Color stability and antioxidant capacity of Crataegus monogyna Jacq. Berry extract influenced by different conditions

Abstract

Hawthorn (Crataegus monogyna) berry is a horticultural product containing antioxidants and pigments. Its extract can be used as a food dye and antioxidant in food engineering. The aim of present study is to research the effects of different possible conditions (temperature, pH, interacting ions, and storage conditions) on the color and antioxidant capacity of hawthorn berry extract. Color was assessed by monitoring the CIELab parameters, while antioxidant capacity was measured using the reaction with ABTS and DPPH radicals. The total phenolic content in berry powder was 1146 mg GAE/100 g and the main polyphenols identified by HPLC were epicatechin, ferulic acid methyl ester, catechin, procyanidins B1 and B2, and various phenolic acids. The main carotenoids, also quantified by HPLC, were mutatoxanthin, lutein, α-cryptoxanthin, β-cryptoxanthin, cis-β-carotene, all-trans-β-carotene, and lycopene. The values of the overall color difference suggest that storage affected the color of the hawthorn extract more than any of the thermal treatments. Alkaline pH values affected color by changing the blue/yellow component, but also luminosity and the green/red parameter. The antioxidant capacity decreased in acidic and neutral media and increased in mildly alkaline media at pH 8.1. The possible presence of interacting salts as potassium nitrate and sodium chloride did not produce any significant changes in antioxidant capacity, while calcium chloride lowered it, but only at 0.001 M. The interaction with the studied salts had little effect on the extract’s color. The obtained results demonstrated that hawthorn berry extracts can be used in the food industry as natural dyes, as it was proven to have very good antioxidant capacity and color stability after different thermal, pH, interacting salt, or storing conditions.