Impact of Processing Techniques on Antioxidant, Antimicrobial and Phytochemical Properties of Curry Leaves (Murraya koenigii Spreng)

Curry leaves (Murraya koenigii Spreng) are widely valued for their nutritional and therapeutic properties, primarily due to their rich phytochemical composition, including flavonoids, alkaloids, essential oils, and also exert several pharmacological activities such as antifungal, antimicrobial, antidiabetic, etc. Although curry leaves are an economical source of nutrients, and generally consumed as seasoning. Various researchers observed that cooking has impact on many of the nutrients therefore, it is necessary to find out the best cooking method to minimise the nutrient loss. In this study, the impact of five common household processing techniques (boiling, pressure cooking, steaming, sautéing & microwave cooking) on in vitro antioxidant activity, vitamin C, β-carotene, antimicrobial efficacy and phytochemical profiles (both qualitative and quantitative) was determined on curry leaves. Steaming (74%) and sautéing (81%) were the most effective in preserving radical scavenging activity, while boiling (612%) and pressure cooking (157%) led to considerable losses. All cooking methods resulted in a reduction of ascorbic acid content (82-93%) and β-carotene (3-38%), while they had a positive effect on the total phenol (16-65%) and flavonoids (54-413%). Boiling had the highest negative impact on the antimicrobial activity of curry leaves. After processing of curry leaves, no zone of inhibition was observed against E. coli. These findings suggest that milder cooking methods, particularly steaming and sautéing, are preferable for retaining the functional quality of curry leaves in culinary applications. Integrating such practices into daily cooking could help maximize the preventive health benefits of this medicinally important plant.