THE USE OF PURPLE EGGPLANT FRUIT CALYX STEM (Solanum melongena L.) AS AN ALTERNATIVE SOURCE OF LACTASE-PRODUCING LACTIC ACID BACTERIA

Lactose intolerance is a condition where body is unable to digest lactose due to an enzyme lactase deficiency in digestive system, leading to various health problems ranging from bloating, diarrhea, and abdominal pain to severe problems that can result in stunting in children. One attempt to prevent stunting due to lactose intolerance is administration of low-lactose dairy products, such as yogurt. The production of yogurt requires a starter known as lactic acid bacteria (LAB). Starter bacteria are often derived from yeast or commercially available bacteria, which are relatively expensive. This research aims to utilize waste products, namely the purple eggplant (Solanum melongena L.) stalks, as a new source of LAB for lactase enzyme production. Fermenting cow's milk using purple eggplant stalks results in yogurt. Inoculating this yogurt onto MRS Broth and MRS Agar media confirms the presence of LAB from the milk fermentation. To test the lactase enzyme, bacterial cell wall degradation is achieved using sonication, allowing for lactase enzyme testing. Characterization test for lactase enzyme is conducted at various temperatures and pH levels to determine the optimum conditions for the lactase enzyme. The optimum temperature for lactase enzyme is at 70°C with a specific enzyme activity of 0.0061 U/mg, optimum pH is 7 with a specific enzyme activity of 0.0044 U/mg. This study demonstrates that purple eggplant stalks can be utilized as a new source of LAB to produce lactase enzyme as an alternative starter bacterium for yogurt production, particularly for lactose intolerance therapy in the future.