Stabilization of L-(+)-Ascorbic Acid in an Iron Fortified Vegetable Product (Cucurbita Moschata Duchesne Ex Poiret) Using an Alginate Coating

DE NOBILI, M.D.; GENEVOIS CAROLINA E.; ROJAS ANA M.; FLORES SILVIA K.; DE ESCALADA PLA MARINA F.

Ascorbic Acid: Properties, Synthesis and Applications

Nova Science Publishers, Inc.

Lugar: New York; Año: 2017; p. 105 - 122

In previous studies it was observed that in fortified pumpkins (Cucurbita moschata Duchesne ex Poiret) with iron (Fe) and L-(+)-ascorbic acid (AA), the latter had a minimum retention because AA stabilization was adversely affected by the presence of Fe. From this, it was proposed compartmentalize these two nutrients, being Fe applied to the impregnation of mesocarp pumpkin, while the AA was dissolved in a coating formulation consisting of alginate. Pumpkins, cut and blanched, were subjected to a dry impregnation. Two batches were prepared, one in which the Fe and AA were incorporated into pumpkin tissue, while in the second batch the vegetable matrix was only fortified with Fe. The studied systems were: a) Control fortified pumpkins with Fe and AA, covered with alginate coating (C); b) fortified with Fe, covered with alginate coating containing AA (F). In addition, two water activity (aW) conditions 0.920 (F1 and C1) and 0.760 (F2 and C2) were tested. All systems were contained in plastic trays, packaged in plastic bags and stored at a constant temperature of 25ºC for 23 days. During storage, AA concentration as well as color changes were registered. The AA loss and also b* and Chroma (Chr) parameter reductions fitted to a first order kinetic. For aw 0.760, the values obtained for the AA initial content were significantly (p < 0.05) higher, while the rate constants of AA loss were lower. The kinetic constants for color parameters were one order lower than AA loss. In general, F systems showed a faster reduction of b* and Chr than controls (C), but the aw assayed did not affect the rate of color changes. When fortified pumpkins were tested at aw 0.92 and storage at 18 and 25ºC, it was observed reduction of AA loss rate only in F1 pumpkin at the lower temperature. The reduction of color parameters showed an important influence of both compartmentalization of AA and storage temperature. It could be concluded that AA supporting on an alginate edible coatings enhances this vitamin retention and then it could be represent an effective strategy when developing food products fortified with iron.