Resumo

LOZANO-GRANDE, María A. et al. Films based on hawthorn (Crataegus spp.) fruit pectin and candelilla wax emulsions: characterization and application on Pleurotus ostreatus. Agrociencia [online]. 2016, vol.50, n.7, pp.849-866. ISSN 2521-9766.

Hawthorn or tejocote (Crataegus spp.) is an underutilized species in Mexico, but its fruit possesses a high pectin content, which may be utilized to give it added value. The objectives of this study were to extract pectin (HP) from hawthorn fruit to be used with candelilla wax (CW) in the preparation of emulsions with 1-2 % HP and 0.5-1 % CW, and to evaluate the potential use of such emulsions as coatings of fresh produce to preserve quality attributes in postharvest. Rheological measurements showed that emulsions behaved as typical structural materials and flow properties were well described by the modified Carreau model. Emulsions were cast to obtain edible films. Increments of HP increased tensile strength (0.16 to 0.22 MPa) but reduced its elongation at break (57.2 to 4.4 %), indicating more fragility. Water vapor permeability varied between 9.3x10-14 and 1.3x10-14 mol m s-1 m-2 Pa-1 for low (1.0 and 0.5 %) and high (2.0 and 1.0 %) concentrations of HP and CW, respectively. Emulsions and films made with HP were equal to or superior to those made with citrus pectin. Emulsions of HP and CW were applied on Pleurotus ostreatus slices, and those that received 2 % HP and 1 % CW had smaller losses of weight, firmness, and lightness, relative to untreated mushroom slices, during 20 d of storage at 4 °C, which indicates good potential for use in postharvest conservation of fresh produce.

Palavras-chave : Candelilla wax; edible films; hawthorn pectin; postharvest; shelf life.

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