In this study ascorbic acid and phenolic compounds contents of eggplant flesh and eggplant peel were determined. Among the investigated eggplant cultivars generally eggplant peel had higher ascorbic acid and phenolic compounds contents than eggplant flesh. Ascorbic acid content in eggplant flesh ranged from 33.62 to 92.75 mg kg−1 and in eggplant peel from 12.45 to 111.01 mg kg−1. Phenolic compounds content ranged from 11.77 to 22.18 g kg−1 in eggplant flesh and from 13.46 to 29.42 g kg−1 in eggplant peel. Eggplant peel is usually treated as waste, i.e. byproduct, omitting its potentially beneficial characteristics. Due to higher ascorbic acid and phenolic compounds contents, further investigations should be directed on possible use of eggplant peel as natural ingredient for functional products formulation.
Sour cherry puree was prepared with addition of sucrose or trehalose (5% and 10%). After stabilization of the mixture (puree with sugars), extracts were prepared and contents of phenolics and anthocyanin, polymeric colour percentage, and antioxidant activity were determined. Extracts were stored for 65 days at 4 °C. Control sample was extract of sour cherry puree without sugars. After extraction, extracts with 10% of sucrose or trehalose had higher phenolic content than the control sample. Anthocyanin content was higher in extracts with trehalose addition. During storage of extracts, samples with trehalose had higher retention of phenolic and anthocyanins than other samples. Addition of sucrose and trehalose as well as their amounts affected the stabilities of phenolics, anthocyanins, and antioxidant activity in sour cherry extracts.