Abstract The generation of value from the strawberry agro-chain requires in some cases the disintegration of the structure and formulation of the fruit, resulting in suspensions that behave as thermodynamically unstable colloidal systems and are affected by various forces, such as Van der Waals, electrostatic, steric, hydration, hydrophobic, and phase separation. The aim of this research was to evaluate the influence of the homogenization process and the concentration of gum arabic (GA) on the stability of strawberry-based suspensions. Strawberries with a 9% solid content were used and a centralized-composite central design was proposed (pressure (P) from 4.14-10.34 MPa), time (t) (3-5 min), and GA (0.2-0.4%)) and the dependent variables zeta potential (ζ), spectral absorption index (R), viscosity (μ), and particle size were evaluated. The ζ potential and R-index were not affected by the homogenization process and GA; the suspension was stabilized by the increase of ζ due to t, the GA effect, and the t-GA interaction. Particle size was affected by P but not by t, whereas GA mainly affected D [3,2], D [4,3], and D90. The results indicate that the homogenization and the use of GA as a hydrocolloid confer chemo-physical stability to the strawberry suspension.

RESUMEN La papa es uno de los cultivos con mayor influencia a nivel mundial y Colombia se destaca por ser el primer exportador de papa criolla o diploide. Nuevas variedades de papa diploide con propiedades antioxidantes y coloración en su pulpa han sido desarrolladas por la Universidad Nacional de Colombia: Primavera, Paola, Violeta, Milagros y Paysandú. El objetivo del presente estudio fue caracterizar y evaluar la estabilidad de las propiedades fisicoquímicas de la papa variedad Primavera, en estado fresco, durante su almacenamiento a 4 °C. Se utilizó papa variedad Primavera, cultivada en Santa Elena, Antioquia, durante los meses de mayo-agosto de 2016. Las propiedades fueron evaluadas mediante la capacidad antioxidante (DPPH y ABTS), fenoles totales (método de Folin-Ciocalteu), humedad, textura en la papa entera y en rodajas, y el color en la pulpa (CIELab). Las muestras fueron almacenadas en bolsas a una temperatura constante de 4 °C y fueron analizadas en los tiempos de control 0, 7, 14, 21 y 30 d. Se realizó una regresión polinomial para cada variable en función del tiempo. En general, las propiedades evaluadas de la papa variedad Primavera no presentaron una tendencia definida, por el contrario, fueron fluctuantes, lo cual podría estar asociado a diversos factores desde la producción primaria; así como a la interacción de fenómenos químicos y físicos de la materia con su entorno. La papa presentó un contenido importante de compuestos antioxidantes comparada con otras variedades (ABTS: 2,89→2,94 mg Trolox g-1; DPPH: 2,33→1,48 mg Trolox g-1; fenoles totales: 6,09→6,27 mg ácido gálico equivalente g-1). La papa criolla variedad Primavera es un alimento que posee importantes propiedades antioxidantes, lo cual le podría conferir un potencial de agro-industrialización a corto y mediano plazo.

ABSTRACT Potatoes are one of the crops with the greatest influence worldwide, and Colombia is the most important exporter of “Criolla” or diploid potato. Universidad Nacional de Colombia has developed varieties of new diploid potatoes with high antioxidant properties and colored flesh: Primavera, Paola, Violeta, Milagros, and Paysandú. The aim of this research was to characterize and evaluate the stability of physicochemical properties of the raw potato cv Primavera during storage at 4 °C. It was used the potato variety Primavera grown in Santa Elena, Antioquia, during season mayo-august 2016. The evaluated properties were the antioxidant capacity (DPPH and ABTS), phenolic compounds (Folin-Ciocalteu method), moisture, texture in whole tuber and slices, and color in the pulp (CIELab). Samples were stored in bags at a constant temperature of 4 °C and were evaluated for 0, 7, 14, 21, and 30 d. Polynomial regression was performed for each variable vs time. In general, properties for potato variety Primavera did not show a defined trend; otherwise, they were fluctuating; this may be associated with various factors such as primary production and the interaction of physic-chemical phenomena of the matter with its environment. Potato presented an important content of antioxidant compounds compared with other varieties (ABTS: 2.89→2.94 mg Trolox g-1; DPPH: 2.33→1.48 mg Trolox g-1; phenolic compounds: 6.09→6.27 mg gallic acid equivalent g-1). The “criolla” potato cv Primavera has a lot of important antioxidant properties which could confer it an agro-industrial potential in a short and medium term.