Ricotta cheese was selected to develop a novel food product. Ricotta is easily obtained from the precipitation of whey and milk proteins, through the application of heat and acidification. This product is characterised by its compact, finely granulated and crumbly mass of limited shelf life. Unlike the conventional methods for ricotta elaboration, a novel processing step was introduced to improve spreadability. The effect of hydrocolloids addition on physicochemical, mechanical and rheological properties was evaluated during storage. Hydrocolloids had a positive effect on the cheese matrix regarding microstructure and rheological properties. Samples showed acceptable physicochemical properties (compared with the control) during storage. Addition of hydrocolloids attenuated syneresis. Preliminary results showed that the best formulation was ricotta cheese containing high gelification capacity gelatin. Results of this study may contribute to the development of a novel dairy product.

Crystallization kinetics of concentrated trehalose and trehalose/salt solutions were followed by proton ( 1 H) pulsed nuclear magnetic resonance ( 1 H p-NMR). Three concentrations (66, 70, and 72.5%) of trehalose and with the addition of ZnCl 2 .2H 2 O, CaCl 2 .2H 2 O, and MgCl 2 .2H 2 O were crystallized at 5, 10, 15, 20, and 25 8C. Supercooling and molecular diffusion determined the crystallization rates. The highest rate of crystallization of 66, 70, and 72.5% trehalose occurred at 20 8C, whereas the lowest rate occurred at 25 8C. The maximum solid content was higher at lower temperatures, as expected based on the higher supercooling values. Crystallization was delayed by the addition of salts and especially of CaCl 2 .2H 2 O.

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