LAUSR

The objective of the present study is to extract the vegetable oil from papaya seeds (Carica papaya L) using Continuous Ultrasound Assisted Extraction (CUAE) method. A face centered–central composite response surface design was applied to explore and optimize the process variables on the oil recovery (%) from papaya seeds. The maximum oil recovery (27.87%) was obtained when CUAE was carried out at 1:13(g/ml) solid–liquid ratio, 80% amplitude level, 48°C temperature and short extraction time of 7 min. Analysis of fatty acid composition revealed that the predominant fatty acid in papaya seed oil was oleic acid (18:1) (74.8%). The cavitation effect on the sample surface for oil extraction was identified using SEM analysis. Thermal stability of oil was analyzed using TGA and results showed that 71% (weight basis) of oil have been stable up to 319°C. FTIR analysis was confirmed that fatty acid functional groups were present in the oil. PRACTICAL APPLICATIONS: The continuous ultrasound acoustic cavitation technique improves the oil recovery (%) with a shorter extraction time and low solvent consumption. Moreover, the high intensity sonicator did not affect the fatty acid composition of the papaya seed oil. The oil sample contains 75% oleic acid (18:1) out of the total fatty acid composition, similar to the oleic acid composition of commercial vegetable oils such as Canola (75%), safflower (77%), olive (>75%), and sunflower (>80%). It can be used for frying purposes in food industry as it has high thermal stability, 71% by weight of oil stable till 319°C. Thus, the results show that this technique is a promising extraction technique for vegetable oil extraction from waste papaya seeds with high quality of fatty acid composition.