Aloe Vera Coating May Prolong Freshness, Safety Of Fruits And Vegetables

Although a number of edible coatings have been developed topreserve food freshness, the new coating is believed to be the first touse Aloe vera, according to study leader Daniel Valero,Ph.D., of the University of Miguel Hernández in Alicante, Spain. Hisstudy will appear in the Oct. 5 print issue of the American ChemicalSociety’s Journal of Agricultural and Food Chemistry, the Society’s peer-reviewed publication.

Valero and his associates dipped a group of common table grapes (Crimson Seedless) into Aloe veragel and stored them for five weeks under low temperature while exposinga group of untreated table grapes to the same conditions. The colorlessAloe gel used in this study was developed through a special processingtechnique that maximized the amount of active compounds in the gel,Valero and associates say. The gel can also be applied as a spray, theyadd.

The untreated grapes appeared to deteriorate rapidly withinabout 7 days, whereas the gel-coated grapes were well-preserved for upto 35 days under the same experimental conditions, the researchers say.The gel-treated grapes were firmer, had less weight loss and less colorchange than the untreated grapes, measures which correspond to higherfreshness, they say.

A sensory panel (10 people) evaluated the quality of both theuntreated and the gel-treated grapes by consuming some of the grapes.They found that the gel-treated grapes were generally superior intaste.

The researchers believe that the gel works through acombination of mechanisms. Composed mostly of polysaccharides, the gelappears to act as a natural barrier to moisture and oxygen, which canspeed food deterioration. But the gel also enhances food safety, thescientists say. Based on previous studies by others, Aloe veragel appears to contain various antibiotic and antifungal compounds thatcan potentially delay or inhibit microorganisms that are responsiblefor foodborne illness in humans as well as food spoilage.

Although the health effects of Aloe gel on humanconsumption were not directly measured in this study, the coating isbelieved to be safe, the researchers say. They note that Aloe veragel has been used as a functional ingredient in some foods andbeverages for years. In addition to preserving table grapes, which arehighly perishable, the gel can be applied to other fruits andvegetables, they say. Further testing of the gel on other types ofproduce is anticipated.

The gel also offers potential environmental benefits, theresearchers add. It could provide a greener alternative to sulfurdioxide and other synthetic food preservatives that are commonly usedon produce and increasingly the target of health concerns, they say.

Valero and his associates have filed a patent application inSpain for their gel. It could appear in the U.S. consumer market withina year, Valero estimates, noting that the gel is a natural product andis unlikely to face any major regulatory hurdles. Funding for thisstudy was provided by the Spanish Ministry of Science and Technologyand the European Commission via FEDER (European fund for regionaldevelopment).