1- Assistant Professor, Department of Food Industry, Faculty of Agriculture, Ilam University, Ilam, Iran , m.hosseini@ilam.ac.ir
2- Master of Veterinary Science, Ilam University, Ilam, Iran
Abstract: (1506 Views)
In this study, the aqueous-alcoholic extract of thyme in yogurt was used with the aim of increasing the acceptability of consumption and improving its quality characteristics. Due to the better quality of local BkezIlam yogurt, inulin was added to its formulation in concentrations (0.05%, 0.075%, 0.1% and 0.125%). The produced samples were evaluated from the point of view of quality tests and compared with the control sample (yogurt without inulin and thyme). For this purpose, thyme extract in concentrations (2%, 4%, 6% and 8%) was added to the milk used in the preparation of yogurt.PH, acidity, hydration, water holding capacity, acetaldehyde, viscosity and total bacterial count were evaluated at 1, 6, 11 and 21 days after production.The results showed that in the experimental treatments, the results of pH, acidity, synersis, water holding capacity, acetaldehyde content, viscosity and total bacterial count during storage were significantly different from each other (P <0.05). However, there was no significant difference in organoleptic properties except odor and other properties as taste, consistency, color, mouthfeel and general acceptance is not significant, which were evaluated by 10 trained judges (P <0.05). According to the results of this study, yogurt sample contains 0.125% inulin and 2% thyme has the lowest pH and increased acidity and water holding capacity for 16 days. Also, the sample containing 0.15 inulin obtained the lowest percentage of synersis and the highest number of bacteria after 21 days. In terms of viscosity and acetaldehyde, samples containing 0.125% inulin and 6% thyme had the highest values at 7 and 16 days, respectively (P <0.05). The experimental results showed that during storage, with decreasing pH in the treatments, dry matter increases and fat decreases in the samples and the percentage of synersis decreases, which increases the viscosity.
Article Type:
Original Research |
Subject:
Food quality control Received: 2022/02/24 | Accepted: 2022/05/18 | Published: 2022/08/1