Title |
Lietuvos senojo genotipo juodmargių galvijų pieno baltymų sudėtis, technologinės savybės ir virškinamumas / |
Translation of Title |
Composition, technological properties and digestibility of milk proteins from native breed - Lithuanian black and white cows. |
Authors |
Kubiliutė, Marija |
Full Text |
|
Pages |
92 |
Keywords [eng] |
native cattle breed ; casein ; coagulation ; digestibility ; bioactive peptides |
Abstract [eng] |
The aim of the master project was to study the composition of proteins and technological properties of raw milk from an individual old genotype Lithuanian Black and White cows and evaluate the biological value of the products manufactured from the analyzed milk. Monthly milk samples were obtained from 20 old genotype Lithuanian Black and White cows (native cattle breed). It is the first study of the fractions of milk proteins of Lithuanian cattle breed. The interrelationships in physico-chemical properties are determined in this project. The digestibility and biologic value of milk proteins was evaluated by degree of hydrolysis, determined by fluorescamin assay, and profile of peptides derived from caseins during gastro- intestinal digestion in vitro. Protein, calcium levels, casein concentration and rennet coagulation time demonstrated seasonal trends, while other properties displayed considerable variations, which apparently unrelated to season. Some significant interrelations in physico-chemical properties were found: acid gel strength is influenced by κ– ir β–caseins. Old genotype Lithuanian Black and White cows milk can be characterized as having good coagulation properties. We found that among the 219 milk samples from 20 individual cows only 2 % were noncoagulating (did not formed rennet/acid induced gel through 60 min.). Lithuanian native cattle breed milk is suitable for cheese and fermented milk products manufacture. Peptides profile analysis has showed that acid and rennet gels produced from old genotype Lithuanian Black and White cows milk and from Holstein cows milk are great source of bioactive peptides (mostly ACE inhibitors). No evident difference between milk gels made from different breeds caws milk was observed, while the type of curd has impact: acid gel degrade faster than rennet gel. Peptides formation starts with technological process (different profiles of peptides derived from different casein fractions depends on used coagulation agent) and changes during digestion in simulated gastroduodenal digestion process in vitro. |
Dissertation Institution |
Kauno technologijos universitetas. |
Type |
Master thesis |
Language |
Lithuanian |
Publication date |
2017 |