Determination of Variability in Ambient Conditions During Cold Storage of Aronia Fruits

Abstract

In this research, temperature and relative humidity in a cold store with an evaporative cooling system were investigated during one-month cold storage of Aronia melanocarpa Nero fruits. Ambient temperature and relative humidity were measured by sensors at 36 points for different levels (top, medium and base level). The research was carried out in accordance with the randomized plot design for the purpose of storing Aronia melanocarpa in a cold store at +3oC for 1 month. The results were evaluated by using variance analyses and descriptive statistics. In addition, spatial variability maps were created for evaluating of temperature and relative humidity variation at different levels. Variation of the temperature was determined between 3.40oC and 5.32oC for top level, 3.80oC and 5.49oC for middle level and 3.92oC and 5.51oC for base level at 3oC storage temperature. Coefficient of variations was determined as 11.47% for top level, 11.48% for middle level and 7.10% for bottom level for temperature. The relative humidity values were changed between 74.00% and 88.09%. Mean coefficient of variation of the relative humidity varied between 3.22% and 4.43%. According to the results; distributions of the temperature and relative humidity for different levels were not uniform. Reason of high variability between measurement of the temperature and the relative humidity for different levels in the cold store was the distribution of the cold air. The cold air was ventilated by an evaporator and distributed according to the design of the cold store (dimensions, shape, and materials) and placement of fruit cases. Different storage conditions were determined at different levels in the cold store during storage of Aronia fruits in this research. In addition, there is generally one temperature/relative humidity sensor located back of the door inside the cold store used to control the cooling system. Measurement of the temperature and relative humidity from one point in a cold store is not enough to give an idea about the ambient conditions of the cold store. When storing agricultural products, the use of more temperature/relative humidity sensors in the cold store will enable the actual situation of the temperature and relative humidity values to be taken into account to control the operation of the cooling system. Additional cold air distribution systems such as ventilator, air curtains and placement of fruit cases may help to improve air distribution and decrease the spatial variability of the storage conditions in the cold store.