Use of Quantitative Descriptive Analysis and Principal Component Analysis for the Sensory Assessment and Analysis of Physicochemical Characteristics and Quality Stability of Kefir Made from Mahabadi and Alpine Hybrid Goat Milk

Background and Objectives: General acceptance of the goat milk products in Iran addresses needs of hybridization of this livestock with increasing characteristics of milk production and adaptation to various climates of Iran. The objectives of this study were to develop a kefir drink from Mahabadi and Alpine Hybrid (F1) and investigate its quality characteristics and sensory stability during production and two weeks of storage. Materials and Methods: Three kefir prototypes were made from Mahabadi and Alpine Hybrid (F1) goat milk with inoculation levels of 1, 2 and 3% w/v. The prototypes were stored at 4 °C and subjected to chemical, microbiological and sensory assays on Days 1, 7 and 14 after production. Quantitative descriptive and principal component analyses were used for data. Results: Kefir prototypes differed significantly in pH, acidity, lactose, ethanol, CO2, number of lactic acid bacteria, odor and flavor of milk, sour odor, sourness, astringency and acceptance; however, quantities of proximate analysis and other sensory characteristics such as goat odor and the flavor between the prototypes were similar. With increasing inoculation proportion and post-production days, pH and lactose decreased within kefir prototypes; however, quantity of acidity, ethanol, CO2, number of lactic acid bacteria, sourness odor, astringency and general acceptance of the prototypes increased. Conclusion: Results showed that three kefir prototypes made from Mahabadi and Alpine Hybrid (F1) goat milk with inoculation levels of 1, 2 and 3% w/v included good sensory quality. Any of the three levels of inoculation could be addressed as the optimal level for producing the final product based on economic and technical characteristics.