Prediction of dry matter, fat, pH, vitamins, minerals, carotenoids, total antioxidant capacity, and color in fresh and freeze-dried cheeses by visible-near-infrared reflectance spectroscopy

Visible-near-infrared reflectance spectroscopy was used to predict dry matter, fat, pH, retinol, alpha-tocopherol, beta-carotene, xanthophylls, sodium chloride, calcium, potassium, magnesium, zinc, total antioxidant capacity, brightness, redness, and yellowness in both fresh and freeze-dried cheeses. A total of 445 cheeses of four cheese varieties were investigated. Composition of samples was analyzed by reference methods. Samples were scanned (400-2500 nm) and predictive equations were developed using modified partial least-squares with both cross-validation and external validation. Coefficient of determination (R(2)) and residual predictive deviation (RPD) in external validation were satisfactory for dry matter (0.97; 5.99), fat (0.90; 3.22), beta-carotene (0.92; 3.43), sodium chloride (0.89; 2.94), calcium (0.95; 4.62), Zinc (0.93; 3.75), brightness (0.96; 4.88), redness (0.96; 5.23), and yellowness (0.93; 3.73) in fresh cheeses. Poor predictions were obtained for pH, retinol, alpha-tocopherol, xanthophylls, potassium, magnesium, and total antioxidant capacity (R(2) < 0.81; RPD < 3).