Background: Lactoferrin is a natural biological active cationic protein that can be used as a yogurt additive to inhibit the growth of foodborne pathogens.Objectives: The present study evaluated the antimicrobial effects of lactoferrin against Bacillus cereus, Enterococcus faecalis, and Candida albicans inoculated in laboratory prepared yogurt at refrigerator temperature.Methods: The pre-warmed skimmed milk was inoculated by commercial starter and then divided into 3 parts, each inoculated by different inoculum and a certain concentration of lactoferrin (0.5% and 1.5%) and incubated at 42oC for 4 h till curd formation. Tenfold serial dilutions were performed for each group and refrigerated at4±1oC  for up to 14 days to be examined every day.Results: The obtained results showed that the treated yogurt samples with lactoferrin had significant reductions in B. cereus, Ent. faecalis, and C. albicans counts than untreated samples (control positive). Generally, yogurt samples treated with 1.5% lactoferrin showed the highest reduction percentages on B. cereus and C. albicans than 0.5% lactoferrin. In addition, B. cereus showed more susceptibility to lactoferrin than Ent. faecalis; the maximum reduction of the inoculated B. cereus was observed on the sixth day of the incubation to be 99.99%. Maximum reduction of the tested C. albicans was observed after the seventh day. Conclusion: The application of lactoferrin showed a potentially significant antimicrobial effect against B. cereus, Ent. faecalis, and C. albicans in refrigerating conditions, so lactoferrin is recommended to be used in yogurt production for safe product manufacturing.

BACKGROUND: The extensive consumption of milk anddairy products makes these foodstuffs targets for potentialadulteration with financial gains for unscrupulous producers.OBJECTIVES: The aim of this study was using PCR assay todetect cow milk in labeled sheep milk, sheep yoghurt, andLighvan cheese (a traditional ripened cheese produced fromsheep's milk). METHODS: The assay utilized primers targetingthe mitochondrial 12s and 16s rRNA gene. In this study, 35samples of sheep milk, 35 samples of sheep yoghurt, and 35samples of Lighvan cheese were purchased from differentsupermarkets in Mashhad city with different batch numbers.RESULTS: The results showed only 21 out of 105 (20%) samplescontained pure sheep milk. Undeclared presence of cow and goatmilk was detected in 33(31.5%) and 68(65%) of the 105 samples,respectively. CONCLUSIONS: It seems the PCR based analyticalmethod is an applicable technique to monitor adulteration indairy products.