Non-destructive quality assessment of fresh and dried-chili peppers: Prediction of vitamin, protein, macro and micro-nutrient content via color models and multivariate analysis

Abstract

Food constituents, particularly antioxidants, vitamins, proteins, fibers, and macro-and micronutrients, are closely linked to the superior quality and desirable sensory attributes of food products, and their composition is influenced by drying methods. Food quality is traditionally assessed using chromatography or chemical analysis methods.Although these techniques provide accurate results, they are time-consuming, labor-intensive, costly, and produce chemical waste. The food industry demands rapid, cost-effective, non-destructive, and chemical-free analytical techniques. Color parameters linked to food quality have contributed significantly to the advancement of colorimetric analytical techniques. This study evaluated the effects of microwave (MD) (0.5 and 1.5 W/g), convective (CD) (50 and 80 degrees C), and vacuum (VD) (100 mmHg at 60 and 80 degrees C) drying methods on the final quality and color of chili peppers. In addition, the potential of predicting the nutritional composition of the dried samples through their color parameters was assessed. Results demonstrated that the highest values for color parameters, vitamins B1, B3, B5, B6, beta-carotene, lutein & zeaxanthin, vitamin c, as well as for protein, P, Ca, Mg, Cu, and Zn, were obtained with MD at 1.5 W/g. Successful PLSR models were developed for predicting vitamins, proteins, and macro-and micro-nutrients using L * a * b * Ch color models. The highest prediction accuracies were found for vitamin K (R2val = 0.86, RMSEP = 0.07 ppm), vitamin B6 (R2val = 0.83, RMSEP = 2.58 ppm), and Cu (R2val = 0.82, RMSEP = 0.64 ppm). Consequently, drying processes have a significant impact on both the final food quality and color parameters; moreover, quality parameters exhibit a strong correlation with color values. The study results indicated that determining food quality parameters through color measurements represents a promising approach.