6 documents found, page 1 of 1
Chlorogenic acid-arabinose hybrid domains in coffee melanoidins: Evidences from...
Moreira, Ana S. P.; Coimbra, Manuel A.; Nunes, Fernando M.; Passos, Claudia P.; Santos, Sonia A. O.; Silvestre, Armando J. D.; Silva, Andre M. N.Arabinose from arabinogalactan side chains was hypothesized as a possible binding site for chlorogenic acids in coffee melanoidins. To investigate this hypothesis, a mixture of 5-O-caffeoylquinic acid (5-CQA), the most abundant chlorogenic acid in green coffee beans, and (alpha 1 -> 5)-L-arabinotriose, structurally related to arabinogalactan side chains, was submitted to dry thermal treatments. The compounds fo...
Influence of molecular weight on in vitro immunostimulatory properties of insta...
Passos, Claudia P.; Cepeda, Marcio R.; Ferreira, Sonia S.; Nunes, Fernando M.; Evtuguin, Dmitry V.; Madureira, Pedro; Vilanova, ManuelInstant coffee was prepared and fractionated into higher (>100 kDa), medium (5-10, 10-30, 30-100 kDa) and lower (1-5, <1 kDa) molecular weight fractions. Sugars and linkage composition characteristics of arabinogalactans and galactomannans were recovered in all fractions. Also, amino acid analysis performed after hydrolysis showed similar compositions in all fractions. On the contrary, free chlorogenic acids an...
Supercritical fluid extraction of spent coffee grounds: Measurement of extracti...
de Melo, Marcelo M. R.; Barbosa, Hugo M. A.; Passos, Claudia P.; Silva, Carlos M.This work addresses scientific and techno-economic aspects of supercritical fluid extraction (SFE) of spent coffee grounds which are of interest under the biorefinery context. Soxhlet experiments were carried out and SFE curves were measured at 190 bar and 40 degrees C/55 degrees C. The extracts were characterized by GC-FID, and the triacylglycerides profiles were almost constant along an extraction curve, and ...
Optimization of the supercritical fluid coextraction of oil and diterpenes from...
Barbosa, Hugo M. A.; de Melo, Marcelo M. R.; Coimbra, Manuel A.; Passos, Claudia P.; Silva, Carlos M.The reported work aimed at the optimization of operating conditions of the supercritical fluid extraction (SFE) of spent coffee grounds (SCG) using pure or modified CO2, with particular emphasis on oil enrichment with diterpenes like kahweol, cafestol and 16-O-methylcafestol. The analysis comprised the application of Box-Behnken design of experiments and response surface methodology, and involved three operatin...
Sequential microwave superheated water extraction of mannans from spent coffee ...
Passos, Claudia P.; Moreira, Ana S. P.; Domingues, M. Rosario M.; Evtuguin, Dmitry V.; Coimbra, Manuel A.The feasibility of using sequential microwave superheated water extraction (MAE) for the recovery of mannans from spent coffee grounds (SCG) was studied. Due to the high contents of mannose still present in the SCG residue left after two consecutive MAE, the unextracted material was re-suspended in water and submitted to a third microwave irradiation (MAE3) at 200 degrees C for 3 min. With MAE3, mannose recover...
Inhibitory effect of phenolic compounds from grape seeds (Vitis vinifera L.) on...
Afonso, Joana; Passos, Claudia P.; Coimbra, Manuel A.; Silva, Carlos M.; Soares-da-Silva, PatricioInhibition of the angiotensin I converting enzyme (ACE) is an important therapeutic approach in the treatment of several cardiovascular disorders. In this study the inhibitory potential of procyanidin-rich fractions of grape seed (Vitis vinifera L.) was evaluated. The inhibitory capacity was assayed by fluorometric determination of the amount of histidyl-leucine released from the substrate utilized in the prese...