Modeling Respiration Rate of Bell Pepper (Capsicum anuum L.) Under Hypobaric Storage Through Dimensional Analysis

Abstract

Knowing the respiration rate of fresh products during storage is very important. One can use direct measurement or available prediction equations to determine the respiration rate. However, the availability of the prediction equations still needs to be improved. This study aims to develop mathematical models of respiration rate for pretreated bell peppers during hypobaric storage. Model development was done by applying dimensional analysis. Mature green bell peppers were used as the experimental samples. Three pretreatments on the bell pepper before storage, namely control, ozone pretreatment, and UV-C pretreatment, combined with three hypobaric storage levels of 26, 64, and 101 kPa, were studied. An apparatus set was built to create hypobaric conditions. An ozone generator and UV-C lamp were used to apply pretreatments to the samples. It was found that respiration rate models could be developed by considering bell pepper surface area, weight, volume, storage time, storage volume, and pressure. At the storage pressures of 101 to 56 kPa, UV-C pretreatment was the best in suppressing the respiration rate of bell pepper. Meanwhile, at a storage pressure of 26 kPa, the application of ozone and UV-C pretreatment gave a higher respiration rate than the control. The three models were found to have different characteristics and showed high accuracy with the experimental results. The dimensionless product of π3 was found to have the most significant effect on RCO2 for the three models. This finding indicated that the ratio between bell pepper and jar volumes is critical to ensure the model works.