R.A. Verdini

Calcium Uptake during Immersion of Strawberries in CaCl2 Solutions

The present study studied calcium uptake in strawberries during immersion in CaCl(2) solutions by analyzing total calcium and cell-wall calcium contents and the relationships between cell-wall calcium content, pectin content, and the degree of pectin esterification, considering different temperatures and concentrations of the immersion solution. In addition, calcium uptake at different zones of the strawberries was studied. Calcium uptake increased significantly when the concentration of the immersion solution increased from 1% to 10% (v/v), and calcium uptake was higher at 38 degrees C at some immersion times, but there were no significant differences between 1 and 24 degrees C. Most of the calcium incorporated by the strawberries was retained in the alcohol insoluble solids and it may be related to calcium bounded to the cell wall. Calcium content did not change during immersion in CaCl(2) solution in the internal or in the central zones; however, it increased significantly in the external zone.

Resistance of phages lytic to pathogenic Escherichia coli to sanitisers used by the food industry and in home settings

Fil: Tomat, David Damian. Universidad Nacional de Rosario. Facultad de Ciencias Bioquimicas y Farmaceuticas. Departamento de Microbiologia; Argentina

Physicochemical Characterization of a Heat Treated Calcium Alginate Dry Film Prepared with Chicken Stock

Solid sodium alginate was dissolved into chicken stock in order to give a final alginate concentration of 0.9 percent (w/v). Calcium ions present in chicken stock were enough to induce ionic gelation. After drying, Fourier transform infrared spectroscopy, thickness and mechanical properties of films obtained were determined. Calcium alginate-chicken stock films were heated at 130 °C for different times between 0 and 15 min. Mechanical and optical studies, differential scanning calorimetry, visual aspect and scanning electron microscopy were carried out to describe physicochemical properties of heat treated films. Heating developed a maroon ochre color and increased the brittleness (crispness) of the films related to the intensity of the treatment. Differential scanning thermometry and study on appearance of the films suggested that Maillard reactions may be responsible for the observed changes. Maillard reactions mainly occurred between reducing sugar monomers and free amino groups of gelatin peptides present in the chicken stock, and between alginate and gelatin peptides to a lesser extent. In addition, the plasticizing effect of fat added with chicken stock was also studied. These studies suggest a potential use of heat treated chicken stock films as a substitute of roasted chicken skin.