Thawing of frozen mackerel using the ohmic method | |
| Author | Eakkarat Suebrosplem |
| Call Number | AIT Thesis no.FB-12-14 |
| Subject(s) | Fish, Frozen Mackerels Frozen seafood Thawing |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Food Engineering and Bioprocess Technology, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. no.FB-12-14 |
| Abstract | The effectsoffrozen mackerel usingdifferent thawing methods were studied on product qualities, including drip loss, textural properties and color properties. Three thawing methods, namely, air thawing, water thawing and ohmic thawing, were used to investigate their effects. Moreover, the effects of processing parameters were also studied, including sample sizes, salt solutions (0.1%, 0.5% and 1.0%) and medium temperatures (20oC, 30oC, 40oC). There were three sizes of frozen mackerel, including 2x2cm, 3.5x3.5cm and 5x5cm. The water thawing and air thawing were studied to compare with ohmic thawing method. The medium temperatures were varied in three levels for water thawing methods and ohmic thawing methods. For ohmic thawing, no controlled temperature was also studied. The frozen mackerel was thawed from -18oC to 5oC. The relationships between temperature and time were plotted for three thawing methods. And then, the physical properties were measured after thawing process. In addition, the utilized energy was studiedfor water thawing using water bath and ohmic thawing method.The sample sizes were not significant difference with thawing time and product quality. But the different medium temperatures were significantly different on thawing time. The medium temperatureincreased with decreasing of thawing time and it affected product quality. The thawing time of frozen mackerel was shortest for ohmic thawing methods at no controlled temperature for 0.5%salt solution that was approximately 18 min. The thawed mackerel wascooked at no controlled temperature for 1%salt solution. The physical properties of thawed mackerel were significant difference with different thawing methods (P<0.05) in term of drip loss, color properties and textural properties. The ohmic thawing method at no controlled temperature was less drip loss than other thawing methods. The air thawing was higher drip loss than ohmic thawing to 7.75%. The textural properties of thawed mackerel were significant difference with different thawing methods and mediumtemperature. The hardness and cohesiveness increased with increasing of medium temperature but springiness of thawed sample decreased with increasing of medium temperature. The ohmic thawing without controlling the temperature was harder than other thawing method to 10.4 N. Finally, the color properties of thawed mackerel were significant difference with different thawing method and medium temperature (P<0.05). The increasing of medium temperature resulted in increasing of lightness values. The water thawing system using water bath was highest on the utilized energy during thawing processup to 3500 kJ at 40oC. The highest utilized energy was 280 kJ for ohmic thawing method at 0.5% for 40oC. Ohmic thawing method can reduce the utilized energy more than 50%. |
| Year | 2012 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. no.FB-12-14 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Food Engineering and Bioprocess Technology (FB) |
| Chairperson(s) | Athapol Noomhorm; |
| Examination Committee(s) | Rakshit, Sudip Kumar;Anal, Anil Kumar;Rittichai Assawarachan; |
| Scholarship Donor(s) | Royal Thai Government;Asian Institute Fellowship; |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2012 |