Accelerated Ripening of UF Feta-Cheese by Using Freeze-Shocked Culture of Lactobacillus helveticus or Barley Extract

Document Type : Original Article

Author

Food Science Department, Faculty of Agriculture, Zagazig University, B.P. 44111, 44511 Zagazig, Egypt.

Abstract

The effect of using freeze-dried shocked culture or barley extract in the manufacture of UF Feta-cheese made from ultrafiltreted retentate containing  different levels of either barley extract at ratio of 0.05% and 0.1% respectively, or freeze-shocked culture of L. delhrueckii subsp. helveticus at ratio of 1% and 2% respectively, on ripening process and quality was studied. Addition of barley-extract did not significantly affect the moisture, fat, total nitrogen or salt content of the resultant cheeses, but significantly increased its acidity, while the incorporation of the freeze-shocked starter cultures had no significant effects on the gross chemical composition of cheeses. These additives significantly increased the formation of soluble nitrogenous compound, free volatile fatty acids, flavour intensity and improved the body and texture characteristics of UF Feta cheese. Especially the cheese made with 0.1% barley extract and 0.2% of freeze-shocked starter cultureof L. delhrueckii subsp. helveticus which resulted  in higher quality after 15 - 30 days of ripening than the other treatments. Microbial counts during preservation of both types of cheese increased steadily and reached similar levels, with the exception of Coliform-bacteria. All types of cheese produced with barley extract or freeze-shocked culture as a starter were approved and accepted by the panel during the preliminary sensory evaluation compared to commercial feta- cheese. 

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