An investigation into effect of thermal processing nutritional value of anchovy kilka (Clupeonella engrauliformis) pre- and post-canning

Measuring the effect of thermal process on nutritional value of food products are one of the most important indicators of qualitative evaluation, this depends on the amount of heat and time of the process, considering that tissue is very important in food products and should be considered for the thermal process. The goal of this research is to obtain the best quality in terms of nutritional value. The principles of keeping food means performing processes that feed the food Protects against corrosive agents , food is fed by biological agents ,chemical and physical reactions are corrupted , human beings always try to prevent the corruption of food being experienced and utilized by a set of maintenance methods. Generally, food storage methods can be classified into two types of thermal and non-thermal methods, application of each of these methods in addition to preventing corruption and thus increasing time Shelf life, also affects its quality. The use of heat is of particular importance among various types of food preservation methods and has long been used. The thermal effect is effective in preventing three types of microbial, chemical, and physical corruption. In relation to microbial degradation, the destruction of pathogenic microorganisms is posed by heating and subsequent packaging.Use of heat to prevent chemical decomposition to prevent enzymatic reactions (by disabling the enzyme system that is used by hot water or hot water vapor) and oxidation. In using thermal methods in relation to physical corruption, preventing tissue damage to materials at different stages of preparation and packaging is important. Pasteurization and sterilization are also two methods of using the thermal process , eliminating all of the microorganisms in an environment is called sterilization. The temperature used in this method is about 240 to 250 degrees Fahrenheit, and because of the high temperature that causes some food nutrients to be lost, trying to avoid high temperatures is avoided. The amount of heat to the extent that it is sterilized during a suitable period can also eliminate the most resistant microbial growths in the food. Today, this method is used in the process of canning and dairy products . Thermal processes are used in two ways in the food industry. One for the destruction of pathogen microorganisms and thus for safe and safe food for consumers, and the other for cooking and providing ready-to-eat food. There are different ways to cook foods such as dry and wet cooking or microwave ovens, grilling and frying, and ... each with its own advantages and disadvantages. That is, it cannot be said that cooking food in a particular way is appropriate or inappropriate for all food groups, and the main advantages of food storage thermal methods are: Relatively easy control of the production process of stable products that do not need to be stored in cold conditions, beneficial nutritional effects include the destruction of anti-nutritional factors , soy-based trypsin inhibitors or the degradation of allergen compounds and increased nutrient availability . The methods of cooking food, the use of many baked foods is more consistent with our physiological conditions. Cooking and making them safer, the nutritional value of such flavored foods . Some food groups like meat. Generally, there are two major thermal methods for cooking , the method of wet cooking is low. Therefore, nutrient degradation is less. But the cooking time, in this way, the temperature is relatively low at such temperatures, which results in the introduction of some soluble nutrients into the water used for cooking. Wet cooking methods include boiling, steaming and calming. The boiling method, which is because the water has a high heat, is a good environment for heat transfer to the food, so boiling is used to cook a lot of food. One of the disadvantages of using water for baking is its high solubility because it can lose some of its nutrients in water. Although heat destroys some nutrients, it increases body access to some other nutrients. As a result, each method of cooking food has some advantages and disadvantages. Even raw materials are not the best. Although most members of the group of meat , fruits and vegetables can be consumed raw. But for some of the other food groups, cooking improves their properties , Another goal of the thermal process is to improve the health of the product through the elimination of microorganisms. Thermal processes are carried out in different ways in order to be healthy, depending on the type of product, the process purpose, the target organism, and the maintenance life of the desired process, from the mild to the extreme. In this research , were studied the effect of thermal processing on the nutritional value (Amino acid profiles), approximate compounds and sensory evaluation in fish before and after canning , this is due to the sensitivity of some nutritional compounds to heat conditions during the production process, and for this purpose . Kilka fish was transferred to the canning plant immediately after catch, kept by ice and after washing , undergoing preliminary preparation and sterilization stages,in150 g cans with sunflower oil , salt was added to the sterilization at 121 o C for 60 minutes , to ensure the application of the appropriate thermal process in quarantine and its quality was investigated, and the thermal process in the canning stages did not have a significant effect on reducing and increasing the percentage of approximate compounds (Protein, Fat, Moisture and Ash content) compared to Kilka fish prior to canning (P> 0.05). In the studies, measurement of 16 types of amino acids in both treatments, respectively, is Glutamic 0.05). In terms of sensory evaluation, the results showed that cooking fish increased its taste due to the increase in aroma taste due to the release of aromatic compounds derived from some amino acids in the final product, which was statistically significant (P <0.05) and finally, Kilka canned fish are better than raw fish.