Forecasting and evaluating antioxidant properties of fruit, and vegetable, juices using polarization curves

Abstract

The qualitative and quantitative constituents of antioxidant properties of fruit, and vegetable, juices were studied by volt-ampere method. The actual redox power of redox systems connected with normal redox potential (qualitative constituents of antioxidant activity) of juices was increased in the line: carrot, pomegranate, cabbage. Reduction current density for carrot juice redox system was proportional to the square root of hydrogen ion concentration, whereas antioxidant properties of cabbage juices were not affected by pH. Redox reactions between phenolic compounds of mixed juices were forecast based on polarization curves of components on Pt. The antioxidant effect of phenolic compounds of cabbage juice' redox system on anthocyans of pomegranate juice influenced the increasing intensity of absorption in 490–510 nm wavelength region in mixed juice compared with the theoretical value calculated as arithmetic means. Thus, polarization curves on Pt electrode can be recommended as criteria for the evaluation of antioxidant properties of juices. Practical applications Polarization curves on Pt can be useful for forecasting the direction of redox reaction in mixed juices. This is vital for color stabilization of products containing anthocyans, and browning decreasing in colorless products. Results obtained in respect of actual reducing power will assist in improving evaluation of antioxidant properties of fruit, and vegetable, products. Results obtained for carrot, cabbage, and pomegranate, juices can be utilized in the area of canned fruit, and vegetable, products.