Location of seed spoilage in mango fruit using X-ray imaging and convolutional neural networks

Detection of the internal damage and insect infestation on intact mango fruit during har-vesting, storage, and exportation is particularly challenging. Visual comparison of infes-tation by spot detection has proven unreliable in determining the presence of insects in seeds and the extent of spoilage in the fruit. The study aimed toward identifying a non-destructive, rapid, and correct method for detecting spoilage in mango seeds. Ninety-eight (98) mature green mango fruits were harvested from a farm (Kintampo, Ghana) for the experiment. The mangoes were numbered for photographic and X-ray imaging. The im-ages were visually examined and classified based on morphology into mango fruit with good seed and bad seed. The dataset was then augmented into 80 0 0 images and split into train (40 0 0) and test (40 0 0) sets. A VGG16 Deep Convolutional Neural Network (DCNN) model was trained, tested, cross-validated (five-fold), and evaluated by saliency maps on visualization algorithm, Grad-weighted Class Activation Mapping, Grad-CAM, and the Con-fusion matrix to ascertain its capacity to identify bad seed from good seed. The model achieved an accuracy rate of 97.66% and 0.988 area under the receiver operations char-acteristics curve. Further application of this model in the mango industry could promote non-destructive early detection of seed deterioration on the field and enhance the quality of products throughout the postharvest supply chain.(c) 2023 The Authors. Published by Elsevier B.V. on behalf of African Institute of Mathematical Sciences / Next Einstein Initiative. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )

Automated summary

Detection of internal damage and insect infestation on intact mango fruit is challenging, and visual comparison is unreliable. This study aimed to identify a non-destructive method for detecting spoilage in mango seeds. A Deep Convolutional Neural Network model achieved an accuracy rate of 97.66% in identifying bad seed from good seed. This model could enhance the quality of mango products by promoting non-destructive early detection of seed deterioration.