Determination of microbiological, sensory, physical and chemical properties of yoghurt enriched with pumpkin seeds

In this research microbiological, sensory, physical and chemical properties of pumpkin seed (%1.5, %3, %4.5) and non-pumpkin seed (control) yoghurt samples were determined on the 1., 7., 14. and 21. days. The pH, dry, ash, protein, fat, acidity, serum separation, viscosity, color, sensory analysis and microbiological analysis results of yoghurt samples were compared with the control sample without pumpkin seeds. The addition of pumpkin seeds significantly increases the pH value, acidity, ash, fat, protein and viscosity of yoghurt samples (p<0.01); and significantly decreases serum separation values (p<0.01). The amount of pumpkin seed increases and the samples dry during the preservation period, pH, fat, protein and viscosity values decreased significantly (p<0.01); acidity, ash and serum separation values increased significantly (p<0.01). According to the results of color values analysis, the addition of pumpkin seeds significantly decreases the L (brightness) and a*(green) values of the samples (p<0.01), b*(jaundice) significantly increases the value (p<0.01). L (brightness) b* (jaundice) significantly decreased the values of the samples during storage a* (foliage) significantly changed the value of the ups and downs significantly (p<0.01). Microbiological analysis revealed that the addition of pumpkin seeds significantly reduced Lactobacillus bulgaricus and Streptococcus thermophilus numbers (p<0.01). L. bulgaricus during storage the number of decreased significantly, S. thermophilus the number of is 7. it was found that there was a significant increase up to the day and then a decrease trend (p<0.01). It was determined that the increase in the amount of pumpkin seeds and the increase in the number of yeast-moulds were observed and this increase continued during the storage period. According to sensory analysis, the highest overall acceptability score was determined in yogurt sample with %4.5 pumpkin seeds. When all analyses were evaluated collectively, it was concluded that the addition of %4.5 pumpkin seeds can increase the quality and textural properties of yoghurt and that a new functional product can be produced with further studies.