Investigation of some Energy and Exergy Factors during Ohmic Heating Processing of Sour Orange

Abstract

Introduction Food is composed of various compounds, and when the food quality expires, it becomes inappropriate for consumption and the end of life leads to some pathogenic microorganisms in food. So food processing is essential. In recent years, various heat treatments have been considered that have various disadvantages, so researchers are looking for alternative technologies in industrial processing to overcome these problems. Electric treatments play an important role in food heating technology and one of the methods of electric thermal processing is ohmic processing, that ohmic heat is based on the flow of electricity through a product. The purpose of this study was to investigate the effect of voltage and weight loss on the amount of energy and exergy during this process in order to obtain the best amount of energy consumed during the heating process, since the most common way to heal the heating is by heating. In addition to maintaining the product's qualitative characteristics, the product has to carefully monitor its own system parameters. Materials and Methods The sour oranges were purchased from a garden located in the city of Gorgan, Golestan province. The prepared oranges were washed and divided into two halves in the middle and immediately after purchase, all samples of juice were taken manually in the same conditions and the samples were prepared to conduct the test during the ohmic process with voltage gradients and the percentages of different weight loss to investigate the amount of energy efficiency, exergy efficiency, exergy loss, and improvement potential during the process. For the heating process, three voltage gradients of 8.33, 10.83 and 13.33 V cm-1 and three percentage values of weight loss of 10% (from 90 g to 81 g), 20% (from 90 g to 72 g), and 30% (from 90 g to 63 g) were selected. Then, the energy and exergy consumed during the process were calculated and analyzed using a factorial experiment in a completely randomized design with SAS statistical software. Results and Discussion Based on the results, it can be concluded that the voltage gradient and weight loss percentages are significant for energy efficiency, exergy efficiency, exergy, and potential improvement at 1% level. Increasing the voltage gradient increases the efficiency of energy and exergy and reduces the potential for recovery and exergy is wasted. The highest energy efficiency was 91.6% in the 13.83 V cm-1 voltage gradient and the weight loss percentages 10% and the lowest value was 51.51% in the voltage gradient of 8.33 V cm-1 and the weight loss percentages 30%. The maximum improvement potential was 8.33 V cm-1 and the weight reduction was 30% and the lowest value was at 13.33 V cm-1 voltage gradient and 10% weight loss percentages. The highest exergy efficiency of 59.51% was found in the 13.83 V cm-1 voltage gradient and the weight loss percentage was 30% and the lowest value was 31.88% on a voltage gradient of 8.33 V cm-1 and a weight percentage of 10%. Conclusions - By increasing the voltage gradient, the energy efficiency had increased and there was a significant difference between all the volatility gradients. - For exergy efficiency, when the voltage gradient increased, the exergy efficiency amount increased, and in all percentages weight loss was a significant difference between the voltage gradient. - By increasing the voltage gradient, the amount of exergy loss decreased significantly and with increasing percentage weight loss, this amount was significantly increased. - The improvement potential was reduced by increasing the voltage gradient and there was a significant difference between the voltage gradients for the improvement potential.

Keywords

• energy and exergy
• ohmic process
• sour orange
• statistical analysis