Enhancement of Shelf Life of Citrus Limon L. (Lemon) Using Plasma Activated Water

The present study investigates the impact of plasma-activated water (PAW) on the shelf life of Lemon (Citrus Limon L.). The plasma is characterized using voltage-current waveform, and the species/radicals formed in the plasma are detected using optical emission spectroscopy. The results of the study indicate that a 30 min exposure of lemons with PAW results in a significantly higher reduction of microbial load on the lemon surface compared to the demineralized water (control). In addition, the PAW exposure of lemons resulted in lower weight loss and spoilage as compared to the control over a long duration. The sensory evaluation (smell, appearance, taste, etc.) and color evaluation showed that PAW exposed lemons have shown improved acceptability compared to lemons exposed to the control. The surface firmness test also revealed that PAW exposure did not damage the lemon surface. The analysis of lemon juice nutrients (titratable acidity, sugar, carbohydrate, protein, and vitamin C) and antioxidant activity (total phenols, flavonoids, antioxidant assays) indicated that the interaction of PAW with lemons did not result in significant changes in these aspects compared to the control. Lastly, the 2 month long-term storage of lemons after PAW and control exposure showed that lemons exposed to PAW had acceptable quality, wherein lemons exposed to control were completely spoiled and covered with mold. The study reveals that PAW has the potential to be used as an environmentally friendly alternative to chemical food preservatives.