Application of portable near-infrared spectroscopy for rapid detection and quantification of adulterants in baobab fruit pulp

Baobab fruit pulp powder (BFPP) is susceptible to economically driven adulteration owing to its incredible nutrient density and rapidly expanding demand worldwide. In this study, a portable NIR spectroscopy (wavelength 900-1700 nm) coupled with chemometrics was used for the detection of BFPP adulteration. BFPP samples separately adulterated with rice flour (RF), wheat flour (WF), and maize flour (MF) at 0%, 1%, 3%, 5%, 10%, 15%, 20%, 25%, 30%, 40%, 50% and 60% concentrations were subjected to NIR spectroscopy. Two-class models proved to be reliable with sensitivity and specificity of above 0.98 and an error of below 0.01. Four-class models attained sensitivity and specificity of above 0.68 and an error of below 0.276. The correlation coefficient (R-2) and root mean square error (RMSE) of the prediction set were above 0.88 and below 6.20% respectively for PLSR models. The LODs were also below 13.79%. Therefore, NIR spectroscopy has a promising potential for rapid screening of BFPP adulterations.

Automated summary

In this study, a portable NIR spectroscopy combined with chemometrics was used for the detection of BFPP adulteration. The results showed that two-class models had high reliability, with sensitivity and specificity above 0.98 and error below 0.01. Four-class models achieved sensitivity and specificity above 0.68 and error below 0.276. The PLSR models had correlation coefficients above 0.88 and root mean square error below 6.20%, with LODs below 13.79%. Therefore, NIR spectroscopy has promising potential for rapid screening of BFPP adulterations.