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Due to public distrust of industrially produced goods and a preference for traditional health products, there's a growing demand for traditional camel-derived food products. Valuable fermented products from camel milk, such as Chal, possess not only desirable nutritional properties but also health-benefiting attributes. Chal is traditionally produced in Golestan Province and marketed in local areas. However, its shelf life under refrigerated conditions remains a subject of debate. Given that this product is prepared from unpasteurized camel milk, there's a high probability of contamination by spoilage-producing bacteria, making the monitoring of its hygienic conditions during storage of paramount importance. Therefore, this study monitored the qualitative characteristics of traditional Chal and hygienically produced Chal over a 28-day refrigerated storage period, evaluating their microbial, physicochemical, nutritional, and sensory properties. In traditional Chal, due to the presence of an uncontrolled microbial flora including molds, yeasts, and bacteria, the levels of proteolysis, lipolysis, peroxide value, and thiobarbituric acid significantly increased (p<0.05), indicating a reduction in quality during storage. Conversely, in hygienically produced Chal, microbial control by lactic acid bacteria led to reduced degradation of proteins and fats, improved lipid stability, and preserved product quality. Antimicrobial activity decreased in both traditional and hygienic Chal during the storage period, but its effect was more pronounced against Staphylococcus aureus than other pathogens. Acidity and pH indices showed gradual changes in both samples, yet the increase in acidity was more pronounced in traditional Chal. Furthermore, antioxidant activity increased in both storage methods, but traditional Chal exhibited significantly higher antioxidant activity than hygienic Chal from day 14 onwards (p<0.05). In traditional Chal, coliform counts increased from 22.2×102 colony-forming units on day 1 to 36.3×102 CFU/mL on day 28, which is considerably higher than the Iranian national standard limit of a maximum of 10 CFU/mL. Mold and yeast counts, initially 29.46×104 CFU/mL on day 1, reached 49.66×104 CFU/mL in traditional Chal and 0.029×104 CFU/mL in hygienic Chal by day 28. The levels in traditional Chal were significantly above the maximum permissible standard for Doogh (a traditional fermented dairy drink), which is 100 CFU/mL. In hygienic Chal, mold and yeast counts were significantly lower, measuring only 0.029×104 CFU/mL on day 28. Consequently, hygienic Chal remains consumable for up to 21 days, free from microbial contamination and maintaining product quality. In conclusion, this study demonstrated that hygienic Chal, with more balanced pH and acidity, possesses superior sensory and antioxidant properties compared to traditional Chal.
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