Modelling dehydration of apricot in a non-conventional multi-component osmotic solution: effect on mass transfer kinetics and quality characteristics

Abstract

The quality and preservation of fresh-cut fruits can be improved by applying mild, non-thermal pre-treatments, such as osmotic dehydration (OD). The aim was to model the effect of OD on mass transfer and quality preservation. Apricot pieces were immersed in multi-component solutions comprising glycerol, erythritol, steviol glucosides and mineral salts, at various time-temperature conditions (25-45 °C for 3-240 min, w/w = 1/5). Water loss (WL), solid gain (SG), water activity (a) as well as main quality indices (colour, texture) were measured during OD. OD apricot exhibited higher quality retention (acceptable level of colour change, increased firmness) suggesting that OD can be an effective pre-processing step in the production of innovative products. A second degree polynomial model was developed, describing the effect of processing conditions and glycerol concentration on WL, SG, a, colour and texture of osmotically dehydrated apricots, and ANOVA was applied to identify the factors that significantly affect the aforementioned parameters.

Optimization of Osmotic Dehydration of Tomatoes in Solutions of Non-Conventional Sweeteners by Response Surface Methodology and Desirability Approach

“…Tomatoes exhibiting lower firmness values are characterized by lower quality [ 61 ]. OD-processed tomato samples presented increased firmness compared to the fresh ones, indicating that OD processing led to tomato texture improvement [ 25 , 37 , 38 , 62 , 63 ]. OD processing induces a greater firmness by filling the pores with the osmotic solution, thus the OD-processed samples present a more compact and less deformed tissue [ 64 ].…”

“…The increasing interest in the natural sweetener steviol glucoside is related to it being a plant extract, calorie-free and with sweetness much higher that the sucrose equivalent, making it an ideal choice for several food and beverage applications [ 35 ]. Osmotic agents including stevia-based sweeteners have been recently reported for plant tissue treatments [ 36 , 37 , 38 ]. Isomaltulose, often mentioned with the commercial name of palatinose (6-O-α-D glucopyranosyl-D-fructose) is a reducing disaccharide which is naturally present in honey and sugar cane juice, with a taste similar to sucrose and about 42% of its sweetness [ 36 , 39 ], making it a potential sucrose substitute [ 40 ].…”

Osmodehydrofreezing: An Integrated Process for Food Preservation during Frozen Storage

“…Frequently addressed in many studies on osmotic dehydration is the mathematical description of mass transfer, expressed by the two main terms, water loss (WL) and solid gain (SG) (Equations (1) and (2)) using either empirical models or equations derived from Fick’s law. In the latter case, most published works apply the mathematical solutions of the differential equations of diffusion (Fick’s law), as presented by Crank 1975 [ 44 ] assuming specific geometries for the food in question [ 45 , 46 , 47 , 48 , 49 ]. In this case, the dehydration step is frequently described assuming that diffusion through cellular membranes and intercellular spaces is the prevailing mechanism of mass transfer [ 23 ].…”

“…The above mentioned empirical equations are often combined with the use of a polynomial model to describe the main effects of the procedure parameters (namely the concentration of the osmotic solution and OD temperature) on mass transfer [ 46 , 47 ].…”

Evaluation of Mass Transfer During Osmo-Convective Drying of Benincasa Hispida Cubes in Salt Solution Using Regressional-Desirability Method

“…The increase in water loss could be due to the changes in semipermeability of the cell membrane in the sample which allowed more water to seep out in a shorter period (Conway et al, 1983;Kar & Gupta, 2003). Besides, at elevated temperatures, the viscosity of the solution also decreased and it caused setting of convection currents in the solution and in turn eliminated local dilution and favoured osmosis (Sodhi et al, 2006;Dermesonlouoglou & Giannakourou, 2018). From the figure 3, it could be seen that the osmotic solution temperature induced higher water loss from the sample.…”