Browsing by Author "Lescano Bocanegra, Leslie"

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    Coverage of chitosan and essential cinnamon oil for strawberry conservation (Fragaria ananassa) var. Aroma, minimally processed
    (LACCEI Inc., 2020-07) Zavaleta, Magaly; Echeverría, Carlos; León-Vargas, Jackeline; Lescano Bocanegra, Leslie; Sánchez-González, Jesús; Linares Luján, Guillermo; Rojas, Meliza Lindsay
    The use of edible coverage represents one of the important methods used to preserve the quality of minimally processed products. The aim of this research was to determine the effect of chitosan and essential cinnamon oil coverage in the phenolic content, antioxidant capacity, mould and yeast count, and general acceptability in minimally processed strawberry along 16 days of refrigerated storage at 10 °C, in order to improve the conservation and characteristics of minimally processed strawberry var. aroma. In this experiment a response surface methodology using a Central Composite Rotational Design (CCRD) was carried out; the variable ranges used were 0.7 – 2% (Chitosan) and 0.02 – 0.1% (cinnamon essential oil). As results, it was found that the significant variable (p<0.05) was cinnamon essential oil for both phenols content and antioxidant capacity. For these characteristics, a concentration of 0.1% cinnamon essential oil was the most effective. The antioxidant capacity and phenolic contents showed an increase during the first 7 days of storage, decreasing after that for all treatments. It was also found that both independent variables significantly influence (p<0.05) in the decrease of microbial load being the optimal range of chitosan (1.33-1.71%) and cinnamon essential oil (0.056-0.087%). In addition, the use of coverage of chitosan and cinnamon essential oil does not negatively affect the sensory acceptability and helps to maintain the shelf life of minimally processed strawberry.
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    Planchas biodegradables a base de almidón de Pituca y cáscara de Cacao: Características físico-mecánicas y degradabilidad
    (LACCEI Inc., 2021-07) Tantarico Huaman, Jeferson; Rojas, Meliza Lindsay; Pagador, Sandra; Vega Anticona, Alexander; Lescano Bocanegra, Leslie; Sánchez-González, Jesús A.; Linares Luján, Guillermo Alberto
    Resumen- 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.
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    Pre-treatments applied to rice husk enzymatic hydrolysis: effect on structure, lignocellulosic components, and glucose production kinetics
    (LACCEI Inc., 2020-07) Linares Luján, Guillermo; Rojas, Meliza Lindsay; Sánchez-González, Jesús A.; Lescano Bocanegra, Leslie; Pagador Flores, Sandra; Aredo, Fernando
    Freezing (-20 °C, 12h) and alkaline (NaOH 8%) pre-treatments 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 pre-treatments 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 pre-treatment. This pre-treatment allowed to obtain higher cellulose (62.51 ± 0.3 %) content. Besides, the glucose content after pre-treatments 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.