Search

Membrane-based processes are increasingly used to clarify and concentrate thermo-sensitive fruit juices and plant extracts as alternatives to conventional processes. This work aimed to evaluate the quality of red fruit juices clarified and concentrated by an integrated membrane process with special regard to the preservation of valuable compounds. A red fruit juice obtained from a blend of pomegranate, cactus pear, and red orange juices of Sicilian origin was clarified by microfiltration (MF) and then pre-concentrated up to 33 °Brix by nanofiltration (NF). The pre-concentrated juice was finally concentrated by osmotic distillation (OD) up to 50 and 60 °Brix. Samples of clarified, pre-concentrated, and concentrated juice were analyzed for their physico-chemical composition and in terms of the antioxidant activity and inhibitory activity against α-amylase and lipase. The results clearly confirmed the assumption of a mild fruit juice processing method, allowing us to preserve the original nutritional and functional properties of the fresh juice. In particular, the OD retentate at 60 °Brix resulted the most active sample against pancreatic lipase and α-amylase inhibitory activity with IC50 values of 44.36 and 214.65 μg/mL, respectively.

Citrus fruits processing is one of the foremost industrial activities in Sicily and the main residual by-product consists in peels and seeds (known as “pastazzo”). Traditionally this by-product has been used for different purposes, and only most recently, it has been described as source of a wide range of healthy bioactive compounds and dietary fibers. In the present work, a debittered food grade orange fiber (DOF), extracted from orange juice by-product, was experimentally obtained and tested as fat-replacer at different percentages (30, 50, and 70%) in bakery confectionery products (brioches). The DOF showed high total fiber content, low water activity and a high water binding capacity. The obtained bakery products were characterized for nutritional, technological and microbiological parameters through storage at room temperature. Results highlighted that the addition of DOF results in final products with increased moisture content, mainly after 1 day of storage, and good textural proprieties. Furthermore, the fat-replacing strategy, at different levels of DOF, resulted in final products with, besides a constant content of carbohydrates, showed lowered fat content, increased content of dietary fiber and protein. In particular, the 50% fat replacement allowed to obtain brioches with improved technological properties and with desirable microbiological traits, mostly within the first 24 h from production and up to 5 days of storage.