FISH (Pangasius pangasius) OIL EXTRACTION BY DIFFERENT EXTRACTION METHODS: A COMPARATIVE STUDY OF PHYSICO CHEMICAL PROPERTIES AND FATTY ACID PROFILE

Abstract

Fish oil from the pangus (Pangasius pangasius) is an important source of long-chain PUFAs, which have been found to help humans heart and vascular health, and it has the potential to be a dynamic sector for economic growth and nutritional supplements. However, selection of efficient oil extraction method is a mandate for obtaining superior quality oil. Therefore, four oil extraction methods including; Soxhlet extraction (SE), Wet rendering (WR), Acid silage (AS) and Microwave assisted extraction (MAE) were assessed to extract oils from Pangus fish. Extracted oils were further evaluated for yield percentage, physico-chemical properties, fatty acid profiling and nutritional quality indices (NQI). Based on analysis of variance; MAE method (21.80±0.23) recovered significantly higher amounts of crude oil (p<0.05), while containing lower free fatty acids (0.70±0.01%), peroxides (2.08±0.70Meq/kg), and saponification value (287.27±0.96mg/g KOH) than other methods. In addition, microwave assisted oils were less viscous (cP=43.00±0.50) and showed better refractive index (1.45±0.00), and melting point (33.50±0.50). A total of 25 fatty acids comprising SFAs, MUFAs, and PUFAs were identified based on GC-MS analysis. EPA and DHA contents in extracted fish oils varied from (0.036−0.229g/100g) and (0.064−0.421g/100g), regardless of different extraction methods. However, highest recovery of PUFAs, MUFAs and SFAs were observed in SE (19.158±1.710g/100g), MAE (7.997±0.193g/100g), and AS (17.330±1.508g/100g) methods, respectively. In terms of NQI, SE method showed better rations of PUFA/SFA, HH, and LA/ALA while AS method reported better EPA+DHA, n-3/n-6, AI, TI and FLQ indices. In addition, MAE method showed better rations of n-3/n-6 and HPI index while WR method reported better AI index of pangus fish oil. Therefore, in this study considering extractability and health issues MAE could be the effective procedure to obtain high quality fish oil compared to other methods