Bacterial contamination during slaughtering process is a safety problem and concern for shelf life in meat production. We compare two different slaughter lines, sheep and cattle samples from Iranian slaughterhouse using PCR‐denaturing gradient gel electrophoresis (DGGE) analysis for evaluation the sources of bacterial contaminations. Bacterial diversity was significantly different between and within cattle and sheep slaughter lines. Samples are contaminated most frequently with Salmonella enterica (28% and 30%), Enterococcus fecalis (18% and 20%), Escherichia coli (13% and 14%) and Pseudomonas fluorescens (8% and 6%), either on equipment surfaces after general cleaning and sanitizing treatments (56%). Biodiversity of carcasses samples is increased during skinning and evisceration process and may indicate similar sources of contamination from hides and rectums of the animal to carcasses and environment. Practical Applications 16S rDNA based denaturing gradient gel electrophoresis‐PCR is a method for assessment of microbial diversity, source of contaminations and changes of microbial population in slaughterhouses.

Forty-four samples of traditional Doogh and yoghurt were collected from 13 regions of 4 provinces in west of Iran (13 area) and analyzed using molecular methods including PCR, denaturing gradient gel electrophoresis (DGGE) of 16S rDNA, and sequencing. Moreover, collected samples as well as samples from industrially Doogh were analyzed with quantitative real-time PCR (RT-PCR). Analyzed 16S rRNA gene sequences of Doogh samples could be allocated to the presence of Lactobacillus spp. The typical yoghurt starter culture bacteria included four different Lactobacillus species with possible probiotic properties, L. acidophilus, L. helveticus, L. kefiranofaciens, and L. amylovorus. DGGE of traditional Doogh and yoghurt and RT-PCR of traditional Doogh and yoghurt and also industrial Doogh samples demonstrated that traditional Doogh and yoghurt show a higher abundance of total bacteria and lactobacilli and a higher bacterial diversity, respectively. Considering diversity and higher probiotic bacteria content in traditional Doogh, consumers’ healthiness in tribes and villages could be promoted with these indigenous products.

Using a cut-off score of 1.7 was sufficient for accurate identification of species. MALDI-TOF MS identification scores for spp. decreased with longer incubation time. species predominantly were isolated from carcasses after skinning and evisceration steps in the slaughterhouse. MALDI-TOF MS could be an accurate way to identify species. Moreover, continuous improvement of the database and MALDI-TOF MS instrument enhance its performance in food control laboratories.

As a typical and ancient Iranian drink based on fermented milk, Doogh is normally produced from yogurt, drinking water, salt, and flavoring agents on both traditional and industri.al scales. Referring to the large production and consumption of Doogh in many countries and the adoption of its Codex standard (2018), considering its technological and health (nutritional and safety) aspects is of special importance. There is versatility and variety in ingredients, production methods, and packaging of Doogh that can affect the physicochemical (i.e., physical, chemical, and rheological) sensory, nutritional, and safety characteristics of the product. On the other hand, its shelf life is regularly an extended shelf life (>2 months) which can be challenging from a technological point of view. This article comprehensively reviews the technological and health aspects of industrial Doogh.