Microbiological Profile, Incidence, and Behavior of Salmonella on Seeds Traded in Mexican Markets

Food safety issues associated with sesame seed value chains: Current status and future perspectives

Sesame (Sesamum indicum) is an oilseed crop which is increasingly recognised as a functional food by consumers due to its nutritional and nutraceutical components. Consequently, global demand for sesame has increased significantly over the last three decades. Sesame is an important export crop in producing countries, contributing to their socio-economic development. However, in recent years, major foodborne incidents have been associated with imported sesame seeds and products made with these seeds. Foodborne hazards are a potential risk to consumer health and hinder international trade due to border rejections and increased import controls. An insight into the routes of contamination of these hazards across the value chain and factors affecting persistence may lead to more focused intervention and prevention strategies. It was observed that Salmonella is a significant microbial hazard in imported sesame seeds and has been associated with several global outbreaks. Sesame is mainly cultivated in the tropical and subtropical regions of Africa and Asia by smallholder farmers. Agricultural and manufacturing practices during harvesting, storage, and processing before export may allow for the contamination of sesame seeds with Salmonella. However, only a few studies collect data on the microbiological quality of sesame across the value chain in producing countries. In addition, the presence of mycotoxins and pesticides above regulatory limits in sesame seeds is a growing concern. Eliminating foodborne hazards in the sesame value chain requires urgent attention from researchers, producers, processors, and regulators and suggestions for improving the safety of these foods are discussed.

Salmonella enterica Outbreaks Linked to the Consumption of Tahini and Tahini-Based Products

Salmonella is a leading cause of bacterial foodborne illness in the world. Although typically associated with foods of animal origin, low-moisture foods, such as tahini, are quickly gaining recognition as an important vehicle of Salmonella exposure. This review offers the Canadian perspective on the issue of Salmonella in tahini and tahini-based products. A summary of several recent food product recalls and foodborne outbreaks related to the presence of Salmonella in tahini and tahini-based products such as halva are presented. The properties of the food vehicles, their production practices, and potential routes of contamination are discussed. Particular focus is placed on the ecology of Salmonella in the tahini production continuum, including its survival characteristics and response to intervention technologies.

Quality Attributes of Sesame Butter (Tahini) Fortified with Lyophilized Powder of Edible Mushroom (Agaricus blazei)

Sesame butter (tahini) is a common appetizer and food additive in the Mediterranean basin. Pathogenic strains and mycotoxin content are the most hazardous issues in the final product. This investigation aimed to enhance the quality and safety properties of tahini products against microbial hazards and mycotoxins. Local samples of tahini were evaluated for natural contamination, including mycotoxin level determinations. Agaricus blazei was utilized as a bioactive source and evaluated for the bioactive content of laccase, B-glucan, antioxidant activity, and phenolic content, as well as antimicrobial and antioxidant potency. Two fortification ratios (0.5% and 1.0%) were chosen to apply Agaricus in tahini sesame as a model. Chemical composition, color attributes, sensory properties, emulsion, and oxidative stability were evaluated for the fortified samples versus the control. The results reflected increments of protein (22.91 ± 0.64% to 29.34 ± 0.96%), fiber content (3.09 ± 0.05% to 6.27 ± 0.06%), emulsion stability (84.9 ± 1.24% to 95.41 ± 0.56%), oxidative stability, and bioactive group content. The fortification process is reflected by the absence of Salmonella, Listeria, and E. coli bacteria from contaminated samples after 30 days of storage. The water activity for 1.0% fortification (0.154 ± 0.001) was recorded as lower than the control sample (0.192 ± 0.002). Moreover, the degradation of aflatoxins and zearalenone content was recorded during storage. The degradation ratio reached 68% and 97.2% for 0.5% and 1.0% fortifications, respectively, while zearalenone degradation recorded a decline of 26.7% and 33.7%, respectively, for the same fortification ratios. These results recommended 1.0% lyophilized mushroom fortification as a quality and ameliorative safety treatment for tahini products.

Nutritional Quality and Safety Characteristics of Imported Biscuits Marketed in Basrah, Iraq

The ingredients and the preparation methods influence biscuit quality and safety. In Iraq, biscuit imports are increasing every year, but no information is available in the scientific literature on their quality and safety features. This work analyzed three types of biscuits (cookies, crackers, and digestives) sampled in the Basrah markets (Iraq) but produced in Spain, Iran, Turkey, and United Arab Emirates. Nine different brands were considered for each country of origin (n = 36), with three replicates per sample. Moisture, ash, fat, proteins, fiber, water activity, peroxide value, 5-hydroxymethyl-2-furfural (HMF), acrylamide, heavy metals, and microbial load were analyzed. All the nutritional parameters were significantly influenced by the variables “Biscuit type” and “Country”. Cookies showed significantly higher fat content and lower protein content than crackers and digestives, as well as higher peroxide value (which was below the limit set by the FAO/WHO within the World Wood Program). Spanish samples had more fat and fewer proteins than biscuits made in other countries. Very high variability was observed in HMF (from not detected to 62.08 mg/kg) and AA content (reaching 1421.8 μg/kg). Cadmium was always absent, and lead was considerably below the allowed limit. Yeasts and molds were above the limits in five samples.

Microbiological Profile, Prevalence, and Characterization of Salmonella enterica in Peanuts, Pecans, Raisins, Sun-Dried Tomatoes, and Chocolate Sprinkles Sold in Bulk in Markets in Querétaro, Mexico

ABSTRACT

In Mexico, the prevalence of Salmonella enterica in low-water-activity foods and its link to outbreaks are unknown. The aim of this study was to determine the microbiological profile and the prevalence of S. enterica in several low-water-activity foods, including peanuts, pecans, raisins, sun-dried tomatoes, and chocolate sprinkles, purchased in retail establishments in Querétaro, Mexico. Seventy samples of each food item sold in bulk were purchased. Aerobic plate count, molds, yeasts, total coliforms, Escherichia coli, and Staphylococcus aureus were quantified in 10-g samples. The prevalence of S. enterica in 25-g samples was determined. From positive samples, S. enterica isolates (60) were characterized based on their antimicrobial susceptibility to 14 antibiotics, the presence-absence of 13 virulence genes, and serotype. The concentration of aerobic plate count, molds, yeasts, total coliforms, and E. coli ranged from 3.1 to 5.2 log CFU g-1, from 2.0 to 2.4 log CFU g-1, from 2.0 to 3.0 log CFU g-1, from 0.6 to 1.1 log most probable number (MPN) g-1, and from 0.5 to 0.9 log MPN g-1, respectively. S. aureus was not detected in any sample (<10 CFU g-1). The prevalence of S. enterica in chocolate sprinkles, raisins, peanuts, pecans, and sun-dried tomatoes was 26, 29, 31, 40, and 52%, respectively. Most isolates (68.3%) were resistant to at least one antibiotic. Chromosome-associated virulence genes were found in all isolates, and only one strain had sopE, and 98.3% of the isolates were grouped in the same virulotype. Among the isolates, the most frequent serotype was Tennessee (51 of 60). According to the characteristics evaluated, we grouped the isolates into 24 clusters. The elevated prevalence of S. enterica highlights the role of low-water-activity food items sold in bulk at markets as potential vehicles for pathogen transmission. Regardless of the low variability among S. enterica isolates, their characterization could be helpful to elucidate which strains are circulating in these foods for improving epidemiological surveillance.

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