Evaluación del comportamiento reológico de un postre lácteo a base de harina de oca (Oxalis tuberosa) y gelatina dispersos en lactosuero dulce.

Abstract

Whey is a by product of the cheese industry that has usually been considered as waste. However at present it is used as an aditive for dairy desserts production in combination with some starchs and hydrocolloids. The oca (Oxalis tuberosa) is an ancestral culture rich in nutrients with potential for industrialization. The aim of the present study was to evaluate the rheological behavior of nine dessert formulations, designed by surface response methodology. The formulations included flour oca (2,00-4,00 percent) and unflavored gelatin (0.50 to 2,00 percent) in sweet whey. Viscosity parameters and the texture profile (cohesiveness, elasticity, firmness, chewiness and gumminess) were determined in the mixtures. All the formulations showed a non-Newtonian behavior with Bingham plastic character (n less to 1) which could be adjusted to a Herschel-Bulckley model. Texture profiles were different among the formulations, finding soft, firm and hard samples. Oca flour and unflavored gelatin concentrations (percentage) did not significantly influence (p greater than 0,05) the viscosity of the evaluated treatments. Whilst the textural properties were affected by the concentration of gelatin. The best treatment was selected based on the surface response results, which showed the optimum values at that central points (2,00 percent oca flour and 1,25 percent unflavored gelatin). These results were confirmed by the sensory analysis. Finally, the proximal composition, the stability and the production cost were evaluated for the best treatment, which was rich in carbohydrates (15,04 percent), proteins (1,94 percent) and fiber (0,07 percent). Shelf-life was of 32 days and the cost of production for one portion of 250 g was 0,81 dollars.