H. M. Arslan Amin (2009-VA-486)
Quality Enhancement Of Buffalo Milk Yoghurt By Using Glutathione Treated Transglutaminase Enzyme As A Gelatin Replacer - 2016. - 70p.;
Yoghurt is a fermented dairy product and intensively used in all over the world. It is very popular in sub-continental region due to its high consumption as compare to other regions of the world. Fermentation of milk is carried out by mixture of lactic acid bacteria. Synergistic effect of Streptococcus thermophillus and Lactobacillus delbrueckii ssp. bulgaricus is a key factor which determines the rate of fermentation process and quality of yoghurt. In traditionally made set yoghurt, protein gel is stabilized by weak non covalent interactions (hydrogen bonding, electrostatic interactions and hydrophobic bonds). Addition of Transglutaminase enzyme (TGase) can provide opportunities to increase covalent bonding and cohesiveness which ultimately enhances the gel consistency with reduction of syneresis.
For the production of yogurt standardized buffalo milk of 5.5% fat and 9.5% SNF contents were used. Milk was pasteurized for 15 seconds at 72°C to kill the pathogenic bacteria and cooled to 42°C. After cooling the Glutathione treated Transglutaminase enzyme was added in the milk with different concentrations (1.25g/250ml, 2.50g/250ml, 3.75g/250ml and 5g/250ml) and cooled to 42°C. While the control sample was prepared without the addition of Glutathione treated Transglutaminase enzyme. After that each treatment was inoculated with standard yoghurt culture (Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus) at the rate of 2% at 42°C for 3-4 hours and each sample was stored at 4°C in a refrigerator for 28 days. The physico-chemical parameters such as pH, acidity %, fat %, protein % and syneresis % were observed weekly till 4 weeks.
The quality comparison of prepared yoghurt was carried out by using Two Way Analysis of Variance (ANOVA) technique under Completely Randomized Design. Significant means were compared using Duncan’s Multiple Range (DMR) Test with the help of SAS 9.1.
Results showed variations in pH, acidity %, fat%, protein %, snf% and syneresis % values due to the production of Yoghurt with Glutathione treated Transglutaminase in different percentages. pH in different treatments decreased from 4.71 – 4.61. Acidity % during storage period increased from 0.40 % to 0.43 %. Fat % also showed some variation during storage period decreased from 5.37% – 4.49 %. Protein % in different treatments increased from 4.10 % – 4.27 % and SNF % in different treatments increased from 9.81% – 10.00 % . Syneresis % in different treatments decreased from 5.17% - 3.48 %. Sensory evaluation was carried out by a panel of 06 semi trained people, using criteria of appearance, taste, color, flavor and whole acceptability on a 9 points hedonic scale. Color, taste, aroma, acidity, appearance and overall acceptability showed non-significant results as compared with controlled sample after 28 days.
Results of the present study showed that yoghurt prepared with Glutathione treated Transglutaminase enzyme reduced the syneresis and enhanced the nutritional aspects of yoghurt.
Department of Dairy Technology
2483-T
Quality Enhancement Of Buffalo Milk Yoghurt By Using Glutathione Treated Transglutaminase Enzyme As A Gelatin Replacer - 2016. - 70p.;
Yoghurt is a fermented dairy product and intensively used in all over the world. It is very popular in sub-continental region due to its high consumption as compare to other regions of the world. Fermentation of milk is carried out by mixture of lactic acid bacteria. Synergistic effect of Streptococcus thermophillus and Lactobacillus delbrueckii ssp. bulgaricus is a key factor which determines the rate of fermentation process and quality of yoghurt. In traditionally made set yoghurt, protein gel is stabilized by weak non covalent interactions (hydrogen bonding, electrostatic interactions and hydrophobic bonds). Addition of Transglutaminase enzyme (TGase) can provide opportunities to increase covalent bonding and cohesiveness which ultimately enhances the gel consistency with reduction of syneresis.
For the production of yogurt standardized buffalo milk of 5.5% fat and 9.5% SNF contents were used. Milk was pasteurized for 15 seconds at 72°C to kill the pathogenic bacteria and cooled to 42°C. After cooling the Glutathione treated Transglutaminase enzyme was added in the milk with different concentrations (1.25g/250ml, 2.50g/250ml, 3.75g/250ml and 5g/250ml) and cooled to 42°C. While the control sample was prepared without the addition of Glutathione treated Transglutaminase enzyme. After that each treatment was inoculated with standard yoghurt culture (Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus) at the rate of 2% at 42°C for 3-4 hours and each sample was stored at 4°C in a refrigerator for 28 days. The physico-chemical parameters such as pH, acidity %, fat %, protein % and syneresis % were observed weekly till 4 weeks.
The quality comparison of prepared yoghurt was carried out by using Two Way Analysis of Variance (ANOVA) technique under Completely Randomized Design. Significant means were compared using Duncan’s Multiple Range (DMR) Test with the help of SAS 9.1.
Results showed variations in pH, acidity %, fat%, protein %, snf% and syneresis % values due to the production of Yoghurt with Glutathione treated Transglutaminase in different percentages. pH in different treatments decreased from 4.71 – 4.61. Acidity % during storage period increased from 0.40 % to 0.43 %. Fat % also showed some variation during storage period decreased from 5.37% – 4.49 %. Protein % in different treatments increased from 4.10 % – 4.27 % and SNF % in different treatments increased from 9.81% – 10.00 % . Syneresis % in different treatments decreased from 5.17% - 3.48 %. Sensory evaluation was carried out by a panel of 06 semi trained people, using criteria of appearance, taste, color, flavor and whole acceptability on a 9 points hedonic scale. Color, taste, aroma, acidity, appearance and overall acceptability showed non-significant results as compared with controlled sample after 28 days.
Results of the present study showed that yoghurt prepared with Glutathione treated Transglutaminase enzyme reduced the syneresis and enhanced the nutritional aspects of yoghurt.
Department of Dairy Technology
2483-T