The New Zealand Institute for Plant & Food Research Limited

Transcription

1 Purification of Alaskan walleye pollock (Theragra chalcogramma) and New Zealand hoki (Macruronus novaezelandiae) liver oil using short-path distillation Prepared by: Matt Miller and Alexandra C.M. Oliveira

2 Assoc. Prof. Alex Oliveira

3 Kodiak, Alaska, USA

4 Objectives Investigate the applicability of short-path distillation to refine crude pollock oils Take 7-year-old rancid hoki oil and see if we can make it meet GOED standard In general, investigate the applicability of using short path distillation on marine oils Add value to respective fisheries

5 Pollock and Hoki oils Pollock Fishery ~ 1 M metric tonnes Major products Surimi, boneless skinless fillets and roe By-products Small amount produced Hoki (Blue grenadier) Quota ~150,000 metric tonnes Major products Boneless skinless fillets, surimi, and roe By-products Fish meal, fish oil, omega 3 concentrates, collagen products

6 Fatty acid profiles of pollock and hoki oils Fatty acid g/100 g Pollock 1 Hoki 2 SFA :1n-9 OA :1n Total MUFA :5n-3 EPA :6n-3 DHA Total n :4n-6 AA Total PUFA Lipid class g/100 g TAG PL Wu TH et al. (2009). JOACS 2 Miller MR et al. (2011) JOACS

7 Oxidation of oils Oxidation is a series of negative (chain) reactions that produce offflavours and smells in oils Polyunsaturated oils are prone to oxidation Double bonds are very reactive Primary oxidation products (peroxides, dienes, free fatty acids) Secondary products (carbonyls, aldehydes, trienes) Acid value measures formation of FFA

8 GOED Monograph Acid value. Maximum 3 mg KOH/g; AOCS Official Method Cd 3d-63 Peroxide value. Maximum 5 meq/kg; AOCS Official Method Cd 8-53 Anisidine value. Maximum 20; AOCS Official Method Cd TOTOX. Maximum 26 (result of calculation, (2 x PV) + AV) Plus PCBs, Dioxins, Furans and Dioxin-like PCBs, Heavy Metals

9 Traditional fish oil purification process Crude oil Bottling/ capsules and storage Deodorization Removes fishy odour (aldehydes and ketones) oxidation products Distillation Degumming Removes soluble & insoluble impurities e.g. proteins, phospholipids, trace metals Washing oil with organic acid & mild heat (e.g. citric acid) Winterisation Removes stearines, waxes, low melting point TAG Short path distillation Neutralization Remove free fatty acids, water sol material Wash oil with caustic soda & mild heat Bleaching Removes pigments, trace soaps, sulphur- and carbonyl-containing compounds & trace metals Treat the oil with an absorbent e.g. activated earth/carbon, chitosan, etc.

10 Short-path distillation Pope - Wiped-film distillation and evaporation process Short residence time of the feed liquid Significantly lowered temperature due to high vacuum capability

11 Short-path distillation

12 meq/kg Peroxide value Hoki oil Pollock oil Crude Temp ( o C)

13 Anisidine value Anisidine value Hoki oil Pollock oil Crude Temp ( o C)

14 mg KOH/g Acid value Hoki oil Pollock oil Crude Temp ( o C)

15 mg KOH/g Acid value Hoki oil Pollock oil Crude Temp ( o C)

16 Results Shows potential Free fatty acids and primary and secondary products of lipid oxidation were effectively removed from hoki and pollock oils with SPD to meet GOED standards. Short-path distillation refines and deodorizes fish oils in a chemicalfree single-step process. Kodiak is a pretty amazing place.

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