Physicochemical, antioxidant and antimicrobial properties of peel, pulp and seeds of different pear cultivars

The aim of this research study was to compare antioxidant and antimicrobial properties of peel and seeds and physiochemical properties of peel and pulp of four different pear varieties. The study examined three exotic varieties (Early Desire, Lucas, and Conference) and one local variety (William Bartlett). The results indicated that the pear seeds consistently exhibited higher values in terms of total phenolic content, total flavonoid content, and antioxidant activity when compared to the peels. Notably, the Early Desire pear variety's seeds displayed the highest values, with a total phenolic content of 6.00 mg GAE/g, a total flavonoid content of 1.97 mg QE/g, and an antioxidant activity of 80.00 % based on the DPPH assay. Furthermore, the study investigated the antibacterial activity of pear extracts from seed and peel against two types of bacteria: the gram-positive bacterium Staphylococcus aureus and gram-negative bacterium Escherichia coli. The results indicated that the pear seed extracts possessed greater antibacterial activity than the peels. Among the pear varieties studied, Early Desire seeds showed the highest inhibition in both the cases. The physicochemical properties showed significant difference among the different varieties. The pulp of the Early Desire variety had the highest total soluble solids (14.70 °Brix), total sugars (11.50 %), reducing sugars (7.20 %), and sweetness index (36.75). The polyphenol oxidase (PPO) activity of pulp of the Early Desire variety had the highest enzyme activity. It was further contended from the results that Lucas peel exhibited significantly higher potassium (539.00 mg/100 g), calcium (26.8 mg/100 g), and phosphorus (73.30 mg/100 g) contents.