Effect of Gradient Vacuum Pressure on Quality Parameters of Vacuum-Fried Bananas Chips

The effect of vacuum pressure mode has not been studied depth yet. Effect of vacuum pressure on the quality of vacuum-fried banana slices was studies in this work. Three vacuum frying processes were conducted and tested. Classically, two constant vacuum pressures 80 (CVF-80) and 180 mmHg (CVF-180) were applied in the frying process at 90°C. One novel frying method with gradient vacuum pressure (GVF) changed from 760 to 80 mmHg was conducted and adapted. The frying temperature was kept at 90°C. The frying processes were monitoring by moisture contents and 4% was generally accepted as moisture content of final product. Meanwhile, the frying times of CVF-80, CVF-180 and GVF were 50, 80 and 60 min, whereas the brightness values (L*) were corresponded to 71.07, 71.36, 67.25, respectively. The GVF samples were brightest with lowest hardness value (30.8 N) and the CVF-180 was darkest with highest hardness value (36.87 N). The microstructure analysis showed that the GVF increase in both size and number of pores in comparison with CVF. Additionally, based on the paired comparison sensorial test the GVF fried banana slices were crisper than CVF samples. Our results revealed that the GVF method improves the quality of vacuum-fried banana slices, thus it can be good alternative method for production of banana snack.