ABSTRACT
Abstract Sweet orange juice is an important part of diet since it is nutritious beverage offering good taste and play significant part in a healthy diet. High hygroscopicity, thermo-plasticity and presence of low molecular weight components in sweet orange juice offer low glass transition temperature (Tg), likely to form soft particle with sticky surface leading to sticky powder during drying. Maltodextrins are amorphous drying aids that tend to inhibit sugar crystallization and form a high Tg product after drying. In this study, the effect of the different spray drying parameters on the quality of powder derived from control and concentrated juice at three inlet air temperatures 120, 130 and 140 °C and at three levels of juice total soluble solids (TSS): maltodextrin levels at 1:0.5; 1:1 and 1:1.5 were studied. The impact of inlet air temperature and maltodextrin concentration has significantly affected various properties of sweet orange powder. For control juice, process yields increased with increase in inlet air temperature and maltodextrin concentration. However, for reverse osmosis (RO) concentrate, process yield increased with increase in maltodextrin concentration and decreased with increase in inlet air temperature. For control juice, process yields obtained were in the range of 12.59-41.16% and in case of concentrated juice, the process yield obtained was in the range of 21.35-56.95% at different combinations of inlet air temperature and maltodextrin concentrations. Spray-dried powder was considered as "possible" and "fair" in terms of flowability and cohesiveness. Vitamin C retention was high at lower inlet air temperature with lower concentration of maltodextrin.
Subject(s)
Polysaccharides/pharmacology , Temperature , Food Production , Citrus sinensis , Fruit and Vegetable Juices/analysisABSTRACT
ABSTRACT Amaranth flour is of high nutritional value, which makes it a potential food. Grinding of the grains is a necessary operation to obtain products with physical properties that provide the food products with adequate characteristics. To analyze the effect of grinding velocity and time on the particle diameters and physical properties of Amaranth flour by ball mill, a Doehlert design with triplicate at the central point was used. The tests were carried out with the mass ratio (balls/samples) (R1:5). Granulometry curve of each design system was fitted to the Rosin-Ramler-Bennet and Holmes-Hukki equations. A found a very significant effect of the velocity on the particle diameters (D50, D63 and D80). The flour obtained were modeled satisfactorily (r2>0.99) by using the Rosin-Ramler-Bennet equation, where the homogeneity index of (n1) was obtained, which was directly influenced by the milling energy. By using the Holmes-Hukki model, were able to model the characteristic diameters with the grinding energy; a critical region was observed between 100μm and 200μm, where lost efficiency in the size reduction. The excess energy, released in the critical region, caused the decrease in starch crystallinity and structural changes in the protein, which affect the functional properties of the flour. The planetary mill is emerging as an effective mean of modifying the functional properties in the development of new food products.
RESUMEN La harina de amaranto es de alto valor nutricional, convirtiéndola en un alimento potencial. La molienda de los granos es una operación necesaria, para brindarle a los productos alimenticios unas adecuadas propiedades físicas. Para analizar el efecto de la velocidad y el tiempo de molienda sobre el diámetro de particular y las propiedades físicas de la harina obtenida por molienda de bolas, se usó un diseño experimental Doehlert, con réplica en el punto central. En las pruebas de molinería se tuvo en cuenta la relación masa de bolas/masa de muestra (R1:5). Las curvas de granulometría de cada punto del diseño experimental fueron modeladas por las ecuaciones de Rosin-Ramler-Bennet y Holmes-Hukki. Se encontró un efecto muy significativo de la velocidad de molienda sobre los diámetros característicos (D50, D63 y D80). El modelo de Rosin-Ramler-Bennet ajustó satisfactoriamente (r2>0.99), además, se obtuvo el índice de homogeneidad (n1), el cual, fue afectado directamente por la energía de molienda. El uso del modelo de Holmes-Hukki permitió relacionar el diámetro de partícula con la energía de molienda y se logró observar una región crítica entre 100μm y 200μm, donde hay una reducción en la eficiencia de la reducción de tamaño de partícula. El exceso de energía liberada en la región crítica causó el descenso en la cristalinidad del almidón y provocó cambios en la estructura de las proteínas, lo cual, modificó las propiedades físicas de la harina. El Molino planetario es una técnica emergente y efectiva para modificar las propiedades funcionales en el desarrollo de nuevo productos alimenticios.
ABSTRACT
Conduziu-se este trabalho,com o objetivo de estudar as propriedades funcionais tecnológicas de extrusados de terceira geração obtidos de misturas de farinhas de pupunha (Bactris gasipaes Kunth.) e mandioca (Manihot esculenta Crantz), por meio das análises de densidade aparente, índice de absorção de água, índice de solubilidade em água e viscosidade de pasta (RVA). Os extrusados foram formulados, adicionando-se 15, 20 e 25 por cento de farinha de pupunha à farinha de mandioca, sendo processados em extrusora monorosca, escala piloto. Os parâmetros de extrusão foram fixos, utilizando-se cinco zonas de extrusão com temperaturas de 30ºC, 40ºC, 60ºC, 65ºC e 70ºC; velocidade do parafuso 177rpm; taxa de alimentação 292g/min e matriz laminar de 1mm. Os extrusados de terceira geração obtidos apresentaram valores relativamente baixos ou intermediários de IAA e ISA, variando de 5,01 a 6,48g/g e 5,37 a 7,34 por cento para IAA e ISA, respectivamente. Após o processo de fritura dos extrusados, observou-se expansão e, consequentemente, redução na densidade aparente dos mesmos. O desenvolvimento ou aplicação de tecnologias como a extrusão, que permitam o aproveitamento de matérias-primas regionais, entre elas a mandioca e a pupunha, é uma forma de agregação de valor às riquezas existentes e, ao mesmo tempo, possibilita a diversificação de novos produtos alimentícios prontos para o consumo.
The objective of this work was to study the technological functional properties of third generation extruded products obtained from cassava (Manihot esculenta Crantz) and pupunha (Bactris gasipaes Kunth.) flour mixtures, in terms of apparent density, water absorption index (WAI), water solubility index (WSI) and paste viscosity. The extruded products were formulated by adding 15 percent, 20 percent or 25 percent pupunha flour to cassava flour, and processing the mixtures in a pilot scale single screw extruder. The extrusion parameters were fixed by using five extrusion zones (at 30ºC, 40ºC, 60ºC, 65ºC, and 70ºC); screw speed, 177 rpm; feed rate, 292g/min; laminar matrix with 1 mm. The formed third generation extruded presented relatively low or intermediate values of WAI and WSI. After being fried, the extruded elements were expanded and thus their apparent density were reduced. Development or application of technologies such as extrusion, which allow utilization of regional raw food materials such as cassava and pupunha, is a way of aggregating value to the natural resources, at the same time allowing development of new food products ready for consumption.