Encapsulation and drying methods in the production of powdered red cabbage ( Brassica oleracea L.): Chemometrics and Fourier transform infrared spectroscopy

Abstract

In this study, powder colorant was obtained from red cabbage (Brassica oleracea L.). The stability of the colorants obtained by spray and freeze drying was investigated in terms of antioxidant capacity and anthocyanin content. The yield of the products increased with the encapsulation for both drying methods and encapsulation application. Drying method and encapsulation application had a significant effect on most of the physical properties of powders except for flowability and adhesiveness values. An increase in L*, a*, and C values was observed with the encapsulation process. Antioxidant activity of the samples increased with the encapsulation process by 13.44% in the spray-dried samples, while it increased by 9.75% in the freeze-dried samples. Total monomeric anthocyanin content was detected as 9039.21 mg/kg for encapsulated freeze-dried samples and 7811 mg/kg for encapsulated spray-dried ones. Nine anthocyanins were detected in the samples by using high-performance liquid chromatography. To discriminate samples according to drying methods with/without encapsulation principal component analysis (PCA) was used based on the Fourier transform infrared (FTIR) data. Four groups were observed for the PCA. The chemometric evaluation was done to predict the antioxidant capacity, anthocyanin content, and individual anthocyanins using FTIR spectra. High correlations were observed between the calculated and reference values for partial least square regression analysis.