Effect of heat and γ‐irradiation on fungal load, pasting, and rheological characteristics of three whole and dehulled millets during storage

Abstract

Generally, heat and γ-irradiation techniques are used in the preservation of millets. Therefore, the effect of heat (150°C to 170°C for 90 s at 300 rpm) and γ-irradiation (1 kGy and 2.50 kGy) on fungal load, pasting, and rheological characteristics of three whole and dehulled millets (sorghum, foxtail millet, and pearl millet) was investigated during storage (90 days). The findings showed that the pasting (e.g., pasting temperature, peak viscosity, and peak temperature, etc.) and rheological (e.g., storage modulus, loss modulus, and yield point, etc.) properties decreased during 90 days of storage. The results indicated that the heat and γ-irradiation collectively reduced the fungal load (154 × 104 to 3.58 × 104 CFU/g) on the whole and dehulled millets. Therefore, the study concluded that the heat and γ-irradiation may improve the millets storability and seems to be a promising postharvest preservation method to reduce fungal incidences in millet-based products. Practical applications The study evaluated the effect of heat and γ-irradiation on pasting, rheological, and microbiological (total fungal count) characteristics of whole and dehulled millets (sorghum, foxtail millet, and pearl millet) during 90 days of storage. The heat and γ-irradiation improved the storability properties of millets by reducing fungal growth. Thus, heat and γ-irradiation treatments could be an alternative and safe postharvest preservation method in grain storage industries to reduce fungal incidences.