Application of Cold Plasma Technology in Quality Preservation of Fresh Fig Fruit (Siyah): A Feasibility Study

Document Type: Research paper

Authors

1 Assistant professor of Agriculture Research Institute, Iranian Research Organization for Science and Technology (IROST), Tehran, Iran.

2 M.Sc. Student of Institute of Materials and Energy, Meshkin-Dasht, Karaj, Iran.

3 Former Student of College of Agriculture & Natural Resources, University of Tehran, Karaj, Iran.

Abstract

Fig (Ficus carica L.) is a perishable fruit and it needs to use new techniques in order to increase shelf life of this product. In present study, atmospheric cold plasma as a non-thermal treatment was utilized for preserving fresh fig quality. Dielectric barrier discharge plasma was applied to fruits in two steps. Durations of first treatments were 1 and 5 minutes. Based on this step results, main experiments were conducted for 30, 90 and 180s and cold plasma was applied to packed and unpacked fig samples. Quality was sensory evaluated in terms of color, texture, odor, appearance and overall acceptance. Firmness, color indices (L*, a* and b*),, total soluble solids and pH were also determined. Subjective measurements showed significant shelf life improvement of treated figs compared to control samples while objective quality attributes were not changed except pH and a* which are not undesired. Direct application of plasma for 90 s and in-package treatment for 30 s were suggested for further investigation and considering the practical aspects, pulsed plasma processing of packed figs for 30 s is recommended. It is concluded that atmospheric cold plasma has a potential for prolonging the shelf life of fresh fig fruits.

Keywords


Fig (Ficus carica L.) is a perishable fruit and there are demands to use new techniques in order to increase shelf life of this product. In the present study, atmospheric cold plasma as a non-thermal treatment was utilized for preserving fresh fig quality. Dielectric barrier discharge plasma was applied to fruits in two steps. Durations of first treatments were 1 and 5 minutes. Based on these results, main experiments were conducted for 30, 90 and 180s and cold plasma was applied to packed and unpacked fig samples. Quality was sensory evaluated in terms of color, texture, odor, appearance and overall acceptance. Firmness, color indices (L*, a* and b*), total soluble solids and pH were also determined. Subjective measurements showed significant shelf life improvement for the treated figs compared to the control samples while objective quality attributes were not altered except for pH and a* index which were not undesired. Direct application of plasma for 90 s and in-package treatment for 30 s were suggested for further investigation. Furthermore, considering the practical aspects, pulsed plasma processing of packed figs for 30 s is recommended. In conclusion, atmospheric cold plasma has the potential to be applied on fresh fig fruits to prolong its shelf life.