Background: The acceptability of grapefruit juice obtained from rehydrated freeze-dried and spray-dried fruit was studied and compared with that of natural freshly squeezed juice and that of a commercial juice. The rheological properties, colour and solute concentration were determined. A sensory evaluation was developed to evaluate juice acceptability. Furthermore, a penalty analysis was used to determine the attributes with improvement potential as well as some CATA (check all that apply) questions, where consumers marked the most characteristic attributes of each sample.
Results: The rehydrated samples were different from the commercial and natural juices. When grapefruit is freeze-dried or spray-dried, gum arabic and bamboo fibre are added and part of the fruit pulp is present; this is not so in the other juices under study. This supposes greater viscosity, luminosity and chroma together with a reddish tone of the rehydrated juices, especially the freeze-dried ones. It also affects their acidity, astringency and sweetness.
Conclusion: Rehydrating the freeze-dried or spray-dried powder to the level of the natural juice, instead of that of the crushed or liquidized grapefruit, and incorporating sugar at this stage would probably improve the quality of the samples. © 2018 Society of Chemical Industry.
Keywords: freeze-drying; grapefruit juice; powdered grapefruit; rehydration; sensory acceptability; spray-drying.
© 2018 Society of Chemical Industry.