Extending shelf-life of minimally processed pumpkin with a carrageenan-based coating
The effect of carrageenan coating at different concentrations on minimally processed pumpkin cubes was studied. Pumpkin cubes were subjected to a 3 min dipping into a solution containing carrageenan-based (0.1, 0.3 or 0.5%, w/v) and glycerol (0.1%, w/v) coating. Samples (130-150 g) were packed into a polypropylene container (volume: 450 mL). Physical (weight loss, appearance and colour), chemical (pH, titratable acidity, soluble solids concentration and ascorbic acid content) and sensory evaluations were assessed during storage at 2°C (70% relative humidity), at 3- or 4-day intervals for 3 weeks. Uncoated and coated minimally processed pumpkin cubes were subjected to a steaming process (100°C) for 5-7 min and were cooled prior to sensory evaluation. Uncoated pumpkin cubes had significant weight loss (p<0.05) and tended to have a drier appearance after 10 days of storage. Higher concentrations of the coating (0.3 and 0.5%) caused a jelly-like appearance and was able to prevent moisture loss. Appearance of microbial spoilage started on the surface of uncoated pumpkin cubes after 17 days of storage. From the study, no significance differences were found for firmness or chemical variables among treatments throughout the storage period. Pumpkin cubes coated with 0.1, 0.3 or 0.5% of carrageenan were found to retain colour, better texture and noted positive sensory scores until the end of the storage period compared to uncoated pumpkin cubes. The results indicated that 0.1% carrageenan coating was the most effective as a coating treatment in terms of sensory quality and ability to prolong shelf-life of minimally processed pumpkin cubes up to 20 days.
Cho, J.L.Y., Latifah, M.N., Syed Abas, S.A.R., Aisyah, A. Siti, Zaulia, O., Nur Azlin, R., Pauziah, M., Nur Syafini, G., Hairiyah, M., Habsah, M., Zaipun, M.Z. and Nurul Adibah, M. (2016). Extending shelf-life of minimally processed pumpkin with a carrageenan-based coating. Acta Hortic. 1141, 175-180
processing, sensory, colour, soluble solids concentration, edible coating