A feasibility study on the use of near infrared spectroscopy to predict fatty acid concentration in intact black soldier fly reared in different waste streams

The black soldier fly larvae (BSFL) are well known to utilise a wide variety of organic waste streams, delivering a product rich in protein (30-50%) and lipids (15-49%) and other micronutrients. The objective of this study was to evaluate the ability of NIR spectroscopy combined with chemometrics to predict the concentration of fatty acids in BSFL reared in different commercial waste streams. Intact BSFL samples were analysed using a bench top NIR instrument where calibration models for fatty acids were developed using partial least squares (PLS) regression. The coefficient of determination in cross validation (R²) and the standard error in cross validation ranged between 0.57 and 0.78 (SECV: 0.67-0.77%) where the best PLS cross-validation model was obtained for the prediction of the concentration of palmitic acid (C16:0) in BSFL. The residual predictive deviation (RPD) values obtained ranged between 1.7 and 2.1. This study demonstrated that NIR spectroscopy has the potential to predict fatty acids in intact BSFL samples collected from different commercial conditions and waste streams. Overall, NIR spectroscopy has shown great potential as a rapid tool to monitor fatty acids in BSFL. Therefore, assisting to develop and improve management quality systems used during the production and quality control of BSFL.