Creamy corn (Zea mays) soup with nopal (Opuntia spp.) mucilage as thickener, its physical quality and sensory acceptance

Abstract

The mucilage from prickly pears (Opuntia spp.) is a polysaccharide classified as nutraceutical because of its beneficial effects on human physiology. On the other hand, it is used as a thickener because when hydrated it forms hydrocolloids. The objective of this study was to add a creamy corn soup with prickly pear mucilage and to evaluate its thickening effect and sensory acceptance. Mucilage was extracted from cladodes of the Atlixco, Milpa Alta, Toluca, Tobarito and Tuna Blanca variants of Opuntia spp. The evaluated concentrations were 0.7 and 1.0 % and starch as control. With some exceptions, the soup of the 10 treatments added with mucilage showed not significant differences (p > 0.05) in their pH (between 6.09 and 6.32) and its viscosity (between 1.623 and 6.043 Pa s) respect to the controls. Regard their colour, its chromaticity (between 17.47º and 18.49º) was like the controls, tended to higher luminosity (between 46.15 and 47.72º) and lower tone (between 78.36 and 79.52º). The sensorial soup viscosity acceptability was like that of the controls, except with mucilage of Atlixco and Toluca variants (17 and 7 % lower), and the overall sensorial acceptability of the soups with mucilage of the five variants was up to 19 % lower compared to controls. The benefit to add corn soup with mucilage, to be used as a functional food, must be weighed over its overall acceptability.