Upcycling Pomegranate Peel Into Functional Yoghurt: Chemical Profile, Antioxidant Capacity, and Anti– <i>Staphylococcus aureus</i> Activity

ABSTRACT The use of natural additives, particularly pomegranate peel extract (PPE), to fortify dairy products has gained global attention, due to its potential health and safety benefits. This study investigated the efficacy of methanolic pomegranate peel extract (MPPE) and ethanolic pomegranate peel extract (EPPE) extracts in controlling Staphylococcus aureus growth in yoghurt while enhancing sensory quality. Major polyphenols were identified and quantified via high‐performance liquid chromatography (HPLC), and total phenolic content (TPC), total flavonoid content (TFC), as well as antioxidant activity (DPPH and ABTS assays) were determined. Moreover, the minimum inhibitory concentration (MIC) of each extract was assessed, and the most effective concentrations (0.1% and 0.3%) were incorporated into yoghurt with 6 log CFU/g of Staphylococcus aureus inoculum. The microbial survival, sensory properties, and pH changes were monitored throughout 21 days of refrigerated storage. Results revealed that MPPE had higher levels of polyphenolic compounds, particularly gallic acid (698.08 μg/mL in MPPE, while 443.86 μg/mL in EPPE), and MPPE also had higher TPC, TFC, and antioxidant activities than EPPE. Both extracts significantly p &lt; 0.05 suppressed Staphylococcus aureus counts, with complete elimination by day 14 of storage at the higher concentration (0.3%). Sensory evaluation indicated that yoghurt fortified with 0.1% MPPE achieved the highest overall acceptability with stable pH. These results highlight PPE as a potent source of a bioactive ingredient with antioxidant and antibacterial properties. It can serve as an effective natural additive that improves the nutritional, sensory, and safety attributes of yoghurt while promoting the sustainable application of agricultural by‐products.