A research abaut the changes in chemical, physical, microbiological and sensorial properties of summer halva with walnut in different storage temperatures

In this study, summer halva with walnut has been analyzed under the 120 days storage for the change in quality of chemical, physical, microbiological and sensory properties in 3 different temperatures. In addition, it has been given information about the production of summer halva with walnut for understanding these analyses. Summer halva with walnut which is the study material has been produced with the isolation of the other spoilage factors in a factory which has been using the latest technology for the production. This study has been carried out analysis of 90 pieces of 150 g package of summer halva which have been taken from the same production with the same properties.In these analyses, it has been found that the amount of ash in summer halva with walnut has been about 1%. Storage time and temperature have made a significant impact on the change of the amount of the ash. This amount is one of the important properties that determining the quality of halva. The amount of the ash, which tahini halva and summer halva with walnut containing; indicates the total level of mineral substances, and it is determined that storage temperature and duration has no effect on the change of these mineral substances.According to research results, the ambient temperature and duration have an influence on the rate of the oil in the product. Therefore, it is estimated that the increase in the duration and temperature cause oil leakage in the product.Pungency shows the amount of the bitterness in the oil and oil products, is an important criterion of quality. It has been observed that on duration of storage at around 8°C the pungency of the halva has negative values along 120 days. However, at 20°C after the 100th day and at 30°C after the 80th day this value has been positive that means there is bitterness in the product. As a result, duration and increase in the temperature have an impact on the formation of pungency.In this study, it has been observed that water activity is not affected excessively from temperature and duration as it is compared with the beginning.According to the results of the study, L, a, b values, which show the change in color; are affected from temperature and duration.Depending on time and temperature, it has been observed hardening in all samples in each three environments. When this case has been examined, the walnuts in the halva have lost their brittleness as they are compared with their first state.It is estimated that storage time and temperature have a negative effect on microbiological load of products.It is observed that the increase in storage time and temperature have also negative effect on sensorial changes in product like color, smell, taste and floury.