Effects of time and extraction temperature on phenolic composition and functional properties of red rooibos (Aspalathus linearis).

Autor: Santos JS; Food Science and Technology Graduate Program, State University of Ponta Grossa, Av. Carlos Cavalcanti, 4748, 84030-900, Ponta Grossa, Brazil., Deolindo CTP; Food Science and Technology Graduate Program, State University of Ponta Grossa, Av. Carlos Cavalcanti, 4748, 84030-900, Ponta Grossa, Brazil., Esmerino LA; Department of Clinical Analysis, State University of Ponta Grossa, Av. Carlos Cavalcanti, 4748, 84030-900, Ponta Grossa, Brazil., Genovese MI; Laboratory of Food Bioactive Compounds, Department of Food and Experimental Nutrition, University of São Paulo, 05508-900, São Paulo, Brazil., Fujita A; Laboratory of Food Bioactive Compounds, Department of Food and Experimental Nutrition, University of São Paulo, 05508-900, São Paulo, Brazil., Marques MB; Department of Chemistry, State University of Ponta Grossa, Av. Carlos Cavalcanti, 4748, 84030-900, Ponta Grossa, Brazil., Rosso ND; Food Science and Technology Graduate Program, State University of Ponta Grossa, Av. Carlos Cavalcanti, 4748, 84030-900, Ponta Grossa, Brazil., Daguer H; Brazilian Ministry of Agriculture, Livestock and Food Supply (MAPA), National Agricultural Laboratory, 88102-600, Santa Catarina, Brazil., Valese AC; Brazilian Ministry of Agriculture, Livestock and Food Supply (MAPA), National Agricultural Laboratory, 88102-600, Santa Catarina, Brazil., Granato D; Food Science and Technology Graduate Program, State University of Ponta Grossa, Av. Carlos Cavalcanti, 4748, 84030-900, Ponta Grossa, Brazil. Electronic address: dgranato@uepg.br.
Jazyk: angličtina
Zdroj: Food research international (Ottawa, Ont.) [Food Res Int] 2016 Nov; Vol. 89 (Pt 1), pp. 476-487. Date of Electronic Publication: 2016 Aug 28.
DOI: 10.1016/j.foodres.2016.08.041
Abstrakt: This work was aimed at assessing the time-temperature effects on the phenolic compounds and in vitro functional properties of aqueous extracts from red rooibos (Aspalathus linearis). The major phenolic composition (tannins, flavonoids, flavonols, ortho-diphenols, total phenolic content), antioxidant (ABTS and DPPH) and reducing capacities (FRAP and total reducing capacity), antimicrobial effects and inhibition of α-amylase/α-glucosidase were measured. Phenolic compounds were also determined by LC-ESI-MS/MS. Aqueous extracts did not inhibit the growth of Escherichia coli, Staphylococcus aureus, and Candida albicans between 7.81 and 1000mgL -1 . Rooibos extracted at 85°C for 10min showed a beneficial interaction with the human erythrocytes, reducing the hemolysis. The correlation analysis showed that the phenolic compounds responsible for the inhibition of α-amylase (IC 50 ) were isohrmanetin, isoquercitrin, luteolin, salicylic acid, and syringaldehyde, whereas the inhibition of α-glucosidase was correlated to syringaldehyde, isoquercitrin, and luteolin. Overall, rooibos extracted at 85°C had the highest antioxidant activity measured by all assays, higher contents of phenolic compounds (spectrophotometric and LC-ESI-MS/MS data), and lower IC 50 values for the digestive enzymes. On the other hand, rooibos extracted at 65°C had the opposite behavior, while rooibos extracted at 75°C presented mean intermediate values for the responses. This result clearly indicates that the extraction temperature is the main factor leading to a higher extraction of bioactive compounds from red rooibos.
(Copyright © 2016 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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