The Influence of the Osmotic Dehydration Process on Physicochemical Properties of Osmotic Solution.

Krzysztof Lech,Adam Figiel,Paulina Nowicka,Anna Michalska,Aneta Wojdyło

doi:10.3390/molecules22122246

Krzysztof Lech, Adam Figiel + Show 3 more

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https://doi.org/10.3390/molecules22122246

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Abstract

The osmotic dehydration (OD) process consists of the removal of water from a material during which the solids from the osmotic solution are transported to the material by osmosis. This process is commonly performed in sucrose and salt solutions. Taking into account that a relatively high consumption of those substances might have a negative effect on human health, attempts have been made to search for alternatives that can be used for osmotic dehydration. One of these is an application of chokeberry juice with proven beneficial properties to human health. This study aimed to evaluate the physicochemical properties of the OD solution (chokeberry juice concentrate) before and after the osmotic dehydration of carrot and zucchini. The total polyphenolics content, antioxidant capacity (ABTS, FRAP), dynamic viscosity, density, and water activity were examined in relation to the juice concentration used for the osmotic solution before and after the OD process. During the osmotic dehydration process, the concentration of the chokeberry juice decreased. Compounds with lower molecular weight and lower antioxidant capacity present in concentrated chokeberry juice had a stronger influence on the exchange of compounds during the OD process in carrot and zucchini. The water activity of the osmotic solution increased after the osmotic dehydration process. It was concluded that the osmotic solution after the OD process might be successfully re-used as a product with high quality for i.e. juice production.

Highlights

The osmotic dehydration (OD) process consists of the removal of water from fresh material wherein the solutes from the osmotic solution are transported to the plant material [1]
The presence of the different weight compounds in the osmotic solution might have a significant influence on the osmotic dehydration process, especially when the non-uniform structure of plant materials is concerned
Besides the fact that during the OD process solids entered from the osmotic solution into the material, causing a decrease in its concentration, the polyphenols content and antioxidant capacity increased

Summary

Introduction

The osmotic dehydration (OD) process consists of the removal of water from fresh material (i.e. fruits and vegetables) wherein the solutes from the osmotic solution are transported to the plant material [1]. OD is a pre-treatment process, which has many advantages such as improving the physical and chemical food properties including colour, flavour, aroma, and texture, as well as possibly improve the biological activity of the products [2]. This process prolongs the storage time of the products, requires a shorter drying time, and is energy efficient when compared to the other drying techniques [1]. OD is usually followed by i.e., conventional drying due to the relatively high moisture content in OD products [3,4,5]. Taking into account that a relatively high consumption of those substances might have a negative effect on human health, numerous attempts have been made to search for alternatives [11,12]

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