The Cooling Process of Agricultural Products After Boxing and Palletizing

Abstract

Assuring that food products have acceptable quality and are safe to consume requires maintaining adequate nutrition levels and fulfilling consumer expectations. Quality losses can lead to food waste, resulting in increased economic costs and low consumer confidence. Therefore, quality expectations should be maintained at an acceptable level for consumer purchase and consumption. It is well known that a cold environment reduces the respiratory activities and kinematics of nutritional degradation. The cooling temperature is critical since lower than recommended cold temperatures may cause chill damage. Therefore, the food industry intensively employs cold storage methods to slow respiration rates, inhibit harmful bacterial growth, reduce water loss, and prolong shelf life in order to maintain product nutritional value and quality. Improving product cooling efficiency will reduce energy costs that are a significant expense for fruit and vegetable processors. Understanding the cooling process is key to the development of new technology and processes. However, most natural food products are not conformed to simple geometric shapes or uniform properties and distributions. Thus, the cooling process of an agricultural product (cucumbers) was investigated in this study. The study was conducted in a packing house, where the cooling temperature of the cucumbers was recorded by placing multiple thermocouples in the produce after boxing and palletizing as well as cold storage. The test results showed that individual produce cooling was relatively easy to predict. However, boxed and palletized cucumber cooling showed significant variations. For example, the temperature of the cucumbers changed depending on their location in the box in addition to the box location on the stack. In the case of boxed produce cooled by natural convection cooling, the temperature changed from 25 to 18 °C after three hours. However, in the case of palletized tunnel cooled, the temperature change ranged from 25 to 11 °C and 25 to 18 °C after nearly three hours of cooling. Indeed, the temperature differences indicated that the cooling rate has significant variations depending on the location of the produce. Some parts of the pallet received more direct contact with the forced cold air than other parts. Thus, it is very important for produce processors to understand cooling system performance. The study emphasized that efficient use of energy is one of the areas that can have not only significant cost savings but can also improve produce shelf life, reduce food waste, and maintain consumer confidence.