Development of a new functional food from freeze-dried broccoli stalks

Abstract

Several studies showed that the consumption of broccoli can prevent some diseases and cancer, as broccoli contains important amounts of health-promoting substances like polyphenols, vitamin C and glucosinolates. Just the florets of broccoli are used in the food industry. Although important amounts of the health-promoting compounds are present in the stalks, they are not used. The quantity of healthpromoting compounds is reduced significantly when treated thermally. The objective of this study was to obtain a natural functional food product by adding the freeze-dried broccoli stalks to mild-treated products such as gazpacho and salmorejo, in a way that broccoli flavor and odor were not perceived in the final product. To achieve a product with ideal rehydration characteristics and an optimal retention of the health-promoting compounds, the freeze-drying process of broccoli stalks was optimized. The best freeze-drying conditions were a fast freezing rate with a 14 hour primary drying. The maximum addition of broccoli with a minimum of changes on the product was achieved, thanks to viscosity analyses and sensory triangle tests. It is possible to add health-promoting compounds from broccoli stalks to food stuffs without a reduction of the acceptability of the product