AN ATTEMPT TO IMPROVE THE QUALITY . OF DOMIATI CHEESE MADE FROM PASTEURIZED MILK

Abstract

f-orty sa mpl es includ ed 26 of Dom i a ti cheese ''-'Cre randoml y collected from shops bel on ging t o Kafr EI-Sheikh and Tanta citi es and 1 4 sa mpl es of Ta ll aga cheese were coll ect ed from Alexandria governorate. Th ese sa m pl es were t est ed for organ olepti c properti es. Eight Domiati and nine Tall aga cheese, which hod the best scores, were sel ected and a na l ysed for chemica l and mi crobiol ogical properties. 200 colonies included 1 36 from Domiati cheese and 64 from Ta ll aga cheese were isol a t ed a nd i denti fi ed to gen era; they were / ,actobacil!us sp, St reptococcus sp, Micrococclls sp, Hacillus sp and yeast. The percent of these genera were (38.24, 24.26, 1 6.9 1 , 7.35 and 1 3.24 for Domiati cheese while they were 46.88, 28. 1 3, 9.37, 7.8 1 and 7 .81 for Tallaga respectivel y. The main genes were i dent ified to speci es as J>ediococcus pentosuceus, / ,actohacil/us plol1fan1111 , /,acto.G·occus lactis ssp lactis, lvlicmhacterium terregens and h'nte mcoccus hirae. These strain s used wit h or with out yogh urt st a rt er as starters t o improve q ua lity of Domiati and Ta ll aga cheese m ade !'rom heated milk (72°Chnin). The resulta nt cheese stored t o 90 days a nd were ana l ysed for chemical , microbiol ogical a nd orga nolepti c properties. The result s revealed that using Streptococcus

thermophilus (0.5%), / ,actohacillus de/brueckii ssp bulgaricus (0.5%), fJ ediococcus pent osaceus (1 %) a nd / ,actohaci/lus plantarum (1 %) as a start er in manufacture Domiati cheese ( 10% sa lt) achieved the best qualit y an d th e result an t cheese charact eri zed with the hi ghest va lues of acidity, formol number, Schil ovi sh number, t yrosine, trypto pha n and T VF1\ whi le it was the l owest in t h e pH va lues. Thi s cheese al so had the hi gh est counts of t ot a l bacteri a , l actic acids bacteria , proteol ytic bacteria and li pol yti c bacteri a and the l owest in co unt s of yeast a nd mould. The best Tallaga cheese (7% sa lt ) achieved by adding Microbacterium terregens ( 1 %) a n d Urct ococcus lactis ssp lactis (1 %) as sta rter cultures and t he rcsulta11t ch eese ch aract eri zed with the same trend of previous results.