Effect of high oleic soybean oil on omega-3 fatty acid elongation and incorporation into egg yolks

Open Access
Author:
Kukorowski, Alexandra N
Area of Honors:
Animal Sciences
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Kevin Harvatine, Thesis Supervisor
  • Troy Ott, Honors Advisor
Keywords:
  • oleic soybean oil
  • omega-3
  • omega-6
  • fatty acid
  • egg
  • egg yolk
  • chicken
  • hen
  • flaxseed oil
  • EPA
  • DHA
  • functional food
  • diet
Abstract:
Production of nutritionally enriched eggs is beneficial to egg producers as it increases the value of their product and is important to consumers because they help meet specific nutrient requirements. Omega-3 fatty acid (FA) enriched eggs have proven to be a functional food that is desired by consumers. Very long chain omega-3 (VLC n-3) FA have been identified as protective against diseases such as diabetes mellitus, cardiovascular disease, and cancer, making their presence in food valuable to the consumer (Yashodhara et al., 2009). This research investigates the effects of high dietary oleic acid on VLC n-3 FA elongation and incorporation into the egg yolk. The effects of dietary high oleic soybean oil (HOSO) and high α-linolenic flaxseed oil (FLAX) were investigated at four different supplementary levels (0%, 1%, 2%, 4%) in a split plot design with four groups of nine white Leghorn chickens. Each feeding period lasted 21 days and egg samples were collected on the final day of the feeding period. The egg yolks and liver tissue samples were directly methylated in a dual methylation procedure and analyzed for FA content by gas chromatography. Oils had little to no effect on egg production including the number of eggs produced and egg composition such as albumin, shell, and yolk weights. Oleic acid was not affected by FLAX and the highest incorporation occurred at 4% HOSO. There was an interaction between the oils for α-linolenic acid (ALA) incorporation, with FLAX increasing and HOSO decreasing at high levels of ALA. There also was an interaction of oils for incorporation of eicosapentaenoic acid (EPA) into egg yolks. EPA increased with increasing FLAX, but decreased with increasing HOSO. There was no interaction of oils for docosahexaenoic acid (DHA) incorporation, but overall FLAX increased and HOSO decreased DHA deposition. There are various critical points in FA absorption and incorporation into eggs that may be modified by oleic acid and ALA levels and their interaction. High dietary FLAX allowed for liver elongation of ALA to increase levels of EPA and DHA in egg yolks. Increasing HOSO increased oleic acid in the yolks, but the oleic acid appears to have competed with the n-3 FA for incorporation into the eggs yolks at one or more critical points of absorption and incorporation.