Monitoring Some Physicochemical and Bacteriological Parameters and Sensory Analysis of Juniperus phoenicea L. Leaves-supplemented Goat Milk: A South-western Algerian Traditional Flavored and Fermented Product

Abstract

Background: Traditional dairy products are widely consumed by the Mediterranean and sub-Saharan countries; they are traditionally prepared by rural women. This work focuses on understanding the traditional practices and enhancing the same by studying the physicochemical, bacteriological and organoleptic properties of fermented raw goat milk, supplemented by the leaves of the Phenician juniper species. Methods: Monitoring of the juniper leaves-supplemented goat milk sample against a control one (without juniper leaves) was conducted. Three physicochemical parameters were tracked: pH, titratable acidity and temperature. However, the bacteriological analysis featured the following parameters: the total aerobic mesophilic flora, thermotolerant coliforms, coagulase-positive Staphylococci, Pathogenic bacteria namely Salmonella spp and Listeria monocytogenes, while the sensory test was based on the descriptive and hedonic analyses. Result: The obtained physicochemical results showed a significant change in the pH and the titratable acidity parameters of the test sample compared to the control sample. This change was marked by an increase in the total aerobic mesophilic flora load (due to the fermentation phenomenon) and a decrease in the thermotolerant coliforms and the coagulase-positive Staphylococci loads for the test sample compared to the control test. A total absence of Salmonella spp and L. monocytogenes as pathogenic microorganisms was also notified for both samples. The qualitative phytochemical screening carried out on the J. phoenicea L leaves showed the presence of several compounds known as constituents having an antimicrobial effect. On the sensory level, the control sample was characterized by a milky and acidic taste, while the herbaceous taste due to the components of the Phenician juniper leaves characterizing the test sample gave it a lower score on the established rating scale. A vision to maintain this type of artisanal practice, traditional knowledge and preserve this important indigenous wealth become necessary which contributes to improving the hygienic, sensory quality and shelf-life of the fermented goat milk.