Implementation of low energy e-beam for dried vegetable treatment: Effect on microbial and physicochemical qualities of dried red chili pepper (Capsicum annuum L.)

Abstract

Low energy electron beam (LEEB) can be used as a surface treatment for microbial decontamination of foods and materials. This study aimed to evaluate the effect of LEEB with energy of 330 keV on naturally occurring microorganisms of dried red chili pepper, as well as on the physicochemical quality. Results showed that the average density determined gravimetrically was 1.2 g/cm³ and the average thickness of chili pepper wall was 0.5 mm. The penetration ability of electrons in environmental conditions measured in stack of B3 dosimetry foil could not exceed 0.3 mm thick of the dried chili pepper wall. Although, electrons generated at 330 keV, led to total inactivation of Staphyloccocus spp. and yeasts at 5, 8 and 10 kGy. The various doses (3, 5, 8 and 10 kGy) led to reduction by more than 4 log CFU of the initial mean concentration of total aerobic plate count and total coliforms. Concerning physicochemical quality, LEEB maintained the ash content, pungency level and decreased the water activity. The bioactive compounds of dried red chili pepper including total phenolic content, flavonoids and antioxidant activity showed an enhancement after LEEB treatment. Sensory attributes were not affected compared to control. Overall, LEEB processing can be conducted as a post drying process to effectively decontaminate dried red chili pepper without affecting nutraceutical physicochemical and sensory properties.