Gamma radiation enhances the bioactivity of fresh parsley (Petroselinum crispum (Mill.) Fuss Var. Neapolitanum)

Research showed the effects of drying, freezing, and irradiation on the bioactivity of parsley, but overlooked comparing them. In the present study, the effect of minimal processing paired with gamma irradiation (0.7-2.7 kGy) was evaluated in respect to the content of ascorbic acid, polyphenols, antiradical capacity and antibacterial activity of parsley methanolic extracts. The results were compared with natural drying (20-22 °C) and rapid freezing (−20 °C). Absorbed doses of 0.7-1.4 kGy can be recommended to no treatment from a nutritional point of view because the content of vitamin C was better preserved and a significant increase of polyphenols content was observed when compared with control samples. Drying can be recommended only in terms of vitamin C and polyphenols content per consumed serving, as it doubles the content of vitamin C and triples polyphenols compared to the same mass of fresh product. Plant extracts with optimal antioxidant and antimicrobial can be obtained from fresh herbs stored at refrigeration temperature as little as possible. Extracts from dried or frozen herbs preserved for long periods of time are not recommended. An absorbed dose of 2.7 kGy may be applied to parsley in order to increase its antibacterial against Gram-negative bacteria such as E. coli and S. Typhimurium.