Antioxidant properties of citrus fibre and the prediction of oxidation in ground beef meatballs made with citrus fibre by ATR-FTIR spectroscopy with principal component analysis

Abstract

The objectives of the present work were (1) to determine the total polyphenol content (TPC), total flavonoid content (TFC), and oxygen radical absorbance capacity (ORAC) of citrus fibre, and (2) to predict, by attenuated total reflection (ATR)-Fourier transform infrared spectroscopy (FTIR), the oxidative stability of ground beef made with different levels (i.e., 0, 1, 3, and 5%) of citrus fibre (CF) during 1, 3, 5, or 7 days of refrigerated storage. The TPC, TFC, and ORAC values of citrus fibre were 3.753 ± 0.49 mg/g, 2.825 ± 0.008 mg/g, and 10.036 ± 1.94 μmol/g in dry basis, respectively. The citrus fibre pH was 4.45 ± 0.075. To monitor lipid oxidation, the peaks at 2924, 2853, and 1743 cm-1 were useful. Principal component analysis (PCA) was applied at a 5% significance level between 1780 - 1700 cm-1. The results of the present work demonstrated that the addition of citrus fibre at higher levels (i.e., 3 and 5%) had a pro-oxidative effect on ground beef meatballs. FTIR helped to predict oxidation in meat products.