Colour analysis method applied to browning of “Pesto” spreads preserved with organic acids and lactoferrin

Abstract

Natural metal-chelating protein, lactoferrin, potentially influences lipid oxidation, microbiology and browning (attributed to combined enzymatic and non-enzymatic oxidation) of minimally-processed green vegetable-based food emulsions, depending on milieu conditions. We have compared the effect of combinations of antioxidative and antimicrobial agents on microbial count, lipid oxidation and browning in fresh basil-based (“pesto”) spreads. Browning was determined by colour lightness changes, applying colour evaluation, by means of multivariate image analysis. Addition of 80 and 400 mg/kg lactoferrin reduced primary lipid oxidation products accumulation (peroxide value) in separated oil phase of the product, as well as Lactobacillus sp. counts, after 1 month of sample storage at 4 ^oC. Oxidation induction time (OIT), determined by differential scanning calorimetry (DSC) and browning rate were slightly negatively affected in samples containing lactoferrin and 0.5 g/kg of ascorbic acid.