Full Length Research Paper

Investigation of enzyme modified cheese production by two species of Aspergillus

Marzieh Moosavi-Nasab*, Mohsen Radi and Hassan Afshari Jouybari

Department of Food Science and Technology, School of Agriculture, Shiraz University, Shiraz, I.R. Iran.

*Corresponding author. E-mail: marzieh.moosavi-nasab@mail.mcgill.ca. Tel: +98-711-6138227. Fax: +98-711-2287029.

Accepted 5 November, 2009

   Abstract

Enzymatic biotransformation of dairy protein and fat is the basis of most commercial cheese flavour ingredient processes; such products are commonly referred to as enzyme modified cheese (EMC). EMCs have approximately 15 - 30 times the flavor intensity of natural cheese. They are available as pastes or spray-dried powders. Aspergillus oryzae and Aspergillus niger are two kinds of molds that were used in this study for production of enzyme modified cheese. The results showed that A. niger and A. oryzae have lipase enzyme activities of about 43.3 and 10 U/g (U = 1 μmol/min), respectively, while the proteolytic activity was 143 U/g for A. oryzea and 38 U/g for A. niger. The EMC produced using both A. oryzae and A. niger had the best score of flavor and odor after 3 days of storage; however the cheese produced by only A. oryzea had good flavor after this period of time and the cheese treated with A. niger only just had a strong odor. The results of this study showed that the mixture of A. oryzea and A. niger can be used to produce EMC in much shorter ripening period and with better flavor.

Key words: Enzyme modified cheese, Aspergillus niger, Aspergillus oryzae, proteolytic enzyme, lipolytic enzyme.