Terpenes are biocidal as a result of their lipophilic (fat-loving) characteristics, which are observed to affect the integrity of cell walls and cell membranes. However, their relatively low molecular weight (for an organic oil) creates two major drawbacks:
In 2004 the major breakthrough of our patented encapsulation technology overcame these drawbacks. This allows terpenes and other biologically active ingredients of a similar nature to be applied using conventional agricultural spraying equipment. Although initial research has focused on agricultural uses, the full potential of encapsulated terpene formulations as commercial biocides extends to a variety of other applications in the healthcare and consumer markets.
The technology used to encapsulate terpenes, either individually or as mixtures, in a natural carrier particle is illustrated in Figure 1. The terpene-carrying particles can be prepared as a liquid suspension or powder formulation, which can in turn be applied to the site of infection.
Figure 1 Encapsulation of terpenes into natural carrier particle
When delivered to the target site, free terpenes in the spray mixture produce an immediate biocidal effect. The carrier particles then dry onto the target, and terpene release ceases temporarily.
Figure 2 Release of terpenes from carrier particle under moist conditions
The terpenes continue to diffuse out of the carrier by the addition of more moisture from rainfall, dew or mist, maintaining an antimicrobial effect over a period of several days under moist conditions that would otherwise be conducive to fungal or bacterial growth.
A similar effect is achieved in the soil when the encapsulated product is applied as a soil drench or via irrigation systems. After soaking into the soil, the free terpenes loosely adhering to the carrier particles kill nematodes and disease-causing microbes. As the soil dries out, activity slows or stops. However, when the soil becomes wet again due to rainfall or irrigation, activity restarts. As a result, the efficacy of the terpenes is maintained over an extended period and controls the re-emergence of disease or pests.
This breakthrough also opened up exciting opportunities in non-agricultural fields, such as medicine and dentistry, where the antimicrobial properties of terpenes can be effectively applied at controlled doses for wound healing and oral health applications.
Working closely with major universities and commercial research organisations in the USA, Europe and parts of the Southern hemisphere, Eden is now concentrating on developing commercial products for agricultural use in the treatment of plant diseases in a wide variety of crops, as well as pest control issues. In addition to earlier research focusing on products to fight vineyard vascular infections (i.e. Pierce’s disease and eutypa), foliar products have been developed to control mildews and moulds, with scope for much wider use. We are also making rapid progress towards developing an effective nematode-control product. More recent agricultural research has revealed the ability of our encapsulated products to control spider mites in glasshouses and to combat foliar and soil borne bacterial diseases.
Eden has therefore reached an advanced stage in the development of a series of competitive antimicrobial and invertebrate-control agents suitable for use in vineyards and greenhouses and on a variety of high-value agricultural/horticultural field crops. The potential for finding further applications of terpene formulations in both the agricultural and healthcare sectors is vast and clearly exciting.