Application of mutual information analysis in determining the effect of ultrasound and microwaves on the jostaberry extracts biological value

Abstract

Jostaberries combine the characteristics and phytochemical properties of the berries of Ribes nigrum and Ribes divaricatum. Josta hybrid varieties are sources of notable nutritional value, due to their increased content of biologically active compounds, such as fiber, carbohydrates, phenolic compounds, vitamins, and minerals. The aim of this work was to apply mutual information analysis in determining the effect of ultrasound (UAE) (5, 10, 15, 20, 25, and 30 min) and microwave (MAE) durations (2, 4, and 6 min) at different magnetron powers (100, 180, and 300 W) on the biological value of jostaberry extracts: total polyphenol content (TPC), total flavonoid content (TFC), total antocyanin content (TA), antioxidant activity (AA) - DPPH, and ABTS and pH. The extracts of frozen (FJ), freeze-dried (FDJ) and oven dried (DJ) jostaberries were used for the determination of biological value. To determine the influence of UAE and MAE on TPC, TFC, TA, AA (DPPH, ABTS) and pH, in jostaberry extracts (FJ, FDJ, DJ) the MATLAB program was used (MathWorks, Inc., Natick, MA, USA). The results of mutual information, measured in bits. The higher the bit value, the more pronounced the influence of the extraction methods. It was shown that the duration of ultrasound application significantly influenced TA content (mutual information 0.367 bits) and TFC (mg QE/g DW) (0.329 bits). Increasing the duration of ultrasound application influenced TPC (0.212 bits), TFC (mg RuE/g DW) (0.199 bits), and AA: ABTS (0.124 bits) and DPPH (0.104 bits). The pH of the jostaberry extracts was slightly influenced, with the mutual information value being 0.048 bits. In the MAE, an application time of 2, 4, and 6 min, at all magnetron powers (100, 130, and 300 W) significantly influenced TA content (0.333 bits), followed by TFC (mg QE/g DW) (0.315 bits), AA: ABTS (0.259 bits), and DPPH (0.241 bits). The pH of the jostaberry extracts obtained in the MAE was influenced more than in the case of UAE, the value being 0.111 bits.