The microbiological quality of ready-to-eat foods with added spices

Probabilistic risk assessment of exposure to multiple mycotoxins in consumers of packaged and unpackaged spices in Iran

The current study assessed the risk posed to Iranian consumers by oral exposure to a mixture of ten mycotoxins in 138 packaged and unpackaged spices collected from the Iran market. Concentrations of mycotoxins in samples were quantified by liquid chromatography, tandem mass spectrometry with triple quadrupole, and ion trap. Probabilistic health risks of oral exposure to these mycotoxins for Iranians were assessed under percent tolerable daily intake (TDI) and cancer risk scenarios. Mean concentrations of mycotoxins in both packaged and unpackaged spice samples showed statistically significant variation among different spice samples. Based on a Monte Carlo simulation model, at the 50th, 80th, and 95th centiles, oral consumption of the analyzed samples poses no carcinogenic risk for exposure to aflatoxin. Moreover, in both packaged and unpackaged samples, while the percent TDIs for ochratoxin A, deoxynivalenol, zearalenone, patulin, fumonisin B1, and fumonisin B2 were below 1.0 at the 50th, 80th, and 95th centiles, the value was above 1.0 for aflatoxin B1, aflatoxin B2, aflatoxin G1, and aflatoxin G2 at each of these centiles.

Inactivation of Bacillus cereus endospores on black pepper by pulsed superheated steam system

In this study, a superheated steam (SHS) system was constructed to inactivate Bacillus cereus endospores on the surface of black pepper, and continuous and pulsed treatment was applied to compare sporicidal effects. Additionally, inactivation mechanisms were analyzed to investigate the differences between pulsed and continuous SHS treatments. SHS at 250 °C and 300 °C for 1 min achieved more than a 3 log reduction, whereas SHS at 200 °C for 1 min achieved less than 2 log reduction in the number of endospores. In addition, higher microbicidal effects were confirmed with pulsed SHS treatment with a shorter duty ratio. To elucidate the inactivation mechanisms, inner membrane damage (dipicolinic acid release), intracellular enzyme activities, and DNA integrity were measured after 300 °C SHS pulsed or continuous treatments. After pulsed SHS treatment for up to 20 s, intracellular enzymes were inactivated more rapidly than after continuous treatment, and more DPA was released after 40 s of treatment, indicating that enzyme inactivation occurred prior to inner membrane damage, and pulsed treatment accelerated this mode of action. DNA integrity was significantly lower after 60 s of pulsed or continuous treatment; however, there was no difference in between pulsed and continuous treatments. Our results provide fundamental insights for the sterilization of black pepper by SHS treatment in food industries.

Validation of γ‐radiation and their effect on phenolic compounds, antioxidant activity, and microbial load of fennel ( Foeniculum vulgare ) seeds and cinnamon ( Cinnamomum verum ) sticks

The aim of this study was to validate the optimum doses of γ-radiation and its effect on the antioxidant capacity and microbial load of fennel seeds and cinnamon sticks. Gamma irradiation was applied in different doses 0.0, 2.5, 5.0, 7.5, 10, and 15 kGy. The findings stated that increasing gamma dose significantly (p < .05) increased the total phenolic content of the fennel seeds; however, it was decreased in cinnamon at doses higher than 5 kGy. The total flavonoid content was found higher after treatments at 5 kGy or more minor. After the gamma irradiation treatments, the antioxidant activities were enhanced. The microbial load of these spices was reduced after treatment. Doses more than 10.0 kGy are required to lower the bacterial load in samples, while only 5.0 kGy is sufficient to eliminate fungi growth. The partial least squares regression analysis stated the application of 7.5 kGy and reflects the most valid treatment doses for radiation treatments of fennel seeds and cinnamon sticks. Accordingly, it can be discovered that the γ-radiation at a dose of 7.5 kGy could be considered a suitable dose for the preservation and decontamination of these spices and also for enhancing its antioxidant capacity. Three spices were subjected to gamma irradiation at different doses. The application of gamma radiation significantly reduces the level of the microbial load in the spices. Gamma irradiation improved the antioxidant capacity of the spices. Gamma irradiation can be applied as an effective preservative method in the food industries.

Dry surface biofilms in the food processing industry: An overview on surface characteristics, adhesion and biofilm formation, detection of biofilms, and dry sanitization methods

Bacterial biofilm formation in low moisture food processing (LMF) plants is related to matters of food safety, production efficiency, economic loss, and reduced consumer trust. Dry surfaces may appear dry to the naked eye, however, it is common to find a coverage of thin liquid films and microdroplets, known as microscopic surface wetness (MSW). The MSW may favor dry surface biofilm (DSB) formation. DSB formation is similar in other industries, it occurs through the processes of adhesion, production of extracellular polymeric substances, development of microcolonies and maturation, it is mediated by a quorum sensing (QS) system and is followed by dispersal, leading to disaggregation. Species that survive on dry surfaces develop tolerance to different stresses. DSB are recalcitrant and contribute to higher resistance to sanitation, becoming potential sources of contamination, related to the spoilage of processed products and foodborne disease outbreaks. In LMF industries, sanitization is performed using physical methods without the presence of water. Although alternative dry sanitizing methods can be efficiently used, additional studies are still required to develop and assess the effect of emerging technologies, and to propose possible combinations with traditional methods to enhance their effects on the sanitization process. Overall, more information about the different technologies can help to find the most appropriate method/s, contributing to the development of new sanitization protocols. Thus, this review aimed to identify the main characteristics and challenges of biofilm management in low moisture food industries, and summarizes the mechanisms of action of different dry sanitizing methods (alcohol, hot air, UV-C light, pulsed light, gaseous ozone, and cold plasma) and their effects on microbial metabolism.

Pathways of Mycotoxin Occurrence in Meat Products: A Review

Documented cases of mycotoxin occurrence in meat products call for further research into potential contamination sources, especially given an ever more increasing consumption of these nutritionally rich products. These foodstuffs can be contaminated with mycotoxins through three pathways: contaminated spices and other raw materials, mycotoxin-producing moulds present on the surface of dry-cured meat products, and carry-over effect from farm animals exposed to contaminated feed. In order to establish meat products’ mycotoxin contamination more precisely, the concentrations of all mycotoxins of relevance for these products should be determined. This manuscript reviews data on major mycotoxins present in different types of meat products, and discusses the contamination pathways, contamination levels and control & preventative measures.

Inactivation of Escherichia coli O157:H7 and Salmonella Typhimurium in black and red pepper by vacuumed hydrogen peroxide vapour

AIMS

In this study, the efficacy of using vacuumed hydrogen peroxide vapour (VHPV) to inactivate foodborne pathogens in whole dried black pepper (Piper nigrum) and powdered dried red pepper (Capsicum annuum) was evaluated.

METHODS AND RESULTS

Black and red pepper inoculated with Escherichia coli O157:H7 and Salmonella Typhimurium were subjected to 3.81, 7.93, 12.33, 17.04 and 21.67 mg l^-1 VHPV for 1 min, and the change in pepper colour was evaluated after treatment. Pathogen quantities decreased with increasing hydrogen peroxide concentration. For black pepper, the 21.67 mg l^-1 VHPV treatment decreased E. coli O157:H7 and S. Typhimurium quantities by >6.12 and 4.52 log CFU per gram, respectively, without causing colour change. In addition, the 21.67 mg l^-1 VHPV treatment caused 4.35 and 2.36 log CFU per gram reductions in these two pathogen quantities in red pepper, respectively. During the VHPV treatment, colour values of peppers did not significantly change.

CONCLUSIONS

VHPV effectively reduced the levels of foodborne pathogens in black and red pepper while inducing minimal colour changes.

SIGNIFICANCE AND IMPACT OF THE STUDY

Hydrogen peroxide vapour (HPV) is typically used as a sterilization method for medical devices, and many studies have confirmed the effectiveness of HPV or the gaseous phase of hydrogen peroxide on the inactivation of micro-organisms. However, using HPV for food pasteurization has rarely been studied. In the present study, we confirmed that VHPV effectively reduced the levels of pathogens in black and red pepper without colour changes.

Assessing the Performance of Food Safety Management System Using Food Safety Management System Diagnostic Tools and Microbial Assessment Scheme: A Case of Powdered Beverage Manufacturers

Background

The objective of the study is to assess the performance of the Food Safety Management System (FSMS) among powdered beverage manufacturers using Food Safety Management System Diagnostic Tools (FSMS-DI) and Microbial Assessment Scheme (MAS).

Methods

FSMS-DI was used to evaluate the context factors, core control and core assurance activities of five powdered beverage manufacturers with different types of FSMS certification. Manufacturer A is not certified with any FSMS, while manufacturers B, C, D and E are complied with MeSTI, GMP, HACCP and ISO 22000, respectively. For MAS, samples were collected from the selected critical sampling locations of two manufacturers who complied FSMS with the least (manufacturer B) and the most stringent (manufacturer E) requirements. The samples consisted of two different types of powdered beverage products were analysed for total plate count (TPC), Salmonella, Escherichia coli, Staphylococcus aureus, yeast and mould count (YMC). Results: The food safety (FS) output of powdered beverages for manufacturer E was better (overall score of 3) than manufacturer B (overall score of 2-3). Manufacturer E was able to achieve their FS objectives. The FSMS activities of manufacturer C, D and E were better (overall score of 2-3) than manufacturer A and B (overall score of 1-2).

Conclusion

The study demonstrated that FSMS-DI and MAS can be used to differentiate the FSMS performance of powdered beverage manufacturers with different types of FSMS certification. Higher scores of FSMS activities obtained by the manufacturer who complied with stringent FSMS certifications contributed to better microbiological safety performance of powdered beverages.

Decontamination of Escherichia coli on dried onion flakes and black pepper using Infra-red, ultraviolet and ozone hurdle technologies

Among spices, onion flakes (OF) and black pepper (BP) are commonly used ingredients in domestic cooking; however, spices have been shown to be highly contaminated with pathogenic bacteria and bacterial spores. A novel method applying a treatments of Ozone Ultraviolet (UV, 255nm) and Infra-red (IR) light in different combinations was assessed for its efficiency in decontaminating OF and BP. In this study, untreated samples, as purchased, were inoculated with 9.5 × 10⁵ cfu/mL Escherichia coli (MG1655) and exposed to each treatment alone and in combination of ozone sequentially followed by UV/IR, and UV/IR combined followed sequentially by ozone. A difference in response towards the treatment was shown among the types of spices, with a high efficacy for BP. Typically 3 log reductions were observed for ozone, UV and IR. The sequential treatments of ozone with UV and IR combined gave improved results than individual ones, with 99.99% of E. coli inactivation, and a shorter exposure duration with ozone (2.5 and 5 min) and UV and IR (2.5 and 5 min). The combined effect (ozone 2.5 min, UV and IR 10 min) yielded a log reduction of 2.69 and 4.20 for OF and BP respectively, greater than the additive effect of the individual treatments alone. The IR lamp was modulated to reduce excessive temperature rise. This novel prototype was shown to be very effective in decontaminating spices. Further studies should be conducted to validate the effectiveness of this method on decontamination of various bacterial strains.

Ca and Mg Concentrations in Spices and Growth of Commonly Sporulated and Non-Sporulated Food-Borne Microorganisms According to Marketing Systems

Ca and Mg levels were determined in five spices according to marketing system (in bulk or commercialized in glass or polyethylene terephthalate (PET) containers) and correlated with microbial growth of commonly sporulated (Clostridium perfringens and Bacillus cereus) and non-sporulated (Listeria monocytogenes, psychrophilic and mesophilic bacteria, and yeasts and molds) food-borne pathogens present in them, when they were previously added to the microbial culture media. The basil had the highest mean Ca and Mg level and showed the highest microbial growth in the food-borne pathogenic microorganisms studied (p < 0.001). For Ca, the lowest levels were measured in cloves (p < 0.001), which had the lowest capacity for microbial contamination. Ca and Mg contents in spices correlated linear and positively (p < 0.05). Ca concentrations weakly and positively correlated (p < 0.05) with microbial counts for almost all studied microorganisms, and Mg levels for B. cereus, C. perfringens, and mesophilic bacteria (p < 0.05), possibly acting as a growing factor for some sporulated and non-sporulated foodborne pathogens. These relationships are especially significant when PET vs. glass was used as a packaging material for spices.

Control of Salmonella in low-moisture foods: Enterococcus faecium NRRL B-2354 as a surrogate for thermal and non-thermal validation

Salmonella has been implicated in multiple foodborne outbreaks and recalls associated with low water activity foods (La_wF). To verify the effectiveness of a process against Salmonella in La_wF, validation using a nonpathogenic surrogate strain is essential. Enterococcus faecium NRRL B-2354 strain has been used as a potential surrogate of Salmonella in different processing of La_wF. However, the survival of Salmonella and E. faecium in La_wF during food processing is a dynamic function of a_w, food composition and structure, processing techniques, and other factors. This review assessed pertinent literature on the thermal and non-thermal inactivation of Salmonella and its presumable surrogate E. faecium in various La_wF and provided an overview of its suitibility in different La_wF. Overall, based on the D-values, survival/reduction, temperature/time to obtain 4 or 5-log reductions, most studies concluded that E. faecium is a suitable surrogate of Salmonella during La_wF processing as its magnitude of resistance was slightly greater or equal (i.e., statistical similar) as compared to Salmonella. Studies also showed its unsuitability which either does not provide a proper margin of safety or being overly resistant and may compromise the quality and organoleptic properties of food. This review provides useful information and guidance for future validation studies of La_wF.

Microbial Contamination of Fresh Produce: What, Where, and How?

Promotion of healthier lifestyles has led to an increase in consumption of fresh produce. Such foodstuffs may expose consumers to increased risk of foodborne disease, as often they are not subjected to processing steps to ensure effective removal or inactivation of pathogenic microorganisms before consumption. Consequently, reports of ready-to-eat fruit and vegetable related disease outbreak occurrences have increased substantially in recent years, and information regarding these events is often not readily available. Identifying the nature and source of microbial contamination of these foodstuffs is critical for developing appropriate mitigation measures to be implemented by food producers. This review aimed to identify the foodstuffs most susceptible to microbial contamination and the microorganisms responsible for disease outbreaks from information available in peer-reviewed scientific publications. A total of 571 outbreaks were identified from 1980 to 2016, accounting for 72,855 infections and 173 deaths. Contaminated leafy green vegetables were responsible for 51.7% of reported outbreaks. Contaminated soft fruits caused 27.8% of infections. Pathogenic strains of Escherichia coli and Salmonella, norovirus, and hepatitis A accounted for the majority of cases. Large outbreaks resulted in particular biases such as the observation that contaminated sprouted plants caused 31.8% of deaths. Where known, contamination mainly occurred via contaminated seeds, water, and contaminated food handlers. There is a critical need for standardized datasets regarding all aspects of disease outbreaks, including how foodstuffs are contaminated with pathogenic microorganisms. Providing food business operators with this knowledge will allow them to implement better strategies to improve safety and quality of fresh produce.

Effect of decontamination treatment on the quality of dehydrated thyme, coriander, and mustard

The objective of this work was to evaluate the effects of different decontamination treatments on the quality of dehydrated thyme, coriander, and mustard. Treatments applied were: (i) ultraviolet radiation treatment irradiation; (ii) steam, (iii) steam-ultraviolet radiation treatment; (iv) humidification-ultraviolet radiation treatment, and (v) steam-humidification-ultraviolet radiation treatment. Their effectiveness to control indigenous aerobic mesophiles and yeasts and molds population was assessed by plate count. The effect of proposed treatments on total polyphenol contents and antioxidant activity was also evaluated. Furthermore, the effect of treatments on spices performance to prevent canola oil oxidation was also analyzed. The use of steam-ultraviolet radiation treatment in aqueous medium was the most effective for decontamination, reducing the aerobic mesophiles and yeasts and molds counts between 1.0 and 2.2 log CFU/g dry spice. This treatment decreased significantly the polyphenol content and the antioxidant capacity of the three spices analyzed. However, in the case of mustard, the residual antioxidant compounds were able to control canola oil oxidation more efficiently than butylated hydroxytoluene. Results suggest that the use of steam-ultraviolet radiation treatment in aqueous medium can be useful in food preservation processes.

Effect of cold plasma on essential oil content and composition of lemon verbena

Cold plasma is known as a novel nonthermal processing method for decontamination of medicinal and aromatic plants (MAPs); however, there are little research studies about its effects on active ingredients of these plants. The aim of this research was to investigate the influence of low-pressure cold plasma (LPCP) treatments (1, 3, and 5 min) on the essential oil (EO) content and composition of lemon verbena leaves. The EO content was determined using hydro-distillation, and the composition of the extracted EOs was quantified using gas chromatography and gas chromatography-mass spectrometry techniques. The results showed that by increasing the LPCP treatment duration, the EO content was reduced from 1.2 to 0.9 (% v/w). The highest content of monoterpene hydrocarbons (e.g., limonene) and oxygenated sesquiterpenes (e.g., spathulenol and globulol) was also observed in LPCP-treated ones, whereas the oxygenated monoterpenes (e.g., citral) content of control was measurably higher than those treated with LCPC.

Microbial Evaluation of Spices in Ethiopia

Introduction:

Since spices are taken as ready-to-eat products, they are not subjected to heat treatment. The use of spices contaminated with pathogens can lead to morbidity and mortality.

Materials and Methods:

The study was conducted on 162 samples of 25 spices collected from retail and production sites in different regions of Ethiopia between January 2010 to December 2017 to determine the concentrations of heterotrophic plate count and Staphylococcus aureus by pour plate method; for coliforms using NMKL Method No. 44; for mould and yeast enumeration using spread method and for Salmonella using ES ISO 6579. The data was analysed using SPSS version 20.0.

Results:

Moulds, yeasts, total coliforms, heterotrophic plate count, total coliforms, thermotolerant coliforms, E. coli and S. aureus above the acceptable limits were observed in 5 (3%), 7 (4.3%), 2 (1.2%), 20 (12.3%), 10 (6.2%), 9 (5.6%) and 19 (11.7%) samples respectively. Salmonella species was not noticed in any of the samples tested. No bacterial and fungal contaminations were observed in 11 of 25 spices.

Conclusions:

Few spices samples had 1.2 to 12.3% of the microbiological indicators, spoilages or pathogens exceeded the ICMFS guidelines. The use of these contaminated spices may pose risk to human health.

Radio-Frequency Processing for Inactivation of Salmonella enterica and Enterococcus faecium NRRL B-2354 in Black Peppercorn

Several Salmonella outbreaks linked to black pepper call for effective inactivation processes, because current decontamination methods result in quality deterioration. Radio-frequency (RF) heating provides a rapid heating rate and volumetric heating, resulting in a shorter come-up time. This allows for choosing a high-temperature and short-time combination to achieve the desired inactivation with minimal quality deterioration. The objectives of this study were to evaluate RF heating for inactivation of Salmonella enterica and Enterococcus faecium in black peppercorn and evaluate quality changes of RF-treated black peppercorn. Black peppercorns were inoculated with a five-strain cocktail of Salmonella or E. faecium to attain initial population levels of 6.8 and 7.3 log CFU/g, respectively, and were then adjusted to a moisture content of 12.7% (wet basis) and a water activity of 0.60 at room temperature. A stability test was performed to quantify the microbial reduction during inoculation and equilibration before RF heating inactivation. During RF heating, the cold spot was determined to be at the center on the top surface of the treated sample. In addition to inoculating the entire sample, an inoculated packed sample was placed at the cold spot of the tray. An RF heating time of 2.5 min provided a 5.31- and 5.26-log CFU/g reduction in the entire sample contained in the tray for Salmonella and E. faecium, respectively. Color parameters (L*, a*, b*), piperine content, total phenolics, scavenging activity, and most of the volatile compounds of 2.5-min RF-treated samples were not significantly different from those of the control samples. These data suggest that RF heating is a promising thermal inactivation treatment for Salmonella without significant quality deterioration, and E. faecium seems to be a suitable surrogate for Salmonella to validate the efficacy of RF heating of black peppercorn.

Inactivation effect of UV-C and mild heat treatment against Salmonella Typhimurium and Escherichia coli O157:H7 on black pepper powder

In this study, UV-C and mild heat treatments were used alone or in combination for the inactivation of Salmonella Typhimurium and Escherichia coli O157:H7 on the black pepper powder. The treated pepper powder was analyzed microbiologically, and the physicochemical properties of the pepper powder were examined. UV-C combined with heat treatment at 60 °C most effectively inactivated the pathogens. However, heat treatment at 60 °C produced many injured cells and greatly reduced moisture content of the pepper powder. UV-C combined with heat treatment at 45 °C showed significantly (p < 0.05) similar inactivation results as that with heat treatment at 60 °C after 18 min. In addition, the combined treatment minimized the moisture loss and color change of the pepper powder compared to heat treatment at 60 °C. Thus, UV-C and heat treatment at 45 °C can effectively inactivate pathogens while maintaining the quality of black pepper powder.

Analysis of enterotoxigenic Bacillus cereus strains from dried foods using whole genome sequencing, multi-locus sequence analysis and toxin gene prevalence and distribution using endpoint PCR analysis

Bacillus cereus strains were isolated from dried foods, which included international brands of spices from South East Asia, Mexico and India purchased from several retail stores, samples of powdered infant formula (PIF), medicated fish feed and dietary supplements. The genetic diversity of 64 strains from spices and PIF was determined using a multiplex endpoint PCR assay designed to identify hemolysin BL, nonhemolytic enterotoxin, cytotoxin K, and enterotoxin FM toxin genes. Thirteen different B. cereus toxigenic gene patterns or profiles were identified among the strains. Randomly selected B. cereus strains were sequenced and compared with reference Genomic Groups from National Center Biotechnology Information using bioinformatics tools. A comprehensive multi-loci sequence analysis (MLSA) was designed using alleles from 25 known MLST genes specifically tailored for use with whole genome assemblies. A cohort of representative genomes of strains from a few FDA regulated commodities like dry foods and medicated fish feed was used to demonstrate the utility of the 25-MLSA approach for rapid clustering and identification of Genome Groups. The analysis clustered the strains from medicated fish feed, dry foods, and dietary supplements into phylogenetically-related groups. 25-MLSA also pointed to a greater diversity of B. cereus strains from foods and feed than previously recognized. Our integrated approach of toxin gene PCR, and to our knowledge, whole genome sequencing (WGS) based sequence analysis, may be the first of its kind that demonstrates enterotoxigenic potential and genomic diversity in parallel.

Dehydrated foods: Are they microbiologically safe?

Dried foods are low water activity foods with water activity ranging from 0.03 to 0.7. They are commonly misconstrued to be inherently safe from food borne pathogenic bacteria. However, there are many reported cases where many food borne illnesses were caused by the consumption of dried foods contaminated with Salmonella spp., Cronobacter spp., Staphylococcus spp. and E. coli. In this work, we have systematically reviewed the literature dealing with the effect of drying/dehydration on the survival of pathogenic microorganisms with special focus on Salmonella spp. We have also reviewed and synthesized the literature dealing with the effect of drying process on microorganisms in dried vegetables, meat, fish, spices, mushroom and powdered foods. This review concludes that dried foods are not inherently safe microbiologically and required other hurdles to achieve microbial safety.

Distribution of Enterotoxin- and Epsilon-Positive Clostridium perfringens Spores in U.S. Retail Spices

The role of spices as vehicles of foodborne illness prompted an examination of bacterial spores in these products. Here, we report on the levels and characteristics of spores of Clostridium perfringens associated with 247 U.S. retail spices. Forty-three confirmed isolates from 17% of samples were obtained, present at levels ranging from 3.6 to 2,400/g. Twenty-seven (63%) of C. perfringens isolates were positive for the enterotoxin gene ( cpe). Seven random spice isolates produced enterotoxin at levels of between 4 and 16 ng/mL, compared with three outbreak (control) strains that each produced enterotoxin levels of >1,024 ng/mL. D_95°C levels (1.0 to 3.3 min) of spores of four randomly selected spice isolates suggests a plasmid-localized cpe, while one had D_95°C (>45 min) consistent with chromosomally located cpe. Five of the 43 isolates possessed the epsilon toxin gene ( etx, as well as cpe). Foods could easily become contaminated with spores of cpe-positive C. perfringens by the addition of spices. Because of its spore-forming ability, its rapid generation times at elevated temperatures, improper heating, cooling, and holding conditions could lead to elevated levels of C. perfringens in foods, a requirement for its implication in foodborne outbreaks.

Processes to Preserve Spice and Herb Quality and Sensory Integrity During Pathogen Inactivation

Selected processing methods, demonstrated to be effective at reducing Salmonella, were assessed to determine if spice and herb quality was affected. Black peppercorn, cumin seed, oregano, and onion powder were irradiated to a target dose of 8 kGy. Two additional processes were examined for whole black peppercorns and cumin seeds: ethylene oxide (EtO) fumigation and vacuum assisted-steam (82.22 °C, 7.5 psia). Treated and untreated spices/herbs were compared (visual, odor) using sensory similarity testing protocols (α = 0.20; β = 0.05; proportion of discriminators: 20%) to determine if processing altered sensory quality. Analytical assessment of quality (color, water activity, and volatile chemistry) was completed. Irradiation did not alter visual or odor sensory quality of black peppercorn, cumin seed, or oregano but created differences in onion powder, which was lighter (higher L^* ) and more red (higher a^* ) in color, and resulted in nearly complete loss of measured volatile compounds. EtO processing did not create detectable odor or appearance differences in black peppercorn; however visual and odor sensory quality differences, supported by changes in color (higher b^* ; lower L^* ) and increased concentrations of most volatiles, were detected for cumin seeds. Steam processing of black peppercorn resulted in perceptible odor differences, supported by increased concentration of monoterpene volatiles and loss of all sesquiterpenes; only visual differences were noted for cumin seed. An important step in process validation is the verification that no effect is detectable from a sensory perspective.

An assessment of the microbiological quality of liver-based pâté in England 2012-13: comparison of samples collected at retail and from catering businesses

The purpose of this study was to investigate the microbiological quality of liver pâté. During 2012-13, a total of 870 samples, unrelated to the investigation of food-poisoning outbreaks, were collected either at retail (46%), catering (53%) or the point of manufacture (1%) and were tested using standard methods to detect Salmonella spp. or Campylobacter spp., and to enumerate for Listeria spp., including Listeria monocytogenes, Clostridium perfringens, coagulase-positive staphylococci including Staphylococcus aureus, Bacillus spp., including Bacillus cereus, Escherichia coli, Enterobacteriaceae, and aerobic colony counts (ACCs). Seventy-three percent of samples were of satisfactory microbiological quality, 18% were borderline and 9% unsatisfactory. Salmonella spp. or Campylobacter spp. was not recovered from any sample. The most common causes of unsatisfactory results were elevated ACCs (6% of the samples) and high Enterobacteriaceae counts (4% of samples). The remaining unsatisfactory results were due to elevated counts of: E. coli (three samples); B. cereus (one sample at 2·6 × 105 cfu/g); or L. monocytogenes (one sample at 2·9 × 103 cfu/g). Pâté from retail was less likely to be contaminated with L. monocytogenes than samples collected from catering and samples from supermarkets were of significantly better microbiological quality than those from catering establishments.

Infrared Drying as a Potential Alternative to Convective Drying for Biltong Production

Two infrared systems set at an intensity of 4777 W/m² with peak emission wavelengths of 2.5 and 3.5 µm were used to produce biltong by drying differently pre-treated meat. In addition to meat texture and colour, the microbial quality of the biltong produced was assessed by quantifying viable heterotrophic microorganisms using a most probable number (MPN) method and by verifying the presence of presumptive Escherichia coli in samples produced using infrared and conventional convective drying. The two infrared drying systems reduced the heterotrophic microbial burden from 5.11 log₁₀ MPN/g to 2.89 log₁₀ MPN/g (2.5 µm) and 3.42 log₁₀ MPN/g (3.5 µm), respectively. The infrared systems achieved an up to one log higher MPN/g reduction than the convective system. In biltong samples produced by short wavelength (2.5 µm) infrared drying, E. coli was not detectable. This study demonstrates that the use of short wavelength infrared drying is a potential alternative to conventional convective drying by improving the microbiological quality of biltong products while at the same time delivering products of satisfactory quality.

Spore prevalence and toxigenicity of Bacillus cereus and Bacillus thuringiensis isolates from U.S. retail spices

Recent incidents of foodborne illness associated with spices as the vehicle of transmission prompted this examination of U.S. retail spices with regard to Bacillus cereus. This study focused on the levels of aerobic-mesophilic spore-forming bacteria and B cereus spores associated with 247 retail spices purchased from five states in the United States. Samples contained a wide range of aerobic-mesophilic bacterial spore counts (< 200 to 8.3 × 10(7) CFU/g), with 19.1% of samples at levels above 10(5) CFU/g. For examples, paprika, allspice, peppercorns, and mixed spices had high levels of aerobic spores (> 10(7) CFU/g). Using a novel chromogenic agar, B. cereus and B. thuringiensis spores were isolated from 77 (31%) and 11 (4%) samples, respectively. Levels of B. cereus were <3 to 1,600 MPN/g. Eighty-eight percent of B. cereus isolates and 91% of B. thuringiensis isolates possessed at least one type of enterotoxin gene: HBL (hemolysin BL) or nonhemolytic enterotoxin (NHE). None of the 88 isolates obtained in this study possessed the emetic toxin gene (ces). Using commercially available immunological toxin detection kits, the toxigenicity of the isolates was confirmed. The NHE enterotoxin was expressed in 98% of B. cereus and 91% of B. thuringiensis isolates that possessed the responsible gene. HBL enterotoxin was detected in 87% of B. cereus and 100% of B. thuringiensis PCR-positive isolates. Fifty-two percent of B. cereus and 54% of B. thuringiensis isolates produced both enterotoxins. Ninety-seven percent of B. cereus isolates grew at 12°C, although only two isolates grew well at 9°C. The ability of these spice isolates to form spores, produce diarrheal toxins, and grow at moderately abusive temperatures makes retail spices an important potential vehicle for foodborne illness caused by B. cereus strains, in particular those that produce diarrheal toxins.

Occurrence of Stachybotrys chartarum chemotype S in dried culinary herbs

Stachybotrys (S.) chartarum is an omnipresent cellulolytic mould which produces secondary metabolites, such as the highly toxic macrocyclic trichothecenes. While it is known to occur in animal feed like hay and straw as well as in water-damaged indoor environments, there is little knowledge about the occurrence of S. chartarum and its secondary metabolites in food. The objective of the present study was to examine selected dried culinary herbs for the presence of S. chartarum chemotype S, to assess the potential risk of a contamination of foods with macrocyclic trichothecenes. In total, 50 Stachybotrys isolates from different types of culinary herbs (n=100) such as marjoram (Origanum majorana Linné (L.)), oregano (Origanum vulgare L.), thyme (Thymus vulgaris L.), and savory (Satureja hortensis L.) were examined by MTT-cell culture test (effect-based bioassay), ELISA, and by liquid chromatography tandem mass spectrometry (LC-MS/MS). Selected toxic and non-toxic isolates (n=15) were genetically characterized by PCR and sequencing. Five isolates (10%) were highly toxic in the MTT-cell culture test, and the production of macrocyclic trichothecenes was proven by ELISA and LC-MS/MS. These five isolates were genetically confirmed as S. chartarum chemotype S. To the best of our knowledge, this is the first report about a contamination of dried culinary herbs with toxigenic S. chartarum.

Identification of volatile organic compounds generated from healthy and infected powdered chili using solvent-free solid injection coupled with GC/MS: application to adulteration

To investigate adulteration in commercial chili powder, the volatile organic compounds of healthy and infected powdered chili pepper were characterized using a solvent-free solid injector (SFSI) coupled with gas chromatography/mass spectrometry (GC/MS). Except for one compound (capillary compound for blank), 43 compounds were identified in healthy and infected chili powder. Specifically, 31, 36, and 41 compounds were identified in healthy, medium-infected, and severely infected chili powder. Among these compounds, acetic acid (13.77%), propanal (2.477%), N-methylpyrrole (1.986%), and 2-methyl-propanal (1.768%) were leading volatiles in the healthy chili powder. In contrast, infected chili powder contained 9,12-octadecadienoic acid, ethyl ester (15.984%), acetic acid (11.249%), hexadecanoic acid, methyl ester (3.3%), N-methylpyrrole (3.221%), and 2-furanmethanol (2.629%) as major compounds. Trimethylamine and isosorbide were detected in both medium and severely infected chili, but not in healthy chili. This means that these compounds could be used as biomarkers to distinguish between healthy and infected chili. The proposed technique was applied to 12 commercial chili powders, and trimethylamine and isosorbide were detected in six samples. These results suggest that a contaminated chili that was added to a healthy one could be successfully identified by a combination of the SFSI and GC/MS.

Simultaneous near-infrared radiant heating and UV radiation for inactivating Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium in powdered red pepper (Capsicum annuum L.)

This study was conducted to investigate the efficacy of the simultaneous application of near-infrared (NIR) heating and UV irradiation for reducing populations of food-borne pathogens, including Salmonella enterica serovar Typhimurium and Escherichia coli O157:H7 in red pepper powder and to clarify the mechanisms of the lethal effect of the NIR-UV combined treatment. Also, the effect of the combination treatment on quality was determined by measuring changes in color and pungency constituents. Simultaneous NIR-UV combined treatment for 5 min achieved 3.34- and 2.78-log CFU reductions in S. Typhimurium and E. coli O157:H7, respectively, which involved 1.86- and 1.31-log CFU reductions, respectively, which were attributed to the synergistic effect. Through qualitative and quantitative analyses, damage to the cell envelope was identified as the main factor contributing to the synergistic lethal effect of NIR-UV combined treatment. Color values and capsaicin and dihydrocapsaicin content of NIR-UV simultaneously treated red pepper powder were not significantly (P > 0.05) different from those of untreated samples. These results suggest that simultaneous application of NIR and UV treatment can be effectively used to control food-borne pathogens in powdered red pepper without affecting quality.

Microbiological quality of retail spices in Tehran, Iran

The microbiological quality of 351 samples of nine types of spices including black pepper, caraway, cinnamon, cow parsnip, curry powder, garlic powder, red pepper, sumac, and turmeric, collected from retail shops in Tehran during 2007, was determined. The numbers of aerobic mesophilic bacteria, Escherichia coli, and molds exceeded Iran's National Standard limits, at 63.2% (>5 × 10(5) CFU/g), 23.4% (>0.3 MPN/g), and 21.9% (>5 × 10(3) CFU/g) of the studied samples, respectively. Coliform contamination was more than 10(3) MPN/g in 24.8% of samples. High contamination of retail spices is considered an indication of environmental or fecal contamination due to unhygienic practices in their production. Use of spices with high microbial content could increase the chance of food spoilage and transmission of foodborne pathogens. Accordingly, application of food safety measurements to reduce microbial counts in spices is strongly recommended.

Listeria spp. in Street-Vended Ready-to-Eat Foods

Street-vended ready-to-eat food sold in Egypt, including sandwiches and dishes of traditional food, was examined for the presence of Listeria species. Out of 576 samples, 24% were found to contain Listeria species. L. monocytogenes and L. innocua were isolated from 57% and 39% of the contaminated samples, respectively. Other Listeria spp. were detected with lower frequency. L. monocytogenes of ≥10(3) CFU/g were detected in 7% of the total examined samples, which represent 49% of the contaminated food samples (meat, poultry, seafood, dairy products, and products of plant origin). Most of the samples contaminated by L. monocytogenes had high levels of total viable bacterial counts. The results obtained may help to clarify the epidemiology of listeriosis in the country and draw the attention of the decision makers to issue hygienic regulations for food processing industries as well as street vendors in order to ensure safe street-vended ready-to-eat food.

Effect of ultraviolet and far infrared radiation on microbial decontamination and quality of cumin seeds

Cumin seeds might be exposed to a high level of natural bacterial contamination, and this could potentially create a public health risk besides leading to problems in exportation. Ultraviolet (UVC) and far infrared (FIR) radiation has low penetration power, and due to that, there might be no detrimental defects to the products during a possible decontamination process. Therefore, the objective of this study was to determine the effect of UVC and FIR treatment on microbial decontamination and quality of cumin seeds. For this purpose, FIR treatment at different exposure times and temperatures were applied followed by constant UVC treatment with an intensity of 10.5 mW/cm² for 2 h. Total mesophilic aerobic bacteria of the cumin seeds were decreased to the target level of 10⁴ CFU/g after 1.57, 2.8, and 4.8 min FIR treatment at 300, 250, and 200 °C, respectively, following a 2 h UVC treatment. Under the given conditions, a complete elimination for total yeast and molds were obtained while there were no significant changes in volatile oil content and color of the cumin seeds. Consequently, combined UVC and FIR treatment was determined to be a promising method for decontamination of the cumin seeds.

PRACTICAL APPLICATION

This research attempts to apply UVC and far infrared (FIR) radiation for pasteurization of cumin seeds. The data suggested that combined UVC and FIR radiation treatments can become a promising new method for pasteurization of cumin seeds without causing any detrimental defect to the quality parameters. The results of this industry partnered (Kadioglu Baharat, Mersin, Turkey--http://www.kadioglubaharat.com) study were already applied in industrial scale production lines.