*Article* **Membrane Filtration-Assisted Enzymatic Hydrolysis Affects the Biological Activity of Potato Juice**

**Przemysław Łukasz Kowalczewski 1,\* , Anna Olejnik <sup>2</sup> , Iga Rybicka <sup>3</sup> , Magdalena Zieli ´nska-Dawidziak <sup>4</sup> , Wojciech Białas <sup>2</sup> and Grazyna Lewandowicz ˙ 2**


**Abstract:** The results of recently published studies indicate that potato juice is characterized by interesting biological activity that can be particularly useful in the case of gastrointestinal symptoms. Moreover, the studies also described the high nutritional value of its proteins. This article is a report on the impact of the enzymatic hydrolysis of proteins combined with membrane filtration. The obtained potato juice protein hydrolysate (PJPH) and its concentrate (cPJPH) were characterized in terms of their nutritional value and biological activity. The amino acid profile and scoring, the content of mineral compounds, and the antioxidant and in vitro cytotoxic activity were assessed. The study proved that the antioxidant activity of PJPH is higher than that of fresh potato juice, and the cytotoxicity against human gastric carcinoma cell line (Hs 746T), human colon cancer cell line (Caco-2), human colorectal adenocarcinoma cell line (HT-29), and human normal colon mucosa cell line (CCD 841 CoN) showed biological activity specifically targeted against cancer cells. Therefore, it can be concluded that the membrane filtration-assisted enzymatic hydrolysis of potato juice proteins may increase their biological activity and allow for potato juice to be used in the production of medicinal preparations.

**Keywords:** antiproliferative activity; antioxidant activity; cancer cells; cytotoxicity; in vitro study; nutritional value
