The effects of washing treatments with ultrasound technology and sanitation agents on the quality attributes of dried figs

The aim of this study was to determine the effects of ultrasound and sanitation agents (peroxyacetic acid and sodium chloride) as an alternative to washing processes applied to dried figs to eliminate possible microbial contaminations in dried figs. In this context, dried figs (Ficus carica L. cv. Sarılop) inoculated (~ 107 CFU g-1) with Escherichia coli NRRL B-59838, Bacillus cereus CCM 99 and Penicillium expansum NRRL 35695, were subjected to washing processes with single and combinations of ultrasound (US), peroxyacetic acid (PAA) and sodium chloride (NaCl) solutions; the optimum conditions were determined by analyzing the effects of the process parameters for each washing process using the response surface methodology (RSM). Optimum process conditions for combined washing processes were determined as 527 W US – 148 ppm PAA; 527 W US – 11.0% NaCl; 108 ppm PAA – 10.6% NaCl and 203 W US - 89 ppm PAA – 10.4% NaCl. Combined washing treatments significantly reduced the parameter levels by increasing the decontamination efficiency. E. coli was the mostly affected microorganism after the treatments. According to decontamination effects, US & PAA binary and US, PAA and NaCl triple washing processes were the prominent treatments where the triple washing process significantly reduced the process parameters. In this condition, the microbial reductions in dried figs were for E. coli; 3.09 ± 0.07, for B. cereus; 0.82 ± 0.03, for P. expansum; 0.98 ± 0.06 log CFU g-1. The effects of the processes on the physicochemical properties were also evaluated by color, carbohydrate, phenolic compound, antioxidant capacity and texture analysis of non-inoculated dried figs which were subjected to washing treatments at optimum conditions.