ORIGINAL PAPER Selection of an Edible Starch Coating for Minimally Processed Strawberry Lorena Costa Garcia & Leila Mendes Pereira & Claire I. G. de Luca Sarantópoulos & Miriam Dupas Hubinger Received: 23 June 2009 / Accepted: 9 December 2009 # Springer Science+Business Media, LLC 2010 Abstract Edible coatings can represent an alternative for extending post-harvest life of perishable fruits, as strawberries. In this work, the effect of cassava starch edible coatings, added or not of potassium sorbate, on mechanical properties, surface color, sensory acceptance, and respiration rate of strawberries was evaluated in order to choose the best coating conditions to minimally processed strawberries. Integrity and water-vapor resistance of the coatings were also evaluated. Three different concentrations of cassava starch (1%, 2%, and 3%) and two concentrations of potassium sorbate (0.05% and 0.10%) were used in the coatings formulations. Minimally processed strawberries without coating were used as control samples. The strawberries treated with different coatings and control fruits did not present differences regarding mechanical properties, surface color, and all the sensory attributes evaluated. A good integrity of cassava edible coatings on strawberries surface was observed for 2% and 3% starch concentration and the use of coatings, in these concentrations, reduced the strawberries respiration rate, representing a possibility to extend the shelf life of fruits. All coatings showed beneficial effects on increasing the water vapor resistance of the samples, but a significant increase was obtained only with the use of coating with 3% of starch. The potassium sorbate improved significantly the resistance to water vapor, but no differences were observed between the two concentrations studied. Based these results, the coatings with 3% of cassava starch and 3% of cassava starch +0.05% of potassium sorbate were those selected for future shelf life study of minimally processed strawberries. Keywords Strawberry . Respiration rate . Edible coating . Cassava starch . Potassium sorbate . Minimal processing Introduction Edible coatings have been widely studied in the last years because of evidence about their beneficial effects on fruits and vegetables. Modification of fruits tissue metabolism by affecting respiration rate, extension of storage life, firmness retention, transportation of antimicrobials, antioxidants, and other preservatives and microbial growth control are the main functional advantages attributed to the use of edible films and coatings (Garcia et al. 1998; Lee et al. 2003; Durango et al. 2005; Reinoso et al. 2008; Karimi et al. 2009). Lipids, resins, polysaccharides, and proteins are the commonly used materials in the production of edible coatings. Depending on the desired characteristics, coatings can be made using one type of material or a mixture of them, considering its advantages and disadvantages (Colla et al. 2006). Among the polysaccharides used in the edible coatings formulation, starch is the natural biopolymer most commonly used (Durango et al. 2005). Cassava is produced throughout the Brazilian territory and so represents an important starch source, besides being abundant and cheap. Sorbic acid and its potassium salt (sorbates) are considered GRAS additives and are active against yeast, molds, and bacteria (Sofos 1989). Addition of sorbate to edible films and coatings has been proposed as a way of Present in the 4th CIGR—International Symposium on Food and Bioprocess Technology—Section VI—Foz do Iguassu (2008) L. C. Garcia : L. M. Pereira : M. D. Hubinger (*) Faculty of Food Engineering, University of Campinas, P.O. Box 6121, 13083-862 Campinas, SP, Brazil e-mail: mhub@fea.unicamp.br C. I. G. de Luca Sarantópoulos Institute of Food Technology, ITAL. Av. Brasil, 2880, P.O. Box 139, 13070-178 Campinas, SP, Brazil Food Bioprocess Technol DOI 10.1007/s11947-009-0313-9