Osmotic dehydration of fruits using unconventional natural sweeteners and non‐thermal‐assisted technologies: A review

Abstract

In the food preservation process, drying or dehydration reduces the moisture content that is needed for the growth and multiplicity of microorganisms that cause food spoilage. Among the most effective and appropriate methods for extending the shelf life of fruits and vegetables is osmotic dehydration. This process encourages the movement of water molecules from the food to the osmo‐active solution and a small amount of solute from the solution into the food, resulting in an organoleptic and functional product. Sugar, which is the most popular osmotic agent, presents many health risks. Therefore, this review discusses the mechanisms of osmotic dehydration and the use of unconventional natural sweeteners like honey, jaggery, coconut sugar, stevia, and sugar beet molasses as an osmotic agent. Furthermore, certain non‐thermal methods to help osmotic dehydration have been reviewed that may improve the drying and quality parameters of different fruits. Practical applications The osmotic dehydration process in fruits reduces postharvest losses, as well as maintaining the initial fruit characteristics such as color, aroma, texture, and nutritional content. The uses of natural sweeteners viz. jaggery and honey as osmotic agents have numerous health benefits. Due to these benefits, it can be used at small scales, home‐scale industries, and large‐scale industries. Various methods can be used to enhance osmotic dehydration, such as pulsed electric fields, high pressure, vacuum, microwave, centrifugal force, or ultrasound, which can be applied to large‐scale industries.

Osmotic dehydration of wild garlic in sucrose–salt solution

“…The uptake of dissolved substances from osmotic solution and the leaching of food constituents (such as vitamins and minerals) result in the alternation of the composition of the original product, which could adversely influence the nutritional profile and organoleptic attributes (Akbarian et al, 2014) . High values of SG in wild garlic are undesirable since the increased uptake of sucrose is associated with the occurrence of diabetes and dental problems and that of salt with hypertension (Kaur et al, 2022) . In order to achieve the greatest possible water loss (0 .409 ± 0 .006 g/g i .s) with the lowest sugar and salt impregnation (0 .144 ± 0 .006 g/g i .s), the sample dehydrated at 20°C after 4 hours was selected for examining the influence of OD in sucrose-salt solution on the chemical composition of wild garlic .…”

Development and standardization of processing technique for ready-to-use lab fermented Kanji mix using refractance window dried black carrot powder

“…Although many techniques for drying of fruits/ vegetables are in practice but some are incapable of preserving the bioactive compounds like open sun drying, solar drying and hot-air drying, etc. 9 , 10 . While the drying techniques that can preserve bioactives are quite expensive like freeze drying.…”

Potential application of domestic solar dryers for coriander leaves: Drying kinetics, thermal efficiency, and quality assessment

“…3,4 Therefore, moisture removal inhibits the growth and production of microorganisms such as bacteria, yeasts, and molds. 5,6 One of the oldest means to remove moisture is drying using the Sun's energy. 7 Open sun drying has many limitations like high-labour costs, large area requirement, unable to control the drying process, deterioration because of insects and microorganisms and moreover the quality of the dried product is far below international standards.…”

“…The presence of water deteriorates the quality of the product 3,4 . Therefore, moisture removal inhibits the growth and production of microorganisms such as bacteria, yeasts, and molds 5,6 . One of the oldest means to remove moisture is drying using the Sun's energy 7 .…”