Improving the infrared drying and rehydration of potato slices using simple approaches: Perforations and ethanol

Abstract

The objective of this work was use ethanol and perforations as simple approaches to improve the infrared drying and rehydration of potato slices. Perforations were performed to study the effect of promoting routes to capillarity flow, while ethanol was impregnated in the samples to evaluate the effect of Marangoni flow. All pretreatments reduced the drying time compared to control treatment. However, a great time reduction was observed with P + E pretreatment: The synergistic combination of both treatments increased the drying rate in more than four times, reducing both drying time and the necessary energy by 44%. The samples with perforations (P and P + E) increased their rehydration rate as well as the water retention capacity. However, the pretreated samples with ethanol shows poor rehydration properties. Possible mechanisms were discussed. These results show simple approaches to enhance food drying and rehydration.

Combining ethanol pre‐treatment and ultrasound‐assisted drying to enhance apple chips by fortification with black carrot anthocyanin

“…Ethanol pre‐treatment has provided interesting results enhancing food drying. Different structural modifications were reported, such as changes on cell wall thickness and the air removal from intercellular spaces, which improves the process and product properties 11–15 . Furthermore, during pre‐treatments, the entrance of ethanol occurs into the food matrix, forming a mixture with the water of samples.…”

Ethanol as a pre-treatment of starchy foods drying: effect on potato drying kinetics and starch properties

“…All these works described a positive impact of ethanol in the rehydration properties. However, a different behavior to this rehydration kinetics was observed when potato slices were dried using infrared radiation Rojas & Augusto (2018b) and Rojas, Silveira & Augusto (2019). The mentioned works, the ethanol pre-treatment negatively affected the potato rehydration.…”

“…However, other studies describe negative aspects of the ethanol pre-treatment. For instance,Rojas & Augusto (2018b) andRojas, Silveira & Augusto (2019) studied the ethanol pre-treatment to the infrared drying of potatoes. Although infrared drying was enhanced, ethanol negatively affected rehydration, which was attributed to the large starch content present in the samples and characteristics of the drying process.…”

Emerging technologies to improve food drying: ultrasound and ethanol on convective and infrared drying

“…This study is described in the article "Improving the infrared drying and rehydration of potato slices using simple approaches: Perforations and ethanol" published in the Journal of Food Process Engineering (Rojas, et al, 2019b), showed in Appendix III.…”

“…When ethanol is applied, different phenomena (related to structure and composition modifications) occurs, especially in the sample surface. The intercellular air is removed, the cell wall is thinning, some compounds are extracted and part of ethanol enters the sample Rojas, et al, 2019b;. Since the ethanol vapour pressure is higher than that of the water, the vaporization of ethanol could start almost instantly during drying.…”