The production of fish oils enriched in polyunsaturated fatty acid-containing triglycerides

Optimisation of Healthy-Lipid Content and Oxidative Stability during Oil Extraction from Squid (Illex argentinus) Viscera by Green Processing

Green extraction was applied to Argentinean shortfin squid (Illex argentinus) viscera, consisting of a wet pressing method including a drying step, mechanic pressing, centrifugation of the resulting slurry, and oil collection. To maximise the oil yield and ω3 fatty acid content and to minimise the oil damage degree, a response surface methodology (RSM) design was developed focused on the drying temperature (45-85 °C) and time (30-90 min). In general, an increase of the drying time and temperature provided an increase in the lipid yield recovery from the viscera. The strongest drying conditions showed a higher recovery than 50% when compared with the traditional chemical method. The docosahexaenoic and eicosapentaenoic acid contents in the extracted oil revealed scarce dependence on drying conditions, showing valuable ranges (149.2-166.5 and 88.7-102.4 g·kg^-1 oil, respectively). Furthermore, the values of free fatty acids, peroxides, conjugated dienes, and ω3/ω6 ratio did not show extensive differences by comparing oils obtained from the different drying conditions. Contrary, a polyene index (PI) decrease was detected with increasing drying time and temperature. The RSM analysis indicated that optimised drying time (41.3 min) and temperature (85 °C) conditions would lead to 74.73 g·kg^-1 (oil yield), 1.87 (PI), and 6.72 (peroxide value) scores, with a 0.67 desirability value.

Lipase-catalyzed esterification of glycerol with n-3 polyunsaturated fatty acids from winterized fish oil Esterificación catalítica de glicerol con ácidos grasos 3-n poliinsaturados de aceite de pescado

Menhaden oil was hydrolyzed using a lipase from Pseudomonas sp. The hydrolysate was cold frac tionated at-72°C. Glyceride synthesis was performed using the same lipase under different reaction environments. The best conditions for the esterification reaction were 39 °C for 18 h in a reaction mixture containing anhydrous glycerol, n-3 polyunsaturated fatty acids (PUFA) enriched solution (2% lipids in hexane), hexane, and phosphate buffer-lipase solution (1% w/v). Product composition was 81.33% triacylglycerides and 18.67% of free fatty acids (w/w). Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) accounted for 36.18% of the esterified fatty acids, of which 58% was EPA and 42% was DHA. This method offers an alternative to produce glycerides rich in n-3 PUFA.

Production and characterization of refined oils obtained from Indian oil sardine (Sardinella longiceps)

Crude Sardinella longiceps oil was refined in different stages such as degumming, neutralization, bleaching, and deodorization. The efficiency of these processes was evaluated on the basis of free fatty acid (FFA), peroxide (PV), p-anisidine (pAV), total oxidation (TOTOX), thiobarbituric acid reactive species (TBARS) values, Lovibond CIE-L*a*b* color analyses, and (1)H NMR or GC-MS experiments. The utilities of NMR-based proton signal characteristics as new analytical tools to understand the signature peaks and relative abundance of different fatty acids and monitoring the refining process of fish oil have been demonstrated. Phosphoric acid (1%) was found to be an effective degumming reagent to obtain oil with the lowest FFA, PV, pAV, TOTOX, and TBARS values and highest color reduction. Significant reduction in the contents of hydrocarbon functionalities as shown by the decrease in proton integral in the characteristic (1)H NMR region was demonstrated by using 1% H3PO4 during the course of the degumming process. A combination (1.25:3.75%) of activated charcoal and Fuller's earth at 3% concentration for a stirring time of 40 min was found to be effective in bleaching the sardine oil. This study demonstrated that unfavorable odor-causing components, particularly low molecular weight carbonyl compounds, could successfully be removed by the refining process. The alkane-dienals/alkanes, which cause unfavorable fishy odors, were successfully removed by distillation (100 °C) under vacuum with aqueous acetic acid solution (0.25 N) to obtain greater quality of refined sardine oil, a rich source of essential fatty acids and improved oxidative stability. The present study demonstrated that the four-stage refinement process of sardine oil resulted in a significant improvement in quality characteristics and nutritional values, particularly n-3 PUFAs, with improved fish oil characteristics for use in the pharmaceutical and functional food industries.

Therapeutic drugs: healing power of marine fish

Marine fish is a major source of high-quality protein, lipids, and a wide variety of vitamins and minerals. These macromolecules and their derivatives show different pharmacological activities, which make the fish as a therapeutic diet. Modern technology has made it easy to explore the therapeutic importance of fish-based diet on cardiovascular diseases, neurodegenerative diseases, radicals-mediated diseases, and cancer. In this review, we focus on exploration of proteins, lipids, carbohydrates, minerals, and their derivatives from marine fish as a major source for bioactive compounds and their medicinal importance.

Downstream processing of algal polyunsaturated fatty acids

Little information exists on recovering polyunsaturated fatty acids from microalgae; however, methods for concentration and purification of PUFAs from fish oil have been extensively reported. This review examines recovery and purification of microalgae derived PUFAs, but techniques developed for use with fish oil are also reviewed as being potentially useful for concentration and purification from microalgae. The two main techniques for concentrating and purifying-urea fractionation and high performance liquid chromatography-are discussed in depth and attention is focused on the process developed by the authors for obtaining highly pure PUFA. Other potentially useful techniques, such as supercritical fluid extraction and lipase-catalyzed processing are detailed.