Fate of Salmonella during sesame seeds roasting and storage of tahini

• Published in: International journal of food microbiology Vol. 163; no. 2-3; pp. 214 - 217
• Main Authors: Torlak, Emrah, Sert, Durmuş, Serin, Pınar
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.05.2013; Elsevier
• Subjects: Biological and medical sciences; Colony Count, Microbial; Food Handling - methods; Food Handling - standards; Food industries; Food Microbiology; Fundamental and applied biological sciences. Psychology; Hot Temperature; Microbial Viability; Roasting; Salmonella; Salmonella - growth & development; Salmonella - physiology; Salmonella Food Poisoning - prevention & control; Seeds - microbiology; Sesame seeds; Sesamum; Sesamum - microbiology; Survival; Tahini; Roasting; Salmonella; Sesame seeds; Survival; Tahini; Sesame seed; Oilseed; Storage; Warehousing; Food preservation; Bacteria; Enterobacteriaceae
• ISSN: 0168-1605; 1879-3460
• DOI: 10.1016/j.ijfoodmicro.2013.03.010

Tahini is usually consumed without further heat treatment, and roasting of sesame seeds is the only Salmonella inactivation step in its traditional production process. This study examined the efficiency of the roasting process in the elimination of Salmonella from sesame seeds and the survival of Salmonella in tahini during storage. Sesame seed and tahini samples were inoculated with a cocktail of three serotypes of Salmonella (S. Typhimurium, S. Newport and S. Montevideo). Complete inactivation of Salmonella in sesame seeds, inoculated with 5.9log cfu/g, was achieved by roasting at 110°C for 60min, 130°C for 50min, or 150°C for 30min. Salmonella levels in tahini (aw=0.17) inoculated with 5.6log cfu/g and stored for 16weeks at 22 or 4°C decreased by 4.5 and 3.3 log, respectively. Results of this study demonstrated that the standard roasting process is sufficient to inactivate Salmonella in sesame seeds and low water activity of tahini prevents microbial growth, but its composition allows Salmonella to survive for at least 16weeks. Therefore, prevention of cross-contamination after roasting is crucial for food safety. •Fate of Salmonella during sesame seeds roasting and storage of tahini was evaluated.•Roasting at 110-150°C for 60 min was enough to inactivate Salmonella in sesame seeds.•Salmonella survived in tahini for at least 16weeks.