COVER FEATURE
Thermal Imaging for Postharvest Handling
By Dr Maimunah Mohd Ali Department of Food Sciences , Faculty of Science and Technology , Universiti Kebangsaan Malaysia
Assoc . Prof . Ir . Dr Norhashila Hashim Department of Biological and Agricultural Engineering , Faculty of Engineering , Universiti Putra Malaysia
SMART Farming Technology Research Centre Faculty of Engineering , Universiti Putra Malaysia
COVER FEATURE
Postharvest handling is a critical phase in the agricultural supply chain that encompasses all activities from the time of harvest until the final delivery to consumers . This phase includes processes such as sorting , grading , packaging , storage , and transportation . The primary goal of postharvest handling is to maintain quality and extend the shelf life of agricultural produce while minimising losses and ensuring food safety . However , the efficiency of these processes is often challenged by various factors including spoilage , disease , quality deterioration , and physical damage to the agricultural produce . These challenges can significantly impact the quality , safety , and marketability of fresh produce , leading to economic losses and reduced consumer satisfaction . In this context , advanced technologies have been increasingly adopted to enhance the effectiveness of postharvest handling .
One such technology that has shown significant promise is thermal imaging . Thermal imaging , which is also known as thermography , involves the use of infrared cameras to detect and visualise temperature variations on the surface of objects . By capturing heat patterns , thermal imaging provides valuable insights into the physiological and physical state of the agricultural produce without the need for direct contact . This noninvasive method allows for real-time monitoring and rapid assessment , making it a powerful tool in postharvest handling and management .
Generally , the basic principle behind thermal imaging is the detection of infrared radiation emitted by objects . Every object with a temperature above absolute zero ( -273.15 ° C ) emits infrared radiation which can be captured by thermal cameras to create thermal images . These images , also known as thermograms , display temperature variations using a colour palette , where different colours represent different temperature ranges . By analysing these thermograms , it is possible to identify areas of concern such as hot spots indicating spoilage , bruises , or infections as well as cold spots pointing to poor cooling efficiency or dehydration .
There have been diverse applications of thermal imaging in the postharvest handling of agricultural produce . For instance , it was used to detect spoilage and diseases by identifying temperature anomalies caused by microbial activity . This early detection is crucial for implementing timely interventions to prevent the spread of infections and reduce losses . Additionally , thermal imaging can assess the ripeness and quality of fruits and vegetables by monitoring temperature changes associated with metabolic processes . This capability helps in determining the optimal harvest time and ensuring that the agricultural produce meets quality standards .
Another significant application of thermal imaging is in detecting physical damage such as bruising , which may not be visible to the naked
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