Production of kiwi snack slice with different thickness: Drying kinetics, sensory and physicochemical analysis

Abstract

In the modern world, light and healthy meals are increasingly consumed between the main meal courses. Therefore, market has made a wide variety of products of this type available, usually without artificial additives. This study aimed to produce snacks through the thin-layer drying of kiwi slices. Circular kiwi slices were cut into various thicknesses (5.0, 10.0 and 15.0 mm) and subject to different drying air temperatures (50, 60, 70 and 80 o C). Drying was described using several mathematical models, both diffusion (boundary condition of the third kind) and empirical (Henderson-Pabis, Lewis, Page, Silva et al.) models. According to diffusion model, kiwi slices showed an almost uniform moisture distribution over time. The Page equation/model showed the best fit to the experimental data, compared to other models. At the end of the drying process (until equilibrium), slices with initial thickness of 5.0 mm had a rigid consistency, suitable for production of flour through grinding. On the other hand, slices with initial thicknesses of 10.0 and 15.0 mm were soft; thus, they can be consumed as snacks. Sensory and physicochemical analyses showed that the product cut with initial thickness of 15.0 mm and dried at temperature of 70 ºC (until moisture content of 0.31 kg water /kg dry matter ) was the tastiest one and showed good results for the analyzed chemical compounds.

Evaluation of thermodynamic properties and antioxidant activities of Achachairu (Garcinia humilis) peels under drying process

“…The parameters ‘a’ and ‘b’ are dimensionless, and the constant ‘a’ found in Page's model was directly related to the increase in temperature. According to Moreira et al, 33 parameter ‘b’ is a constant of proportionality between the drying rate and the humidity ratio. During the drying process of achachairu peels, there was no correlation between this parameter and the temperature applied.…”

Modelagem e simulação do processo de secagem das cascas de jabuticaba (Myrciaria cauliflora)

“…Segundo Giner et al (2010) e Bezerra et al (2015), o número de Biot é um número adimensional que correlaciona a taxa de condução interna com a taxa de convecção externa e é capaz de indicar a resistência interna do produto ao processo de transferência de calor e massa. Portanto, cabe ressaltar que, segundo Silva et al (2012) e Moreira et al (2018), para um número tão baixo de Biot, a série infinita que representa a solução da equação de difusão pode ser representada apenas pelo seu primeiro mandato, com erro insignificante de truncamento.…”

Cinética de secagem e determinação do coeficiente de difusão efetivo das polpas de noni e umbu

“…As curvas de cinética de secagem de um produto depende de vários fatores como velocidade do ar de secagem, teor de água inicial, teor de água final, umidade relativa do ar, temperatura, composição, pressão, entre outros (Moreira et al, 2018). observaram o efeito da temperatura (40, 50 e 60 °C) sobre as curvas de secagem em camada delgada da polpa de carambola, notando que com o aumento da temperatura do ar de secagem, ocorreu uma elevação das taxas de remoção de água do produto.…”