Production of phytotherapeutics from broccoli juice by integrated membrane processes

- A natural therapeutic concentrate from broccoli juice was produced.
- A complete recovery of sulforaphane and organic acids was achieved.
- Phenolic compounds and ascorbic acid were recovered more than 87%.
- Permeate was 6-fold concentrated by osmotic distillation, up to 42.6 °Brix.
- The amount of all the phytotherapeutics were preserved during osmotic distillation.

An integrated membrane process for the recovery and concentration of phytotherapeutics in broccoli juice was investigated to develop a natural product that could be of interest for food and/or pharmaceutical industry. Following a pretreatment step to remove suspended solids, the juice was ultrafiltered through a 50 kDa MWCO polyethersulfone membrane. The permeate stream was further concentrated by osmotic distillation up to 42.6 °Brix. During ultrafiltration, a complete recovery of sulforaphane, malic acid and citric acid was achieved, where total phenolic content and ascorbic acid were recovered at a ratio of 94.5 and 92.4%, respectively. All the bioactive compounds identified in broccoli juice was well preserved during subsequent 6-fold concentration by osmotic distillation. No significant difference was observed in total antioxidant activity of the juice throughout the operation. The proposed integrated membrane process has shown promising potential to produce a natural concentrate enriched in phytotherapeutics of the broccoli juice.