The Chinese Institute of Thermal Sciences has made new progress in the field of new materials for the preservation of polysaccharide-based antibacterial films for mangoes

Recently, the South Asia Institute of the Chinese Academy of Thermal Sciences has made new progress
in the creation of new materials for mango antibacterial film preservation.
The results of this study systematically and comprehensively elaborate the effect and mechanism of antibacterial coating materials on mango preservation from the aspects of synthesis of new coating film preservation materials, analysis of antibacterial activity, evaluation of mango preservation application effect and antibacterial preservation mechanism
of materials.
This study has important theoretical guiding significance for achieving green, long-term and safe preservation effects in the postharvest storage, transportation and sale of mangoes, and also provides a theoretical basis and technical support
for the development and application of new preservation materials.

Mango is an important tropical and subtropical fruit
.
However, mangoes often ripen in the high temperature and high humidity season, and are susceptible to a series of pathogens such as anthrax after harvest, which accelerates the rot of mango, resulting in a short preservation cycle of mango, and affecting the quality of
harvest results 。 In view of the limitations of traditional preservation methods such as refrigeration and chemical preservatives, based on the previous research basis, after analyzing the causes of mango decay, the research team started from the antibacterial mechanism of the material, and grafted small molecules with broad-spectrum antibacterial activity to chitosan molecule (CS) with good biocompatibility, degradability and film-forming properties.
A double-modified chitosan-based antibacterial coating material (CS-QP-SA) with synergistic antibacterial effect was synthesized, which significantly improved the antibacterial and water-soluble properties
of chitosan materials.
The CS-QP-SA material uses the positive electricity of quaternary phosphonicum salt to produce electrostatic adsorption with the surface of the cell membrane (negatively charged) of pathogenic bacteria, thereby affecting the metabolism of pathogenic bacteria cells to achieve the antibacterial mechanism
of killing pathogenic bacteria.
At the same time, the phenolic hydroxyl group of salicylic acid is also used to destroy the structure of bacterial cells, resulting in the leakage of bacterial cytoplasm and other antibacterial mechanisms
that kill bacteria.
In addition, one of the advantages of CS-QP-SA coating film preservation new material is that by soaking mango in the prepared antibacterial agent solution, a breathable bio-based antibacterial film is formed on the surface of the mango, which can not only regulate the respiration intensity of the fruit, but also kill harmful bacteria on the surface of the fruit, and effectively resist the infection of harmful bacteria in the environment, which plays a good role in fruit preservation; The second advantage is that the material is soluble in water, and the fruit can clean off the coating film on the surface after soaking in water, and does not affect the later consumption, and the coating film preservation material is green and safe
.
The results show that after 20 days of storage of mango treated with CS-QP-SA film preservation material, the rot rate is reduced by 38%, the average content of Vc is reduced by 67%, the fruit rot rate is effectively reduced, the quality of mango is guaranteed, and the safe and efficient preservation effect
is realized.

The results were published in the International Journal of Biologic under the title "Synergistic antibacterial activity of chitosan modified by double antibacterial agents as coating material for fruits preservation.
" Macromolecules》
。 Ruan Xiangmei and Li Puwang, graduate students of the South Asia Institute of the Chinese Academy of Thermal Sciences, are the co-first authors of the paper, and Wang Chao, assistant researcher and Yang Ziming, associate researcher of the South Asia Institute of the Chinese Academy of Thermal Sciences, are the co-corresponding authors
of the paper.
The research was supported
by the Natural Science Foundation of Hainan Province, the Key R&D Program of Hainan Province, the Natural Science Foundation of Guangdong Province and the Basic Research Funds of the Chinese Academy of Tropical Agricultural Sciences.

Full text link: https://doi.
org/10.
1016/j.
ijbiomac.
2022.
10.
084

Source: Chinese Academy of Tropical Agricultural Sciences