| EPSRC Reference: |
EP/J501694/1 |
| Title: |
Innovative fat reduction in chilled products using fresh mayonnaise |
| Principal Investigator: |
Murray, Professor B |
| Other Investigators: |
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| Researcher Co-Investigators: |
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| Project Partners: |
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| Department: |
School of Food Science and Nutrition |
| Organisation: |
University of Leeds |
| Scheme: |
Technology Programme |
| Starts: |
23 April 2012 |
Ends: |
22 October 2013 |
Value (£): |
100,263
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| EPSRC Research Topic Classifications: |
| Analytical Science |
Food processing |
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| EPSRC Industrial Sector Classifications: |
| Manufacturing |
Food and Drink |
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| Related Grants: |
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| Panel History: |
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Summary on Grant Application Form |
Bakkavor have developed a new low fat mayonnaise (LFM) that shows great promise in providing similar mouth feel to
traditional (higher fat) mayonnaise. However, on contact with certain vegetable ingredients - namely onions, garlic, chives
or cabbage - the LFM starts to go extremely thick and viscous, giving the whole product the appearance of a gel which
precludes the use of this mayonnaise in many dips, dressings, dressed salads and other applications such as sandwich
fillings that also include these ingredients. This phenomenon has not been documented previously, so its origin is a
mystery at present.
Mayonnaise is a concentrated emulsion of oil droplets in a watery phase containing egg yolk and various other minor
ingredients, although the new LFM also contains added polysaccharide thickeners. As such, the instability is almost
certainly related to strong aggregation of the oil droplets and/or other ingredients within the formulation. Aggregation could
occur via: (a) the vegetable ingredients adding components to the aqueous phase that significantly decrease the repulsive
forces between the droplets or (b) the ingredients adding some extra cross-linking agent that strongly and irreversibly pulls
the droplets together. The principal aim is therefore to establish whether mechanisms (a) and/or (b) are operating in order
to suggest a viable commercial solution to this problem.
Mechanism (a) will be revealed through observations of the microscopic structure of the system and measurements on the
aggregation tendency of the droplets under controlled conditions. The change in the full apparent droplet size distribution
will be evaluated using various light scattering techniques in our laboratory. The surface charge properties of the the
droplets in selected systems will also be measured. Changes in the droplet size when samples are subjected to dilution
with simply water or detergents will be used. This can distinguish between very strongly aggregated droplets, which
appear still as large particles on dilution, versus weakly aggregated droplets that separate simply on dilution with water. A
possible mechanism of the gelation via (a) is the high ratio of polysaccharide thickeners to droplets, resulting in so-called
depletion flocculation (aggregation) of the system, but this should be entirely reversible on dilution. Droplet 'charge' (zeta
potential) measurements will provide evidence of any significant change in the surface structure or composition of the
stabilizing layer on the droplets that could help to explain their dramatic change in stability.
Mechanism (b) may be biochemical, since onions, garlic and chives are all produce enzyme (alliinase) activity on
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Proposal original proforma document
Impact Summary
Impact Summary (please refer to the help for guidance on what to consider when completing this section) [up to 4000 chars]
cutting/crushing that can produce free sulphydryl compounds that could cross-link the protein present (protein in the
aqueous phase or adsorbed to the droplet surfaces) and produce the gelation observed. Cabbage and other Brassica spp.
produce reactive isothiocyanates, nitriles, thiocyanates and also other sulphur species via the action of myrosinase
enzymes, so there is again the capability for protein cross-linking. Cross-linking reactions with the cellulose,
hemicelluloses and pectin components of the polysaccharide thickeners have not been documented, but the
polysaccharide may aid the formation of strong gels as they become incorporated into a cross-linking protein network.
The above measurements will therefore be performed on formulations where potential cross-linking agents are present or
absent. For example: whole onion puree, filtrate from filtered onion puree, enzyme-inactivated filtrate. Enzymes will be
deactivated by various heat treatments and or addition of cross-linking
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Key Findings |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Potential use in non-academic contexts |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Impacts |
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| Description |
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk |
| Summary |
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| Date Materialised |
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Sectors submitted by the Researcher |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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| Project URL: |
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| Further Information: |
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| Organisation Website: |
http://www.leeds.ac.uk |