Edible coatings containing chitosan and moderate modified atmospheres maintain quality and enhance phytochemicals of carrot sticks.

Abstract Carrot sticks are increasingly in demand as ready-to-eat products, with a major quality problem in the development of white discoloration. Modified atmosphere packaging (MAP) and edible coating have been proposed as postharvest treatments to maintain quality and prolong shelf-life. The combined application of an edible coating containing 5 mL L−1 of chitosan under two different MAP conditions (10 kPa O2 + 10 kPa CO2 in Pack A and 2 kPa O2 + 15–25 kPa CO2 in Pack B) over 12 d at 4 °C was studied. Respiration rate, microbial and sensory qualities as well as the contents of vitamin C, carotenoids and phenolics of coated and uncoated carrot sticks were evaluated. The use of the edible coating containing chitosan preserved the overall visual quality and reduced surface whiteness during storage. Microbial populations were very low and not influenced by coating or MAP. Edible coating increased respiration rates of carrot sticks, although this was only noticeable in the package with the less permeable film (Pack B). Vitamin C and carotenoids decreased during storage particularly in coated carrot sticks. In contrast, the content of total phenolics markedly increased in coated carrot sticks stored under moderate O2 and CO2 levels, while it was controlled under low O2 and high CO2 levels. The combined application of edible coating containing chitosan and moderate O2 and CO2 levels maintained quality and enhanced phenolic content in carrot sticks.

[1]  Charles L. Wilson,et al.  Chitosan as a potential natural compound to control pre and postharvest diseases of horticultural commodities , 2006 .

[2]  J. Espín,et al.  Induction of antioxidant flavonol biosynthesis in fresh-cut potatoes. Effect of domestic cooking. , 2002, Journal of agricultural and food chemistry.

[3]  R. Hamilton,et al.  Antioxidant compound responses to chilling stress in differentially sensitive inbred maize lines , 1996 .

[4]  Mohammed Mathlouthi,et al.  Food Packaging and Preservation , 1994 .

[5]  M. Margaret Barth,et al.  Impact of edible coatings on nutritional and physiological changes in lightly-processed carrots , 1998 .

[6]  M. Saltveit,et al.  Identification of a phenylalanine ammonia-lyase inactivating factor in harvested head lettuce (Lactuca sativa) , 1996 .

[7]  S. Hajare,et al.  Radiation Processing of Minimally Processed Carrot (Daucus carota) and Cucumber (Cucumis sativus) to Ensure Safety: Effect on Nutritional and Sensory Quality , 2006 .

[8]  J J Kester,et al.  EDIBLE FILMS AND COATINGS: A REVIEW , 1986 .

[9]  D. Joyce,et al.  Elicitors of induced disease resistance in postharvest horticultural crops: a brief review , 2004 .

[10]  F. Tomás-Barberán,et al.  Characterization and quantitation of antioxidant constituents of sweet pepper (Capsicum annuum L.). , 2004, Journal of agricultural and food chemistry.

[11]  Chitosan,et al.  Chitin in Nature and Technology , 1986, Springer US.

[12]  D. O'beirne,et al.  Quality of Shredded Carrots as Affected by Packaging Film and Storage Temperature , 2000 .

[13]  R. Carle,et al.  Quality of Shredded, Packaged Carrots as Affected by Different Washing Treatments , 2004 .

[14]  M. Mínguez-Mosquera,et al.  Chlorophyll and carotenoid presence in olive fruit (Olea europaea) , 1989 .

[15]  P. Visalakshy.  Effect of silt coverage of water hyacinth roots on pupation of Neochetina eichhorniae Warner and N. bruchi Hustache (Coleoptera: Curculionidae) , 1996 .

[16]  R. Mayer,et al.  Elicitors of Plant Defensive Systems Reduce Insect Densities and Disease Incidence , 2004, Journal of Chemical Ecology.

[17]  L. Cisneros-Zevallos.  The Use of Controlled Postharvest Abiotic Stresses as a Tool for Enhancing the Nutraceutical Content and Adding-Value of Fresh Fruits and Vegetables , 2003 .

[18]  Frank Devlieghere,et al.  Chitosan: antimicrobial activity, interactions with food components and applicability as a coating on fruit and vegetables , 2004 .

[19]  D. O'beirne,et al.  The effects of modified atmospheres, edible coating and storage temperatures on the sensory quality of carrot discs , 2007 .

[20]  Reinhold Carle,et al.  Quality of minimally processed carrots as affected by warm water washing and chlorination , 2005 .

[21]  R. Avena-Bustillos,et al.  Application of casein-lipid edible film emulsions to reduce white blush on minimally processed carrots , 1994 .

[22]  F. Nigro,et al.  Effects of Pre‐ and Postharvest Chitosan Treatments to Control Storage Grey Mold of Table Grapes , 2002 .

[23]  A. Kader.  Mode of action of oxygen and carbon dioxide on postharvest physiology of 'Bartlett' pears , 1989 .

[24]  J. Arul,et al.  Antifungal Activity of Chitosan on Two Postharvest Pathogens of Strawberry Fruits , 1992 .

[25]  Reinhold Carle,et al.  Influence of washing treatment and storage atmosphere on phenylalanine ammonia-lyase activity and phenolic acid content of minimally processed carrot sticks. , 2005, Journal of agricultural and food chemistry.

[26]  M. Mathlouthi,et al.  Food packaging and preservation : theory and practice , 1986 .

[27]  M. Saltveit,et al.  Hygroscopic Coatings Control Surface White Discoloration of Peeled (Minimally Processed) Carrots During Storage , 1997 .

[28]  Catherine Barry-Ryan,et al.  Effects of peeling methods on the quality of ready-to-use carrot slices , 2000 .

[29]  J. Dufour,et al.  Ascorbic, Dehydroascorbic and Isoascorbic Acid Simultaneous Determinations by Reverse Phase Ion Interaction HPLC , 1992 .

[30]  M. Byun,et al.  Effects of gamma irradiation on the microbiological, nutritional, and sensory properties of fresh vegetable juice , 2007 .

[31]  N. Soares,et al.  Microbiological evaluation of an edible antimicrobial coating on minimally processed carrots , 2006 .

[32]  Luis Cisneros-Zevallos,et al.  Modeling Wound‐induced Respiration of Fresh‐cut Carrots (Daucus carota L.) , 2003 .

[33]  N. Benhamou,et al.  Induction of systemic resistance to Fusarium crown and root rot in tomato plants by seed treatment with Chitosan , 1994 .

[34]  D. Hornero-Méndez,et al.  Separation and quantification of the carotenoid pigments in red peppers (Capsicum annuum L.), paprika, and oleoresin by reversed-phase HPLC , 1993 .

[35]  Amparo Chiralt,et al.  Quality of cold-stored strawberries as affected by chitosan–oleic acid edible coatings , 2006 .

[36]  V. Cliffe-Byrnes,et al.  The effects of preparatory procedures and storage temperature on the quality of carrot discs packaged in modified atmospheres , 2007 .

[37]  L. Howard,et al.  Minimal processing and edible coating effects on composition and sensory quality of mini-peeled carrots , 1996 .

[38]  N. Benhamou,et al.  Chitosan Treatment: An Emerging Strategy for Enhancing Resistance of Greenhouse Tomato Plants to Infection by Fusarium oxysporum f.sp. radicis-lycopersici , 1996 .

[39]  J. Espín,et al.  Vitamin C retention in fresh-cut potatoes , 2002 .

[40]  F. López-Gálvez,et al.  Role of commercial sanitizers and washing systems on epiphytic microorganisms and sensory quality of fresh-cut escarole and lettuce , 2008 .

[41]  Yanyun Zhao,et al.  Using Edible Coating to Enhance Nutritional and Sensory Qualities of Baby Carrots , 2002 .

[42]  Encarna Aguayo,et al.  Quality changes and nutrient retention in fresh-cut versus whole fruits during storage. , 2006, Journal of agricultural and food chemistry.

[43]  J. Weichmann,et al.  Postharvest physiology of vegetables , 1987 .

[44]  Y. Hamauzu,et al.  Phenolic compounds and their antioxidant properties in different tissues of carrots (Daucus carota L.) , 2004 .