Lipids

, Volume 43, Issue 6, pp 549–557 | Cite as

The Digestibility and Accumulation of Dietary Phytosterols in Atlantic Salmon (Salmo salar L.) Smolt Fed Diets with Replacement Plant Oils

  • Matthew R. Miller
  • Peter D. Nichols
  • Chris G. Carter
Original Article

Abstract

Phytosterols occur in high concentration in canola (Brassica napus L.) and other vegetable oils such as from the borage plant Echium (Echium plantagineum L.). We investigated if Atlantic salmon (Salmo salar) digest and accumulate dietary phytosterols in significant amounts in muscle and liver. Phytosterols are lipid soluble, lower cholesterol and reduce the risk of coronary heart disease in humans. We aimed to determine if fatty fish, such as salmon, can be used as a delivery source of this functional food component. Three diets containing canola oil (CO), Echium oil (EO) and fish oil (FO) were fed to Atlantic salmon smolt over 9 weeks. The digestibility of natural abundances of phytosterols by Atlantic salmon was poor compared to cholesterol. However, phytosterols accumulated in liver and muscle of fish. Significantly increased concentrations of 24-methylenecholesterol, campesterol, β-sitosterol and total phytosterol occurred in livers of EO fed fish compared to FO fed fish. Campesterol concentrations increased in CO fed fish compared to the FO fed fish. We demonstrated that natural abundances of dietary phytosterols are digested by and accumulated in liver and white muscle of Atlantic salmon smolt. However, phytosterol levels in salmon muscle will not be a major source of phytosterols in human diets and would not be expected to significantly effect human cardiovascular health.

Keywords

Replacement oil Fatty acids Phytosterols Canola oil Echium oil Sitosterol Vegetable oil Fish oil 

Abbreviations

ADC

Apparent digestibility coefficients

ALA

α-Linolenic acid

ANOVA

One-way analysis of variance

BSFTA

N,O-Bis(trimethylsilyl)-trifluoroacetamide

CHD

Coronary heart disease

CMC

Carboxymethyl cellulose

DM

Dry matter

FA

Fatty acid(s)

GC

Gas chromatography

GC–MS

Gas chromatography–mass spectroscopy

LC

Long chain (≥C20)

LDL

Low-density lipoprotein

PCB

Polychlorinated biphenyls

PUFA

Polyunsaturated fatty acid(s)

SDA

Stearidonic acid

SE

Standard error

ST

Sterol(s)

TLC–FID

Thin layer chromatography–flame ionised detection

TLE

Total lipid extract

tr

Trace amounts

ω3

Omega 3

ω3 LC-PUFA

Omega 3 long chain (≥C20)-polyunsaturated fatty acid(s)

ω6

Omega 6

WW

Wet weight

Notes

Acknowledgments

The authors gratefully acknowledge Keith Irwin and Nafisa Priti Sanga for technical assistance at UTAS, Danny Holdsworth for management of the CSIRO GC–MS facility, Rhys Hauler at Skretting Australia for the supply of feed ingredients and Springfield fisheries hatchery for the supply of fish.

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Copyright information

© AOCS 2008

Authors and Affiliations

  • Matthew R. Miller
    • 1
    • 2
  • Peter D. Nichols
    • 2
  • Chris G. Carter
    • 1
  1. 1.School of Aquaculture, Tasmanian Aquaculture and Fisheries InstituteUniversity of TasmaniaLauncestonAustralia
  2. 2.School of AquacultureCSIRO Food Futures Flagship and CSIRO Marine and Atmospheric ResearchHobartAustralia

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