The impact of using vacuum and isomaltulose as an osmotic agent on mass exchange during osmotic dehydration and their effects on qualitative parameters of strawberries

Abstract

The impregnation of isomaltulose is an interesting strategy for the enrichment of strawberries since it is a carbohydrate with low glycemic and cariogenic indexes. The osmotic enrichment of strawberries with isomaltulose was performed considering the vacuum pulse in the first 0, 10, and 20 min in a total process time of 300 min, at 25°C. The tested solution concentrations were 25% and 35% (w w−1) of isomaltulose. The kinetics of solid gain, water loss, moisture content, and weight reduction were obtained. The fresh and final products had some physical and nutritional parameters evaluated. Osmotic processes resulted in a reduction of moisture content, water activity (aw), acidity, total anthocyanins and phenolic contents and antioxidant capacity, increased pH, influenced colorimetric parameters and caused shrinkage of the samples. The higher impregnation of isomaltulose was obtained with the vacuum pulse, which was 82% higher than the osmotic process without the vacuum pulse. The atmospheric process resulted in higher bioactive compounds levels and lower shrinkage and lower total color difference. Therefore, the 35% solution and use of vacuum were recommended when the objective was to maximize mass exchanges, while the 25% solution and without vacuum pulse were indicated for higher retention of strawberry bioactive compounds. The time of vacuum application at the beginning of the osmotic dehydration process and the use of osmotic solutions of different concentrations can result in different rates of dehydration and impregnation of isomaltulose in the strawberry and can influence important qualitative parameters. The evaluation of these factors helps in the optimization of the production of osmo‐dehydrated strawberries, increasing the process efficiency and the preservation of product quality. Practical Applications The time of vacuum application at the beginning of the osmotic dehydration process and the use of osmotic solutions of different concentrations can result in different rates of dehydration and impregnation of isomaltulose in the strawberry and can influence important qualitative parameters. The evaluation of these factors helps in the optimization of the production of osmo‐dehydrated strawberries, increasing the process efficiency and the preservation of product quality.

Use of coconut sugar as an alternative agent in osmotic dehydration of strawberries

“…The OD and PVOD significantly reduced the TAC of the samples, presenting retentions of 25%–70%. Values close to the percentage of retention of TAC in strawberries are in the range of those reported in other studies (Macedo, Corrêa, Araújo, et al., 2022; 2022; Noshad et al., 2018). In addition to solute impregnation during osmotic processes, leaching is an important cause of anthocyanin losses during OD and PVOD of strawberries (Macedo et al., 2022) as these compounds have high solubility in water (Bendokas et al., 2020).…”

“…The pH determination of the samples was carried out using a digital pH meter (Tecnal, TEC‐5, Niort, France). Acidity was determined by the titration of sodium hydroxide 0.1 M, up to pH 8.20 (Macedo, Corrêa, Vimercati, et al., 2022). The result was expressed in %, kg of citric acid per 100 kg of sample on a dry basis.…”

Desidratação Osmótica De Banana Usando Sacarose E Açúcar De Coco Como Agentes Osmóticos

“…A concentração da solução osmótica, temperatura, duração e o tipo de agente osmótico são exemplos dos principais parâmetros do processo que influenciam nas transferências de massa durante a DO. Além disso, a porosidade, tamanho, formato, atividade de água estão entre os fatores relacionados a matéria-prima que influenciam nas trocas de massa durante a DO (GONZÁLEZ-PÉREZ; RAMÍREZ-CORONA; LÓPEZ-MALO, 2021;MACEDO et al, 2023b).…”

“…Este processo foi realizado para cessar as trocas de massa entre as fatias e as soluções osmóticas. Posteriormente, as fatias foram drenadas com auxílio de papel absorvente (MACEDO et al, 2022a(MACEDO et al, , 2023a.…”

Combined Pulsed Vacuum Osmotic Dehydration and Convective Air-Drying Process of Jambolan Fruits

“…Mass transfer during OD depends on some factors, including the product's geometry, temperature, agitation, type, and concentration of the osmotic agent, among others [14][15][16][17]. Recently, calcium salts have been employed to reduce damages caused by the cell wall structure and improve the mass transfer of the osmo-dehydrated products [18,19].…”