Effectiveness of ultrasonication and high pressure processing pasteurization on quality characteristics and shelf life of fermented salgham drink

Processing of traditional fermented salgham juice by high hydrostatic pressure (HPP) and ultrasonication (US) with respect to quality attributes, microbial inactivation and shelf-life was studied. Explanatory varibles for HPP were time (3-15 min), temperature (4-40 ⸰C), pressure (200-500 MPa) and factors for US were (5-45 min), temperature (4-40 ⸰C) and amplitude (50-90 A), and both spicy and sweet shalgam juices were processed by HPP and US according to the conditions determined by Box-Behnken design. Color intensity, color tone, total mold and yeast, survived Lactococcus lactis subsp. cremoris and Lactobacillus paracasei of 3.43 A, 0.69 A, 3.09 log kob/mL, 2.51 log kob/mL, and 2.68 log kob/mL, were the optimum conditions for HPP (34.23 ⸰C, 15 min, 500 MPa) processed spicy turnip juice; conductivity, total antioxidant activity, total reducing sugar, total number of mesophilic aerobic bacteria, survived L. paracasei of 8.65 mS/cm, 63.56 %, 0.39 g/L, 3.16 log kob/mL, and 2.94 logkob/mL were the optimum conditions for HPP processed (40⸰C, 15 min, 363.6 MPa) sweet turnip juice; total acidity, total mesophilic aerobic bacteria, total yeast and mold, survived L. paracasei and L. lactis subsp. cremoris of 0.393 g/L, 3.37 log kob/mL, 3.22 log kob/mL, 3.22 log kob/mL, and 3.40 log kob/mL were the optimum conditions for US (17.09 ⸰C, 36.51 min, 79.89 A) processed spicy turnip juice; conductivity, total acidity, total mesophilic aerobic bacteria, survived L. paracasei and L. lactis subsp. cremoris of 16.23 mS/cm, 0.439 g/L, 3.06 log kob/mL, 3.15 log kob/mL, and 3.27 log kob/mL were the optimum conditions for US (4 ⸰C, 28.84, 90 A) processed sweet turnip juice, respectively. Turnip juices processed under optimum conditions were stored at both 4 and 22 °C for 90 days, and sensory, physicochemical and microbiological analyses were performed on 0, 15, 39, 45, 60, 75 and 90th days of storage. As a result of 90 days shelf life studies, it was determined that there was no sensory deterioration in the samples and no significant loss in quality criteria. Results revealed that HPP was more successful for spicy turnip juice and sweet turnip juice. KEYWORDS: Turnip Juice, High Hydrostatic Pressure, Ultrasonication, Box-Behnken design, Shelf life