Effect of formulation and storage on physicochemical and flow properties of custard flavored with caramel jam

• Custard dairy products were made with caramel jam as a novel flavor.
• Caramel jam and whey protein affected the physicochemical and flow properties of the systems.
• Caramel jam and whey protein improved the consistency and the chocolate flavor of pea-protein custards.
• Several combinations of formulation components contributed to decrease the syneresis phenomenon.
• A novel flavored custard product was formulated and studied.

The effects of formulation and storage time on the physicochemical and flow properties of dairy custards with caramel jam as a new flavor were studied. Systems were formulated following a factorial design including three concentrations of starch, three of caramel and three of protein. Both, the formula and storage time, influenced at different degree the analyzed physicochemical properties and flow behavior. Moisture was stable, while a decreasing in pH and brightness, an increasing in acidity, redness and yellowness, were observed. The non-Newtonian response was adjusted to the Herschel–Bulkley and Bingham plastic equations at the upward and downward flow curves, respectively. The custards consistency increased with the addition of formula components and decreased with storage, while the shear thinning nature of the fresh systems declined with storage as a result of changes in gel structure. Quantification of the thixotropic area completed the rheological analysis of the custards as non-Newtonian time dependent food materials.