15E-7 |
Preparation and characterization of restructured mango peel fiber-pectin gels through autoclaving and fungal pectinesterase treatment |
J. C. CONTRERAS-ESQUIVEL1, J. C. Montañez-Sáenz, L. Banda-Reyes, M. L. Reyes-Vega, and C. N. Aguilar. (1) Food Research Department. School of Chemistry, Universidad Autónoma de Coahuila, PO Box 252, Saltillo, Coahuila, 25000, Mexico Mango (Mangifera indica) is an industrial tropical crop considered to have a great potential. Peel and stone are the waste materials of the mango processing industries. Mango peel fiber (MPF) is a good source of dietary fiber and its chemical composition may be compared to that of citrus fiber. Furthermore, MPF shows higher values of antioxidant activity and glucose retardation index, and its aroma and flavor are more pleasant. The main goal of our work was to study the behavior of MPF-pectin applying autoclaving and enzymatic treatments in order to improve the use of this by-product in view of its application for the elaboration of functional restructured foods. Oven- or solvent-exchange drying methods were employed to obtain MPF-pectin. Materials were sieved and analyzed for galacturonic acid (AGA) contents. Pectic polysaccharides were extracted from MPF-pectin through an autoclave treatment (5 to 60 min, 121°C, 15 lb/in2) with additional citric acid (pH 2.30). Once the pectin was extracted, pH was adjusted to 4.5 with NaOH and treated with fungal pectinesterase. The pectin was solubilized in the autoclave at 121ºC for 5-10 minutes adding citric acid and the gel was formed in a solution of calcium ions. An Instron universal traction machine was used to measure gel firmness. Galacturonic acid contents were higher when the method of solvent exchange was used (29 mg AGA/100 mg fiber; mesh 25). The oven-drying method yielded 22 mg AGA/100 mg fiber (mesh 25). Maximum compression strength was 1.9 N for the gel obtained through the solvent-exchange drying method (mesh 25; 10 min). These results justify the proposed use of a gentle but effective method for the preparation of healthy restructured gels.
Session 15E, Nutraceuticals & Functional Foods I
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