High pressure processing combined with thyme essential oil on sterilization histamine-forming bacteria and preservation application of marlin meat
| Autor: | Zeng, Siang-Mei, 曾湘媚 |
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| Rok vydání: | 2019 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 107 Histamine is primarily produced in fish via decarboxylation of free histidine by the activity of various species of histamine-forming bacteria (HFB). Some fish included marlin, tuna, mackerel, and bonito, are the type of fish commonly involved in histamine fish poisoning. High pressure processing (HPP) is an emerging non-thermal technology that can inactivate pathogenic and spoilage microorganisms in food, and extend the shelf life of foods. Plant essential oils components are gaining a wide interest in health industry for their potential as antioxidant and antimicrobial agents, as they are generally recognized as safe. Hurdle technology is a method that uses a combination of two or more physical or chemical preservation techniques to eliminate pathogens and increase the shelf life of foods instead of chemical preservatives and bactericidal agents. In recent years, the use of natural extracts to replace chemical agents has become popular and has been proven to have an antibacterial effect. In the food industry, the addition of essential oils to foods can not only increase the flavor of the products, but also enhance the antibacterial properties of the products. This study was to determine the effects of thyme essential oil (TEO) combined with HPP treatments on inhibitory effects of HFB such as Enterobacter aerogenes and Staphylococcus capitis. The result showed that bacterial counts of HFB subjected to HPP decreased with increasing pressure level and holding time. HFB had a higher D value in marlin meat slurry compared with that in phosphate buffer, indicating that the HFB were more resistant to pressure in marlin meat slurry. E. aerogenes had a higher D value than S. capitis in phosphate buffer, whereas S. capitis had a higher D-value than E. aerogenes at the same pressure in marlin meat slurry, indicating it was more resistant at HPP treatment. In addition, the aerobic plate count (APC) of raw marlin meat after TEO combined with HPP treatment decreased with increased pressure from 5.66 Log CFU/g (control) to 3.61 Log CFU/g (500 MPa, 5 min). In color of marlin meat, L* value (lightness) increased significantly with increased pressure, whereas a* value (redness) was significantly reduced with increased pressure. In general, the TEO combined with HPP treatments (>200 MPa) significantly retarded the increase of APC, total volatile basic nitrogen (TVBN) and histamine contents in marlin meat stored at 4 oC and 15 oC, regardless of non-inoculated or inoculated with E. aerogenes samples. However, the APC and TVBN levels were retarded, and histamine was completely inhibited in TEO combined with HPP samples (>300 MPa) stored at 4 oC. In summary, this result suggested the marlin meats treated with TEO combined with HPP treatments and stored at below 15 oC could prevent deterioration of product quality, extend shelf life, and reduce histamine hazard and risk. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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