This work studied three emerging approaches to improve the convective drying (50 °C, 0.8 m/s) of celery. Celery slices of 2 mm thick were pretreated for 5 min using ultrasound (32 W/L, 40 kHz), vacuum (75 kPa vacuum pressure) and ethanol (99.8% v/v, as drying accelerator) applied individually or in combination. To evaluate individual effects of ultrasound and vacuum, the treatments were also performed with distilled water or air medium, respectively. Moreover, the cavitational level was characterized in each condition. Drying kinetics was evaluated tending into account the drying time required by each treatment and the Page’s model parameters. In addition, microstructural effects and shrinkage were evaluated. As results, ethanol combined with ultrasound significantly improved drying kinetics reducing drying time by around 38%. However, vacuum pretreatment did not affect drying kinetic...

This research aimed to optimize the microwave popping process of 5 cultivars of ñuña beans under different moisture content. This work was divided into two stages: determining the optimal time and microwave power for maximum popping and studying the effect of initial grain moisture content on popping percentage. For this, grains were conditioned to 9%, 11%, 13% and 15% of moisture content. The results suggested that only the cultivars “Vaquita poroto”, “Negra” and “Jabona” cultivars reach the highest popping percentages selecting optimum microwave power and process time. In addition, this work found that for every studied cultivar, moisture content between 9 to 11% w.b (wet basis). is suitable to maximize popping percentage. Moisture contents greater than 13% w.b. drastically reduced the popping percentage but increased expansion percentage. In conclusion, this work recomme...

Terahertz time-domain spectroscopy is a useful technique to determine some physical characteristics of materials, which is based on the selective frequency absorption of a broadspectrum electromagnetic pulse. In order to investigate the potential of this technology to classify maturity states of Gruyere-type cheese, terahertz spectra (0.5-10 THz) of 4 samples of cheese made in the livestock area of Cajamarca - Peru were examined during 60 days. The acquired data matrices were analyzed with the application of MATLAB 2019b where absorbance curves were obtained and maturity states were classified by testing 24 classifier models, achieving differences of around 90%, obtained by the Gaussian SVM Algorithm Model with a 0.35 Kernel Scale and a multiclass method one vs one. It was concluded that the combined processing and classification of images obtained from Terahertz time-domain spectroscopy...

ABSTRACT This work studied the effect of ultrasound power and sodium bicarbonate (NaHCO3) concentration during soaking process on the hydration and cooking kinetics of pigeon pea (Cajanus cajan). The pigeon pea grains were hydrated using 0, 1, 1.5, and 2% m/m NaHCO3 solutions without and with ultrasound assistance (17 W/L; 40 kHz and 43 W/L; 40 kHz) at 27 °C. Cooking process was studied using softening kinetics. Grains were cooked in boiling water and their softening was evaluated with a texturometer. Both hydration and softening kinetics were fitted to suitable models and their parameters were used for evaluating the effect of ultrasound power and salt concentration. Ultrasound accelerated hydration kinetics but did not affect the cooking process. Soaking in NaHCO3 solution, delayed hydration kinetics, but accelerated the softening kinetics. The synergetic effect of ultrasound (17 W/L)...

RESUMEN El presente trabajo estudió las isotermas de adsorción a 25 °C de harina de tres variedades de quinua (Chenopodium quinoa Willd.): INIA Salcedo (IS), Pasankalla Roja (PR) y Negra Collana (NC) sin maltear y malteada, así como su vida útil. Las isotermas fueron determinadas colocando 2g de muestra en un analizador de actividad de agua. Se programaron lecturas de 0.05 a 0.90 de actividad de agua, para construir las isotermas y la humedad inicial se determinó por el método gravimétrico. Los datos experimentales fueron ajustados con los modelos matemáticos de GAB, BET, Henderson, Halsey y Oswin. La bondad del ajuste se evaluó con el coeficiente de regresión y el porcentaje de error medio relativo (%E). Como resultado se verificó que el modelo de GAB y Oswin presentaron un buen ajuste de los datos experimentales con un coeficiente de correlación superior a 0.98 y un %E men...

ABSTRACT This work aimed to optimize the production capacity of oyster mushroom (Pleurotus ostreatus), using as substrates vegetables residues: pine chips (Pinus sylvestris), eucalyptus chips (Eucalyptus globulus) and corn cob (Zea mays). For this the Simplex Centroid design (mixture design) was used, considering 10 treatments (0 – 100% of the three substrates). An ANOVA was applied to evaluate differences (p<0.05) among the treatments. As main results, pine chips increased the production capacity of oyster mushrooms and eucalyptus chips reduced it. By the desirability function of this methodology, the optimum mixture of substrates was found. This mixture should be made of 100% of pine chips, 0% of eucalyptus chips and %g of corn cob. Finally, a mathematical model was obtained (R2>0.98) which predicts the production capacity of oyster mushrooms using these three substrates.

ABSTRACT This work aimed to automate the most popular method to determine the cooking time of grains: the Mattson Bean Cooker apparatus. The proposed system is a low-cost and a simple approach, offering the possibility of calibration according to the size of the analyzed grains. The automation is based on the use of magnets, Hall effect sensors, potentiometers, and an operational amplifier to monitor the plungers' positions. The time required for each grain to be cooked is shown in a LCD display, and the connection among all the components is made by an ATmega328 microcontroller from the Arduino UNO R3 board. The proposed system can be assembled in an already existent device, costing ~US$200. Its validation was made with two different grains: carioca beans (Phaseolus vulgaris) and lentils (Lens culinaris). Despite the differences between sizes, both grains were suitably analyzed with the...

ABSTRACT This work aimed studied the effect of ionizing irradiation on the nutritional and technological properties of cooked Carioca beans (Phaseolus vulgaris). The dry beans were irradiated with different doses (1, 5 and 10 kGy) of γ-radiation using 60Co as source. The composition and nutritional properties (protein, fat, ash, tannin, phytic acid content and protein in vitro digestibility) of the cooked beans were analyzed, with and without previously soaking process. In addition, the technological properties (hydration index, cooking time and color) of the beans were also evaluated. The results showed that protein, fat, ash and tannin content, as well as color, were not affected by irradiation, while the phytic acid was significantly reduced by the irradiation. Further, hydration index was slightly reduced only by using 10 kGy suggesting probable structure changes. Irradiation re...

RESUMEN El presente estudio tuvo por finalidad evaluar las características físicas, texturales y aceptabilidad general de barras energéticas elaboradas con granos de quinua (Chenopodium quinoa Willd), kiwicha (Amaranthus caudatus L.) y semillas de chía (Salvia hispanica L.). Para obtener las combinaciones de los tratamientos se utilizó un diseño de mezclas, con restricciones, simplex con centroide ampliado, con los componentes: quinua (Q: 70 - 80%), kiwicha (K: 10 - 20%) y chía (C: 10 - 20%). El análisis estadístico reportó que, la proporción de Q:K:C, afectaron significativamente los valores de dureza, fracturabilidad, masticabilidad y cohesividad, el valor de los picos sonoros generados al momento del corte, así como la textura sensorial y aceptabilidad general de las barras energéticas. El tratamiento T3 (Q: 70%, K: 10%, C: 20%) obtuvo mayores de dureza, fracturabilidad y...

El texto completo de este trabajo no está disponible en el Repositorio Académico UPN por restricciones de la casa editorial donde ha sido publicado.

This work aimed to evaluate how cut orientation affects mass transfer during the drying and rehydration process. Sweet potato cylinders of 1.90 cm of diameter and 0.50 cm of height were prepared. Three cut orientations were carried out regarding the vascular tissue orientation, preparing longitudinal, transverse and oblique (45°) cuts. In addition, osmotic pretreatment (50°Brix sucrose solution) was also evaluated. Convective drying and rehydration kinetics were evaluated at a constant temperature. As results, cut orientation and osmotic pretreatment did not affect the drying kinetics. However, transverse cut without osmotic pretreatment presented less shrinkage than the other cut orientations. On the other hand, rehydration process was affected by cut orientation, being longitudinal cut the slowest sample absorbing water. In conclusion, both the cut orientation and osmotic dehydra...

ABSTRACT Waste from fruit processing can be used for obtaining additives as colorants and antioxidant compounds by extraction processes. Despite there are many works optimizing parameters as temperature and solvent concentration during this process, the mixture of solvents has not been optimized yet. Therefore, the present work aimed to find the optimum solvent mixture among water, ethanol, and acetone to obtain the maximum yields of phenolic compounds and monomeric anthocyanins from blue berry and grape marc by ultrasound-assisted extraction. For that, the Reticular Simplex Mixtures Design was used to obtain the models that can predict the optimum values of extraction yields. As a result, the quadratic model successfully fit the experimental data, demonstrating the best mixture solvents were the ones that presented a high percentage of water. This result was obtained not only for phenol...

El texto completo de este trabajo no está disponible en el Repositorio Académico UPN por restricciones de la casa editorial donde ha sido publicado.

RESUMEN El presente trabajo tuvo como objetivo caracterizar física, funcional y estructuralmentemente los almidones extraídos de cinco variedades de papas nativas (Solanum tuberosum) var. Andígena: Águila (AG), Bretaña (BR), Manzana (MN), Perla (PE) y Shuita (SH). La extracción se realizó con agua y decantaciones sucesivas. Se caracterizaron los almidones mediante determinación de color, contenido de amilosa aparente, claridad, poder de hinchamiento y solubilidad, forma y tamaño del gránulo, cristalinidad, espectroscopía de infrarrojo con transformada de Fourier, propiedades térmicas, propiedades reológicas y texturales. El almidón Águila presentó el menor contenido de amilosa, el menor poder de hinchamiento y solubilidad; y el almidón Manzana presentó temperaturas de gelatinización más altas. En el estudio reológico, los geles de los almidones se ajustaron al modelo...