2020 Fiscal Year Annual Research Report
Sensing protein oxidation by spectroscopy - Find a marker from nutrition and digestion point of view -
|Research Institution||National Agriculture and Food Research Organization |
本山 三知代 国立研究開発法人農業・食品産業技術総合研究機構, 畜産研究部門, 主任研究員 (20414683)
|Foreign Research Fellow
DUCONSEILLE ANNE 国立研究開発法人農業・食品産業技術総合研究機構, 畜産研究部門, 外国人特別研究員
|Project Period (FY)
2019-10-11 – 2022-03-31
|Keywords||Lipids / oxidation / TBARS / beef / cooking method|
|Outline of Annual Research Achievements
To understand the impact of cooking on the nutritional potential of beef, the lipids composition was analyzed on cooked and raw meat using gas chromatography. Wagyu meat was used in this experiment for its high fat content. The cooking methods chosen were boiling, grilling and sous-vide cooking. Two endpoint core temperatures were achieved: 55°C and 77°C which correspond to rare and well-done cooking respectively. We observed that the different cooking methods and core temperatures did not impact the lipids composition of beef in the present conditions, as the proportion of various fatty acids were conserved before and after cooking.
Lipids oxidation was analyzed with TBARS measurements in beef cooked in different ways to understand the impact of cooking method on lipids oxidation. Different breeds of beef with different fat contents were used to study the effect of fat contents and composition in fatty acids on lipids oxidation under cooking. In parallel, the lipids, moisture and protein contents were measured using Soxhlet method for lipids and microwave system for moisture content. The protein content was deduced from the two previous results.
On Reiwa 1, a histological study on the effect of different cooking methods on beef tissues was performed. On Reiwa 2, the results were analyzed, and an article was written.
Finally, in vitro digestion experiments were planned to measure the impact of cooking method on beef digestibility. Some enzymes activities were measured, and the rest needs to be checked before launching the digestions on raw and cooked meat.
|Current Status of Research Progress
Current Status of Research Progress
3: Progress in research has been slightly delayed.
A paper regarding the results of the histological study was written and the suggestions of a researcher, an expert in histology of meat, were required. This took more time than expected.
Moreover, on Reiwa 2, it was planned to launch Raman spectroscopy analyses to study the impact of cooking method on oxidation of lipids and proteins of beef. Although some acquisitions were performed, Raman system turned out of service on Reiwa 2 because of trouble of its excitation laser. In reason of import stagnation of a new laser device due to COVID pandemic, the replacement took time. Thus, the rest of Raman spectra will be acquired on Reiwa 3. The experiment begun on 11th of May and will last until the beginning of July of Reiwa 3.
Digestion experiments were planned on Reiwa 2. Before launching the experiments, all the digestive enzymes activities should be precisely evaluated. On Reiwa 2, some enzymes activities were checked but the analyze of enzyme activities is still on going. Indeed, some of the enzymes needed to be imported from foreign country which added a delay due to COVID pandemic. The verification of enzymes activities needs some specific systems, depending on the enzyme to be tested. So, it is very important to verify the systems and the experiment method before launching such enzyme activities testing. For these reasons, I choose to take more time to be more precise in the checking of enzymatic activities. It will allow to settle relevant experiment on Reiwa 3.
|Strategy for Future Research Activity
On Reiwa 3, the paper on histological study will be published.
Cooking may affect the oxidation degree of lipids and proteins. When oxidized, proteins and lipids may not be completely digested, or different toxic compounds can be created and released in digestive tract such as free radicals, or HNE (Hydroxynoenal) which are produced from lipid peroxidation. These compounds have toxic effect on cells and are being considered as possible causal agents of numerous diseases, such as chronic inflammation, neurodegenerative diseases, or diabetes.
One objective is to identify the molecular changes after different methods of cooking using Raman Spectroscopy, to understand the impact of cooking method and temperature on oxidation of proteins and lipids. The second objective is to study the impact of cooking on the digestion degree of both lipids and proteins. Finally, these two previous experiments should help to choose a best cooking method from a nutritional point of view, that induces less oxidation and promotes a higher digestibility.
Digestions of raw and cooked meat with different cooking methods will be launched on Reiwa 3 and Raman spectra will be acquired on same meat. Finally, statistical analyses will be run on the whole data obtained to allow the study of correlation between cooking methods and chemical and spectral changes.