A study by Fadini et al. in the journal Food Hydrocolloids outlines a method to develop edible films with hydrolyzed collagen and cocoa butter plasticized with sucrose.
Shellac: beetle secretion
Conventional chocolate panned products are coated with shellac - derived from a substance secreted by the Lac insect - and used in solutions with ethyl alcohol or isopropyl.
Although, shellac produces a desirable gloss and acts as a good moister barrier it has many disadvantages, said the researchers.
“Alcohols are miscible with the fats and oils contained in chocolate and may cause undesirable bitter taste and off-flavors,” said the study.
It added that using alcohol as solvent produced compounds that are hazardous to the environment.
“The development and characterization of water-based edible films that could replace shellac with desirable barrier properties is important for the environment and for health especially because chocolate panned products have great appeal among children,” said the researchers.
Previous research has also indicated that consumers could be turned-off by products containing ingredients derived from beetle exudates.
Scientists in the present study found that hydrolyzed collagen film and cocoa butter were feasible flexible film alternatives.
Products coated with hydrolyzed collagen film had a less intense brightness than those produced with shellac, but were nonetheless attractive to consumers, said the study.
The researchers said that additional investigation was needed to assess the behavior of the films during storage, which may affect sucrose crystallization.
Food Hydrocolloids, Vol. 30, Issue 2, March 2013, Pages 625–631
‘Mechanical properties and water vapour permeability of hydrolysed collagen–cocoa butter edible films plasticised with sucrose’
Authors: A.L. Fadinia, F.S. Rochab, I.D. Alvima, M.S. Sadahiraa, M.B. Queiroza, R.M.V. Alvesa, L.B. Silvaa