Naslov
Characterization and selection of Lactococcus lactis strains from ewe's milk as potential cheese starter culture

Autori
Pajač, Lucija ; Kiš, Marta ; Kazazić, Snježana ; Zdolec, Nevijo

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of Abstract of the 9th International Congress Veterinary Science and Profession / Brkljača Bottegaro, Nika ; Lukač, Maja ; Zdolec, Nevijo ; Vrbanac, Zoran - Zagreb, 2021, 57-57

ISBN
978-953-8006-36-4

Skup
9th International Congress: Veterinary Science and Profession

Mjesto i datum
Zagreb, Hrvatska, 09.10.2021

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Lactococcus lactis ; ewe's milk ; cheese ; starter culture

Sažetak
Raw milk and traditional dairy products are a source of indigenous strains that have great potential for developing and protecting the recognizable sensory quality of local products. Therefore, the aim of this study was to select lactic acid bacteria strains from Pag raw sheep milk and test their technological and biochemical properties under controlled laboratory conditions. The lactic acid bacteria were isolated from sheep milk using MRS and M17 agar and identified by MALDI-TOF mass spectrometry. Out of the 18 identified strains of Lactococcus lactis subsp. lactis, five (M1-M5) were selected for further characterization. Strains were tested for growth in M17 broth at 10 °C, 30 °C, and 45 °C, at pH values of 6.5, 5.5, 4.5, 3.5, and 2.5, and at salt concentrations of 4.5%, 5.5%, and 6.5%. Cell growth was measured by plating on M17 agar and absorbance (OD600). The acidification capacity of the strains was measured in MRS broth using the titration method. In addition, the lipolytic, proteolytic and antimicrobial activities of the isolates were tested, as well as their ability to produce gasses. Data analysis was performed using Statistica 13.5 software. The significance of differences between groups was evaluated using analysis of variance at the 0.05 level. The results show that none of the isolates produced gas by glucose degradation, all of them show the same proteolytic, lipolytic and antimicrobial activity and have a high level of acidifying ability. At different temperature conditions, pH values and salt concentrations, all isolates grew but with significant differences (p<0.05), with Lc. lactis subsp. lactis M1 showing the best technological performance. It can be concluded that all the selected strains of Lc. lactis subsp. lactis can be used as potential cheese starter cultures. Considering the above differences, the final selection of strains should be based on the technological process and organoleptic characteristics of the desired cheese variety.

Izvorni jezik
Engleski

Znanstvena područja
Veterinarska medicina

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