ABSTRACT

The cassava flour from dry group is marketed and consumed under three different particle sizes (coarse, medium and fine), mostly in the North and Northeast regions of Brazil. Thus, as a contribution to the packaging, storage and handling of this type of flour, moisture sorption isotherms were made at 25°C, 35°C and 45°C, for three different particle sizes. Five mathematical models were fitted to the moisture sorption data and the isosteric heat of sorption (Q_st) was calculated. The sorption isotherms indicated that the particle size did not interfere on the product’s hygroscopicity and moistures below 9.55 g H₂O/100 g ensures the product’s microbiological stability when stored between 25°C and 45°C. The Oswin model displayed the best fit and the Q_st values indicated that great amount of energy is involved in the product’s drying process. The storage time of the product was estimated in 136 days.

摘要

干燥组的木薯粉以三种不同的粒径（粗，中，细）销售和食用，主要分布在巴西的北部和东北部地区。因此，为了对这种类型的面粉的包装，储存和处理做出贡献，针对三种不同的粒径在25℃，35℃和45℃下进行了水分吸收等温线。将五个数学模型拟合到水分吸附数据，并计算出等规吸附热（Q _st）。吸附等温线表明，粒径不影响产品的吸湿性，湿度低于9.55 g H ₂ O / 100 g可以确保产品在25°C至45°C之间储存时的微生物稳定性。Oswin模型显示出最佳拟合和Q _st值表明产品的干燥过程涉及大量能量。产品的储存时间估计为136天。