Effect Of Infrared Heating Research Articles

Effects of Infrared Radiation on Eggplant (Solanum melongena L.) Greenhouse Cultivation and Fruits' Phenolic Profile.

The implementation of Infrared (IR) radiation in heated greenhouses possesses the advantage of high directional control and focused compensation of energy losses, appropriate for creating local microclimate conditions in highly energy-consuming systems, such as greenhouses. Moreover, it can efficiently maintain favorable environmental conditions at the plant canopy. The present study studies the application of Infrared (IR) heating in an experimental greenhouse with eggplant (Solanum melongena L.) cultivation. The experimental results are presented from a full cultivation period inside two identical, small scale experimental greenhouses, with IR and forced air heating system, respectively. The effects of IR heating over plant growth parameters, including the yield of the fruits as well as the total phenolic content and the antioxidant profile of eggplants fruits’ extracts are measured and discussed. The results indicate a greater uniformity production in the IR heating greenhouse in terms of antioxidant and radical scavenging activities, as well as the total phenolic content. Moreover, the phenolic profile of eggplant fruits from both greenhouses revealed the existence of numerous bioactive compounds, some of which were only characteristic of the eggplant fruits from IR heated greenhouses.

Effects of IR heating on distribution and transport of gaseous air pollutants in urban and mountain churches in Poland

Abstract The spatial distribution and temporal concentration variation of a set of gaseous air components (e.g., CO2, CO, H2CO, H2O) have been monitored with a multi-channel photoacoustic gas-analyzer in an urban church (Saint Catherine's, Cracow) and a mountain church (Saint Michaels Archangel, Szalowa) of Poland, in order to assess the likely effects of air pollution indoors under the influence of provisory electrical infrared (IR) heaters and without heating. Likewise, the ventilation characteristic and the leakage of these buildings with different constructions (i.e., plastered stone and wooden structures) with the assistance of decay curves of SF6 tracer gas was evaluated and compared. The wooden building in Szalowa, due to its more open structure, developed about one order higher ventilation rates (e.g., 0.9–1.3 h−1) than the stone church in Cracow (e.g., 0.1 h−1). The IR-heating affected only modestly the ventilation rate of the wooden church (e.g., 1.2–1.6 h−1), but it increased significantly that of the plastered stone church (e.g., 0.27 h−1). The ventilation rates were also assessed with the use of the CO2 curve decay method, and satisfactory agreement was found with those observed by the use of SF6 tracer. The spatial distribution of the studied gaseous pollutants (CO2, H2O) was found to be in some occasions nonhomogeneous in both buildings, due to the active usage of the IR-heating, especially, during a couple of consecutive liturgical services. Besides the pollution events due to ingress of gaseous air pollutants, present at enhanced levels outdoors, increased CO, CO2 and H2CO peaks were observed indoors too, which, in most cases, could be associated with incense burning.

Effect of infrared heating on degradation kinetics of key lime juice physicochemical properties

The effect of IR heating on retention and kinetics of some physicochemical properties of key lime juice were investigated. The juice was thermally treated at 60, 70, 80 and 90 °C in 15, 10, 5, 2.5 min using IR and conventional thermal treatment in water bath. The effect of heating on ascorbic acid (AA), pectin methylesterase (PME), cloud stability and color of the juice were studied. The higher Z-value of AA during IR heating (25.12 °C) indicated the higher thermal resistance of this vitamin compared to conventional method (24.15 °C)). Higher PME inactivation and cloud stability were observed during conventional treatment. IR heating was effective in color preservation of the juice because of lower changes in browning index and L* × a* × b* combination. All these obtained results were related to shorter come up time during IR heating. Finally, correlation matrix was used to evaluate the linear relation between the juice properties. In this study, infrared (IR) heating was used as an alternative method for key lime juice thermal processing. Come up time decreased due to quick rising in initial temperature of the juice to the target temperature during IR heating. Hence, the juice was heated less during this method compared to the conventional thermal treatment in water bath. Totally, IR heating could be introduced as a new and effective method for the preservation of nutritional values and color of juice such as key lime juice.