Chitosan nano-biopolymer/Citrus paradisi peel oil delivery system enhanced shelf-life and postharvest quality of cherry tomato.

Grapefruit peel essential oil (CpEO) was loaded on chitosan (Cs) nano-biopolymer by ionic gelation method and its effect on physicochemical properties of cherry tomatoes was evaluated during 18 days of storage at 10 °C. The highest loading capacity and encapsulation efficiency were obtained from the weight ratio of 1:0.25 Cs to oil. TEM, DLS and FTIR were used to characterize the nanoparticles. The release of the oil from the nanoparticles followed the Fickian diffusion model. CpEO-CsNPs-CO and CpEO-CsNPs-RE treatments reduced ethylene production and respiration rate and indicated a significant and promising effect on increasing the level of antioxidant enzymes (CAT and POD), slowing down the loss of ascorbic acid and total phenolic content and consequently, maintaining antioxidant capacity. These treatments prevented a rapid decline in TSS and TA and an increase in lycopene and MDA level, and maintained the firmness, weight, and color of the fruits throughout storage period.

Chitosan nanoparticles-loaded Citrus aurantium essential oil: a novel delivery system for preserving the postharvest quality of Agaricus bisporus.

BACKGROUND: One of the main problems in the button mushroom industry is the rapid deterioration of fruit bodies after harvest. Today, nanotechnology has become a more reliable technique to improve the quality of products in food packaging. In the present study, the effectiveness of chitosan nanoparticles containing Citrus aurantium essential oil on postharvest quality of white button mushroom was examined and compared to essential oil fumigation and control treatments. RESULTS: Based on high-resolution transmission electron microscopy and dynamic light scattering, nanoparticles exhibited a spherical shape of 20-60 nm diameter. The results revealed that the application of chitosan nanoparticles loaded with C. aurantium oil significantly decelerated the rate of color change, weight loss and firmness compared to fumigation with essential oil and control treatments. Treatment of fruit bodies with chitosan nanoparticles loaded with C. aurantium oil promoted the accumulation of phenolic compounds and ascorbic acid, and resulted in increases in catalase and superoxide dismutase and a decrease in polyphenol oxidase activities, as the highest antioxidant capacity was observed after 15 days of cold storage. CONCLUSION: This present research demonstrates that gradual release of C. aurantium essential oil from chitosan nanoparticles could be an effective and practical method for extending the shelf life of white button mushroom up to 15 days without significant decrease in antioxidant capacity. © 2018 Society of Chemical Industry.

Development and characterization of nano biopolymer containing cumin oil as a new approach to enhance antioxidant properties of button mushroom.

The aim of present study was to design a controlled release system using Cuminum cyminum essential oil loaded chitosan nanoparticles (CEO-CSNPs) and evaluate its effect on catalase (CAT), glutathione reductase (GR), peroxidase (POD) activity and ascorbic acid content of Agaricus bisporus fruit bodies during 20days of storage at 4°C. The success of encapsulation was evaluated through TEM, DLS, FT-IR and spectrophotometry and its release behavior was studied in buffer solutions with different pH. The CEO-CSNPs exhibited an average size of 30 to 80nm with a spherical shape. Encapsulation efficiency (EE) and loading capacity (LC) were 4.46 to 17.89% and 2.47 to 6.68%, respectively. The highest CAT and GR activity was observed in samples packed with CEO-CSNPs after 15days of storage. In contrast, POD activity reached a peak at the end of storage in control samples. Interestingly, after 20days the level of POD increased 17.13% in CEO-CSNPs treatment, as compared with the initial level of the mentioned enzyme. At the end of storage, ascorbic acid content in samples treated with CEO-CSNPs was significantly higher than that detected in the control samples. In brief, application of CEO loaded chitosan nanoparticles in packages effectively increased the antioxidant activity in white button mushroom and showed promising results for extending the shelf life of treated samples.