Resumo

PUENTE, LUIS et al. INFLUENCE OF OSMOTIC PRETREATMENT ON THE HOT AIR-DRYING OF GRANNY SMITH APPLE. Dyna rev.fac.nac.minas [online]. 2010, vol.77, n.164, pp.274-283. ISSN 0012-7353.

In this paper we study the influence of an osmotic pre-treatment (DO) at three concentrations (30, 40 and 50 ºBrix) on the implementation of a process of dehydration of apple by hot air (SAC) at two temperatures (55 and 60 ºC ). It was found that higher concentrations in the osmotic dehydration pretreatment occurred nondimensional moisture curves more pronounced. The drying rate was higher for apples pretreated compared with that of fresh product, distinguishing a short induction phase only in SAC, and in both types of treatment (OD + SAC) a second stage imperceptible speed and a clear third stage of decreasing drying rate I and II. The drying rate was modeled using the equations of Newton and Page. The best goodness of fit was obtained by Page model, follow by Newton and Henderson-Pabis. The two performed temperatures levels ( 55 ºC y 65 ºC) were significative, since the meaningful interaction with osmotic dehydration. The better process condition was DO 50º Brix and SAC 65 ºC.

Palavras-chave : Apple; osmotic dehydration; hot air drying.

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