest disinfectants that inactive pathogens while maintaining the sensory quality of fresh produce.
Cogent Food & Agriculture, 2015
Fruits and vegetables comprise an essential part of human diet as they are the major source of dietary nutrients of great importance. Consumption of fruits has been found to counteract many of the chronic diseases, including cancers and cardiovascular diseases. Therefore, recommendations for a balanced diet must include the consumption of fresh fruits and vegetables. Consumers in developing countries have become more concerned about the nutritional and sensory aspects as well as the safety of the food they eat due to growing health awareness. At the same time, consumer demand for convenience products is increasing and so is the demand for fresh-cut fruits and vegetables. Fresh-cut market has expanded considerably in recent years. However, quality and safety of such products are an issue of concern as these products can act as vehicles for transmitting infectious diseases. Furthermore, fresh-cut produce is more susceptible to spoilage and can facilitate rapid growth of spoilage microorganisms as well as the microorganisms of public health significance. Nonetheless, keeping in consideration the vast scope of fresh-cut products, this article intends to thoroughly review information about microbiology and public health risks associated with them. Discussions regarding different approaches to extend the shelf life and to minimize the risk of infection associated with their consumption are also included.
Comprehensive Reviews in Food Science and Food Safety, 2003
The ef cacy of sanitizers in killing human pathogenic microorganisms on a wide range of whole and fresh-cut fruits and vegetables has been studied extensively. Numerous challenge studies to determine the effects of storage conditions on survival and growth of pathogens on raw produce have also been reported. Results of these studies are often dif cult to assess because of the lack of suf cient reporting of methods or, comparatively, because of variations in procedures for preparing and applying inocula to produce, conditions for treatment and storage, and procedures for enumerating pathogens. There is a need for a standard method to accurately determine the presence and populations of pathogenic microorganisms on produce. The adoption of standard, well-characterized reference strains would bene t a comparative assessment of a basic method among laboratories. A single protocol will not be suitable for all fruits and vegetables. Modi cations of a basic method will be necessary to achieve maximum recovery of pathogens on various types of produce subjected to different sanitizer or storage treatments. This article discusses parameters that must be considered in the course of developing a basic standard method against which these modi cations could be made.
International Journal of Microbiology, 2020
Microbes are found all over the globe with some few exceptions, including sterilized surfaces. They include normal flora that is nonpathogenic, which contribute to the larger percentage, and pathogenic species which are few. Hence, the activities of humans cannot be completely separated from microbes. Thus, many pathogenic microbes have found their way into fresh fruits and vegetables which are a great source of a healthy diet for humans. The growing demand for fresh fruits and vegetables has necessitated larger production. The larger production of vegetables within the shortest possible time to meet the growing demand has placed them at a higher risk of contamination with the pathogenic microbes, making the safety of consumers uncertain. Study of sources of contamination and type of pathogenic etiological agents isolated from fresh fruits and vegetables includes Bacillus cereus, Campylobacter jejuni, Clostridium botulinum, E. coli O157: H7, Listeria monocytogenes, Salmonella spp., ...
Food Preservation and Packaging - Recent Process and Technological Advancements [Working Title]
Fresh cut fruits and vegetable have gained penetration and popularity since last few years. These fresh cut commodities are in great demand among the consumers as these are ready-to-eat fresh and provide all essential nutrients. The increasing trend in fresh cut produce tends to increase the investment in research and development to address various issues regarding the product supply, refrigeration, packaging technology, processing and shelf life extension. Cutting and peeling causes physical damage to the raw fruit and vegetable that make them more perishable. In these review latest developments that plays the key role in extending the shelf life of the fresh cut are discussed. These technologies help in reducing the microbial load over the fresh cut without much altering the physicochemical properties. Future researches should consider various combined technologies which allow better preservation as well as supplemented with nutritional factors.