Uticaj skladištenja smrznutog kozjeg mleka, gruša i grude na svojstva sira u salamuri

Abstract

Mleko i proizvodi od mleka malih preživara imaju veliki značaj u ekonomiji određenih zemalja. Bez obzira na značajan porast proizvodnje kozjeg mleka i proizvoda, kravlje mleko je i dalje dominantno na tržištu. Značajan porast proizvodnje kozjeg mleka svakako ukazuje na potrebu da se intenziviraju istraživanja u ovoj oblasti. Dostupnost proizvoda od kozjeg mleka je ograničena u zimskom periodu godine zbog sezonskog karaktera proizvodnje. U praksi su se pojavile razne mogućnosti da se ovo ograničenje prevaziđe. Smrzavanje kozjeg mleka, gruša ili grude je najjednostavniji način da se postigne prisustvo kozjih sireva na tržištu u toku cele godine. Smrzavanje, generalno, može imati negativan uticaj na sve prehrambene proizvode. Tri mehanizma su glavni uzročnici negativnog uticaja: mehanička oštećenja u proizvodu, koja nastaju uvećavanjem kristala leda; denaturacija i agregacija proteina, koja nastaje usled povećanja koncentracije elektrolita tokom smrzavanja; smanjenje sposobnosti reapsorbcije vode nakon odmrzavanja i pojava velike količine izdvojene tečnosti u odmrznutom proizvodu. Ciljevi ove doktorske disertacije su: ispitivanje i analiziranje sezonskih varijacija sastava i svojstava kozjeg mleka u toku različitih perioda laktacije, ispitivanje uticaja smrzavanja kozjeg mleka na reološke parametre sirišne koagulacije i ispitivanje kozjih sireva u salamuri proizvedenih nakon kratkotrajnog (7 dana) i dugotrajnog (60 dana) skladištenja kozjeg mleka, gruša i grude u smrznutom stanju. Navedeni ciljevi su sprovedeni kroz četiri serije ogleda. U prvoj seriji ogleda su ispitivane sezonske varijacije kozjeg mleka tokom četiri laktacije, kao i uticaj klimatskih faktora na fizičko-hemijska svojstva mleka...

Milk and milk products of small ruminants have great importance in the economy of certain countries. Regardles of the significant growth of goat milk production, dominant presence of cow milk products is decreasing the competitivity of goat milk products on the market. Significant growth of goat milk production, certainly imply the need for intensive research in that area. Seasonal production of goat milk is the reason why goat product are not available in the winter. In practice there are several possibilities to overcome this limitation. The freezing of goat milk, curd or precheese is the simpliest way, which would make goat milk products available throughout the entire year. Freezing could have negative impact on food products in general. Three mechanisms are the main causes for this negative impact: mechanical breakdown of product structure, caused by large ice crystals; denaturation and aggregation of protein, which happens due to higher concentration of electrolytes durin freezing; lesser water holding capacity after thawing and occurrence of great amount of exudate. The aim of this doctoral dissertation is: to determine the seasonal variation of physicochemical characteristics of goat milk throughout the lactation, to determine the changes in coagulation properties caused by frozen storage of goat milk, as well to determine the possibility to produce the brined cheese from thawed goat milk, curd and precheese, after short-term (7 days) and long-term (60 days) frozen storage. The aim of this research is achived through four sets of experiments. In the first set of experiments, variations of goat milk characteristics throughout the lactation period are examined, as well as the influence of climatic condition parameters on goat milk characteristics...