PHENOLIC CONTENT AND ANTIOXIDANT CAPACITY OF LYCHEE PEEL: A COMPARISON ANALYSIS BETWEEN TWO HARVEST BATCHES

Lychee peel constitutes 15% of the fruit weight and is normally discarded by the food industry. Although not directly consumable, lychee peel contains bioactive compounds with potential medicinal or other applications perspectives. This study compared the total phenolic compounds (TPC) and total antioxidant capacity (TAC) of two lychee peel batches from different harvest years. Lychees were purchased in Lavras-MG, with batch 1 acquired in January 2022 and batch 2 in January 2023. To extract bioactive compounds, a tincture was prepared with 1 g of lychee peel flour from each batch was combined with 10 mL of 70% ethanol in amber glass bottles. The mixtures were manually shaken twice daily for seven days, then filtered and stored at -20 ºC. TPC was quantified using the Fast Blue and Folin-Ciocalteu methods, while TAC was assessed through the Beta Carotene/Linoleic Acid, ABTS⁺, and Phosphomolybdenum Complex assays. The Student’s t-test was used for statistical comparisons (p < 0.05). Results showed significantly higher TPC in batch 2 compared to batch 1 as measured by the Fast Blue (239.15 and 0.64 g gallic acid/g peel, respectively) and Folin-Ciocalteu methods (24.57 and 0.21 g gallic acid/g peel, respectively). However, no significant difference (p > 0.05) in TAC was observed between batches, with both showing similar values across assays: 25.25% and 23.58% protection in Beta Carotene/Linoleic Acid, 27,542 and 27,621 µM trolox/g peel in ABTS⁺, and 241.70 and 271.00 g ascorbic acid/g peel in the Phosphomolybdenum Complex test. In conclusion, while batch 2 exhibited higher TPC, TAC did not differ significantly, indicating that TPC levels in lychee peel tincture are not necessarily proportional to TAC.