Fourier Transform Near-Infrared Spectroscopy (FT-NIR(S)) and artificial neural network for the quantitative detection of grape juice adulteration by the addition of apple juice

Grape juice is popular for its taste and nutritional value, but due to its high commercial value, it is sometimes adulterated with apple juice, which contains naturally occurring sorbitol. This study used Fourier Transform Near-Infrared Spectroscopy (FT-NIR) alongside Artificial Neural Networks (ANN) to detect sorbitol in grape juice, aiming to identify adulteration. Two key NIR spectral bands, 12400–7400 cm−1 and 6400–5500 cm−1, were strongly correlated with sorbitol concentration in adulterated samples. The combination of FT-NIR and ANN provided accurate quantification of sorbitol levels, demonstrating that this method is a promising tool for the rapid detection of adulteration in grape juice with apple juice.