The syrups were diluted with distilled water to reach the same solid concentration (10° Brix, 25°C) of
sugar extracts. The pH of each extract was adjusted to 6–8 and centrifuged at 9,300 g for 30 minutes. The
supernatant was recovered and then used as the extract for in vitro assays. Extractions were performed in
duplicate. The total phenolic contents of samples were quantified by the Folin- Ciocalteu’s reagent and were
expressed as gallic acid equivalents 3
. Ascorbic acid content was determined by spectrophotometer 4
. α -amylase
inhibitory activity as from Worthington Enzyme Manual5