‘Nano-net’ protects tomatoes against microbial decay
doi:10.1038/nindia.2021.25 Published online 9 February 2021
A coat of copper and chitosan nanoparticles protects tomatoes against microbial infection, extending their shelf-life during storage1.
The coat, called nano-net, controls moisture loss and retards respiration that usually speeds up ripening, decreasing the shelf-life of tomatoes, according to a team of Indian researchers from the Maharana Pratap University of Agriculture and Technology in Udaipur, the ICAR-Indian Institute of Maize Research in Ludhiana and the ICAR-National Institute of Abiotic Stress Management in Pune.
The coat could also potentially be used to protect other fruits and vegetables, they claim.
Existing tools are inefficient in preventing the post-harvest loss of tomatoes, resulting in an economic loss for farmers. To find a better way to check such losses, the scientists loaded copper ions into the matrix of chitosan nanoparticles.
They then coated the tomatoes with the nanoparticles, forming a nano-net over the surface of the tomatoes. Unlike the uncoated tomatoes, which showed signs of decay, the coated ones remained fresh over a period of three weeks at room temperature.
The nanoparticles inhibited the growth of microbes, checking microbial decay and preventing weight loss of the tomatoes considerably during storage.
Sophisticated imaging techniques revealed that the nano-net formed an invisible barrier at possible openings over the surface of the tomatoes, retaining their freshness and desired colour for up to three weeks at room temperature.
The nano-net also maintained the levels of ascorbic acid – a key antioxidant present in high concentrations in green tomatoes – which usually decreases during ripening.
1. Meena, M. Cu‑chitosan nano‑net improves keeping quality of tomato by modulating physio‑biochemical responses. Sci. Rep. 10, 21914 (2021)