Digital image analysis of diverse Mexican rice cultivars.

BACKGROUND: Digital image analysis has an important role in geographical provenance of grains, as it can provide parameters of size, shape and color, which are important quality parameters for the design of engineering processes such as drying and milling of grains. In this study, digital image analysis was used to classify nine rice cultivars based on different morphometric parameters using the three sides of the grain (lateral, ventral and axial), Feret diameter, and 10 different form factors and color parameters (CIE L*, a* and b*). RESULTS: Result of principal component analyisis was an equation with seven variables (area, perimeter, length, width, thickness, sphericity and color), which was useful for distinguishing between nine different cultivars. The morphometric and color parameters for the Mor A-98 and Mor A-92 varieties showed they had 88% similarity. The variability was expressed with a confidence of 95%. CONCLUSION: Multivariate analysis indicated that the lateral side is the most sensitive for the classification of Mexican rice grains because of its color and morphometric characteristics. These results showed the application of image analysis for the future classifications of grains.

Efecto de las condiciones de almacenamiento sobre el color, contenido de polifenoles y capacidad antioxidante de una bebida de Borojoa patinoi Cuatrecasas / Effect of storage conditions on color, polyphenol content and antioxidant capacity of a Borojoa patinoi Cuatrecasas beverage

In Latin America, popular tradition in some places have been attributed properties to borojó fruit, making it a potential source for the design and development of a functional product, but there is little scientific literature reference biological activity of this fruit. The aim of this study was to evaluate color changes, polyphenol content and antioxidant capacity of borojo (Borojoa patinoi Cuatrecasas) pulp beverage without chemical preservatives, it was stored at 4° C, 17° C and 37° C for 17 days. Coordinate a* was adjusted to zero order kinetics and the total polyphenol content (TP) and the antioxidant capacity (CA) had adjustments to first-order kinetics, suggesting a linear correlation between the degradation rates. The results showed that beverage storage at 4°C allowed a better retention of color changes, polyphenols and antioxidant compounds in nature, compared with the other storage temperatures.

En Latinoamérica, la tradición popular en algunas poblaciones le han atribuído al fruto del borojó propiedades, que lo hacen fuente potencial para el diseño y desarrollo de productos de carácter funcional; sin embargo es poca la literatura científica aún, que referencia alguna actividad biológica de este fruto. El objetivo de este trabajo fue evaluar los cambios de color, el contenido de polifenoles y la capacidad antioxidante de una bebida de pulpa de borojó (Borojoa patinoi Cuatrecasas.) sin conservantes químicos, ésta fue almacenada a 4º C, 17º C, y 37º C durante 17 días. En color la coordenada a* se ajustó a una cinética de orden cero; el contenido de polifenoles totales (PT) y la capacidad antioxidante (CA) presentaron ajustes a una cinética de primer orden, sugiriendo una correlación lineal entre las velocidades de degradación. Los resultados obtenidos indicaron que el almacenamiento de la bebida a 4° C permitió una mejor retención en los cambios de color, polifenoles y compuestos de carácter antioxidante, en comparación con las demás temperaturas de almacenamiento.