The edible cocktail: the effect of sugar and alcohol impregnation on the crunchiness of fruit

This investigation focused on the change in crunchiness as a result of the impregnation of different sugar and alcohol containing solutions. When hypotonic solutions were used, the impregnation resulted in the rupture of the cells, thereby leading to a decrease in crunchiness. When hypertonic solutions were used, the cells shrunk, which also resulted in a decrease in crunchiness. Isotonic solutions resulted in crunchiness comparable to its fresh version. When alcohol was used, the crunchiness decreased at all concentrations investigated.Crunchiness of fruit can only be maintained when impregnated with isotonic sugar solutions. When the sugar or alcohol content deviates from that in the fruit, impregnation of these liquids will lead to a decrease in crunchiness. This has consequences for the creation of edible cocktails: for an optimal crunchiness, the sugar content of the impregnation liquid has to be equal to the sugar content of the fruit or vegetable.The impregnation of different solutes into porous materials is an important process in the food industry. As the demand for healthy and natural products is increasing, processes are being used to adjust food system formulations by processes like osmotic dehydration, impregnation and ultrasound treatments [1-7]. Examples can be found where fruits and vegetables are enriched with cryoprotectants, calcium or zinc [8-10]. The amount of solutes and liquid that can be absorbed by the porous products depends on two diffusion processes: molecular and capillary diffusion [2,11,12], which are influenced by parameters such as surface tension, pore size, porosity, and others. The process is often slow and absorption of liquids is limited. To overcome these limitations, vacuum impregnation is more often used [2-4,10]. This technique applies a reduced pressure to porous materials, which expands the air in the open spaces and forces it to leave the porous material [13]. As the air flows out of the pores, any surrounding liquid is a