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Currently, approximately 34% of fruit is lost and wasted in emerging economies due to inefficient post-harvest processes, technological shortcomings, lesser valorization of surpluses, and byproducts. Peach (Prunus persica L.) is a fruit with a good yearly growth rate but higher postharvest losses in Colombia. One way to take advantage of this type of product is through the application of drying processes that increase its shelf life and its inclusion in the food chain. Refractance Window Drying (RWD) is a fourth generation drying technique implemented by the food industry in the last few decades and has been applied to several dehydrated food products. This study compared the effects of different drying methods on the physical and sensory properties of peaches surplus. Treatments consisted of (i) peaches were sliced (1, 2, and 3 mm thickness) and dried using RWD at 86°C, (ii) peach pulp mixed with maltodextrin (MD) (0.12–0.33 kg of MD/kg of sample) and RWD (RWD-MD), and (iii) conventional oven drying (OD) at 60°C (3 mm thick) dried for 24 h. The study found that the drying method significantly (p < 0.05) affected the texture, color, and general taste of peaches. The results showed that processing treatments combined with different drying conditions affected the physical properties of the peach. RWD in slices reduced water content to 0.05 kg H2O/kg in 40 min, showing fewer effects on color attributes. A surface response analysis on RWD showed good correlations for water activity (R2 = 0.8652–0.9894) and moisture content (R2 = 0.7048–0.9826). A higher diffusion coefficient (1.63 × 10−6 m2 s−1) was observed for RWD in slices with 3 × 10−3 m of thickness; however, for RWD-MD, differences in diffusion coefficients were present for the lowest MD addition (0.12 kg/kg), vitamin C was not detected on the dried slices, and higher concentration of β-carotene (175.88 μg/100 g) was found on the thinner slices. Principal component analysis showed that RWD in the slices was the most suitable drying process, followed by OD. Sensory analysis showed good acceptability for RWD slices after 30 days of storage.

The main aim of this study was to evaluate the impact of mechanical drying on the sensory quality of specialty coffee produced on three Colombian coffee farms. The technique involved a study of the coffee bean drying process parameters, such as temperature (35, 45 and 55 ℃), airflow (100 m3/min∙m2) and thickness (0.2 m) for mechanical drying, vs conventional drying in the open sun until 11% of moisture content was reached. For mechanical drying, the effective diffusion coefficient, electrical conductivity and drying kinetics were evaluated. A sensory test was performed for three storage periods (3, 6 and 9 months) using the Specialty Coffee Association (SCA) protocol. The results showed that the effective diffusion coefficient varied from 3.21 to 8.02 × 10−7 m2/s for mechanical drying and from 4.21 × 10−11 m2/s for drying in the open sun. The time drying time was established at 20.35 ± 0.06, 29.10 ± 0.09 and 71.52 ± 0.11 hours for mechanical drying at 55 ℃, 45 ℃ and 35 ℃ respectively and 54.48 ± 11.37 hours for drying in the open sun system. The average moisture content at the end of all drying operations was 12.5%. Electrical conductivity rose from 11.71 to 16.86 µS/cm∙g at drying temperatures ranging from 35 to 55 ℃. The sensory test revealed that storage duration had no effect on the quality of the coffee drink when in touch with the drying process, with mechanical drying yielding higher sensory ratings. The coffee beans were dried at 55 ℃, yielding coffee samples with SCA scores more than 85 points. In overall, it is determined that the convective mechanical drying method is a viable approach for the processing of specialty coffee beans since it allows for the retention of high-quality sensory qualities, allowing it to command higher market pricing.

Contextualización: el mercado de cafés especiales ha aumentado su popularidad debido a sus características relacionadas con una mejora y una exclusividad en sus factores sensoriales de calidad, a través de diferentes procesos y actores determinados, con los que se busca garantizar la excelencia en cada etapa de la cadena productiva de los cafés especiales. Esto implica aspectos como la selección de las mejores condiciones de temperatura, altitud y suelo, así como la importancia de la recolección, el tueste, la preparación y el disfrute, los cuales influyen directamente en la experiencia de calidad. Vacío de conocimiento: con relación al campo de conocimiento de los cafés, es deficiente la aplicación de revisiones de literatura, especialmente mediante técnicas de análisis bibliométrico. Adicionalmente, no se encuentra ningún documento que aborde la temática de cafés especiales y describa de forma exhaustiva las diferentes líneas de investigación e indicadores. Propósito: esta investigación pretende sintetizar la literatura académica relacionada con el campo de los cafés especiales por medio de un análisis bibliométrico, por lo que se hace necesaria una búsqueda histórica en relación con el campo de conocimiento para determinar diferentes indicadores que describan el estado actual de la producción científica. Metodología: para la revisión se recolectaron 417 documentos de la base de datos Scopus. Se construyeron diferentes indicadores que describen los principales tópicos en relación con la producción, autores, revistas, países y artículos más citados, además, se construyen redes bibliométricas para identificar tendencias. Finalmente, mediante un análisis cualitativo se describen futuras líneas de investigación. Resultados y conclusiones: los resultados revelan cómo el contexto de producción y comercialización influye de manera determinante en la investigación, especialmente considerando que Brasil ostenta el liderazgo como principal productor académico en este campo. A través de indicadores y redes bibliométricas, se reconocen líneas de investigación que analizan los componentes fisicoquímicos, la calidad sensorial del café, el mercado, consumo y gobernanza de los cafés especiales.

El objetivo de la presente fue modelar el comportamiento térmico de un secador solar típico para café tomando en consideración algunas configuraciones geométricas en la apertura de ventanas, en pos de mejorar las condiciones de secado natural al interior de la estructura. El modelo se simuló con datos experimentales en un secador solar típico en Colombia con Ansys CFX®. Los resultados mostraron que la geometría con una apertura del 25 % en la ventana para la salida del aire aumentó la temperatura sobre la capa de café hasta 4,2 °C con respecto a la temperatura ambiente, lo cual garantiza uniformidad en el secado, mientras la geometría típica con una apertura del 100 % aumentó la temperatura hasta 3,6 °C, no obstante, con ambas aperturas se aumentó la humedad relativa sobre la capa de café hasta 0,7 % con respecto a la humedad relativa ambiental. Con la apertura máxima de las ventanas disminuyó la humedad relativa del aire.

Background: Sugarcane is one of the world's largest crop. It grows in the tropical and subtropical regions, and its harvest provides 80% of the world's sugar. In Latin America unrefined cane sugar is widely available and much less expensive than refined sugar. Sugarcane is a crop of great interest in Colombia due to the economic impact on the rural population and its application as sweetener agent. The powder of sugarcane (Saccharum officinarum L.) is widely used as a raw material in a wide range of industries such as foods, pharmaceutical, cosmetic and chemical. Objectives: The aim of the research work was the evaluation of the adsorption thermodynamics of sugarcane powder obtained by spray drying technology. Methods: The adsorption isotherms of sugarcane powder were evaluated at temperatures of 4 ± 0.1, 20 ± 0.2 and 30 ± 0.3 °C and its thermodynamic properties such as Gibbs free energy (G), differential heat of adsorption (ΔH) and differential entropy (ΔS) were calculated as a function of moisture content. Experimental data of adsorption isotherms were fitted to the GAB (Guggenheim - Andersen - de Boer), BET (Brunauer - Emmett - Teller), Henderson, Caurie, Smith, Hasley, Peleg, and Oswin models. Results: The results showed a type-II sigmoidal behavior, with temperature having a statistically significant effect. The GAB equation showed a better fit to the experimental data modeling (0.11≤a w≤0.87) although all models showed validity and goodness of fit to the experimental data. The net isosteric heat increased to a maximum value (57 kJ mol-1) and then decreased with the increase in moisture content. Conclusions: The sugarcane powder with maltodextrin, obtained by spray drying got low adsorption thermodynamic stability, as it required very low energy to occur this phenomenon, being obtained the maximum net isosteric heat when moisture content of 4.7% (d.b). This value is within the range of the monolayer moisture content found in the GAB and BET models.

Yacon is a tuber known as a healthy food due to its effects as an antidiabetic, anti-inflammatory, anticancer, and prebiotic agent; it is rich in fructooligosaccharides (FOS) and antioxidants, and due to its sweet taste and low-calorie content, it is used as a substitute for ordinary sugar. This research aimed to evaluate the influence of the composition of the feed and the microencapsulation process by spray drying (SD) on the properties of a yacon powder mixture (YP). Response surface methodology with a central composite design with a face-centered composition (α = 1) was used, considering the independent variables: inulin (IN) (3–5% w/w), maltodextrin (MD) (3–5% w/w), air inlet temperature (AIT) (140–160 °C), air outlet temperature (AOT) (75–85 °C) and atomizer disc speed (ADS) (18000–22000 rpm), and the dependent variables: moisture (Xw), water activity (aw), hygroscopicity (Hy), solubility (S), particle size (percentile D10, D50, and D90), total phenols (TP), antioxidant capacity (ABTS and DPPH), color (CIE-Lab*) and yield (Yi). The suspension formulation contained xanthan gum (0.167 %) and a mixture of ascorbic and citric acids (0.3 %). The aw and Xw values of the YP guarantee its microbiological stability; however, the process formulation produces a complex matrix (FOS- sugars- MD - IN) with high affinity for water, which favors adsorption phenomena (hygroscopic material) and high reconstitution (high solubility). The independent variables that best fit the experimental optimization criteria were: IN = 3.0 %, MD = 5.0 %, AIT = 143.7 °C, AOT = 80.1 °C, ADS = 22000 rpm, where Yi = 84.2 %, and the quality of the YP: Xw = 2.4 %, aw = 0.220, Hy = 23.0 %, S = 96.9 %, D10 = 10.6 μm, D50 = 23.4 μm and D90 = 169.3 μm, TP = 1228.2 mg gallic acid equivalent/100 g, ABTS = 2295.9 mg Trolox equivalent (TE)/100 g, DPPH = 5192.3 mg TE/100 g, L* = 80.5, a* = 5.1 and b* = 17.4. SD is an effective technology that positively impacts the development of new food products. In addition, the YP could have multipurpose applications for the industry, generating value in this agri-chain.

Estudios de encapsulación de sabores artificiales de mandarina no han sido reportados. En este estudio fue avaluado el efecto de maltodextrina, proteína de soja, goma arabiga y un agente de tensioactivo (polisorbato 80), en la estabilidad de una emulsión formulada con sabores artificiales de mandarina, para ser encapsulado mediante secado por aspersión. Usando la metodología de superficie de respuesta, las condiciones de operación del secador (temperatura de entrada y de salida de aire y la velocidad del disco atomizador), se optimizaron en función de las propiedades de calidad del producto en polvo y desempeño del secador. Los resultados mostraron que las temperaturas de entrada y de salida de aire de 213°C y 90°C, respectivamente, junto con una velocidad de disco atomizador de 35000rpm son las más adecuadas para obtener un producto con alta eficiencia de encapsulación de d-limoneno y α-linalol (>95%), baja formación de depósitos (