Chemical and biological insights on aronia stems extracts obtained by different extraction techniques: From wastes to functional products

The present study aimed to evaluate chemical and biological potential of aronia stems for providing new raw material for food and pharmaceutical industries. Aqueous extracts of aronia stems were prepared by three different techniques (microwave-assisted, ultrasound-assisted and subcritical water extraction). For biological activities, antioxidant, antimicrobial and cytotoxic activities were evaluated. For chemical characterisation, phenolic compounds and essential elements were analysed as well as total phenolic contents. Subcritical water extracts exhibited the strongest antioxidant activity with the highest content of phenolics. Minimum inhibitory concentrations for analysed extracts were in the range from 9.76 to 156.25 μg/mL in antimicrobial assays. The extracts exerted prominent cytotoxicity against different cell lines. Rutin was detected as the major compound in the studied extracts and these extracts were also rich in essential elements. Our study suggested that subcritical water extract of aronia stem could be considered as a new raw material in developing novel functional/industrial products.