الفهرس 
Starter cultures in cheese makingOnly 14 pages are availabe for public view
 |  | from | 107 |  |  |
| | | from | 107 | | |
Abstract
The main objective of this study was to evaluate the effect of different
heat treatments (thermization and pasteurization), natural whey culture and
black cumin oil as a natural preservative on the physicochemical, textural,
free amino acids, organic acids, volatile compounds, microbiological, and
sensorial properties of Edam cheese during the ripening period. The study
consists of three main parts.
The first part aimed to evaluate the effect of raw, thermized (65°C/15sec),
pasteurized (72°C/15sec) milk on the physicochemical, free fatty acids,
volatile compound, textural, microbiological and sensory characteristics of
Edam cheese ripened for 45days. Heat treatment had a significant effect on
the physiochemical, proteolysis, volatile compounds and free fatty acids of
experimental Edam cheese.
The second part aimed to investigate the effect of different levels of
Natural Whey Culture (NWC) (2, 3 and 4%) on the quality of Edam cheese
made from heated milk (72 oC/15 sec.). The results showed that the titratable
acidity, moisture, ash, WSN/TN, NPN/TN%, free amino acids and organic
acids were significantly higher while protein and fat contents were lower in
experimental cheese. Edam cheese with NWC showed higher values in
textural evaluation. Overall, Edam cheese made with 4% NWC was higher in
quality characteristics than that with starter culture and was similar to control
cheese made of raw milk.
The third part of this study aimed to evaluate the physicochemical,
microbiological and sensorial characteristics of Edam cheese produced by
three different concentrations of black cumin oil (0.2, 0.4 and 0.6%).
Significant differences in physicochemical and ripening indices between
treated cheese samples and control cheese were observed in all examined
parameters. Incorporation of black cumin oil in Edam cheese reduced the
total viable counts, Yeast & Molds at the end of ripening period and inhibited
the growth of coliform groups. Panelists accepted the taste of Edam cheese
with high concentration of black cumin oil (0.6%) with no complains on
appearance and smell, while they favored the texture of Edam cheese with
higher percentage of oil.
Keywords: Edam cheese, heat treatments, natural whey culture, starter
culture, Black cumin oil.