THE RATE OF THE TEMPERATURE DROP IN SWEET PEPPERS AT THE TECHNICAL STAGE OF RIPENESS DURING THEIR COOLING

Abstract

The leading vegetables in Ukraine are cabbages, cucumbers, tomatoes, sweet peppers, and aubergines. More than 27 million tons of sweet pepper is grown in the world yearly, and only about 161,600 tons of it in Ukraine. However, it takes one of the leading places in vegetable growing, and it is a traditional and the most common type of the vegetable.The article presents the results of research on the rate of the temperature drop in sweet peppers at the technical stage of ripeness during their cooling and warming. Fruits of the sweet pepper of the Sondela variety at the technical stage of ripeness, with a weigh of 375, 208, and 104 g, ripening and harvested at the same time, were taken for the experiments.The studies have shown that the fruit temperature dropped most actively in the first 40–50 minutes of storage, and then the rate of cooling decreased, the decrease starting in the pepper fruit weighing the least. Fruits weighing 104 g, 68 mm in diameter, reached their optimum temperature (0.0°С) in 2 hours. The cooling of peppers weighing 208 g, 80 mm in diameter, was only 10 minutes longer. The temperature of the largest fruits became 0°C after 3 hours 40 min. The enthalpy of the fruits, too, slowed down rapidly. If the rate of the decrease in the enthalpy is the same, it will have a positive effect on maintaining an even temperature of storage of peppers. Besides, it will make it possible to avoid the external sweating caused by an uneven temperature of the fruits. Also, the cooling process is not smooth and uniform: the temperature remains the same for some time, and then it sharply decreases, in percentage terms, between the indices. These processes indicate the resistance of a plant organism to unfavourable temperature conditions of the environment.

Keywords

• sweet pepper
• cooling and warming rate
• physical and thermophysical parameters of the sweet pepper
• heat capacity
• enthalpy