Antioxidant potential and phenolics content of horseradish root juice encapsulated within different carbohydrate matrices

Abstract

Horseradish is a plant grown for its succulent and spicy root, which presents a rich source of antioxidants such as phenolic compounds, vitamin C, and isothiocyanates. Due to its antioxidant properties, cold-pressed horseradish root juice could be an active ingredient in functional foods. However, fresh juices undergo enzymatic and microbiological changes, so it is necessary to preserve them. One of the approaches commonly used for this purpose is encapsulation by spray-drying, which involves the entrapping of bioactive components within carrier agents. This ensures the protection of the bioactive component from undesirable external factors and its controlled release. Many studies have shown that the use of a combination of maltodextrin and hydrocolloids as encapsulation carriers results in highquality encapsulates. So, the aim of this study was the encapsulation of horseradish root juice and the characterization of the obtained encapsulates as potential antioxidants in food production. Maltodextrin/guar gum (MD/GG) and maltodextrin/gum Arabic (MD/GA) were used as carriers to encapsulate horseradish root juice by spray-drying. Total phenolic, flavonoid, and phenolic acid contents (TPC, TFC, and TPAC, respectively) and antioxidant activity (DPPH, ABTS, and FRAP methods) were determined by standard spectrophotometric methods. MD/GG and MD/GA with encapsulated horseradish root juice contained 1628 and 1568 mg gallic acid equivalents/100 g, respectively, of TPC; 264 and 253 mg catechin equivalents/100 g, respectively, of TFC; and 3272 and 3397 mg caffeic acid equivalents/100 g, respectively, of TPAC. Results for the antioxidant activity (expressed as mmol Trolox equivalents/100 g) of MD/GG and MD/GA were 0.8 and 0.7, respectively (DPPH); 6.9 and 7.6, respectively (ABTS); and 8.8 and 8.6, respectively (FRAP). In conclusion, horseradish root juice encapsulated within carbohydrate biopolymers contained significant amounts of phenolic compounds and high antioxidant activity, which makes it a potential replacer for synthetic antioxidants in the food industry and opens the possibility for further research on this topic.