摘要
Tiger nut (Cyperus esculentus), commonly referred to as chufa, is a “nut-like” tuber, native to tropical and Mediterranean regions. It is often consumed in the form of a beverage (horchata de chufa). Health benefits of tiger nut have been attributed to presence of phytochemicals and their antioxidant potential. Tiger nut is often processed in order to enhance sensory characteristics. The objective of study was to determine effects of processing on antioxidant content, potential and inhibition of metabolizing enzyme activities of tiger nuts. Total phenolic content (TPC), total flavonoid content (TFC), free radical scavenging activity by 1,1-diphenyl-2-picryhydrazyl (DPPH), trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP) and inhibition of lipase and α-amylase were evaluated in raw tiger nuts extracted with water (TRWA) and methanol (TRWM) and roasted (110°C – 115°C for 10 mins) tiger nuts extracted with water (TRA) and methanol (TRM). Highest phenolic content was observed in TRWA (1186.68 GAE/100g) and TRWM had lowest (43.77 GAE/100g). TRWA also exhibited highest ferric reducing ability with a FRAP value of 169.83 mm Fe2+/100g). TRWM had a higher flavonoid content (220.68 CAE/100g) compared to all other extracts. At a concentration of 0.02 mg/ml, all extracts reached at least 50% inhibition of DPPH, while highest scavenging activity was observed in TRM (58%). Highest TEAC was observed in TRM with 55.66% of ABTS radical scavenged. TRA had a significantly higher ability to inhibit α-amylase and lipase compared to other extracts. Results suggest that processing had an effect on the antioxidant potential of tiger nut, and this tuber may benefit consumers by improving their antioxidant status.
Tiger nut (Cyperus esculentus), commonly referred to as chufa, is a “nut-like” tuber, native to tropical and Mediterranean regions. It is often consumed in the form of a beverage (horchata de chufa). Health benefits of tiger nut have been attributed to presence of phytochemicals and their antioxidant potential. Tiger nut is often processed in order to enhance sensory characteristics. The objective of study was to determine effects of processing on antioxidant content, potential and inhibition of metabolizing enzyme activities of tiger nuts. Total phenolic content (TPC), total flavonoid content (TFC), free radical scavenging activity by 1,1-diphenyl-2-picryhydrazyl (DPPH), trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP) and inhibition of lipase and α-amylase were evaluated in raw tiger nuts extracted with water (TRWA) and methanol (TRWM) and roasted (110°C – 115°C for 10 mins) tiger nuts extracted with water (TRA) and methanol (TRM). Highest phenolic content was observed in TRWA (1186.68 GAE/100g) and TRWM had lowest (43.77 GAE/100g). TRWA also exhibited highest ferric reducing ability with a FRAP value of 169.83 mm Fe2+/100g). TRWM had a higher flavonoid content (220.68 CAE/100g) compared to all other extracts. At a concentration of 0.02 mg/ml, all extracts reached at least 50% inhibition of DPPH, while highest scavenging activity was observed in TRM (58%). Highest TEAC was observed in TRM with 55.66% of ABTS radical scavenged. TRA had a significantly higher ability to inhibit α-amylase and lipase compared to other extracts. Results suggest that processing had an effect on the antioxidant potential of tiger nut, and this tuber may benefit consumers by improving their antioxidant status.
