Dehulled seed from four lentil market classes (large- and small-sized green and red types) were tempered to15% moisture and micronized to a surface temperature of 135 °C, and their compositional, physical, and functional properties were investigated. Micronization of lentil modified starch- and protein-related properties. Approximately 2.5 to 5.6% of the starch was gelatinized following micronization. Differential scanning calorimetry (DSC) results showed a 13 to 40% decrease in heat enthalpy, and viscosity analysis (Rapid Visco Analyzer) showed a 21 to 55% increase in peak viscosity and a 1 to 3 °C reduction in pasting temperature. Nitrogen solubility decreased across the pH range of 2 to 9, and lipoxygenase activity was reduced by 100-fold. There was a 25 to 43% increase in water holding capacity with no change in oil absorption capacity. The colour intensity of the pigments in the green and red lentil were reduced upon micronization of seed, and the particle size of flour was lowered with 7 to 13% more flour passing into the finest (<75 um) sieve.
Flours from dehulled green and red lentil (large type) were incorporated as a binder into low-fat (<10%) beef burgers at levels of 6 and 12%. Cooking properties, colour, texture, oxidative status, and sensory properties of these burgers were analyzed. Overall, increasing binder addition to low-fat beef burgers increased cooking yield up to 86% and minimized dimensional shrinkage upon cooking. Storage of raw, fresh burgers for 7 days under simulated retail display (4 °C) resulted in gradual reductions in HunterLab a* values, with those containing micronized lentil flour generally displaying significantly greater retention of redness from days 1 to 5 of storage. Thiobarbituric acid reacting substances (TBARS) of burgers containing micronized lentil flour were significantly lower compared with those containing non-micronized lentil after 9 to 11 weeks of frozen storage. A trained sensory panel (n=13) reported increasing burger juiciness and tenderness with the incorporation of up to 6% and 12% of lentil flour, respectively. Although off-flavour increased in burgers with non-micronized lentil flour addition, it was significantly reduced when seed was micronized. Consumer panel analysis (n=107) showed higher acceptability for burgers containing 6% micronized lentil flour or toasted wheat crumb compared with those containing non-micronized lentil flour or no binder. These results demonstrate that the conditions used to micronize lentil altered the functional properties of the flours, and when used as a meat binder at an optimal level improved cooking properties, texture, and flavour profiles in low-fat beef burgers.
| Identifer | oai:union.ndltd.org:USASK/oai:usask.ca:etd-09062010-144452 |
| Date | 13 September 2010 |
| Creators | Der, Tanya J. |
| Contributors | Wanasundara, Janitha, Thacker, Phil, Tanaka, Takuji, Tyler, Robert, Shand, Phyllis |
| Publisher | University of Saskatchewan |
| Source Sets | University of Saskatchewan Library |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://library.usask.ca/theses/available/etd-09062010-144452/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Saskatchewan or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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