Document Type: Original Article


1 Department of Horticultural Science, Ardakan University, Ardakan, Iran

2 Agricultural and Natural Resources Research Center of Yazd, Yazd, Iran

3 Department of Horticultural Science, Ardakan University, Ardakan, Iran.


Edible coatings are an environmentally friendly technology that is applied to many products to control moisture transfer, soluble and aromatic materials, gas exchange or oxidation processes. The objective of this research was to study the effect of tragacanth gum at the concentrations of 0, 5, 10, and 15 kg m-3 on storage life and edible quality of apple cvs. Red Delicious and Golden Delicious. After applying treatments, the fruits were kept in a cold storage at a temperature of 0±1 ˚C and relative humidity of 85-95 percent. The weight reduction, external quality, microbial load, and general acceptability of the samples were evaluated after 0, 30, 60, 90 and 120 days of storage, then compared with uncoated apples. It was found that the tragacanth gum significantly reduced fruit weight loss compared to the control, so that weight reduction in uncoated apples was eight times greater than fruits treated with tragacanth gum at 10 kg m-3. This coating preserved firmness of fruit tissue in storage and prevented the softening and senescent breakdown of apples. The tragacanth gum coating desirably preserved the external quality and improved the microbial load, sensory and external properties of the fruits, preserved quality factors of the apples, and prevented fruit ripening during storage. Among the various treatments, the coating at 10 kg m-3 was more effective than the other treatments, maintained fruit juice acidity and pH at desirable levels, and prevented increases in the contents of soluble solids during the storage.


  • The tragacanth gum coating improved fruit quality and extend shelf-life.
  • The tragacanth gum coating desirably preserved the external quality and improved the microbial load, sensory and external properties of the fruits.


Main Subjects

Adetunji, C., Fawole, O., Arowora, K., Nwaubani, S., Ajayi, E., Oloke J., Majolagbe, O., Ogundele, B., Aina, J., & Adetunji, J. (2012). Effects of edible coatings from Aloe vera gel on quality and postharvest physiology of Ananas comosus (L.) fruit during ambient storage. Global Journal of Science Frontier Research, 12, 39-43.

AOAC. (1997). Official Methods of Analysis of the Association of Official Analytical Chemists (AOAC) International, 16th ed. AOAC International, Washington.

AOAC. (2002). Acidity (Titratable) of Fruit Products. Gaithersburg, MD: official methods of analysis of AOAC International, Official Method 942.15.

AOAC. (2002). Solids (Soluble) in Fruits and Fruit Product: Refractometer Method. Gaithersburg, MD: Official Methods of Analysis of AOAC International, Official Method 932.12.

Asnaashari, M., Motamedzadegan, A., Farahmandfar, R., & Rad, T. K. (2016). Effect of S. macrosiphon and L. perfoliatum seed gums on rheological characterization of bitter orange (Citrus aurantium L.) and pomegranate (Punica granatum L.) paste blends. Journal of Food Science and Technology, 53, 1285–1293.

Balaghi, S., Mohammadifar, M. A., & Zargaraan, A. (2010). Physicochemical and rheological characterization of gum tragacanth exudates from six species of Iranian Astragalus. Food Biophysics, 5, 59–71.

Balaghi, S., Mohammadifar, M. A., Zargaraan, A., Gavlighi, H. A., & Mohammadi, M. (2011). Compositional analysis and rheological characterization of gum tragacanth exudates from six species of Iranian Astragalus. Food Hydrocolloids, 25, 1775–1784.

Baldwin, E. A., Burns, J. K., Kazokas, W., Brecht, J. K., Hagenmaier, R. D., Bender, R. J., & Peris, E. (1999). Effect of two edible coatings with different permeability characteristics on mango (Mangifera indica L.) ripening during storage. Postharvest Biology and Technology, 17, 215-226.

Benitez, S., Achaerandio, I., Sepulcre, F., & Pujola, M. (2013). Aloe vera based edible coatings improve the quality of minimally processed ‘Hayward’ kiwifruit. Postharvest Biology and Technology, 81, 29-36.

Carneiro-da-Cunha, M. G., Cerqueira, M. A., Souza, B. W. S., Souza, M. P., Teixeira, J. A., & Vicente, A. A. (2009). Physical properties of edible coatings and films made with a polysaccharide from Anacardium occidentale L. Journal of Food Engineering, 95(3),379–385.

Cerqueira, M. A., Bourbon, A. I., Pinheiro, A. C., Martins, J. T., Souza, B. W. S., Teixeira, J. A., & Vicente, A. A. (2011). Galactomannans use in the development of edible films/coatings for food applications. Trends in Food Science and Technology, 22(12), 662–671.

Duan, J., Wu, R., Strik, B. C., & Zhao, Y. (2011). Effect of edible coatings on the quality of fresh blueberries (Duke and Elliott). Postharvest Biology and Technology, 59, 71–79.

Emamifar, A., & Bavaisi, S. (2017). Effect of mixed edible coatings containing gum tragacanth and Aloe vera on postharvest quality of strawberries during storage. Iranian Food Science and Technology Research Journal, 13(3),39-54.

Ergun, M., & Satici, F. (2012). Use of Aloe vera gel as biopreservative for ‘Granny Smith’ and ‘Red Chief’ apples. Journal of Animal and Plant Science, 22, 363-368.

Farahmandfar, R., Asnaashari, M., Salahi, M. R., & Rad, T. K. (2017). Effects of basil seed gum, Cress seed gum and Quince seed gum on the physical, textural and rheological properties of whipped cream. International Journal of Biological Macromolecules, 98, 820–828.

Garcia, L. C., Pereira, L. M., de Luca Sarantopoulos, C. I. G., & Hubinger, M. D. (2012). Effect of antimicrobial starch edible coating on shelf-life of fresh strawberries. Packaging Technology and Science, 25, 413–425.

Gentry, H. S. (1957). Gum tragacanth in Iran. Economy Botany, 11(1), 40-63.

Ghayempour, S., Montazer, M., & Mahmoudi Rad, M. (2015). Tragacanth gum as a natural polymeric wall for producing antimicrobial nanocapsules loaded with plant extract. International Journal of Biological Macromolecules, 81,514-520.

Gil, M.I., Tomas-Barbern, F.A., Hess-Pierce, B., Holcrofi, D.M., & Kader A. A. (2000). Antioxidant activity of pomegranate juice and its relationship with phenolic composition and processing. Journal of Agricultural and Food Chemistry, 48, 45-81.

Gol, N. B., Patel, P. R., & Rao, T. V. R. (2013). Improvement of quality and shelf-life of strawberries with edible coatings enriched with chitosan. Postharvest Biology and Technology, 85, 185–195.

Hassanpour, H. (2015). Effect of Aloe vera gel coating on antioxidant capacity, antioxidant enzyme activities and decay in raspberry fruit. Food Science and Technology, 60, 495-501.

Hernandz Munoez, P., Almenar, E., Ocio, M. J., & Gavara, R. (2006). Effect of calcium dips and chitosan coatings on postharvest life strawberries (Fragaria × ananassa). Postharvest Biology and Technology,39, 247-253.

Hernandez-Munoz, P., Almenar, E., Del Valle, V., Velez, D., & Gavara, R. (2008). Effect of chitosan coating combined with postharvest calcium treatment on strawberry (Fragaria ananassa) quality during refrigerated storage. Food Chemistry, 110, 428–435.

Ju, Zh., & Curry, E. A. (2005). Stripped corn oil emulsion alters ripening, reduces superficial scald, and reduces core flash in Granny Smith apples and decay in Anjou pears. Postharvest Biology and Technology, 20(1), 185- 193.

Makki, A., & Panahi, B. (2013). Effect of applying vegetal oils, heat treatment and polyethylene coatings after harvest on the storage life of ‘Valencia’ orange. International Journal of Agriculture and Crop Sciences, 6 (2), 97-99.

Maqbool, M., Ali, A., Alderson, P. G., Zahid, N., & Siddiqui, Y. (2011). Effect of a novel edible composite coating based on gum arabic and chitosan on biochemical and physiological responses of banana fruits during cold storage. Journal of Agricultural and Food Chemistry, 59, 5474-5782.

Martinez-Romero, D., Alburquerque, N., Valverde, J.  M., Guillen, F., Castillo, S., Valero, D., & Serrano, M. (2006). Postharvest sweet cherry quality and safety maintenance by Aloe vera treatment: a new edible coating. Postharvest Biology and Technology, 39, 93-100.

Pasquariello, M. S., Rega, P., Migliozzi, T., Capuano, L. R., Scortichini, M., & Petriccione, M. (2013). Effect of cold storage and shelf life on physiological and quality traits of early ripening pear cultivars. Scientia Horticulturae, 162, 341–350.

Prusky, D. (2011). Reduction of the incidence of postharvest quality losses, and future. Food Security, 3(4),463-474.

Sophia, O., Robert, G. M., & Ngwela, W. J. (2015). Effect of Aloe vera gel coating on postharvest quality and shelf of mango (Mangifera indica L.) fruits var. Ngowe. Journal of Horticulture and Forestry, 7(1),1-7.

Tanda-palmu, P., & Grosso, C. R. (2005). Effect of edible wheat gluten-based films and coatings on refrigerated strawberry (Fragaria ananassa) quality. Postharvest Biology and Technology, 36, 199-208.

Valverde, J. M., Guillen, F., Martinez-romero, D., Castillo, S., Sarrano, M., & Valero, D. (2005). Improvement if table grapes quality and safety by the combination of modified atmosphere packaging and eugenol, menthol or thymol. Journal of Agricultural and Food Chemistry, 53(19), 7458-7464.

Vieria, J. M., Flores-Lopez, M. L., Jasso de Rodriguezc, D., Sousa, M. C., Vicente A.A., & Martin, J. T. (2016). Effect of chitosan–Aloe vera coating on postharvest quality of blueberry (Vaccinium corymbosum) fruit. Postharvest Biology and Technology, 116, 88-97.

Wang, L., Liu, L., Kerry, J. F., & Kerry, J. P. (2007). Assessment of film-forming potential and properties of protein and polysaccharide-based biopolymer films. International Journal of Food Science and Technology, 42, 1128-1138.

Weiping, W., & Branwell, A. (2000). Handbook of hydrocolloids. Tragacanth and Karaya, 231–238.