Computational modelling of extrusion process temperatures on the interactions between black soldier fly larvae protein and corn flour starch.

Insects such as the black soldier fly (BSF) are recently being studied as food sources to address concerns about how to meet the food demand of the growing world population, as conventional production lines for meat proteins are currently unsustainable sources. Studies have been conducted evaluating the use of insect proteins to produce extruded foods such as expanded snacks and meat analogues. However, this field of study is still quite new and not much has been studied beyond digestibility and growth performance. The purpose of this work was to evaluate the compatibility of protein extracted from BSF flour with corn flour starch within an extruded balanced shrimp feed model through molecular dynamics simulations, for which cohesive energy density and solubility parameter (δ) of both components were determined. The calculations' results for the protein molecule systems yielded an average δ of 14.961 MPa0.5, while the δ for starch was calculated to be 23.166 MPa0.5. The range of difference between both δ (10 > Î´ > 7) suggests that the interaction of the BSF protein with corn starch is of a semi-miscible nature. These results suggest that it is possible to obtain a stable starch-protein mixture through the extrusion process.

Improvement in the Thermostability of a Recombinant ß-Glucosidase Immobilized in Zeolite under Different Conditions.

ß-Glucosidase is part of the cellulases and is responsible for degrading cellobiose into glucose, a compound that can be used to produce biofuels. However, the use of the free enzyme makes the process more expensive. Enzyme immobilization improves catalytic characteristics and supports, such as zeolites, which have physical-chemical characteristics and ion exchange capacity that have a promising application in the biotechnological industry. This research aimed to immobilize by adsorption a recombinant ß-glucosidase from Trichoderma reesei, obtained in Escherichia coli BL21 (DE3), in a commercial zeolite. A Box Behnken statistical design was applied to find the optimal immobilization parameters, the stability against pH and temperature was determined, and the immobilized enzyme was characterized by SEM. The highest enzymatic activity was determined with 100 mg of zeolite at 35 °C and 175 min. Compared to the free enzyme, the immobilized recombinant ß-glucosidase presented greater activity from pH 2 to 4 and greater thermostability. The kinetic parameters were calculated, and a lower KM value was obtained for the immobilized enzyme compared to the free enzyme. The obtained immobilization parameters by a simple adsorption method and the significant operational stability indicate promising applications in different fields.

Reduction in the in vitro ruminal methane production with the inclusion of Cucurbita foetidissima / Reducción en la producción ruminal de metano in vitro con la inclusión de Cucurbita foetidissima

ABSTRACT Objective. This research aimed to evaluate the inclusion of Cucurbita foetidissima (BG) leaves as a partial or total substitution of alfalfa hay (AH) in beef cattle diets on in vitro methane output, gas kinetics and volatile fatty acids production. Materials and Methods. Five experimental treatments were formulated with the inclusion of BG as alfalfa hay (AH) substitute at 0, 25, 50, 75 and 100% in experimental treatments denominated CON (control), BG25, BG50, BG75 and BG100, respectively. Results. Lignin and organic matter decreased with BG inclusion (p<0.05). However, NDF, CT and TPC increased with higher levels of BG (p<0.05). Maximum gas production diminished with BG inclusion (p<0.05); whereas, microbial protein production, specific gas production rate and latency period were not affected (p>0.05). Methane production decreased linearly with BG inclusion (p<0.05). Nevertheless, CO2 production showed no changes with inclusion of graded levels of BG in the experimental treatments (p>0.05). Additionally, acetate and butyrate were not affected by BG inclusion (p>0.05); although, propionate increased linearly among treatments (p<0.05). Furthermore, inclusion of 75% of BG reduced 31% in vitro methane production without changes in CO2 production, suggesting an inhibition of endogenous methanogenesis. Conclusions. These results promote the inclusion of BG leaves as a potential and environmentally friendly forage source for beef cattle feeding.

RESUMEN Objetivo. El objetivo de este estudio fue evaluar la inclusión de hojas de Cucurbita foetidissima (BG) como sustituto parcial o total de la alfafa (AH) en la dieta de ganado de engorda sobre la cinética de producción de gas y producción ruminal in vitro de metano y ácidos grasos volátiles. Materiales y Métodos. Se formularon cinco dietas con la inclusión de BG como sustituto de heno de alfalfa a 0, 25, 50, 75 y 100% en los tratamientos experimentales que se denominaron CON (control), BG25, BG50, BG75 y BG100, respectivamente. Resultados. La lignina y la materia orgánica disminuyeron con la inclusión de BG (p<0.05). La máxima producción de gas disminuyó con la inclusión de BG (p<0.05); mientras que la producción de proteína microbiana, la tasa específica de producción de gas y el tiempo de latencia no mostraron cambios(p>0.05). La producción de metano disminuyó linealmente con la inclusión de BG (p<0.05). No obstante, la producción de CO2 no mostró cambios con la inclusión de BG en los tratamientos (p<0.05). Adicionalmente, el acetato y el butirato no fueron afectados por la inclusión de BG (p>0.05); a pesar de que el propionato se incrementó linealmente (p<0.05). Además, la inclusión de BG en un 75% redujo la producción de metano 31% sin afectar la producción de CO2, lo que sugiere una inhibición de la metanogenesis endógena. Conclusiones. Estos resultados promueven la inclusión de hojas de BG como una fuente de forraje potencial y amigable con el ambiente en la alimentación de ganado de engorda.