The "sugar to acid ratio" or "Brix to acid ratio" is used to describe the taste or tartness of fruit juices. Higher Brix to acid ratios indicate a higher sugar content resulting in a less tart juice. This ratio can be manipulated by adding pulp-wash to adulterate the juice with the aim of achieving lower tartness levels.
A recent conference presentation reported a novel feasibility study to use two handheld NIR spectrometers as rapid screening techniques, in combination with class modelling (DD-SIMCA and soft-PLS-DA) and discrimination strategies (ensemble learning and hard-PLS-DA) to authenticate orange juice samples and identify levels of Brix to citric acid ratio in pulp-wash as adulterants.
It was reported that both NIR spectrometers coupled with DD-SIMCA demonstrated 100% sensitivity and specificity in calibration and prediction sets. Furthermore, ensemble learning approaches such as Gradient Boosting Tree (GBT) and Adaptive Boosting (Adaboost) coupled with the NIR Tellspec spectrometer were able to perfectly predict the levels of adulterants with a limit of detection (LOD) of 2% and 5% for Brix to citric acid ratio and pulp-wash, respectively. This outperformed hard-PLS-DA, which is the most commonly used technique in food control studies.
The abstract, and contact details of the authors, are here.
Photo by Greg Rosenke on Unsplash
Comments