Integrating microbial decontamination with organic acids in HACCP programmes for muscle foods: prospects and controversies

Mastering Quality: Uniting Risk Assessment With Quality by Design (QbD) Principles for Pharmaceutical Excellence

The aim of this article is to present ideas and tools of risk assessment that can be implemented to overcome various pharmaceutical quality challenges. These elements cover the development, production, distribution, inspection, and reporting of review procedures for drug substances, drug products, and biological products at every stage of their lifecycle. In light of the constant requirement to ensure the drug's efficacy, safety, and quality, the pharmaceutical sector is always evolving. A key strategy for attaining pharmaceutical excellence in this dynamic environment is incorporating novel methods like quality by design (QbD) and risk assessment. Risk assessment is a methodical strategy to locate, assess, and minimize any risks in the manufacturing and development of pharmaceuticals. On the other hand, QbD principles place more emphasis on end-product testing and place it in the context of designing quality into the product from the beginning. The major goal of this paper is to address and examine the integration of risk assessment approaches with the QbD principle workflow to ensure pharmaceutical quality. Recent articles on how risk assessment has been used in pharmaceuticals were evaluated. To provide a useful overview, the various assessment methodologies have been highlighted, emphasizing their benefits and drawbacks.

Research Progress on Bacteria-Reducing Pretreatment Technology of Meat

Reducing the initial bacteria number from meat and extending its shelf life are crucial factors for ensuring product safety and enhancing economic benefits for enterprises. Currently, controlling enzyme activity and the microbial survival environment is a common approach to reducing the rate of deterioration in raw meat materials, thereby achieving the goal of bacteria reduction during storage and preservation. This review summarizes the commonly used technologies for reducing bacteria in meat, including slightly acidic electrolyzed water (SAEW), organic acids, ozone (O3), ultrasound, irradiation, ultraviolet (UV), cold plasma, high-pressure processing (HPP), and biological bacterial reduction agents. This review outlines the mechanisms and main features of these technologies for reducing bacteria in meat processing. Additionally, it discusses the status of these technologies in meat storage and preservation applications while analyzing associated problems and proposing solutions. The aim is to provide valuable references for research on meat preservation technology.

Commercial probiotic products in public health: current status and potential limitations

Consumption of commercial probiotics for health improvement and disease treatment has increased in popularity among the public in recent years. The local shops and pharmacies are brimming with various probiotic products such as probiotic food, dietary supplement and pharmaceuticals that herald a range of health benefits, from nutraceutical benefits to pharmaceutical effects. However, although the probiotic market is expanding rapidly, there is increasing evidence challenging it. Emerging insights from microbiome research and public health demonstrate several potential limitations of the natural properties, regulatory frameworks, and market consequences of commercial probiotics. In this review, we highlight the potential safety and performance issues of the natural properties of commercial probiotics, from the genetic level to trait characteristics and probiotic properties and further to the probiotic-host interaction. Besides, the diverse regulatory frameworks and confusing probiotic guidelines worldwide have led to product consequences such as pathogenic contamination, overstated claims, inaccurate labeling and counterfeit trademarks for probiotic products. Here, we propose a plethora of available methods and strategies related to strain selection and modification, safety and efficacy assessment, and some recommendations for regulatory agencies to address these limitations to guarantee sustainability and progress in the probiotic industry and improve long-term public health and development.

Nair M, Hernandez-Sintharakao MJ, Geornaras I, Engle T, Belk KE, Woerner DR. Changes in the flavor profile of ground beef resulting from the application of antimicrobial interventions

The objective of this study was to characterize flavor, fatty acid composition, and volatile compounds of beef treated with common antimicrobial interventions in beef processing facilities. The effect of three pre-chilling antimicrobial interventions (4.5% lactic acid, LA; 400ppm peroxyacetic acid acidified to pH 1.2 with a sulfuric acid and sodium sulfate blend, aPAA; or untreated, CON) and four post-chilling treatments (CON; LA; aPAA; or a 2.5% solution of a commercial blend of lactic and citric acid, LAC) were analyzed. Briskets (n=30/treatment) were treated in a 3x4 factorial arrangement of pre- and post-chilling interventions using a custom-built pilot-sized spray cabinet, ground twice, and formed into patties. Cooked patties were analyzed by a trained sensory panel, and a subset of raw samples (N=72, n=6) were analyzed for fatty acid composition and volatile compounds. Trained taste panelist ratings for sour and chemical were rated highest (P < 0.01) for the LA pre-chilling treatment compared to CON and aPAA. Ratings for browned attributes were greater (P < 0.05) for samples subjected to aPAA than CON or LA samples. No differences (P > 0.05) were found for beef flavor ID, roasted, metallic, fat-like, rancid, warmed over, or liver-like ratings due to the pre-chilling treatments. Post-chilling treatments did not create any significant (P > 0.05) flavor attribute differences. Fatty acid analysis showed minimal differences due to the use of chemical interventions, and only C10:0 was affected by LAC treatment post-chilling, with greater (P < 0.05) concentrations of C10:0 compared to LA-treated samples.  Among the volatile compounds, the relative abundance of pentanal was greater (P < 0.05) in LA-treated post-chilling intervention samples than in the other treatments. Overall, these results demonstrated that the pre-chilling antimicrobial interventions impacted ground beef flavor, whereas the pre- and post-chilling antimicrobial treatments had minimal impact on fatty acid and volatile compounds.

Development of an organic acid compound disinfectant to control food-borne pathogens and its application in chicken slaughterhouses

During poultry slaughter, cross-contamination of chicken carcasses with microorganisms (including drug-resistant bacteria) can occur because of incomplete disinfection during the pre-cooling process, and surface contact with contaminated tools and equipment. The use of disinfectants is the most common way to reduce the risk of cross-contamination and bacterial spread, as they can effectively reduce the number of bacteria. We developed a disinfectant consisting of organic acids and sodium dodecyl sulfate (SDS) and tested its bactericidal effects at different concentrations against Salmonella and Campylobacter. The main effective components in the disinfectant were citric acid, lactic acid, and SDS, and together they exerted a synergistic bactericidal effect. The bactericidal efficacy of the disinfectant increased with increasing concentrations of the 3 active ingredients. To reach a 100% reduction rate during a 15-s treatment in vitro, for Salmonella, the lowest concentrations of citric acid, lactic acid, and SDS were 0.06, 0.08, and 0.02%, respectively; and for Campylobacter, the lowest concentrations were 0.02, 0.025, and 0.0125%, respectively. The disinfectant remained effective in presence of interfering substances (e.g., 15% fetal bovine serum). Further experiments showed that the disinfectant inactivated sensitive bacteria as well as 23 drug-resistant strains of Salmonella and Campylobacter. Treatment with the disinfectant for 15 s decreased the concentrations of all tested strains by more than 4.7 log colony forming units per mL, and the reduction rate was as high as 100%. In on-site disinfection tests in chicken slaughterhouses, the disinfectant significantly reduced the number of pathogenic bacteria on carcasses during the pre-cooling process, and on tools (such as knives and gloves) during the segmentation process. Thus, this disinfectant has potential uses in preventing cross-contamination of food-borne pathogens (including resistant bacteria) in slaughterhouses.

Quality of Cattle Meat and Its Compositional Constituents

Meat is the most valuable livestock product since it is one of the main sources of protein for human consumption. Meat quality can be evaluated according to the following parameters: pH, amount of lactic acid, volatile fatty acids, bounded water, solubility of proteins, color, and tenderness. The meat composition and physical properties of muscles have been characterized for ensuring improved eating quality. Thus, the purpose of this paper was to review the major chemical compositional and physicochemical properties of meat and, at the same time, its quality attributes and factors that affect quality of meat. A number of structural features of meat as connective tissue, muscle fibers, and tendon that attaches the muscle to the bone are visible in joint meat examined through naked eyes. Water is quantitatively the most important component of meat comprising up to 75% of weight. Meat is also composed of amino acids, fatty acids, vitamins, minerals, and other important ingredients. Quality factors perceived by consumers are related to sensory attributes (e.g., color, tenderness, and flavor), nutritional properties (e.g., calories, vitamins' content, and fatty acids' profile), and appearance (e.g., exudation, marbling, and visible amount of fat). However, fresh meat quality can be defined instrumentally including composition, nutrients, color, water-holding capacity, tenderness, functionality, flavors, spoilage, and contamination. Visual inspection based on sensory quality attributes and different chemical methods are used to analyze meat quality. Other methods such as computer vision and imaging spectroscopy, gas chromatographic analysis, near-infrared technology, dual-energy X-ray absorptiometry, and computerized tomography scanning are also used in the meat industry. So, the aim of the present review is to review quality characteristics of cattle meat and its composition constituents.

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

Simple Summary

Goat 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.

Abstract

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.

Effect of Decontamination Treatments on Campylobacter jejuni in Chicken

The ability of different decontaminating treatments (acetic, citric and fumaric acids, and potassium sorbate) to decrease Campylobacter jejuni on chicken legs was evaluated. Fresh chicken legs were inoculated with C. jejuni and washed with either acetic, citric, or fumaric acid (1% and 2%), or potassium sorbate (1%, 2%, and 5%) solutions or distilled water. Evolution of C. jejuni, Pseudomonas, and Enterobacterales counts, and sensorial acceptability were evaluated after treatment (day 1) and on days 2, 4, 7, and 9 of storage at 4 °C. The lowest Pseudomonas counts were found in those legs dipped in 2% fumaric acid, while the lowest Enterobacterales populations were found in those legs dipped in 2% fumaric or 2% acetic acid. The shelf life of the legs treated was widened by at least 2 days over the control legs. The highest C. jejuni reductions after treatment were obtained in samples dipped in 2% citric acid, which were approximately 2.66 log units lower than in non-treated legs. However, the efficacy of citric acid decreased during storage. After day 2 of storage, the highest reductions of C. jejuni were found in those legs dipped in 2% acetic acid.

Combined Effect of Organic Acids and Modified Atmosphere Packaging on Listeria monocytogenes in Chicken Legs

The combined effect of organic acid (citric, propionic or acetic acid) treatment and modified atmosphere packaging (MAP) on the growth of L. monocytogenes in chicken legs kept at 4 °C for 10 days was evaluated. Chicken legs were inoculated with L. monocytogenes and washed with either 2% citric, 2% propionic or 2% acetic acid solution or distilled water (control). Legs were packaged under the following conditions: air, vacuum, 80% N2/20% CO2, 60% N2/40% CO2 or 40% N2/60% CO2. The greatest L. monocytogenes growth reductions after treatment were observed in chicken legs washed with propionic acid (2.14 log units lower compared to control legs). The lowest growth rates of L. monocytogenes were found in samples washed with acetic acid and packaged in atmospheres containing CO2. An extended shelf life was observed in legs packaged in 40% N2/60% CO2, but these packaging conditions did not reduce L. monocytogenes growth. Consequently, it is necessary to design measures in order to control this bacterial pathogen. Washing of chicken with 2% propionic acid or 2% acetic acid can decrease L. monocytogenes counts in chicken packaged in MAP.

Application of MS bacteriophages on contaminated trimmings reduces Escherichia coli O157 and non-O157 in ground beef

According to the United States Food and Drug Administration (FDA) agency, bacteriophage solutions targeting the serotype O157:H7 are Generally Recognized as Safe (GRAS) to control STEC during beef processing. However, outbreaks involving the "Big Six" STEC increased the industry concern about those serotypes. The objective of this study was to test the efficacy of MS bacteriophages to reduce the "Big Six" non-O157 STEC in beef. The lysing efficacy of phages isolated for each specific serotype varied from 96.2% to 99.9% in vitro. When applied to contaminated trim, reductions ranging from 0.7 to 1.3 Log of all STEC were observed in ground beef. Bacteriophages may provide an additional barrier against the "Big Six" STEC in ground beef. Results of this research provide support documentation to the FDA to extend GRAS status for bacteriophages as processing aids against all adulterant STEC.

Effects of Chemical and Natural Additives on Cucumber Juice's Quality, Shelf Life, and Safety

Microbial contamination affects beverages' lifetime, quality, and safety. Cucumber crops are seasonally spoiled because of the overproduction. The current study aimed to maximize the importance of natural preservatives and reduce the usage of artificial ones to prolong the cucumber juice's storage life, enhance flavor, and control the microorganisms after protein isolate and organic acids supplementation. The additions included control (no addition), citric, benzoic acid, sodium salts, kidney bean pepsin hydrolysate (KPH), chicken egg protein isolate (CEPI), duck egg protein isolate (DEPI), and quail egg protein isolate (QEPI) as J-Control, J-Citric, J-Benzoic, J-sod. Citrate, J-sod. Benzoate, J-KPH, J-CEPI, J-DEPI, and J-QEPI, respectively. The antioxidant activity of these additives and juices was evaluated by DPPH radical scavenging activity. The antimicrobial activity, including antibacterial and antifungal activities, was evaluated by using disc assay and the radial growth of fungal mycelium, respectively. The phenolic compounds and flavonoids were estimated by a spectrophotometer as Gallic acid equivalent (GAE) and quercetin equivalent (QE), respectively. Moreover, chemical parameters such as pH, total soluble solids (TSS), Titratable acidity (TTA), and Vitamin C were evaluated by AOAC. Finally, the color properties were estimated by a spectrophotometer, using the Hunter method. KPH had higher significant (p ≤ 0.05) antioxidant activity (88%), along with antimicrobial activity. It significantly (p ≤ 0.05) reduced the growth of G+ and G- bacteria by 71%-97% and 58%-66% respectively. Furthermore, it significantly (p ≤ 0.05) inhibited the tested fungi growth by 70%-88% and the other additives less than that. During the storage of cucumber juice for an interval of zero, two, four, and six months, the phenolic compounds and flavonoids were significantly (p ≤ 0.05) decreased. Consequently, the potential activity of the juice was reduced; in addition, pH and vitamin C were significantly (p ≤ 0.05) decreased during the storage period. Meanwhile, the TSS and Titratable acidity were significantly raised. As for color and sensory properties, J-sod. Benzoate, J-KPH, J-CEPI, and J-DEPI had significantly (p ≤ 0.05) high scores in color, taste, and flavor against the control. Generally, the usage of natural additives extends the cucumber juice's lifetime and increased the manufacture of high-quality and valuable juice.

Efficacy of Lactic Acid and Modified Atmosphere Packaging against Campylobacter jejuni on Chicken during Refrigerated Storage

The present study was conducted to evaluate the combined effect of lactic acid washing and modified atmospheres packaging on the counts of Campylobacter jejuni on chicken legs stored at 4 °C. In experiment 1, inoculated chicken legs were washed with either 1% or 2% lactic acid solution for 5 min or distilled water (control). The treatment with 2% lactic acid reduced C. jejuni counts 1.42 log units after treatment (day 0). In experiment 2, inoculated samples were packaged under different conditions: air, 100%N2, vacuum, 20%CO2/80%N2, or 40%CO2/60%N2. C. jejuni counts were higher in samples packaged under vacuum or atmospheres containing CO2 than in air. In experiment 3, inoculated chicken legs were washed with a 2% lactic acid solution for 5 min or distilled water (control). Samples were packaged under different conditions: air, vacuum, 20%CO2/80%N2, or 40%CO2/60%N2. C. jejuni counts were lower in samples treated with lactic acid than in samples non-treated. However, C. jejuni counts were higher in chicken legs treated with lactic acid and packaged in modified atmospheres than in those treated and packaged in air. Immersion of chicken legs in a solution containing 2% lactic acid can reduce C. jejuni counts on fresh chicken packaged in modified atmosphere.

Efficacy of bacteriophage and organic acids in decreasing STEC O157:H7 populations in beef kept under vacuum and aerobic conditions: A simulated High Event Period scenario

After High Event Periods, beef subprimals are usually removed from vacuum and treated with antimicrobials. After re-packaging, subprimals are tested to verify the presence of STEC. In this study, bacteriophage and organic acids were applied on beef contaminated with STEC O157:H7 to evaluate the efficiency of industry practices. Beef samples inoculated with STEC were treated with bacteriophage, lactic acid, and peroxyacetic acid and kept under vacuum or aerobic conditions. STEC loads were evaluated 30 min and 6 h after antimicrobial applications. Under aerobic conditions for 30 min and 6 h, phage reduced STEC in beef by approximately 1.4 log whereas organic acids led to a 0.5 log reduction. Under vacuum for 30 min, bacteriophage significantly reduced STEC by 1 log. No effects were observed when samples were treated with organic acids. Under vacuum after 6 h, bacteriophage reduced STEC loads by 1.4 log, lactic acid reduced by 0.6 log, and no effects were observed when peroxyacetic acid was applied.

Peracetic acid reduces Campylobacter spp. on turkey skin: Effects of a spray treatment on microbial load, sensory and meat quality during storage

Handling and consumption of Campylobacter-contaminated poultry meat is the most common cause of human campylobacteriosis. While many studies deal with interventions to reduce Campylobacter spp. on chicken carcasses, studies on other poultry species are rare. In the present study, a spray treatment with peracetic acid (PAA) on turkey carcasses was evaluated. For this, parts of breast fillets with skin and Campylobacter (C.) jejuni DSM 4688 (108 cfu/ml) inoculated drumsticks were sprayed for 30 s with PAA (1200 ppm) or water as control solution. Samples were packaged under modified atmosphere and stored at 4°C until analysis on day 1, 6 and 12. The breast fillets were used for determination of the total viable count, sensory and meat quality examination as well as myoglobin content and biogenic amines. The drumsticks were used for C. jejuni counts. PAA had a significant effect in reducing total viable counts on all days by up to 1.2 log10 compared to the untreated control. Treatment with water alone showed no effect. C. jejuni counts were significantly reduced by PAA (0.9-1.3 log10), while water achieved a 0.5 log10 reduction on C. jejuni counts on day 1. No differences in sensory, pH, electrical conductivity and myoglobin content could be found. The skin of the PAA treated fillets had lower redness values than the water control on day 1, whereas on day 12 parts of the water treated muscles were lighter than the untreated control. A lower putrescine content of the water sprayed fillets in comparison to the control sample on day 12 was the only significant difference concerning the biogenic amines. Results from this study indicate that a spray treatment with 1200 ppm PAA would be a useful measure to lower the Campylobacter spp. counts on turkey carcasses without having a negative influence on product quality.

An assay for determining the susceptibility of Salmonella isolates to commercial and household biocides

Poultry and meat products contaminated with Salmonella enterica are a major cause of foodborne illness in the United States. The food industries use a wide variety of antimicrobial interventions to reduce bacterial contamination. However, little is known about Salmonella susceptibility to these compounds and some studies have shown a concerning link between biocide resistance and antibiotic resistance. To investigate this, a 96 well panel of 17 common household and commercially used biocides was designed to determine the minimum inhibitory concentrations (MIC) of these compounds for Salmonella. The panel contained two-fold serial dilutions of chemicals including Dodecyltrimethylammonium chloride (DC), Benzalkonium chloride (BKC), Cetylpyridinium chloride (CPC), Hexadecyltrimethylammonium bromide (HB), Hexadecyltrimethylammonium chloride (HC), Acetic acid (AA), Lactic acid (LA), Citric acid (CA), Peroxyacetic acid (PXA), Acidified sodium chlorite (ASC), Sodium hypochlorite (SHB), 1,3 dibromo, 5,5 dimethylhydantoin (DBH), Chlorhexidine (CHX), Sodium metasilicate (SM), Trisodium phosphate (TSP), Arsenite (ARI), and Arsenate (ARA). The assay was used to test the susceptibility of 88 multidrug resistant (MDR) Salmonella isolates from animal sources. Bacteria are defined as multidrug resistant (MDR) if it exhibited non-susceptibility to at least one agent in three or more antimicrobial categories. The concentration of biocide at which ≥50% of the isolates could not grow was designated as the minimum inhibitory concentration or MIC50 and was used as the breakpoint in this study. The MIC50 (μg ml-1) for the tested MDR Salmonella was 256 for DC, 40 for BKC, 80 for CPC. HB and HC, 1,640 for AA, 5664 for LA, 3,156 for CA, 880 for PXA, 320 for ASC, 3.0 for CHX, 1,248 for DBH, 3,152 (6%) for SHB, 60,320 for SM, 37,712 for TSP, 56 for ARI and 832 for ARA. A few isolates were not susceptible at the MIC50 breakpoint to some chemicals indicating possible resistance. Isolates with MICs of two 2-fold dilutions above the MIC50 were considered resistant. Biocides for which resistant isolates were detected included CPC (n = 1 isolate), HB (1), CA (18), ASC (7), CHX (22), ARA (16), and ARI (4). There was no correlation detected between the biocide susceptibility of Salmonella isolates and antibiotic resistance. This assay can determine the MICs of bacteria to 17 biocides in a single test and will be useful in evaluating the efficacy of biocides and to detect the development of resistance to them.

Green process development for apple-peel pectin production by organic acid extraction

To extract pectin in food industry, HCl is generally used as the major extracting solvent for releasing the pectin from the plant tissues, however it has an environmental issue to use. In this study, food-grade tartaric-, malic, and citric acids were used to produce apple peel pectin as an eco-friendly protocol instead of HCl. Finely-ground lyophilized apple peel was applied as the raw material, and the pectin was extracted by organic acids at 85 °C. The pectin extracted with citric acid displayed greater molecular weight and apparent viscosity compared to other organic acid treatments. Analysis of degree of methyl esterification revealed that the pectins extracted with organic acids were highly methoxylated. From these results, it was suggested that organic acids could be utilized to extract apple peel pectin effectively as a green process. Especially, the extraction process with citric acid as the solvent showed great potential to produce high-viscosity apple peel pectin.

Recent Advances in Shiga Toxin-Producing Escherichia coli Research in Latin America

Pathogenic Escherichia coli are known to be a common cause of diarrheal disease and a frequently occurring bacterial infection in children and adults in Latin America. Despite the effort to combat diarrheal infections, the south of the American continent remains a hot spot for infections and sequelae associated with the acquisition of one category of pathogenic E. coli, the Shiga toxin-producing E. coli (STEC). This review will focus on an overview of the prevalence of different STEC serotypes in human, animals and food products, focusing on recent reports from Latin America outlining the recent research progress achieved in this region to combat disease and endemicity in affected countries and to improve understanding on emerging serotypes and their virulence factors. Furthermore, this review will highlight the progress done in vaccine development and treatment and will also discuss the effort of the Latin American investigators to respond to the thread of STEC infections by establishing a multidisciplinary network of experts that are addressing STEC-associated animal, human and environmental health issues, while trying to reduce human disease. Regardless of the significant scientific contributions to understand and combat STEC infections worldwide, many significant challenges still exist and this review has focus in the Latin American efforts as an example of what can be accomplished when multiple groups have a common goal.

Rapid screening and quantification of major organic acids in citrus fruits and their bioactivity studies

Organic acids (OAs) are small non-volatile molecules with widespread usage in processed foods, feeds and instant beverages. The prime aim of this study was to explore major OAs in local citrus fruits (Citrus limetta, Citrus aurantifolia, Citrus nobilis, Citrus karna, Citrus medica, Citrus ichangensis and Citrus aurantium) and assessment of their bioactivities. A RP-HPLC-DAD method was developed using buffer free solvent system for rapid detection and quantification of major OAs from citrus fruits and derived products. Method validation studies showed good linear calibration curve (0.985-0.998) for all OAs. The values of %RSD ranged between 0.0001-1.129 and 0.142-1.941 for interday and intraday variability respectively. The limit of detection and limit of quantification values for different OAs were ranged between 1.5-12 and 5-40 µg mL^-1. The juice of above mentioned citrus fruit cultivars were assessed for OAs, total phenolics, free radical scavenging antioxidants and their antimicrobial potential against selected bacterial and fungal strains. The results showed variable contents of phenolics [0.28 ± 0.001-1.17 ± 0.014 mg (GAE) mL^-1] and antioxidant compounds (1.26 ± 0.009-2.84 ± 0.006 mg of trolox equivalents mL^-1) in all juice samples besides significant antifungal activity against C. albicans and A. niger strains. However, in case of antibacterial activity, only C. aurantifolia showed inhibitory effects against selected strains. It was found that citrus fruits have immense potential for their utilization as economic source of natural OAs and development of value added products, beverages and bio-preservatives.

Adduction to arginine detoxifies aflatoxin B1 by eliminating genotoxicity and altering in vitro toxicokinetic profiles

Aflatoxin B1 (AFB1), a class 1 carcinogen and prominent food contaminant, is highly linked to the development of hepatocellular carcinoma (HCC) and plays a causative role in a large portion of global HCC cases. We have demonstrated that a mixture of common organic acids (citric and phosphoric acid) along with arginine can eliminate >99% of AFB1 in solution as well as on corn kernels and convert it to the AFB2a-Arg adduct, acting as a potential detoxification process for contaminated foods. Evaluation of toxicokinetic changes after AFB2a-Arg formation show that the product is highly stable in biological fluids, is not metabolized by P450 enzymes, is highly plasma protein bound, has low lipid solubility, and has poor intestinal permeability/high intestinal efflux compared to AFB1. Ames' test results show that at mutagenic concentrations of AFB1, AFB2a-Arg does not have any measurable mutagenic effect which was confirmed by DNA adduct identification by liquid chromatography-mass spectrometry. Evaluation in HepG2 and HepaRG cells showed that AFB2a-Arg did not cause any significant decreases in cell viability nor did it increase micronuclei formation when administered at toxic concentrations of AFB1. These results show that conversion of AFB1 to AFB2a-Arg is a potential strategy to detoxify contaminated foods.

Efficacy of antimicrobial compounds on surface decontamination of seven Shiga toxin-producing Escherichia coli and Salmonella inoculated onto fresh beef

Several antimicrobial compounds have been used in commercial meat processing plants for decontamination of pathogens on beef carcasses, but there are many commercially available, novel antimicrobial compounds that may be more effective and suitable for use in beef processing pathogen-reduction programs. Sixty-four prerigor beef flanks (cutaneous trunci) were used in a study to determine whether hypobromous acid, neutral acidified sodium chlorite, and two citric acid-based antimicrobial compounds effectively reduce seven Shiga toxin-producing Escherichia coli (STEC) serogroups and Salmonella on the surface of fresh beef. Two cocktail mixtures were inoculated onto prerigor beef flank surfaces. Cocktail mixture 1 was composed of STEC serogroups O26, O103, O111, O145, and O157; and cocktail mixture 2 was composed of STEC serogroups O45, O121, and O157 and Salmonella. The inoculated fresh beef flanks were subjected to spray treatments with four antimicrobial compounds. Following antimicrobial treatments, both control and treated fresh beef samples were either enumerated immediately or were stored for 48 h at 4°C before enumeration. All four antimicrobial compounds caused 0.7- to 2.0-log reductions of STEC, Salmonella, aerobic plate counts, and Enterobacteriaceae. Results also indicated that the four antimicrobial compounds were as effective at reducing the six non-O157 STEC strains as they were at reducing E. coli O157:H7 on the surfaces of fresh beef. The recovery of all seven STEC strains and Salmonella in a low-inoculation study indicated that none of the four antimicrobial compounds eliminated all of the tested pathogens.

Efficacy of Acetic Acid against Listeria monocytogenes Attached to Poultry Skin during Refrigerated Storage

This work evaluates the effect of acetic acid dipping on the growth of L. monocytogenes on poultry legs stored at 4 °C for eight days. Fresh inoculated chicken legs were dipped into either a 1% or 2% acetic acid solution (v/v) or distilled water (control). Changes in mesophiles, psychrotrophs, Enterobacteriaceae counts and sensorial characteristics (odor, color, texture and overall appearance) were also evaluated. The shelf life of the samples washed with acetic acid was extended by at least two days over the control samples washed with distilled water. L. monocytogenes counts before decontamination were 5.57 log UFC/g, and after treatment with 2% acetic acid (Day 0), L. monocytogenes counts were 4.47 log UFC/g. Legs washed with 2% acetic acid showed a significant (p < 0.05) inhibitory effect on L. monocytogenes compared to control legs, with a decrease of about 1.31 log units after eight days of storage. Sensory quality was not adversely affected by acetic acid. This study demonstrates that while acetic acid did reduce populations of L. monocytogenes on meat, it did not completely inactivate the pathogen. The application of acetic acid may be used as an additional hurdle contributing to extend the shelf life of raw poultry and reducing populations of L. monocytogenes.

Staphylococcal biofilm formation as affected by type acidulant

Staphylococcal growth and biofilm formation in culture medium where pH was lowered with weak organic (acetic and lactic) or strong inorganic (hydrochloric) acids were studied. The effects were evaluated by biomass measurements, cell-surface hydrophobicity, scanning electron microscopy (SEM), and confocal laser scanning microscopy (CLSM). The results demonstrated that the inhibition was related to type of acidulant and pH value. At pH 5.0, the antibacterial effect was more pronounced in the presence of acetic acid (58-60% growth reduction) compared with that in the presence of lactic (7-16% growth reduction) and hydrochloric acids (23-24% reduction). The biofilm biomass of Staphylococcus aureus and Staphylococcus epidermidis was reduced by 92, 85, 63, and 93, 87, 81% after exposition to acetic, lactic, and hydrochloric acids, respectively. Increasing the pH from 5.0 to 6.0 resulted in a noticeable reduction in the effectiveness of acids. A minor cells hydrophobic character was also documented. The SEM and CLSM revealed a poorly structured and thinner biofilm compared with the dense and multilayered control. Acidic environment could have important implications for food-processing system to prevent bacterial colonization and control biofilm formation. The findings of this study lead to consider the rational use of the type of acid to achieve acidic environments.

Impact of sodium lactate and vinegar derivatives on the quality of fresh Italian pork sausage links

Sodium lactate and acetic acid derivatives were evaluated for their impact on fresh Italian pork sausage using commercial trimmings. Analysis over storage included total plate count (TPC), TBARS, sensory analysis, cooking loss, pH, and color. Treatments included: (a) vinegar and sodium lactate mixture (V), (b) sodium lactate (S), (c) positive control with BHA/BHT (B) and (d) negative control, seasoning only (C). Treatments S and V had lower TPC (P<0.05) from days 5 to 14 when compared to B and C. TBARS values increased (P<0.05) for C, S, and V while B did not change (P>0.05) over time. While CIE a* surface values for redness generally decreased over storage time for all treatments, B maintained more redness. There were few major differences in descriptive sensory evaluation over time, but S and V precluded early onset of rancidity, oxidation and other off-flavors contrary to some of the analytical results. Of consumers tested, 85.6% rated all treatments between like slightly and like very much.

Effectiveness of a polyamide film releasing lactic acid on the growth of E. coli O157:H7, Enterobacteriaceae and Total Aerobic Count on vacuum-packed beef

The suitability of a polyamide 6 monolayer film containing lactic acid for use as an antimicrobial package for fresh beef cuts was studied. The release of lactic acid in an aqueous environment was immediate (within 1h) and was from approx. 55 μg lactic acid/cm(2) film at 0-8°C to approx. 67 μg lactic acid/cm(2) film at 12-20°C. Beef was contaminated with an Escherichia coli O157:H7 isolate with known minimum inhibitory concentration against lactic acid (0.09% v/v), then wrapped with the lactic-acid polyamide film and vacuum packaged. During storage at 12°C, the numbers of E. coli were 1 log unit lower than that of a control (untreated polyamide film) and decreased by an additional 1 log during storage for 14 days.

Inactivation of Escherichia coli O157:H7 on cattle hides by caprylic acid and β-resorcylic acid

Two naturally occurring, generally recognized as safe compounds, namely, caprylic acid (CA) (1%) and b -resorcylic acid (BR) (1%), and their combination, applied at 23 and 60°C were evaluated for their antimicrobial effects against Escherichia coli O157:H7 on cattle hides in the presence and absence of bovine feces. Fresh cleaned cattle hides were cut into pieces (5 cm(2)), air dried, and inoculated with a five-strain mixture of nalidixic acid-resistant (50 μg/ml) E. coli O157:H7 (∼8.0 log CFU). The hide samples were air dried under a biosafety hood for 2 h and sprayed with 95% ethanol, 1% CA, 1% BR, or a mixture of 1% CA and 1% BR at 23 or 60°C. The hide samples were kept at 23°C, and E. coli O157:H7 populations were determined at 2 and 5 min after treatment. Both CA and BR were effective in decreasing E. coli O157:H7 populations on hides by 3 to 4 log CFU/cm(2) (P < 0.05). Sterile bovine feces had no effect on the decontaminating property of CA and BR on cattle hides (P > 0.05). Results of this study indicate that CA and BR could potentially be used to decontaminate cattle hides, but follow-up research under slaughterhouse conditions is warranted.

Microbiological effects of carcass decontaminating treatments at four beef packing plants

The effects on the microbiological conditions of carcasses of decontaminating treatments at four beef packing plants were examined. Spraying with 2% lactic acid, vacuum-hot water cleaning and trimming were generally ineffective. Washing reduced numbers of bacteria on carcasses when numbers were relatively high but not when they were relatively low. Pasteurizing with steam or hot water was consistently effective. The results suggest that the maximum reduction of bacteria on carcasses may be obtained by washing and pasteurizing without the other decontaminating treatments that are currently applied to carcasses.

Effects of lactic acid on the growth characteristics of Listeria monocytogenes on cooked ham surfaces

The surfaces of ready-to-eat meats are susceptible to postprocessing contamination by Listeria monocytogenes. This study examined and modeled the growth characteristics of L. monocytogenes on cooked ham treated with lactic acid solutions (LA). Cooked ham was inoculated with L. monocytogenes (ca. 10(3) CFU/g), immersed in 0, 0.5, 0.75, 1.0, 1.25, 1.5, and 2.0% LA for 30 min, vacuum packaged, and stored at 4, 8, 12, and 16°C. LA immersion resulted in <0.7 log CFU/g immediate reduction of L. monocytogenes on ham surfaces, indicating the immersion alone was not sufficient for reducing L. monocytogenes. During storage, no growth of L. monocytogenes occurred on ham treated with 1.5% LA at 4 and 8°C and with 2% LA at all storage temperatures. LA treatments extended the lag-phase duration (LPD) of L. monocytogenes and reduced the growth rate (GR) from 0.21 log CFU/day in untreated ham to 0.13 to 0.06 log CFU/day on ham treated with 0.5 to 1.25% LA at 4°C, whereas the GR was reduced from 0.57 log CFU/day to 0.40 to 0.12 log CFU/day at 8°C. A significant extension of the LPD and reduction of the GR of L. monocytogenes occurred on ham treated with >1.25% LA. The LPD and GR as a function of LA concentration and storage temperature can be satisfactorily described by a polynomial or expanded square-root model. Results from this study indicate that immersion treatments with >1.5% LA for 30 min may be used to control the growth of L. monocytogenes on cooked meat, and the models would be useful for selecting LA immersion treatments for meat products to achieve desired product safety.

Microbiological and sensory effects of the combined application of hot-cold organic acid sprays and steam condensation at subatmospheric pressure for decontamination of inoculated pig tissue surfaces

We studied microbiological and sensory effects of treating pig tissue for 15 s with 55 and 10°C sprays of acetic acid (AA; 0.15 to 0.3 M) and lactic acid (LA; 0.1 to 0.2 M) solutions prior to the tissue being subjected to steam condensation (18 s at 65°C or 10 s at 75°C). LA or AA spraying and then steam treatment resulted in 3- to 4-log average reductions of Pseudomonas fragi and Yersinia enterocolitica inocula (6 to 7 log CFU/cm(2)), regardless of acid temperature or concentration. Buffered LA or 1:1 mixtures of AA:LA and then steam treatment yielded similar reductions. Most of the acid-steam-treated samples had microbial counts below the limit of detection (2 log CFU/cm(2)); thus, the results likely underestimate the potential of this procedure. When the period between inoculation and acid-steam treatment was extended from 0.5 to 24 h, up to a 1-log-higher microbial reduction was observed, due to a 1- to 2-log-greater initial contamination. Increasing the LA contact time to 6 min increased the microbial reduction by 0.8 log. Acid-steam treatment effected lower L* values (darker color) on pigskin, but higher L* values on muscle and fat tissue (paler color). Many muscle samples exhibited lower a* values and off-color brown hues. Off-odors were observed immediately after treatment, but with the exception of fat tissue and AA-treated samples, they largely disappeared during further storage. Off-flavors were only detected in AA-treated muscle samples.

Characterization of an extremely heat-resistant Escherichia coli obtained from a beef processing facility

AIMS

This study aimed to determine the survival of Escherichia coli strains during steam and lactic acid decontamination interventions currently used by the beef-processing industry, and to determine their heat resistance.

METHODS AND RESULTS

Strains were grouped into cocktails of five strains each differing in their RAPD patterns for subsequent identification. Steam and lactic acid treatments on meat reduced cell counts of E. coli strain cocktails by 90-99%. The 20 slaughter plant isolates exhibited only minor variation in their resistance to steam and lactic acid treatments but were more resistant than reference strains (three strains) or isolates from live cattle (seven strains). D(60) values of strains from live cattle, and reference strains ranged from 0·1 to 0·5 min, in keeping with literature data. However, D(60) values of current slaughter plant isolates ranged between 15 for E. coli DM18.3 and 71 min AW 1.7. Cell counts of E. coli AW 1.7 were reduced by <5 log(10) CFU g(-1) in ground beef patties cooked to an internal temperature of 71°C.

CONCLUSIONS

Strains of E. coli that survive cooking of ground beef to the recommended internal temperature of 71°C can be isolated from beef-processing facilities.

SIGNIFICANCE AND IMPACT OF THE STUDY

Pathogen interventions in current commercial beef slaughter may select for extremely heat-resistant strains of E. coli.

Identification of Escherichia coli O157:H7 surrogate organisms to evaluate beef carcass intervention treatment efficacy

We compared the survival of potential pathogen surrogates-meat-hygiene indicators (non-Escherichia coli coliforms), biotype I E. coli, and lactic acid bacteria starter cultures-with survival of an E. coli O157:H7 (ECO157:H7) inoculum in beef carcass intervention trials. Survival of one lactic acid bacteria starter culture (Bactoferm LHP Dry [Pediococcus acidilactici and Pediococcus pentosaceus]), a five-isolate biotype I inoculum, and a five-isolate non-E. coli coliform inoculum, was compared with survival of a 12-isolate ECO157:H7 inoculum in interventions by using beef brisket (adipose and lean), cod fat membrane, or neck tissue. Treatments were grouped by abattoir size: small (6-day dry aging; 22°C acid treatment [2.5% acetic acid, 2% lactic acid, or Fresh Bloom], followed by 1-day dry aging; hot water) and large (warm acid treatment [5% acetic acid or 2% lactic acid] with or without a preceding hot water treatment). Reductions in pathogen and surrogate inocula were determined with excision sampling. A surrogate was considered a suitable replacement for ECO157:H7 if the intervention produced a reduction in surrogate levels that was not significantly greater (P≥0.05) than that observed for ECO157:H7. All three surrogate inocula were suitable as ECO157 surrogates for dry aging and acid spray plus dry-aging treatments used by small abattoirs. No one inoculum was suitable as an ECO157 surrogate across all intervention treatments used by large abattoirs. Effects seen on neck tissue were representative of other tissues, and the low value of the neck supports its use as the location for evaluating treatment efficacy in in-plant trials. Results support using nonpathogenic surrogate organisms to validate beef carcass intervention efficacy.