Mehdi Qavanloo; Mohsen Azadbakht; Feryal Varasteh; mohammad vahedi torshizi
Abstract
AbstractIn this research, for cooking of mushrooms, an ohmic heating device was used to evaluate the performance of the ohmic system in three voltage gradients (7.5, 9.25 and 11.5 V/cm), three types of electrodes (steel, brass and aluminum) and three concentrations of the ohmic solution, 20 ml of water ...
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AbstractIn this research, for cooking of mushrooms, an ohmic heating device was used to evaluate the performance of the ohmic system in three voltage gradients (7.5, 9.25 and 11.5 V/cm), three types of electrodes (steel, brass and aluminum) and three concentrations of the ohmic solution, 20 ml of water and three amounts of salt (1, 2 and 3g). Also, in this process, the input current, electrical conductivity coefficient and system performance coefficient during the mushroom cooking process were calculated and the obtained data were analyzed using statistical software. Results showed that all three factors of voltage gradient, electrode type and solution concentration had a significant effect on the investigated factors and the greatest effect was shown in voltage gradient and then the electrode type and ohmic solution concentration had a significant effect on the input current factors, electrical conductivity coefficient and system performance coefficient. Based on results, it can be stated that the best type of electrode used is aluminum electrode and the best concentration is 3 grams of salt and 20 milliliters of water. The highest values of input current, electrical conductivity coefficient and performance coefficient are obtained in this concentration with this electrode.
Mohammad Vahedi Torshizi; Mohsen Azadbakht; Mahdi Kashaninejad
Abstract
Given that color is one of the appearance characteristics of food products for customer selection and marketability, in this study, an ohmic heating system had made in three input voltage gradients (8.33, 10.83, 13.33 V/cm) and three percent weight loss (10, 20 and 30%) of the total weight in the heating ...
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Given that color is one of the appearance characteristics of food products for customer selection and marketability, in this study, an ohmic heating system had made in three input voltage gradients (8.33, 10.83, 13.33 V/cm) and three percent weight loss (10, 20 and 30%) of the total weight in the heating process. After the heating process, the color change was analyzed using Image J software and the factors L *, a *, b *, BI, C, TCD were measured and the results were analyzed using the response surface method. The results showed that for L *, b *, browning index, chroma index and TCD had the highest estimation coefficient for weight loss percentage and for a * value of process voltage had the highest estimation coefficient. Also, except for the factor a *, where the quadratic model is suitable for the two model factors, for the other factors, the linear model is obtained against the mean of the appropriate model by the response surface. In the analysis of response surface diagrams, the L * and a * factor had the highest value in the voltage range of 50 to 65 volts and the weight loss percentage of 20%, and for b *, the browning index and TCD had the highest values at voltages of 70 and above and a weight loss of 25%.
Mohsen Azadbakht; Mohammad Javad Mahmoodi; Mohammad Vahedi Torshizi; Reza Ghazagh Jahed
Abstract
In this research, the carrot was first grounded in equal pieces; the pieces underwent pretreatment using Ohmic and blanching methods. The treatments were preheated at 3 ohmic voltage levels as 40, 60 and 80 Volt and 3 period levels of 2, 4 and 6 minutes. Then parameters examined in the pretreatment blanching ...
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In this research, the carrot was first grounded in equal pieces; the pieces underwent pretreatment using Ohmic and blanching methods. The treatments were preheated at 3 ohmic voltage levels as 40, 60 and 80 Volt and 3 period levels of 2, 4 and 6 minutes. Then parameters examined in the pretreatment blanching in 3 period levels of 2, 4 and 6 minutes. After the pre-treatment, samples were dried in microwave in 3 power levels of 360, 600 and 900 W. The qualitative properties of samples including antioxidant, flavonoids and total phenol content were determined for pre-treated and dried samples. A multilayer neural network of perceptron was used to teach data using 3 and 6 neurons in the hidden layer and three functions of hyperbolic, sigmoid, and linear tangent activation. According to the results obtained from the network, for Ohmic premixing method the best values of R2 and RMSE were observed for antioxidant content (sigmoid-6 neuron), flavonoids content (hyperbolic tangent-6 neuron) and total phenol content (sigmoid-6 neuron). Also, the activation network with 3 neurons in the hidden layer and the hyperbolic tangent activation function were able to obtain the best values of R2 and RMSE for the total phenol content, flavonoids and antioxidants in the blanching pre-treatment.
