Optimisation of rancidity stability 6 in long-chain PUFA 7 concentrates obtained from a rainbow trout (Oncorhynchus 8 mykiss) by-product

10 páginas, 5 figuras, 2 tablasThis research was focused on the production of polyunsaturated fatty acid concentrates from a farmed rainbow trout (Oncorhynchus mykiss) by-product (i.e. belly muscle). The effect of different process variables (urea/fatty acids (FA) contents ratio, crystallisation time and temperature and stirring speed of the urea/FA mixture) on the lipid oxidation development during the urea complexation process was investigated. For this purpose, an experimental design (26 runs) following the response-surface methodology was developed. As a result, peroxide value and TOTOX index showed to be dependent on the crystallisation time and temperature and the urea/FA ratio, while no influence of the crystallisation stirring speed was detected on both indices; additionally, polyene index was affected by the urea/FA ratio and its interaction with the crystallisation time. An optimised desirability score near 1.0 was attained provided values of 2.8 °C, 3.05 h and 3.57 were applied for crystallisation temperature, crystallisation time and urea/FA ratio, respectivelyThe work was supported by the FONDECYT program (Government of Chile) throughout the Project N° 1120627Peer reviewe

Acylglycerol synthesis including EPA and DHA from rainbow trout (Oncorhynchus mykiss) belly flap oil and caprylic acid catalyzed by Thermomyces lanuginosus lipase under supercritical carbon dioxide

13 pages, 3 figures, 3 tablesSupercritical carbon dioxide (SCCO2) was studied as a medium for the esterification of eicosapentaenoic acid (n-3 C20:5, EPA) or docosahexaenoic acid (n-3 C22:6, DHA) and caprylic acid (C8:0, CA) in structured triacylglycerols (sTAG) using Thermomyces lanuginosus lipase as biocatalyst. Process variables (n-3 long-chain polyunsaturated fatty acid: CA, n-3 LCPUFA:CA content ratio), glycerol content (wt. %), and supercritical time, temperature and pressure were optimized by the Response Surface Methodology through a central composite design of 25–1 + star. Synthesis of sTAG with EPA, DHA and CA under SCCO2 was significantly affected by the n-3 LCPUFA:CA content ratio and supercritical time. MALDI-TOF mass spectrometry revealed that acylglycerols with the highest levels of EPA or DHA content in the sn-2 position were obtained when the following variables conditions were applied: 50% (n-3 LCPUFA:CA content ratio), 40 °C (supercritical temperature), 20 MPa (supercritical pressure), 4 h (supercritical time) and 20.0 wt. % (glycerol concentration). For such experimental conditions, esterification catalyzed by Thermomyces lanuginosus lipase under supercritical carbon dioxide allowed obtaining sTAG synthesized with 54.95% of CA, 11.64% of EPA and 13.77% of DHAThis work was supported by the Comisión Nacional de Investigación Científica y Tecnológica, FONDECYT program (Government of Chile) (Grant number 1120627) and the Faculty of Chemical and Pharmaceutical Sciences, University of Chile, Santiago, ChilePeer reviewe