Effect of Gamma Radiation and Storage Time on the Microbial and Physicochemical Properties of Dried Byadgi Chili (<i>Capsicum annuum</i>)

Abstract

The effects of gamma radiation up to 10 kGy and storage time (0 to 16 weeks) on microbial and physicochemical properties of dried Byadgi chili were investigated. After 2.5, 5.0, 7.5, and 10.0 kGy of radiation, the samples were kept at room temperature with the control sample (0 kGy) and analyzed at 0, 4, 8, 12, and 16 weeks. Microbial aspects including total aerobic count (TAC), E. Coli, coliform, yeast, and mold were tested, as were physicochemical characteristics such as moisture, water activity, surface color (L*, a*, b*, chroma, and hue), aflatoxin, capsaicin, and dihydrocapsaicin. As the radiation dose and storage period were increased, water activity rose in lockstep with moisture. Gamma radiation had no effect on the color of the surface up to 10 kGy, although it did not aid with the retention of the initial color value during storage. Mold growth was observed in the control, 2.5, 5.0, and 7.5 kGy radiated samples, but no aflatoxin was found. The increase in radiation dose and storage time had a negative effect on capsaicin and dihydrocapsaicin. TAC was also observed at the end of the storage time, despite radiation at 10.0 kGy successfully sterilizing dried Byadgi chili. The principal component analysis (PCA) biplot revealed two distinct groupings based on duration of storage times. Radiation at 10.0 kGy had an excellent response to the microbial profile, with only minimal changes in quality attributes after eight weeks of storage.

Keywords

• capsaicin
• dihydrocapsaicin
• principal component analysis (PCA)
• high performance liquid chromatography (HLPC)