Effect of micronization of maize grains on shelf-life of flour

Abstract

The efficacy of micronization of maize (Arjun, EH‐434042) in inactivating enzymes responsible for lipid degradation and extending the shelf‐life of whole maize flour was evaluated. Micronization at 200°C for 4 min resulted in complete inactivation of peroxidase enzyme and reduction in lipase activity by 84%. Maize flour packaged in low density polyethylene pouches were exposed to accelerated (90% RH/38°C) and ambient (65% RH/27°C) storage conditions. The results indicated no significant change in free fatty acid content in micronized flour whereas a significant increase was observed in raw flour under both the storage conditions. The color and carotenoid content did not vary much during storage in both the maize flours. While micronized maize flour was stored for 60 and 120 days under accelerated and ambient conditions, respectively, without significantly affecting quality, the storage duration was only 15 and 30 days for raw maize flour under similar conditions. Practical applications Most of the thermal processing methods employed for enzyme inactivation to extend the shelf‐life of whole grain flour often involve longer processing time and in cases such as wet heating require additional drying to keep the moisture content at safe levels. Infrared‐based micronization of grains is one novel method that combines benefits like improved starch digestibility and enhanced shelf‐life. The present study on micronization of maize grain was effective in inactivating peroxidase and lipase activity and significantly reducing the formation of free fatty acids during storage. Micronization enhanced the shelf‐life of whole maize flour packed in low density polyethylene pouches by fourfold when stored under ambient conditions. The outcome of this study indicates that micronization of maize grain can be effectively employed to extended the “shelf‐life whole maize flour,” which otherwise is very less.

Impact of hydrothermal processing on squalene, α‐tocopherol, and fatty acid content in Job's tears grain milled fractions: evaluation of their storage stability

“…The storage stability of the grains has been reported to improve and to retain its physicochemical properties with hydrothermal treatment in sorghum, pearl millet, finger millet, proso millet, maize, and oats 26,27,28 . This could be due to the inactivation of endogenous lipase in the grain, preventing the degradation of lipids during storage 27,28 . However, with prolonged storage, there was a significant decrease in the content of squalene and α ‐tocopherol.…”

Effect of extrusion-cooking conditions on the physical properties of Jerusalem artichoke straw

“…The pasting characteristics of extrudates may serve as a measure of component processing intensity relative to the process variables employed in extrusion-cooking (Deepa and Hebbar, 2017;Hagenimana et al, 2006;Koh and Singh, 2009). The pasting profiles of the selected samples of extruded Jerusalem artichoke straw are presented in Figs 1 and 2, relative to the initial moisture level and screw rpm used in the experiment.…”

Vida útil en masas y productos derivados del maíz: estudio bibliométrico

“…Así mismo, se determinó una tendencia creciente a partir del año 2014 del número de publicaciones realizadas en las revistas de mayor impacto para esta área de conocimiento, exponiendo que entre los temas publicados en el último año estaban basados en aspectos de la estabilidad de la vida útil y la calidad de productos a base de maíz como masas y tortillas mediante la adición de conservantes proteicos (Phillips et al, 2017;Yue et al, 2017) y en las condiciones reológicas y microbiológicas del grano y las masas de maíz que favorecen la vida anaquel (Deepa & Umesh Hebbar, 2017b;Valderrama-Bravo et al, 2017).…”

“…Uno de los autores con mayor relevancia en las investigaciones sobre el tema con respecto a los documentos encontrados; es la profesora Constantina Tzia del departamento de Ingeniería Química de la Universidad Nacional de Atenas en Grecia, con un total de 3 publicaciones, un índice H de 3 y 71 citaciones. La Tabla 1 muestra los autores y su correspondiente índice H, marcando la productividad y evaluando el impacto en el acumulado y relevancia de las publicaciones, analizando la correlación entre la producción científica generada y la cantidad de citas recibidas de su producción académica en relación al tema, aunque se registran índices relativamente bajos, esto se asocia a la baja producción científica relacionada con el tema durante el periodo de estudio; no obstante se resalta el trabajo en conjunto de los autores Deepa, C y Hebbar, HU cuyos temas se enfocan en los procesos de micronización (jet-milling) sobre los granos de maíz con posterior transformación a harina de maíz para conservar su vida útil (Deepa & Umesh Hebbar, 2014;Deepa & Umesh Hebbar, 2017a, 2017b.…”