Please use this identifier to cite or link to this item:
Title: Determination of whey-based medium requirements and growth characteristics for the production of yoghurt starter cultures
Authors: Harsa, Hayriye Şebnem
Soydemir, Elçin
Issue Date: 2008
Publisher: Izmir Institute of Technology
Abstract: Yoghurt is an important dairy product which is produced by thermophilic starter cultures including; Streptococcus thermophilus and Lactobacillus bulgaricus. They grow synergistically in milk by acidifying milk, produce specific aroma compounds and lactic acid which impact the quality of the yoghurt. Imported cultures are widely used in dairy industry to stabilize the technological properties which cause a change in our natural flora and flavour. Starters from traditional yoghurts have to be preserved. Under this perspective, the aim of this study was to determine the medium requirements of mixed starter cultures for production of starter bacteria which has been isolated and characterized before.Determination of medium requirements were done in a whey-based media. Since bacteriophages were one of the most important problem in dairy industry, to prevent cultures from phage adsorption, media was treated with different salts which can bind free calcium ions. Salts were examined for cell viability and phage infection effects.From these studies Na2HPO4 + KH2 PO4 with 2% of medium addition was chosen as the most effective. Mineral requirements of the mixed cultures were determined. The best combination; 10, 5, 50 ppm for Fe2+, Mn2+, Mg2+ ions with 0,939 desirability were used for initial mineral content of medium. Fermentation constants for mixed cultures were determined. Pure culture fermentations and mixed culture fermentations were performed. According to results mixed culture inoculations gave higher maximum specific growth rates; 0,9188h-1 and 0,7323h-1 for cocci and bacilli while 0,855h-1 and 0,659h-1 were obtained for cocci and bacilli from single strain fermentations.
Description: Thesis (Master)--İzmir Institute of Technology, Biotechnology and Bioengineering, İzmir, 2008
Includes bibliographical references (leaves: 63-66)
Text in English;Abstract: Turkish and English
xii, 87 leaves
Appears in Collections:Master Degree / Yüksek Lisans Tezleri

Files in This Item:
File Description SizeFormat 
T000772.pdfMasterThesis1.44 MBAdobe PDFThumbnail
Show full item record

CORE Recommender

Page view(s)

checked on Dec 4, 2023


checked on Dec 4, 2023

Google ScholarTM


Items in GCRIS Repository are protected by copyright, with all rights reserved, unless otherwise indicated.