ABSTRACT
In a preliminary study, commercial insect powders were successfully identified using infrared spectroscopy combined with multivariate analysis. Nonetheless, it is necessary to check if this technology is capable of discriminating, predicting, and quantifying insect species once they are used as an ingredient in food products. The objective of this research was to study the potential of using attenuated total reflection Fourier transform mid-infrared spectroscopy (ATR-FTMIR) combined with multivariate analysis to discriminate doughs and 3D-printed baked snacks, enriched with Alphitobius diaperinus and Locusta migratoria powders. Several doughs were made with a variable amount of insect powder (0-13.9%) replacing the same amount of chickpea flour (46-32%). The spectral data were analyzed using soft independent modeling of class analogy (SIMCA) and partial least squares regression (PLSR) algorithms. SIMCA models successfully discriminated the insect species used to prepare the doughs and snacks. Discrimination was mainly associated with lipids, proteins, and chitin. PLSR models predicted the percentage of insect powder added to the dough and the snacks, with determination coefficients of 0.972, 0.979, and 0.994 and a standard error of prediction of 1.24, 1.08, and 1.90%, respectively. ATR-FTMIR combined with multivariate analysis has a high potential as a new tool in insect product authentication.
ABSTRACT
The aim of this work was to study the potential of using infrared spectroscopy and chemometrics to monitor Maillard reaction. Sodium caseinate (NaCAS) and gum Arabic (GA) or sodium carboxymethyl cellulose (CMC) powders were mixed at 1:1, spray-dried, and incubated at 60 °C and 76% of relative humidity from 0 to 72 hr. Sample infrared spectra were collected, and browning degree, conjugation efficiency, and stabilization properties of the conjugates were analyzed by spectrophotometry, fluorescence spectroscopy, turbidity, and zeta potential measurements. Pairwise soft independent modeling of class analogy (SIMCA) models showed significant chemical differences among NaCAS-GA mixtures incubated for 0 (Control) and 16 hr, attributed to functional groups linked to different Maillard reaction products such as Schiff's base and pyridine compounds. Infrared spectroscopy combined with SIMCA is a powerful tool to monitor the formation of protein-polysaccharide conjugates by Maillard reaction. PRACTICAL APPLICATION: Protein-polysaccharide conjugates obtained by Maillard reaction are currently used as novel food emulsifiers. However, conventional methods to study this chemical reaction are time consuming or involve the use of toxic and harmful reactants. Infrared spectroscopy combined with multivariate analysis is evaluated to be used as a rapid tool to monitor Maillard reaction.
