Posted by When α-Cyclodextrin Meets 1-MCP: Supramolecular Chemistry Behind Fruit Storage
Keeping harvested fruit fresh is, at its core, a race against time. After harvest, the natural ripening process continues, driven in large part by ethylene – a plant hormone that promotes a range of physiological changes, including softening, colour development and senescence. One intriguing example of how supramolecular chemistry can be translated into agricultural technology is a Russian innovation involving the use of 1-methylcyclopropene (1-MCP) in combination with α-cyclodextrin.
The company Fresh-Forma uses this principle in its 1-MCP-based technologies for controlling fruit ripening. According to the company’s product information, its formulations contain 1-MCP in a complex with α-cyclodextrin.
Why is 1-MCP difficult to handle?
1-MCP is a small cyclopropene derivative that acts as an inhibitor of ethylene perception. However, its physicochemical properties present a practical challenge: under normal conditions it is a volatile and highly reactive compound. Handling and delivering a defined amount of free 1-MCP directly to fruit-storage environments is therefore far from straightforward.
For 1-MCP, the α-CD cavity provides a temporary molecular environment in which the volatile guest molecule can be physically accommodated. In other words, α-CD transforms a difficult-to-handle small volatile molecule into a more convenient solid inclusion complex.
This concept is not merely theoretical, some already published 1-MCP laboratory formulations identify α-cyclodextrin as a principal sorption/complexation material for stabilising and delivering 1-MCP. Commercial products, including Fresh-Forma, have been described as complexes of 1-MCP with α-CD.
From molecular complex to agricultural technology
The real technological advantage of the α-CD/1-MCP system is not simply that the cyclodextrin capturing 1-MCP. The complex provides a practical way of transporting, dosing and subsequently releasing the active compound.
When the complex encounters an appropriate aqueous environment, the equilibrium between complexed and free 1-MCP shifts, allowing the volatile molecule to be released. The patent description of 1-MCP/α-CD systems (RU2797670C1) specifically describes the release of gaseous 1-MCP following contact with water; formulation and process parameters can be used to influence the rate of release.
Fresh-Forma’s current product information also illustrates how the same supramolecular concept can be incorporated into a more complex agricultural formulation. Its “Apple Guard” product is described as a dry composition containing an industrial ethylene inhibitor based on 1-MCP complexed with α-cyclodextrin, together with a magnesium-based mineral fertiliser complex. The manufacturer describes application by preparing an aqueous suspension immediately before spraying.
According to the manufacturer’s instructions, the formulation is intended for pre-harvest treatment of intensive apple orchards, with application several days before the anticipated beginning of harvest. The stated objective is to influence ripening processes and extend the practical harvesting window.
Source:
https://freshforma.ru/katalog/preparat-%C2%ABfresh-forma-%C2%AB1-mczp-zhidkaya-forma%C2%BB.html