Search results for "Water extraction"
showing 6 items of 16 documents
Pressurized hot water extraction (PHWE) for the green recovery of bioactive compounds and steviol glycosides from Stevia rebaudiana Bertoni leaves
2018
Stevia rebaudiana Bertoni leaves are a natural source of diterpenic glycosides, and various bioactive compounds. The objectives were to characterize antioxidants and steviol glycosides in the extracts obtained from Stevia after "green" pressurized hot water extraction (PHWE). PHWE extracts were obtained at different temperatures (100, 130, 160 °C); static extraction times (5 and 10 min), and cycle numbers (1, 2, 3) using a constant pressure of 10.34 MPa. Temperature was the most important parameter for extraction, where the highest recoveries of all bioactive compounds (except for carotenoids) were at 160 °C. Extracts obtained at longer static times had more steviol glycosides, condensed ta…
Hydrogen and methane yields of untreated, water-extracted and acid (HCl) treated maize in one- and two-stage batch assays
2011
Abstract In the present study, two-stage H 2 and CH 4 production was compared with one-stage CH 4 production from maize subjected to water extraction and acid (HCl) treatment. In addition, the effect of duration (2 and 14 days) of the first-stage H 2 process on the H 2 yields and subsequent CH 4 yields from the second-stage was also investigated. Results showed that the average H 2 yields from untreated maize were 5.6 and 9.9 ml/g volatile solids added (VS added ) after 2 and 14 days, respectively. On the other hand, H 2 yields from water-extracted and HCl-treated maize were 18.0 and 20.5 ml/gVS added (14 d), respectively. On comparison to one-stage CH 4 assays, the average increase in CH 4…
Organics in soda-anthraquinone black liquors from hot-water-extracted non-wood feedstocks
2019
The chemical compositions of black liquors (BLs) obtained from the soda-anthraquinone (AQ) pulping of untreated and hot-water-extracted non-wood feedstocks (okra stalk, miscanthus stalk, and wheat straw) were determined. These under-utilized renewable and widely available feedstocks could provide a cheaper source for producing fiber and precursors for manufacturing green chemicals. These BLs were mainly characterized in terms of carbohydrate-derived volatile carboxylic acids (acetic and formic acids) and non-volatile carboxylic acids (hydroxy acids) as well as lignin. Additionally, in each case, the average molar mass and molar mass distribution of the dissolved lignin were measured. Result…
Sensory and Chemical Analysis of Fractions Obtained by Gel Permeation of Water-Soluble Comte Cheese Extracts
1995
The pure water extraction of Comte cheese solubles and their chromatographic separation facilitate sensory analysis experiments with the fractions directly collected from the column. Two extracts, one obtained after ultrafiltration, the other after chromatography on Sephadex G25, have been separated on Toyopearl HW-40S. The sensory evaluation of the obtained fractions shows in the two cases that some fractions have interesting flavors. However, physicochemical analysis shows that organoleptic characteristics are linked more to the presence of amino acids and salts than to the presence of peptides. Apart from monosodium glutamate, most of the amino acids are present in the fractions at conce…
Advanced biorefinery concepts related to non-wood feedstocks
2018
Agricultural residues, such as wheat straw (Triticum aestivum), okra stalk (Abelmoschus esculentus), and giant miscanthus (Miscanthus × giganteus, a hybrid of M. sinensis and M. sacchariflorus) were investigated to assess their possible consumption for integrated lignocellulosic biorefining. The efficient fractionation and recovery of all important chemical components (cellulose, hemicelluloses, and lignin) of such feedstocks are a prerequisite for realistic biorefinery concepts. Water is one of the most eco-friendly solvents with the highest potential for industrial use, and it is also suitable for full-scale biorefinery purposes. For example, under pressure at elevated temperatures over 1…
In-Depth Characterization of Bioactive Extracts from Posidonia oceanica Waste Biomass
2019
© 2019 by the authors.