a large scale makes it an invaluable tool for maintaining produce quality and reducing waste . As the technology evolves and becomes more accessible , thermal imaging is set to play an increasingly vital role in modern postharvest management practices .
Monitoring Ripeness and Quality
Monitoring the ripeness and quality of agricultural produce is a critical aspect of postharvest handling that directly impacts market value , consumer satisfaction , and food waste reduction . The ripening process in agricultural produce involves metabolic activities that generate heat , which can be detected as temperature variations on the surface of the produce . For example , as fruits ripen , they undergo physiological changes , such as increased respiration and ethylene production , that could lead to detectable heat patterns . Thermal imaging allows for the assessment of ripeness and quality without damaging the agricultural produce , preserving its market value and extending its shelf life . In this sense , thermal imaging provides immediate feedback by enabling continuous monitoring of ripeness and quality throughout the supply chain . This real-time capability is crucial for making timely decisions in sorting , packaging , and distribution .
Thermal imaging has been successfully applied in various studies to monitor the ripeness and quality of a wide range of fruits and vegetables . In assessing ripeness in tomatoes , thermal imaging has been utilised to detect temperature changes for the identification of optimal harvest times and the segregation of fruits based on ripeness levels . For monitoring postharvest quality in grapes , thermal imaging was used to track the cooling process after harvest , ensuring uniform temperature distribution and preventing quality degradation due to uneven cooling . Thermal imaging has shown promising results for the quality evaluation of different pineapple varieties during postharvest storage ( see Figure 2 ).
The interpretation of thermal images can be complex , requiring advanced image processing techniques and expertise to accurately correlate temperature variations with ripeness and quality parameters . While thermal imaging provides
Figure 2 : Prediction of quality parameters of pineapple using thermal imaging . Courtesy : Mohd Ali et al . ( 2022 ).
valuable data on surface temperature variations , integrating it with other sensing technologies such as near-infrared ( NIR ) spectroscopy or hyperspectral imaging , can offer a more comprehensive assessment of ripeness and quality . The future of thermal imaging in monitoring ripeness and quality lies in the development of advanced , user-friendly systems that can be easily integrated into existing postharvest handling processes . As technology advances and integration with other sensing methods improves , thermal imaging is set to become an indispensable component of modern postharvest management practices , ensuring high-quality produce reaches consumers while minimising waste .
Assessing Physical Damage
Physical damage to agricultural produce during postharvest handling can significantly affect quality , shelf life , and marketability . Bruises , cuts , and other forms of mechanical damage often lead to increased respiration rates , ethylene production , and microbial invasion which accelerate the deterioration process . Thermal imaging detects infrared radiation emitted from the surface of an object , converting it into a temperature map . When agricultural produce is physically damaged , the affected areas exhibit different thermal properties compared to undamaged regions . For example , bruises on fruit can cause localised changes in heat transfer due to disrupted cell structures
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