Effect of Different Preservation Methods on the Microbiological Quality, Physicochemical, and Antioxidant Properties of Red Prickly Pear (Opuntia streptacantha) Juice

The red prickly pear (<i>Opuntia streptacantha</i>) is a fruit that is distinguished by its sensory properties and high content of bioactive compounds. Its rapid spoilage rate significantly impacts its commercialization, underscoring the urgent need for effective preservation methods. This study investigated the effectiveness of various juice preservation techniques-refrigeration, freezing, pasteurization, and vacuum packaging -in maintaining the microbiological quality, physicochemical properties, and antioxidant capacity of red prickly pear juice during storage. The most effective preservation method was found to be freezing the vacuum-packaged and pasteurized juice, referred to as J4. This method adequately maintained key nutritional and physicochemical qualities after 12 months, which was evidenced by a reduction in the microbial growth and the preservation of pH (4.64), acidity (0.74 g citric acid L^-1), antioxidant activity (2.6-2.9 mmol TE L^-1), as well as the content of phenols (506 mg GAE L^-1), betalains (141.2 mg L^-1), and total sugars (125 g L^-1). Furthermore, sensory analysis comparing J4-treated juice to control juice revealed no significant differences, confirming that J4 is an effective method for preserving the nutritional, functional, and sensory qualities of red prickly pear juice.