No abstract

No abstract

No abstract

Summary To evaluate the use of lixiviate roselle calyxes as an alternative source of bioactive compounds, they were subjected to dehydration in a vibrofluidised bed dryer after which some chemical parameters such as the retention of monomeric anthocyanins (MA), phenolic compounds, polymeric colour and antioxidant activity were determined. Drying curves showed both a constant drying period and a decreasing falling rate period. The different drying conditions showed significant differences in the chemical parameters. Using the dry residue with the best bioactive compounds content, it was possible to develop a dairy beverage (yogurt). The results confirmed that lixiviated roselle calyxes could be a competitive alternative for traditional products, such as grapes or bilberries, in terms on their antioxidant activity and stability when it is added as a source of bioactive compounds.

Quality assessment of carrot cubes preserved through batch dehydration introducing tempering cycles was performed in this study. The parameters considered were: the percentage of carotene retention, peroxidase inactivation and retention of invertase activity, as well as the degree of rehydration. Although, a similar final moisture content was always reached through the different carrot dehydration process, that with tempering cycles had better qualities than those without tempering. Carotene and invertase activity retention showed higher values, and peroxidase showed lower values compared to a control samples in all cases. Respect to the rehydration tests, no differences were found in all samples. As of the treatments with tempering cycles, the best scheme was 20 min drying time and 20 min tempering time at 70°C.