Abstract
The present study optimized the extraction protocol conditions to obtain the antioxidant-rich bioactive extracts from Carica papaya L. (Papaya) leaves. A Box and Behnken Design (BBD) consisting of three different extracting variables viz. extracting temperature (60-70 °C), time (10-20 min) and solvent concentration (55-65%) was used. Antioxidant efficacy was recorded by evaluating four responses viz. ABTS, DPPH, SASA and total phenolic contents. The optimized model predicted, solvent concentration of 60% with extraction time of 15 min and extracting temperature of 65 °C with bioactive-rich antioxidants having highest total phenolic activity. The efficacy of obtained bioactive-rich papaya leaves extracts (PLE) were subjected for in-vivo evaluation in chevon emulsion added with the level of T-1 (0.10%); T-2 (0.25%); T-3 (0.50%) and control (without extract) stored under refrigeration (4 ± 1 °C) for 9 days by evaluating various physicochemical, microbiological, sensory quality characteristics. The pH was significantly higher for control than all treatments and water activity (aw) showed decreasing trend throughout storage period. Oxidation efficiency values showed an increasing drift during storage period, irrespective of added level of PLE, showing lowest oxidation in samples treated with 0.5% PLE. Sensory panellists awarded comparatively higher scores to all PLE treatments than control. Microbiological quality of emulsion incorporated with different levels of papaya leaves extract successfully improved and was lower in 0.5% PLE treated samples. It was concluded that extraction of bioactive antioxidants from Carica papaya L. leaves improved by optimising extraction parameters using RSM. Carica papaya L. leaves extracts have proven prospects as natural anti-oxidants in chevon emulsion as a meat emulsion system.