Bacterial spores in spices and dried herbs: The risks for processed food

Abstract

Production and world consumption of spices are constantly increasing. Although the antimicrobial properties of some spices are well documented, their use in the agri‐food industry is also responsible for microbial contamination and spoilage. Bacterial spores introduced by spices can withstand different preparation processes, particularly thermal treatments, leading to food alterations during storage. This review brings together data from the literature about the prevalence and concentrations of spore‐forming bacteria in all commercially available spices. The sporeformers found in spices belong mainly to the genera Bacillus and Clostridium. Such contaminations are very common and sometimes reach high levels, as in pepper and turmeric. Bacillus licheniformis and Bacillus cereus are the most frequently detected species. Studying the harvesting, processing, and storage procedures for spices provides elements to explain why high prevalence and concentrations are observed. Spices are mostly produced in developing countries on small farms using traditional production methods. Spices become contaminated by bacterial spores in two main ways: by contact with soil during harvesting or drying, as for pepper, or by cross‐contamination during the water‐cooking step, as for turmeric. From these observations, we propose some recommendations. Different methods that can be used to eliminate bacterial spores from spices are presented indicating their efficiency and the limitations of their use.

Lichenysin Production by Bacillus licheniformis Food Isolates and Toxicity to Human Cells

“…High temperatures in evaporators (operated under vacuum) in combination with a low Aw in the concentrated product stream put selective pressures that favor outgrowth and subsequent spore formation by B. licheniformis (Burgess et al, 2010;Eijlander et al, 2019;Delaunay et al, 2021). Besides dairy products, the organism is also frequently found in spices, dry herbs (e.g., pepper and turmeric) (Mathot et al, 2021), and flours (Rosenkvist and Hansen, 1995;Iurlina et al, 2006). As a common contaminant in food ingredients, the processing conditions will determine whether viable spores are present in the finished product (Postollec et al, 2012).…”

Spices and Seasoning Mixes in European Union—Innovations and Ensuring Safety

“…As shown in Table 2, the share of notifications questioning the microbiological status of herbs and spices is significant. It is postulated that one of the reasons for the low microbiological quality is non-compliance with the principles of good hygienic practice after harvesting the raw material, especially during the drying process of herbs and spices [60,61]. Hence, the solution to this problem is seen in new, innovative methods of preserving the raw material for the production of spices [62].…”

Effect of hot-fill processing at reduced temperatures on tomato sauce microbiological stability in plastic packaging

“…While KR product is a homogenous thick liquid, consisting mainly from tomato paste and water, KGH product contains dried spices in relatively large amounts (Table 1). Since spices are generally considered as a heat stable spore-forming bacteria contaminant [19], it is fair to suggest that KGH TPC results should be less homogenous in comparison with the KR TPC results. Statistical data analysis showed that there is no significant statistical difference (p > 0.05) between product types or filling temperature effectiveness.…”