Primena ultrafiltracije genetski modifikovanog himozina i proteolitičkih enzima u tehnološkom procesu proizvodnje kačkavalja

Abstract

Apstrakt je obrađen tehnologijama za optičko prepoznavanje teksta (OCR). Imajući u vidu naučni i praktičan značaj i nedostatak podataka o aplikaciji ultrafiltracije (UF), alternativnih koagulišućih enzima, posebno genetskog himozina, kao i enzima za akceleraciju zrenja u tehnologiji tvrdih sireva, za predmetna istraživanja je odabran Kačkavalj, popularni sir mediteranskog porekla. U okviru istraživanja je u industrijskim uslovima izvršena proizvodnja KačkavaIja iz retentata dobijenog nakon ultrafiltracije mleka po LCR (Low Concentrated Retentate) postupku (UF Kačkavalj). Ispitan je uticaj koagulanasa mikrobiološkog porekla (M. miehei proteaza, Rennilase) i genetski modifikovanog himozina (Maxiren) na kvalitet finalnog sira i upoređen sa klasičnim analozima (kontrolni Kačkavalj). Istražena je mogućnost skraćenja perioda zrenja obe varijante Kačkavalja (klasični i UF) dodatkom „koktela" enzima za ubrzanje zrenja proteolitičkog (Accelase) i lipolitičkog (Paletase) dejstva. Na osnovu rezultata dobijenih ispitivanjem fizičko-hemijskog sastava, mikro-strukture i senzornog kvaliteta varijanti konvencionalnog Kačkavalja i UF analoga tokom jednogodišnjeg zrenja, utvrđeno je da se dejstvo rekombinovanog himozina (Maxiren-a) i standardnog himozina signifikantno ne razlikuje, potvrđujući dosadašnja saznanja da je genetski modifikovani himozin potpuno kompetentan proteolitički agens za koagulaciju mleka u procesu proizvodnje sira. Kod konvencionalnog i UF Kačkavalja proizvedenog primenom mikrobiološke M. miehei proteaze (Rennilase) ustanovljena je najniža koncentracija mlečne masti u suvoj materiji tokom celokupnog ispitivanog perioda, što se sa ekonomskog aspekta negativno odražava na kvalitet sira. Sve varijante UF Kačkavalja se tokom zrenja razlikuju od klasičnih analoga po hemijskom sastavu (sadržaj mlečne masti, ukupnog N, NPN, RN itd.), profilu proteolitičke degradacije as- i p-kazeina, modelu distribucije identifikovanih is- parljivih komponenata arome, reološkim i senzornim karakteristikama i mikrostrukturi usled usporenog intenziteta promena proteinske i lipidne faze UF sireva tokom zrenja. Efekat ubrzanja zrenja Kačkavalja tretiranog „koktelom" enzima lipolitičkog i proteolitičkog dejstva je izraženiji kod konvencionalnog nego UF uzorka.

Abstract was processed by technology for Optical character recognition (OCR). The scientific and practical significance and the lack of literature data on the application of ultrafiltration (UF), as well as the alternative coagulating enzymes, particularly genetic chymosin, and enzymes for accelerated ripening in hard cheese technology were essential reasons for choosing this field for research. The object of presented investigations was Kashkaval, the popular mediterranean hard variety cheese. In the scope of these investigations, Kashkaval was industrially produced using retentate obtained by UF of milk according to LCR (Low Concentrated Retentate) procedure (UF Kashkaval). Effects of clotting enzymes of microbiological origine (M. miehei protease, Rennilase) and of genetically modified chymosin (Maxiren) on the quality of final cheese product was also investigated and compared to conventional analogues (control Kashkaval). The possibility for reduced ripening period of both Kashkaval types (traditional and UF) was investigated by the addition of „coctail" of enzymes which accelerate the cheese ripening, involving the proteolytic (Accelase) and lypolytic (Palatase) activity. According to the results obtained by the investigations of physico-chemical composition, microstructure and sensory quality of conventional Kashkaval and UF analogues in the course of one-year ripening period, it was possible to derive the conclusion that the effects of recombined chymosin (Maxiren) and the standard one are insignificantly different, confirming thus the former knowledge that the genetically modified chymosin is an adequate proteolytic agent for milk coagulation in cheese production. The lowest level of milk fat in dry matter over the whole investigated period was established both for conventional and UF Kashkaval samples produced by the application of M. miehei protease (Rennilase), whereas from the economic standpoint this indicated negative effects on cheese quality. All UF Kashkaval varieties differ during the period of ripening from conventional analogues concerning chemical composition (content of milk fat, total N, NPN, RN etc.), profile of proteolytic degradation of as- and p-casein, distribution of identified volatile aroma components, rheological and sensory characteristics as well as the microstructure due to the slower intensity of changes in protein and lipid phases of UF cheese samples during ripening. The „cocktail" of proteolytic and lipolytic enzymes showed more pronounced effects on the Kashkaval ripening in the case of conventionally produced cheese sample.