Background: Long chain omega-3 (n-3) polyunsaturated fatty acids (LC3PUFA) offer numerous health benefits throughout the life cycle, including improved cognititve and cardiovascular function. Currently, UK. intakes fall short of dietary guidelines. especially amongst vegetarians. Nanoemulsions are novel systems with small droplet sizes ti at can be used to enrich functional foods with LC3PUF A offering a vehicle to increase habitual intakes and bioavailability. Previous combinations of LC3PUFA and water I based emulsions have however been found to create problems with consumer acceptability and oxidative rancidity. This PhD set out to develop and analyse a novel, vegetarian, LC3PUF A nanoemulsion system for incorporation into a functional yogurt product. Methods: A nanoemulsion system was designed and used to create a strawberry yogurt drink, which was evaluated for consumer acceptability using sensory analysis. A full study assessed the oxidation stability of the nanoemulsion system and enriched yogurt. This was followed by a single blinded, randomised crossover intentention trial to compare the bioavailability of a vegetarian algae oil nanoemulsion with the same dose of the bulk algae oil as a control. Participants ingested 200g of yogurt enriched with bulk or nano-emulsified oil providing 1264mg DHA. Results: Droplet measurement results confirmed that nanoemulsion systems can be created using ultrasound with 7, 20 and 50 per cent oil loads in combination with lecithin and/or Tween 40 emulsifiers. Oxidation testing indicated that nanoemulsion of did not have a significant negative effect in terms of oxidation when products at 4°C and that sensory qualities improved after 16 days of storage (P < 0.001). oil the addition of the algae oil nanoemulsion had a significant adverse effect on cJ nsumer acceptability (P S 0.05). The affected attributes (aroma, flavour, texture, aftertaste and overall acceptability) were all significantly reduced when compared with a bulk oil enriched and control yogurt (P S 0.05). The addition of the algae oil nanoemulsion (4.29g1l00g yogurt, l264mg OHA) significantly increased the bioavailability of LC3PUF A compared to the same dosage of untreated bulk oil as indicated by under the curve calculation (AUC), (P < 0.05). Baseline adjusted omega-6 to n-3 ratios (n- 6: n-3) were also statistically significantly reduced by 4.52 per cent for the nanoemulsion I compared to 1.48 per cent for bulk oil (P < 0.05). Conclusions: The incorporation of vegetarian LC3PUFA oil nanoemulsions into functional foods offers a potential vehicle to improve omega-3 status within the general population. In comparison to untreated oils, increases were noted in the bioavailability of DHA. LC3PUFA and reductions in n-6:n-3 ratios. Further research is now needed to improve the consumer acceptability of the enriched yogurt and to study the bioavailability of vegetarian LC3PUF A nanoemulsions in the form of larger and longer randomised controlled trials.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:593640 |
| Date | January 2013 |
| Creators | Lane, Katie Elizabeth |
| Publisher | Manchester Metropolitan University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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