Effect of Nano-SiOx/Chitosan Complex Coating on the Physicochemical Characteristics and Preservation Performance of Green Tomato

Abstract

A novel nano-silicon oxides (SiOx)/chitosan complex film was prepared using ultrasonic assistant in the process of dissolving chitosan and silicon oxides (SiOx), and characterized by transmission electron microscopy. Its effect on quality preservation of tomatoes (Solanum lycopersicum L. cv. Zheza 205) was investigated under ambient temperature. The results revealed that the nano-SiOx/chitosan complex (NSCC) film retarded weight loss and softness, delayed the titratable acids and total soluble solids loss, and thus markedly extended shelf life of green tomatoes. The antimicrobial activity of tomatoes coated with NSCC film was also recorded higher compared to chitosan (Ch) films and control. In addition, the NSCC film-coated tomatoes prevent the increase of malondialdehyde content and total polyphenol content. Moreover, the peroxidase activity, phenylalanine ammonia-lyase activity, and polyphenoloxidase activity of tomatoes coated with NSCC film were found lower than that in other treatments. These data indicated that the beneficial effects of nano-SiOx/chitosan complex coating on postharvest quality were possibly associated with the lower rate of O 2 /CO 2 transmission coefficient, limiting food-borne pathogenic bacterial growth, higher antioxidant activities, and also higher reactive oxygen species (ROS) scavenging and anti-browning activities of related enzymes in the tomatoes. Further, the results of the study could be used to successfully develop a novel nano-SiOx/chitosan complex film for improving the postharvested quality of tomatoes and thus effectively utilized by the food packaging industry.

Chitosan-Phenylalanine Nanoparticles (Cs-Phe Nps) Extend the Postharvest Life of Persimmon (Diospyros kaki) Fruits under Chilling Stress

“…It seems that the application of Cs-Phe NPs could increase fruit tolerances to chilling injury by inducing the defense responses which could reduce ROS and preserving the cell membrane via the formation of phenolic and antioxidant compounds [40]. Zhu et al [41] showed that fruit coating using edible polymer such as chitosan has improved inhibition of ROS production and prevented chilling damage in fruit, which is in agreement with our findings. Some recent studies reported that coating with Cs prevented the increasing of chilling injury in fruit.…”

“…Chitosan provides uniform and stiff binding to surfaces of persimmon fruits that prevents increased respiration and delays transpiration rates [44]. Some recent studies reported that fruit coated with Cs were prevented from reducing in weight, water vapor transmission rate and O 2 /CO 2 by increasing surface and interface roughness and due to a smaller pore size, thus preventing the percentage of weight loss [41]. Menna et al [25] reported Cu-chitosan nano significantly prevented weight loss in tomato during 21 days storage, which is in accordance with our study.…”

“…Decreasing of firmness was associated with increased respiration and cell wall destroyer enzyme activities that cause breakdown of structural polysaccharides, especially hemicellulose and pectins in the cell wall [46]. Cs-Phe NPs treatment formed a thin layer on the surface of the fruit and modified the exchange of gas O 2 and CO 2 in the fruit, directly affecting the fruit respiration rate and further delaying the decrease in firmness [41]. Meena et al [25] reported that fruit coated with Cs prevented the reducing of firmness; for example, cu-chitosan nano-net maintained firmness in tomato fruit for 15 days with the entire surface of the fruit covered and controlled moisture loss and gas exchanges and decreased respiration rate.…”

Composite coatings based on konjac glucomannan and sodium alginate modified with allicin and in situ SiOx for ginger rhizomes preservation

“…POD activity in the coated groups is significantly lower than in the control at 6–15 days, suggesting that the KGM/SA composite coating provide a more suitable environment for gingers storage and inhibited oxidation of phenolics (Zhu et al, 2019a). Similar changes of POD activity affected by coating were found in Pholiota nameko mushroom coated with sodium alginate‐based composite coating (Zhu et al, 2019a,b), and by sodium chloride treatment for fresh‐cut gingers preservation were found from Jia (2019).…”

“…Fruits and vegetables may soften and change in texture caused via cell wall degradation during storage (Zhu et al, 2019b). Cellulase can degrade both cellulose and the b‐1,4‐glucan backbone of xyloglucan in cell wall, and thus is related to qualities of the fruits and vegetables (Zhou, Li, Yan, & Xie, 2011).…”