Carrot cubes were ohmically heated with 2 different frequencies 1 Hz and 60 Hz to evaluate change in color, texture and rehydration properties. Carrot samples were stored under 4 different relative humidity (RH) conditions 11.1 %, 32.7%, 55.7 % and 75.3 %. Experiments were conducted to monitor the textural parameters of hardness, fracturability, adhesiveness, cohesiveness and chewiness and color changes in terms of CIE color values. Results showed that the hardness, fracturability and adhesiveness of 1- Hz samples stored at 75.3 % RH were different from those at 55.7 % RH. The adhesiveness, cohesiveness and chewiness of 1-Hz samples were different from the control at 55.7 % RH. There was significant correlation between cohesiveness and chewiness and moisture content of the rehydrated samples. For the moisture content after ohmic heating a negative correlation was observed with properties of chewiness, hardness and adhesiveness. Color lightness (L*) values of rehydrated carrots decreased (i.e. became darker) with the increase in storage time. At both 1-Hz and 60-Hz the difference in the L values of fresh and rehydrated carrots was significantly different from that of the control. The degree of redness (a*) of 1-Hz rehydrated samples after 1 Hz treatment were different from the control stored at 55.7 % RH. The water absorption capacity values decreased throughout the six-day storage period for both the treated and control carrot samples. Thus there exists a great potential to enhance mass and heat transfer properties in food process engineering using ohmic heating, particularly because ohmic treatment has been shown to significantly alter rehydration, texture and color efficiencies. This study demonstrated that ohmic treatment significantly affects color, texture and rehydration properties of carrots stored under different RH environments.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-03022004-132725 |
| Date | 04 March 2004 |
| Creators | Bhale, Sandeep Dattatraya |
| Contributors | Marybeth Lima, Witoon Prinyawiwatkul, Steven G. Hall |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-03022004-132725/ |
| 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 LSU 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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