Valorisation of Carrot Pomace Through Enzymatic Treatment for the Development of Food Supplements

Carrot pomace (CP) is a fibre-rich by-product of juice production whose application in food products is limited by the predominance of insoluble dietary fibre. This study aimed to evaluate differences in dietary fibre composition and technological and functional properties between untreated and enzyme-treated CP and to assess its potential application in food supplement formulations. CP was treated with the commercial enzyme preparation Sternzym® Oilex, containing pectinase and hemicellulolytic side activities. Soluble (SDF) and insoluble (IDF) dietary fibre contents, technological and functional properties, phenolic compounds, and antioxidant activity were determined. Bacterial growth promotion was evaluated in vitro using the prebiotic index (PI). Untreated and enzyme-treated CP were subsequently evaluated as carriers for Lactiplantibacillus plantarum in freeze-dried food supplement formulations, and bacterial viability was monitored during three months of storage. Compared with untreated CP, enzyme-treated CP contained less SDF and IDF and exhibited a different SDF:IDF ratio. Pomace modification increased water- and oil-retention capacities, solubility index, and the content of soluble phenolic compounds, but decreased water swelling capacity. The enzymatically modified CP exhibited higher PI values than inulin in assays with both L. plantarum and L. acidophilus. Enzymatic treatment also improved cholesterol- and sodium cholate-binding capacities under neutral pH conditions, while glucose adsorption decreased. During storage, the highest L. plantarum viability was maintained in the sample containing untreated CP and remained at approximately 8 log10 CFU/g after three months. Overall, CP is a promising source of dietary fibre and bioactive compounds and may serve as a carrier for probiotic bacteria in food supplements.