Improved multilayered antimicrobial alginate-based edible coating extends the shelf life of fresh-cut watermelon (Citrullus lanatus)

This study evaluated the effectiveness of an improved multilayered antimicrobial alginate-based edible coating in increasing the shelf life of fresh-cut watermelon without affecting its quality attributes. A set of solutions containing sodium alginate (0.5, 1, 2 g/100 g), beta-cyclodextrin and microencapsulated transcinnamaldehyde (natural antimicrobial agent), pectin, and calcium lactate were used as coating systems and made into a coating using the layer-by-layer (LbL) technique. The samples were coated using the layer-by-layer dipping technique and stored at 4 degrees C for 15 days. Texture, color, weight loss, oBrix, pH, and growth of total coliforms, yeasts and molds, aerobics, and psychrotrophs were monitored every 3 days throughout storage. Controls were uncoated washed fruits. A consumer acceptance test showed high acceptance (P < 0.05) of the coated samples except for the 2 g/100 g alginate coating. Texture (firmness) was particularly enhanced (P < 0.05) by application of the coating. Both the 1 and 2 g/100 g alginate coatings extended the shelf life of fresh-cut watermelon from 7 (control) to 12-15 days. The application of the multilayered edible coating with 1 g/100 g alginate will maintain the quality and sensory acceptance of fresh-cut watermelon while extending its shelf life. (C) 2012 Elsevier Ltd. All rights reserved.