magistrsko delo
Ida Simončič (Author), Lea Demšar (Reviewer), Andreja Čanžek Majhenič (Mentor)

Abstract

Na slovenskem trgu je vedno večje povpraševanje po izdelkih iz senenega mleka. Zato se je največja slovenska mlekarna odločila za proizvodnjo sira iz surovega senenega mleka. Namen magistrske naloge je bil določiti mikrobiološko in sestavo osnovnih hranilnih snovi surovega senenega mleka ter njegovo uporabnost kot surovine za izdelavo sira. Ko smo določili mikrobiološko in kemijsko kakovost surovega senenega mleka, smo ga uporabili za izdelavo poltrdega tipa sira z uporabo komercialne starterske kulture. Dva dni kasneje smo poskus ponovili z novo serijo surovega senenega mleka, le da smo tokrat izdelali poltrd tip sira s kombinacijo starterske in zaščitne kulture, ki proizvaja nizin. Enak protokol sirjenja smo izvedli vsak mesec v trajanju 12ih mesecev, od junija 2018 do maja 2019, v mlekarni Celeia v Arji vasi. Poleg analiz surovega senenega mleka smo opravili tudi mikrobiološke, kemijske in senzorične analize sirov. Mikrobiološko kakovost sirov smo spremljali v skladu s smernicami za mikrobiološko varnost sirov iz surovega mleka z uporabo klasičnih mikrobioloških tehnik cepljenja na trda gojišča. Ker smo sirili skozi celo leto, smo tako spremljali tudi morebitni vpliv letnega časa na mikrobiološko kakovost surovega mleka in sirov. Rezultati so pokazali, da so tako vse serije surovega senenega mleko kot vsi siri (starterska kultura, starterska + zaščitna kultura) skozi vse leto izpolnjevali kriterije mikrobiološke kakovosti, podane v mikrobioloških smernicah za surovo mleko in sire iz surovega mleka. Analizo sestave osnovnih hranljivih snovi sirov smo izvedli po znanih in standardiziranih metodah. Izvedli smo tudi senzorično analizo sirov z 20-točkovnim sistemom. Ocene sirov (skrajšan analitičen test) so variirale od 18 do 12 točk.

Keywords

seneno mleko;surovo mleko;siri iz surovega senenega mleka;zaščitna kultura;mikrobiota sira;primerjava sirov;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [I. Simončič]
UDC: 637.33:637.12:579.67
COBISS: 74463747 Link will open in a new window
Views: 248
Downloads: 42
Average score: 0 (0 votes)
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Other data

Secondary language: English
Secondary title: Use of a protective starter culture for cheese production from raw hay milk
Secondary abstract: Due to increasing interest for dairy products made from hay milk on the Slovenian market, the largest Slovenian dairy plant has decided to manufacture cheese from raw hay milk. The main goal of the master's thesis was to determine the microbiological and chemical quality of raw hay milk and its applicability as raw material for cheese production. After determining the microbiological and chemical quality of raw hay milk, same batch of milk was used for production of semi-hard type of cheese, using a commercial starter culture. Two days later, the experiment was repeated, but with a new batch of raw hay milk, and this time a semi-hard type of cheese was produced with a combination of starter and protective culture that produces nisin. The same cheesemaking protocol was accomplished every month and lasted 12 months, from June 2018 to May 2019, at the Celeia Dairy plant in Arja vas. Besides analysing raw hay milk, microbiological, chemical, and sensorial analyses of cheeses were performed as well. Microbiological quality of cheese was monitored in accordance with the guidelines for microbiological safety of raw milk cheeses with classical pour-plate microbiological techniques. As cheese-making was carried out throughout the year, the possible impact of the seasons on the microbiological quality of raw milk and cheeses was monitored as well. Results revealed that raw hay milk and both cheeses (starter culture, starter + protective culture) complied with the microbiological guidelines throughout the year. Chemical analyses of cheeses were performed according to known standardised methods. We also performed a sensory analysis of cheeses with a 20-point system. Sensorial evaluation (a short analysis test) of cheesees ranged from 18 to 12 points.
Secondary keywords: hay milk;cheeses made from raw hay milk;protective culture;cheese microbiota;comparison of cheeses;
Type (COBISS): Master's thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo
Pages: X, 45 f., [2] f. pril.
ID: 13292535