Application of Gamma Irradiation to Ensure Safety and Preserve the Quality of Fresh Blueberries (Emerald)

ABSTRACT

This study aimed to evaluate the effect of gamma irradiation (0.6, 1.2, and 1.8 KGy doses) on rotavirus inactivation (RVA) and the quality of Esmerald fresh blueberries. Dosimetry measurements revealed absorbed doses of 0.72, 1.46, and 2.16 KGy. The D₁₀ value for RVA inactivation was determined to be 3.03 ± 0.03 KGy, exceeding the maximum 2.5 KGy dose permitted for fresh fruit, indicating that gamma irradiation alone is insufficient for effective RVA inactivation without significantly impacting blueberry quality. On the other hand, the absorbed doses (0.72, 1.46, and 2.16 KGy) did not affect most of the physicochemical parameters or the nutritional profile. However, a dose-dependent decrease in mechanical properties and enzyme activity was observed. Therefore, achieving effective RVA inactivation in fresh blueberries could require a combined approach, integrating gamma irradiation, ideally at doses up to 1.46 KGy, with complementary methods. This combined strategy could offer a promising intervention for the inactivation of RVA in fresh produce.

Practical Application

Blueberries, due to their specific characteristics, are particularly susceptible to viral contamination. Conventional sanitation methods, such as washing, are inadequate as they can affect the texture, integrity, and appearance of the fruit. Gamma irradiation is a non-thermal preservation method that improves food safety and extends shelf life while causing minimal alterations to the natural attributes of fresh produce. According to our results, gamma irradiation showed potential to inactivate RVA in blueberries. However, to achieve complete inactivation, a dose higher than the allowed dose (2.5 KGy) is required. Furthermore, our study revealed that irradiation treatments with doses lower than 2.5 KGy had a negative impact on the mechanical properties of blueberries, while they had a limited impact on the inactivation of the enzyme. In this regard, further studies are needed to explore combined strategies that effectively inactivate RVA and enzymes without compromising the delicate quality of fresh produce.