Ethanol pretreatment in taioba leaves during vacuum drying

Abstract

Non-conventional vegetables are those with limited distribution, restricted to certain regions. As a globalization and food industrialization result, its cultivation and consumption has decreased. The taioba [Xanthosoma sagittifolium (L.) Schott] is an example of this vegetable category. The drying process increases the food stability, but it can negatively alter the nutritional value and the final quality of the product. Ethanol pretreatment reduces the drying time and can assist in the preservation of the nutritional characteristics. The aim of this work was to evaluate the effect of vacuum drying and ethanol pretreatment on the drying behavior, mathematical modeling, and final quality of taioba leaves. Higher temperatures and ethanol pretreatment lead to a shorter drying time. Thin-layer equations were evaluated for their ability to predict the drying kinetics, of which the Logarithmic and Midilli & Kuçuk equations performed best. A significant difference (p ≤ 0.05) was observed in the ascorbic acid content, antioxidant activity and total phenolic compounds in the different treatments. There was preservation in ascorbic acid content in treatments in which ethanol was applied; moreover, lower total phenolic compounds and antioxidant activity were observed when ethanol was used. There was no significant difference (p > 0.05) in pH values and titratable acidity.

Literature review: use of ultrasound and ethanol as pre-treatment in the drying of vegetable products with bioactive compounds

“…Additionally, green onion slices pre-treated with ethanol and ethanol + vacuum showed better water loss than the control and water + vacuum samples, which, in turn, shortened the drying time and increased the retention rate of ascorbic acid in the samples. Junqueira et al (2021) assessed the effect of ethanol pre-treatment on the phenolic compound content during vacuum drying of taioba leaves. In the study, taioba leaves were sprayed with ethanol (4.0 × 10-4 L), and drying experiments were conducted at two different temperatures (40 and 50°C) with a vacuum pressure of 10 kPa.…”

Infrared Drying of Bocaiuva (Acrocomia Aculeata) Slices: Drying Kinetics, Energy Consumption, and Quality Characteristics

“…Consequently, a greater gradient in both moisture and heat is achieved, resulting in an increased drying rate. Junqueira et al (Junqueira et al, 2021) observed that taioba leaves dried at higher temperatures presented higher drying rates (lower drying periods). The commencement of the moisture diffusion from the inside to the outside of bocaiuva slices requires energy, which is expressed as E a .…”

Two-stage power level to improve microwave vacuum drying of restructured peruvian carrot chips

“…Drying is a food conservation technique for several types of foods (Junqueira et al, 2021). It inhibits enzymatic and microbial activity, extending product shelf life.…”