Antioxidant Activity from the Leaves of Different Citrus (Citrus species) under Sub-tropical Conditions of Punjab

The lab experiment was conducted during 2019-2021 to assess the antioxidant activity from the leaves of different citrus (Citrus species) in the laboratories of Guru Nanak Dev University (GNDU). The leaves of different citrus species were procured from the orchard of Department of Agriculture, Sri Guru Granth Sahib world University, Fatehgarh Sahib, Punjab. The antioxidant activity of leaves of different citrus species (lime, lemon, pummelo, mandarin, grapefruit and sweet orange) were measured using the 2, 2-diphenyl-1-picrylhydrazyl radicals (DPPH) and ferric reducing antioxidant power (FRAP) assays. For anti-oxidant properties studies, about 35 leaves/species were collected from the orchard of citrus. They were cleaned with running water, freed of dust and then shadow dried in the shade and then transferred to a hot air oven for 24 hours at 40. Until a stable weight. Drying leaves will be formed into fine powder by using grinder method. After it, the powder was closed in a tight container and stored in a cool and dry place. The results of lab analysis revealed that the antioxidant activity of leaves extract of citrus species in both assays viz. DPPH scavenging activity and FRAP assay showed that the highest activity was displayed by grapefruit with an IC₅₀ = 2.492 mg/ml and EC₅₀=0.835 mg/ml whereas, the least activity was revealed by sweet orange species with an IC₅₀= 4.113 mg/ml and EC₅₀ = 2.240 mg/ml. Thus, this knowledge could be utilized subsequently by food ingredients industries for various applications and innovation, specifically related to flavour compounds.