The days of cheeses coated with synthetic substances may be drawing to a close as new research suggests that natural polysaccharides may provide edible coatings for household favourites.
Galactomannan from Gleditsia triacanthos was found to give the best cheese coating properties and prevented mould growth, according to findings in the Journal of Agricultural and Food Chemistry (JAFC).
“The present work can serve as a guide for the use of new coatings for cheese as alternatives to synthetic coatings and may also be a guide for the study of future new materials for this purpose,” wrote lead author Miguel Cerqueira from the Universidade do Minho in Portugal.
In collaboration with researchers in Brazil, the Portuguese researchers studied three different polysaccharides from non-traditional sources to coat cheese: Galactomannan from Gleditsia triacanthos, chitosan, and agar from Glacilaria birdiae.
“The cheese studied in this work is a cylindrical, yellow, and semi-hard cheese; it is sold unpackaged, covered with a synthetic/ antibiotic coating, and under normal storage conditions, it suffers excessive water loss,” explained Cerqueira. “The present work evaluates the possibility of using functional polysaccharides as coatings on semi-hard cheese.”
Potential of polysaccharides
Tests included how the coatings affected the ‘wettability’ of the cheese, and how much water, oxygen, and carbon dioxide passed through, either in or out. The coatings were made from the polysaccharide, glycerol as a plasticiser, and corn oil.
According to the findings in JAFC, the solutions of G. triacanthos made from 1.5 per cent galactomannan, 2.0 per cent glycerol, and 0.5 per cent corn oil, had the best properties.
The consumption of oxygen and production of carbon dioxide by the cheese with and without the coating showed that the edible coating decreased the cheese’s ‘respiration’ rate.
Furthermore, galactomannan coating significantly decreased the growth of mould on the cheese, compared to the un-coated cheese.
“Further work has to be made to confirm the suitability of this coating to increase the shelf life of cheese after ripening and at different storage temperatures,” wrote Cerqueira and his co-workers.
“The cheese with coating has lower gas transfer rates as well as a decrease of the relative weight loss (ca. 8-fold less the value in the absence of coating). Visual evaluation also confirmed that the uncoated cheese suffered from an extensive mold growth when compared with the coated cheese,” they concluded.
Source: Journal of Agricultural and Food Chemistry 2009, Volume 57, Issue 4, Pages 1456-1462, doi: 10.1021/jf802726d“Functional Polysaccharides as Edible Coatings for Cheese” Authors: M.A. Cerqueira, I.M. Lima, B.W. S. Souza, J.A. Teixeira, R.A. Moreira, A.A. Vicente