Writing in its international patent, the company said the blend was made using a number of natural wax components, lipids, proteins, carbohydrates and synthetic materials that worked synergistically to provide bactericidal and fungicidal action. The protective wax, it said, could be applied directly to citrus fruits, apples, mangoes, tomatoes, and cucumbers, among others.
Post-harvest decay has 'high economic impact'
Margrey Industrial said fruit and vegetables currently went through a lengthy process of storage and transport before reaching the end consumer, during which time they were exposed to a number of environmental conditions that caused loss of moisture and increased risk of putrefaction. In addition, the products were often poorly stored by consumers at home, contributing to post-harvest decay.
All of this, the company said, had a “high economic impact” on production.
Whilst many efforts had been made to extend the shelf-life of fresh fruit and veg, including cold storage and coatings, these methods either changed the nutritional and organoleptic characteristics of the produce or left unwanted residues
The company said its blend, by contrast, improved shelf-life in a “significant manner” without altering the organoleptic properties of the fruit or veg because it was permeable to gaseous exchange, enabling “aerobic respiration” of the produce. All of the components in the blend were also, importantly, non-GMO and FDA-approved for human consumption, it said.
Margrey Industrial said one aspect that differentiated its blend from previous inventions was its bactericidal and fungicidal action, thanks to the addition of glutaraldehyde and forming a non-toxic polymer when reacting with ammonia.
“The present invention relates to the development of improved compositions, specifically in the field of food engineering and post-harvest technologies,” the company wrote in its patent filing.
“...The invention relates to a highly effective and harmless anti-fungal for [humans] and the environment,” it said.
In addition, due to a “multi-layer configuration” of the coating, the composition was capable of rapidly distributing the stresses generated by thermal shock, avoiding the generation of white spots.
Application and formulation details
Margrey Industrial said the coating composition was quick-drying and enabled uniform coating with very little product: one liter of blend was sufficient to coat one ton of fruit.
The blend could also be applied to the walls of boxes transporting the fresh fruit to minimize loss of water, thanks to such a high stability, it said.
The composition had to contain at least one natural waxy component; at least one plasticizing agent; at least one surfactant; an anti-foaming agent; at least one alkali; glutareldehyde; gibberellic acid and water, Margrey Industrial detailed in the patent. The natural waxy component could be sourced from carnauba wax, pine resin, beeswax or candelilla wax, among others; the plasticizer from glycerol, xylitol or maltol, among others.
Source: WIPO International Patent No. 2018174699
Published: September 27, 2018. Filed: March 21, 2017.
Title: “Wax composition for coating fruit and vegetables”
Authors: Margrey Industrial S.A. De C.V. - JM. Benitez Talamantes, JJ. Martinez Gonzales and FJ. Martinez Gonzalez