Full Length Research Paper

Evaluation of the effects of some plant derived essential oils on shelf life extension of Labneh

Habib M Thabet*, Qais A Nogaim, Ali S Qasha, Omar Abdoalaziz and Najib Alnsheme

Food Science and Technology Department, Ibb University, Yemen.

*Corresponding Author E-mail: habeeb30@gmail.com

Accepted January 13, 2014

Abstract

Concentrated yogurt (labneh) was produced by straining cow milk set yogurt in cloth bags. Three plants derived essential oils cinnamon, cumin and mint oils, were added to final concentrations of 0.3, 0.5 and 0.8% each to extend the shelf life of labneh. The chemical, microbiological and organoleptic properties of the labneh stored at 6±1ºC for up to 24 days were determined. Addition of plant derived essential oils affected the pH and total volatile fatty acid values of the prepared labneh, while total solids and fat values were only slightly affected. Total therapeutic bacterial count, Streptococcus thermophilus and Lactobacillus delbrueckii ssp. Bulgaricus in the treated labneh increased and reached a maximum after 8 days of storage where after it decreased until the end of the storage period. Coliform and staphylococcus bacteria were not detected, while yeasts and moulds were detected at insignificant in some treated labneh. Labneh containing 0.3% cinnamon, cumin or mint oils were organoleptically the most acceptable and it had a good body and texture that was similar to the untreated one. From the results of this study, it can be concluded that 0.3% of cinnamon can be used in order to increase the shelf life of labneh for up to 24 days, with higher level of total volatile free fatty acid and therapeutic bacteria counts and low level of total viable, molds and yeast count.

Keywords: Labneh, cinnamon oil, shelf life, microbiological properties.