Changes in the psysical-chemical composition, total polyphenols and antioxidant activity of fresh celery (Apium graveolens L.) dehydrated by hot air and by lyophilization

The food industry aims at offering food that provides not only nutritional but also functional properties. Celery has been used for a long time, but its bioactive compounds have remained unknown. The objective of this research is to measure the changes in the physical and chemical characteristics, total polyphenols (TP) and antioxidant activity (AA) after applying hot air dehydration (DA) and lyophilization (LF) with two different cut types: rod-shaped (R) and sliced (S). It was found that dehydration treatments can enhance some characteristics in celery. When comparing the results, the treatment of (LF-S) presented the best characteristics with less water activity, 46 % of total dietary fiber constituted by 41 % of insoluble fiber and 5 % soluble fiber, 377.69 mg GAE/100g in total polyphenol content and an antioxidant activity of 82.17 μmol TE/100g. These results allow to conclude that celery is a raw material with functional attributes and that it can be industrialized with dehydration technologies, which will enable a long useful life for its bioactive compounds.