Visible/near-infrared Spectroscopy as a Novel Technology for Nondestructive Detection of Escherichia coli ATCC 8739 in Lettuce Samples

Recent advancements in NIR spectroscopy for assessing the quality and safety of horticultural products: A comprehensive review

“…Interestingly, preprocessing techniques remained similar for most of the quality traits irrespective of the crop, demonstrating the potential for efficiency at the point of analysis. Both transmittance and reflectance methods performed similarly, though the latter had a slight upper hand due to its higher penetrating power ( 21 , 35 , 36 ) and more robust system. Thin-peeled fruits such as pomegranate obtained improved results in reflectance mode, suggesting that this method can be used for thick-walled fruits such as coconut, areca nut, and cocoa.…”

“…PCA and HCA trended toward a coarser classification, whereas SIMCA and SVM produced finer classifications into subgroups. The E. coli analysis was carried out in baby spinach using the PLS method ( 35 ). For contamination studies, outliers need to be eliminated using feature selection techniques such as PCA.…”

“…For contamination studies, outliers need to be eliminated using feature selection techniques such as PCA. In studies carried out to detect E. coli and Z. rouxii , PCA used to remove outliers ( 6 , 35 ). In the case of E. coli detection in spinach, Q-residual-Hotelling's T2 plot was used to find out the outliers ( 35 ).…”

“…In studies carried out to detect E. coli and Z. rouxii , PCA used to remove outliers ( 6 , 35 ). In the case of E. coli detection in spinach, Q-residual-Hotelling's T2 plot was used to find out the outliers ( 35 ). E. coli was detected using PLS-DA supervised learning in the 450–994 nm range, with a 100% accuracy rate in the prediction set ( 35 ).…”

“…In the case of E. coli detection in spinach, Q-residual-Hotelling's T2 plot was used to find out the outliers ( 35 ). E. coli was detected using PLS-DA supervised learning in the 450–994 nm range, with a 100% accuracy rate in the prediction set ( 35 ). The model could not predict unsafe samples in the early stages.…”