Author
ROJAS-GRAU, MARIA - UNIV. OF LLEIDA, SPAIN | |
RAYBAUDI-MASSILIA, ROSA - UNIV. OF LLEIDA, SPAIN | |
SOLIVA-FORTUNY, ROBERT - UNIV. OF LLEIDA, SPAIN | |
Avena-Bustillos, Roberto | |
McHugh, Tara | |
MARTIN-BELLOSO, OLGA - UNIV. OF LLEIDA, SPAIN |
Submitted to: Postharvest Biology and Technology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/22/2007 Publication Date: 8/1/2007 Citation: Rojas-Grau, M.A., Raybaudi-Massilia, R.M., Soliva-Fortuny, R.C., Avena Bustillos, R.D., Mc Hugh, T.H., Martin-Belloso, O. 2007. Apple Puree-Alginate Edible Coating as Carrier of Antimicrobial Agents to Prolong Shelf-Life of Fresh-Cut Apples. Postharvest Biology and Technology. 45(2):254-264. Interpretive Summary: The effect of lemongrass, oregano oil and vanillin incorporated in apple puree-alginate edible coatings, on the shelf-life of fresh-cut Fuji apples, was investigated. Changes in headspace atmosphere, color, firmness, sensory quality and microbial growth were measured during cold storage. A significant reduction in the rates of O2 depletion and CO2 evolution was observed in samples containing high concentrations of essential oils. Ethylene production in the coated apples remained low while production of this gas increased continuously in uncoated apples and those coated without essential oils during storage. Apples coated with apple puree-alginate exhibited ethanol and acetaldehyde formation in the first week. Vanillin containing coatings were the most effective in terms of sensory quality after two weeks storage. All antimicrobial coatings significantly inhibited the growth of psychrophilic aerobes, yeasts and molds. Lemongrass and oregano oil containing coatings exhibited the strongest antimicrobial activity against L. innocua. Technical Abstract: Edible coatings with antimicrobial agents can extend the shelf-life of fresh-cut fruit. The effect of lemongrass, oregano oil and vanillin incorporated in apple puree-alginate edible coatings, on the shelf-life of fresh-cut Fuji apples, was investigated. Coated apples were packed in air-filled polypropylene trays and wrapped with a polypropylene film of 110 cm3 O2 m-2 bar-1 day-1 oxygen permeability. Changes in headspace atmosphere, color, firmness, sensory quality and microbial growth were measured during 21 days of storage at 4 degrees C. A significant reduction in the rates of O2 depletion and CO2 evolution was observed in samples containing high concentrations of essential oils (EOs). Ethylene production in the coated apples remained below 50 microliters l-1, while production of this gas increased continuously in uncoated apples and those coated without EOs during storage. Apples coated with apple puree-alginate exhibited ethanol and acetaldehyde formation in the first week. Coatings with calcium chloride and N-acetylcysteine helped to maintain firmness and color, while lemongrass containing coatings induced severe texture softening. Vanillin containing coatings (0.3% w/w) were the most effective in terms of sensory quality after two weeks storage. All antimicrobial coatings significantly inhibited the growth of psychrophilic aerobes, yeasts and molds. The antimicrobial effect of EOs against L. innocua inoculated into apple pieces before coating was also examined. Lemongrass (1.0 and 1.5% w/w) and oregano oil containing coatings (0.5% w/w) exhibited the strongest antimicrobial activity against L. innocua (4 log reduction). |