Pasteurization of traditional hardaliye drink by innovative food processing technologies

The purpose of this work is to pasteurize traditional hardaliye drink, which is of value not only in terms of nutrient composition, but also its positive impacts on human health with innovative process technologies, such as; high hydrostatic pressure (HHP) and ultrasonication (US) and identify the impact of these technologies on significant quality criteria of hardaliye drink. In this context; alongside of physico-chemical analysis, such as; pH, total acidity (g/L), °Brix, conductivity (mS/cm), turbidity (NTU), color measurement (L*, a*, b*, C*, h0, ΔE), color intensity (IC), color tone, color composition (%OY420, %OY520, %OY620), total phenolic content (mg/L), total antioxidant activity (%), total monomeric anthocyanin (mg/L) and reducing sugar (g/L); microbial analysis had been carried out to determine reductions in total mesophilic aerobic viable bacteria (log cfu/mL) and total yeast and mold load (log cfu/mL), as well. Besides, the acceptability of the products processed with these technologies were tested in terms of sensorial properties. An experimental design was constituted according to Box-Behnken method by benefiting from response surface designs for HHP and US applications. Sub and upper limits for pressure, temperature and time, which are the explanatory variables in reference to HHP, were identified in turn as; 200-500 MPa, 4-40 °C, 3-15 min. Sub and upper limits for amplitude, temperature and time, which are the explanatory variables in reference to US, were identified in turn as; 50-90 %, 4-40 °C, 5-45 min. HHP applications did not induce alteration in estimation of pH, total acidity, °Brix, L*, a*, b*, C*, h0, ΔE, total phenolic content, total antioxidant activity, total monomeric anthocyanin and reducing sugar in a significant degree (p > 0.05). The effect of US applications on the estimation of pH, total acidity, °Brix, conductivity, L*, a*, C*, ΔE, total phenolic content and total monomeric anthocyanin was determined in an insignificant degree (p > 0.05). Both HHP and US applications generated considerable augmentation in %OY520 value of hardaliye drink (p ≤ 0.05). In pasteurization of hardaliye drink with HHP, initial total mesophilic aerobic bacteria load, which is 5.10 log cfu/mL, HHP3 (350 MPa, 15 min., 40 °C), HHP9 (500 MPa, 9 min., 4 °C) and HHP14 (500 MPa, 9 min., 40 °C) at experiments; total yeast and mold load, which is 4.21 log cfu/mL, HHP3 (350 MPa, 15 min., 40 °C), HHP7 (500 MPa, 3 min., 22 °C), HHP9 (500 MPa, 9 min., 4 °C), HHP11 (500 MPa, 15 min., 22 °C) and HHP14 (500 MPa, 9 min., 40 °C) at experiments were completely annihilated. In pasteurization of hardaliye drink with US, initial total mesophilic aerobic bacteria load, which is 4.84 log cfu/mL, US3 (1207.50 W, 25 min., 40 °C) at experiment; total yeast and mold load, which is 4.00 log cfu/mL, US3 (1207.50 W, 25 min., 40 °C), US5 (1207.50 W, 45 min., 22 °C) and US9 (1207.50 W, 25 min., 4 °C) at experiments were completely inactivated. Based upon the detection of hardaliye drink could be pasteurized with these technologies, it was envisioned that utilization of the additives, such as; sodium benzoate and potassium sorbate in industrial production of this drink could be obviated. Besides, hardaliye drink that treated with HHP and US, was not found different from its control sample in terms of sensorial properties (p > 0.05). In this work, although obtaining positive results in both HHP and US technologies for hardaliye drink; while more inactivation was being provided in microbial load, minimum alteration was be observed in physico-chemical properties in HHP technology. KEYWORDS: Hardaliye drink, High hydrostatic pressure, Ultrasonication, Nonthermal innovative technologies, Alternative food preservation