Phytochemical profiling and anti‐bacterial activity of Red Delicious apple pomace with integrated hydrolysis to obtain fermentable sugars: a biorefinery approach

Abstract

Apple pomace (AP) is a byproduct of juice processing, rich in nutritionally important compounds like carbohydrates, phenolic compounds, dietary fiber, and minerals. It is a potential feedstock for sugar‐based biorefineries. This study explored AP physicochemical and bioactive compounds and their hydrolysis to extract fermentable sugar. Results showed that AP had a below‐neutral pH, moisture, acidity, and ash. The AP contained crude fiber (27.22%), total sugar (36.75%), and reduced sugar (12.22%). The extracts contained minerals like potassium, calcium, magnesium, aluminum, iron, boron, and zinc. A GC–MS study analyzed the phytochemicals present in AP extracts, revealing prominent antibacterial activity. The optimal conditions for enzymatic hydrolysis were found to be 1 mg/g substrate of cellulase and pectinase at 50°C and pH 5.0 at 24 h of incubation. Enzymatically hydrolyzed AP showed a high yield of reducing sugar (38.33%) compared to non‐hydrolyzed AP (12.22%). The study suggests that AP, currently discarded as industrial bio‐waste, is still a source of phytochemicals with significant antioxidant and antibacterial activities.