Pre-treatments applied to rice husk enzymatic hydrolysis: effect on structure, lignocellulosic components, and glucose production kinetics

ABSTRACT Freezing (-20 °C, 12h) and alkaline (NaOH 8%) pretreatments were applied individually and combined in rice husk (Oryza sativa L.) before their hydrolysis with cellulase (EC: 3.2.1.4.). The effects on structural modifications, lignin content, cellulose, hemicellulose content and glucose production were evaluated. In addition, the glucose production kinetics were described by using the Peleg model. The homogenous rice husk (1 g) with and without pretreatments was hydrolysed with 150 U of Cellulase in 10 ml of acetate for 60 h (37 °C, pH 5.5, 100 rpm). As results, the SEM images evidenced porous microstructures with less agglomeration generated by all pre-treatments, which were intensified by the combined pretreatment. This pre-treatment allowed to obtain higher cellulose (62.51 ± 0.3 %) content. Besides, the glucose content after pretreatments increased. The Peleg model parameters from glucose production kinetics during enzymatic hydrolysis were related to initial glucose content (G0), glucose production rate (1/k1) and maximum glucose yield (1/k2). After enzymatic hydrolysis process, compared to control glucose yield (0.359 ± 0.002 g G/g rice husk), this was 27%, 71% and 88% higher for freezing, alkaline and combined pre-treatments respectively

Efecto de la temperatura y tiempo de transesterificación en el rendimiento y poder calórico de biodiesel a partir de grasa refinada de pollo

The main objective of this research was to determine through the response surface methodology conditions of temperature and time of transesterification which could achieve the higher yield and calorific value in the biodiesel obtained. We used the Central Composite Rotational Design type 22 +2*2, including 4 repetitions at the central point. Chicken fat passed through refining processes, esterification and transesterification weather conditions and temperature of each experiment. The best conditions of temperature were between 50 and 70 oC and time of transesterification between 60 and 120 min, we have obtained an average yield of 94.5% and calorific value in the biodiesel obtained from 40.2 MJ / Kg. We conclude that using the temperature of 56 oC and time of 108.4 minutes,biodiesel is obtained with characteristics required by the ASTM D6751-07, EN 14214 and NTP 321.003.2005standards.El objetivo principal de esta investigación fue determinar a través de la metodología de superficie de respuesta las condiciones de temperatura y tiempo de transesterificación que permitan obtener el mayor rendimiento y poder calórico en el biodiesel obtenido. Se utilizó el Diseño Compuesto Central Rotacional del tipo 22+2*2, incluyendo 4 repeticiones en el punto central. La grasa de pollo pasó por procesos de refinación, esterificación y transesterificación a las condiciones de tiempo y temperatura de cada experimento. Las mejores condiciones de temperatura estuvieron entre 50 y 70 oC y tiempo de transesterificación entre 60 y 120 min, que permitieron obtener rendimientos promedio de 94.5% y poder calórico en el biodiesel obtenido de 40.2 MJ/Kg. Se concluye que al utilizar la temperatura de 56 oC y tiempo de 108.4 minutos, se obtiene biodiesel con características exigidas por las normas ASTM D6751 – 07, EN 14214 y NTP 321.003.2005

Efecto de la temperatura y tiempo de transesterificación en el rendimiento y poder calórico de biodiesel a partir de grasa refinada de pollo

The main objective of this research was to determine through the response surface methodology conditions of temperature and time of transesterification which could achieve the higher yield and calorific value in the biodiesel obtained. We used the Central Composite Rotational Design type 22 +2*2, including 4 repetitions at the central point. Chicken fat passed through refining processes, esterification and transesterification weather conditions and temperature of each experiment. The best conditions of temperature were between 50 and 70 oC and time of transesterification between 60 and 120 min, we have obtained an average yield of 94.5% and calorific value in the biodiesel obtained from 40.2 MJ / Kg. We conclude that using the temperature of 56 oC and time of 108.4 minutes,biodiesel is obtained with characteristics required by the ASTM D6751-07, EN 14214 and NTP 321.003.2005standards.El objetivo principal de esta investigación fue determinar a través de la metodología de superficie de respuesta las condiciones de temperatura y tiempo de transesterificación que permitan obtener el mayor rendimiento y poder calórico en el biodiesel obtenido. Se utilizó el Diseño Compuesto Central Rotacional del tipo 22+2*2, incluyendo 4 repeticiones en el punto central. La grasa de pollo pasó por procesos de refinación, esterificación y transesterificación a las condiciones de tiempo y temperatura de cada experimento. Las mejores condiciones de temperatura estuvieron entre 50 y 70 oC y tiempo de transesterificación entre 60 y 120 min, que permitieron obtener rendimientos promedio de 94.5% y poder calórico en el biodiesel obtenido de 40.2 MJ/Kg. Se concluye que al utilizar la temperatura de 56 oC y tiempo de 108.4 minutos, se obtiene biodiesel con características exigidas por las normas ASTM D6751 – 07, EN 14214 y NTP 321.003.2005

Efecto de la temperatura y tiempo de transesterificación en el rendimiento y poder calórico de biodiesel a partir de grasa refinada de pollo

The main objective of this research was to determine through the response surface methodology conditions of temperature and time of transesterification which could achieve the higher yield and calorific value in the biodiesel obtained. We used the Central Composite Rotational Design type 22 +2*2, including 4 repetitions at the central point. Chicken fat passed through refining processes, esterification and transesterification weather conditions and temperature of each experiment. The best conditions of temperature were between 50 and 70 ºC and time of transesterification between 60 and 120 min, we have obtained an average yield of 94.5% and calorific value in the biodiesel obtained from 40.2 MJ / Kg. We conclude that using the temperature of 56 ºC and time of 108.4 minutes, biodiesel is obtained with characteristics required by the ASTM D6751-07, EN 14214 and NTP 321.003.2005 standards.El objetivo principal de esta investigación fue determinar a través de la metodología de superficie de respuesta las condiciones de temperatura y tiempo de transesterificación que permitan obtener el mayor rendimiento y poder calórico en el biodiesel obtenido. Se utilizó el Diseño Compuesto Central Rotacional del tipo 22+2*2, incluyendo 4 repeticiones en el punto central. La grasa de pollo pasó por procesos de refinación, esterificación y transesterificación a las condiciones de tiempo y temperatura de cada experimento. Las mejores condiciones de temperatura estuvieron entre 50 y 70 ºC y tiempo de transesterificación entre 60 y 120 min, que permitieron obtener rendimientos promedio de 94.5% y poder calórico en el biodiesel obtenido de 40.2 MJ/Kg. Se concluye que al utilizar la temperatura de 56 ºC y tiempo de 108.4 minutos, se obtiene biodiesel con características exigidas por las normas ASTM D6751 � 07, EN 14214 y NTP 321.003.2005

Effect of transesterification temperature and time on yield and calorific value of biodiesel from refined fat of chicken

The main objective of this research was to determine through the response surface methodology conditions of temperature and time of transesterification which could achieve the higher yield and calorific value in the biodiesel obtained. We used the Central Composite Rotational Design type 22 +2*2, including 4 repetitions at the central point. Chicken fat passed through refining processes, esterification and transesterification weather conditions and temperature of each experiment. The best conditions of temperature were between 50 and 70 ºC and time of transesterification between 60 and 120 min, we have obtained an average yield of 94.5% and calorific value in the biodiesel obtained from 40.2 MJ / Kg. We conclude that using the temperature of 56 ºC and time of 108.4 minutes, biodiesel is obtained with characteristics required by the ASTM D6751-07, EN 14214 and NTP 321.003.2005 standards

Effect of transesterification temperature and time on yield and calorific value of biodiesel from refined fat of chicken

The main objective of this research was to determine through the response surface methodology conditions of temperature and time of transesterification which could achieve the higher yield and calorific value in the biodiesel obtained. We used the Central Composite Rotational Design type 22 +2*2, including 4 repetitions at the central point. Chicken fat passed through refining processes, esterification and transesterification weather conditions and temperature of each experiment. The best conditions of temperature were between 50 and 70 ºC and time of transesterification between 60 and 120 min, we have obtained an average yield of 94.5% and calorific value in the biodiesel obtained from 40.2 MJ / Kg. We conclude that using the temperature of 56 ºC and time of 108.4 minutes, biodiesel is obtained with characteristics required by the ASTM D6751-07, EN 14214 and NTP 321.003.2005 standards

Gluten-Free Snacks Based on Brown Rice and Amaranth Flour with Incorporation of Cactus Pear Peel Powder: Physical, Nutritional, and Sensorial Properties

An agroindustrial by-product (cactus pear peel) and whole grains flour (brown rice and amaranth) were used to present a gluten-free snack proposal. The effect of 5% (F1), 7% (F2), and 10% (F3) substitution of brown-rice flour for yellow cactus pear peel powder (Opuntia ficus-indica) on the snack physical, sensorial, and nutritional properties was evaluated. In addition, 20% of amaranth flour (Amaranthus caudatus) was used for all formulations. As the percentage of substitution increased, the a⁎ value increased, while the L⁎ decreased. The control snacks presented higher hardness, while the snacks with 10% substitution presented a greater crispness. The sensorial properties (overall liking, colour, crispness, and oiliness) reported that the samples containing cactus pear peel powder were the most accepted. The fat content decreased as the substitution percentage increased. The F3 formulation presented the best physical and sensorial properties and when compared with other commercial snack brands, it presented low fat and an adequate protein and fibre content. Therefore, snacks based on brown rice, amaranth, and cactus pear by-product could be considered as a good option of gluten-free product, contributing to reducing the lack of gluten-free products on the markets

Biodegradable plates based on Pituca starch and Cocoa shell: Physical-mechanical characteristics and degradability [Planchas biodegradables a base de almidón de Pituca y cáscara de Cacao: Características físico-mecánicas y degradabilidad]

En el presente estudio se elaboró planchas biodegradables a base de almidón de pituca con sustitución parcial por harina de cáscara de cacao. Las planchas se procesaron empleando diferentes formulaciones de cáscara de cacao (0% - 15%, p/p) después se evaluaron sus características físico-mecánicas (humedad, color, densidad, capacidad de absorción de agua y resistencia mecánica) y de degradación. La sustitución de almidón de pituca por cáscara de cacao generó un color marrón con menor luminosidad, y capacidad de absorción de agua, comparados con el control. Se encontró que, al agregar más fibra, disminuye la densidad y humedad. Además, la formulación con 10% de sustitución presentó mayor resistencia mecánica. Finalmente, las planchas presentaron baja tasa de degradación por microorganismos y hongos en un periodo de 40 días, sin embargo, empleando los tratamientos de sustitución se obtuvo un incremento de hasta 9% en el porcentaje de degradación. Se recomienda aplicar las planchas para elaborar bandejas y estudiar su aplicación en el almacenamiento de frutas y/o vegetales.In the present study, biodegradable plates were made based on pituca starch with partial replacement by cocoa shell flour. The plates were processed using different formulations of cocoa shell (0%-15%, w/w) then their physical-mechanical characteristics (humidity, color, density, water absorption capacity and mechanical resistance) and degradation were evaluated. The substitution of pituca starch for cocoa shell generated a brown color with less luminosity, and water absorption capacity, compared to the control. It was found that, by adding more fiber, the density and humidity decreased. In addition, the formulation with 10% substitution presented higher mechanical resistance. Finally, the plates presented a low rate of degradation by microorganisms and fungi in a period of 40 days, however, using the substitution treatments, an increase of up to 9% in the percentage of degradation was obtained. It is recommended to apply the plates to make trays and study their application in the storage of fruits and/or vegetables