Valorization of coffee industry residues by subcritical water hydrolysis: Recovery of sugars and phenolic compounds

Yadav

et al. 2017

Bioresour. Bioprocess.

351

148

Food waste, a by-product of various industrial, agricultural, household and other food sector activities, is rising continuously due to increase in such activities. Various studies have indicated that different kind of food wastes obtained from fruits, vegetables, cereal and other food processing industries can be used as potential source of bioactive compounds and nutraceuticals which has significant application in treating various ailments. Different secondary metabolites, minerals and vitamins have been extracted from food waste, using various extraction approaches. In the next few years these approaches could provide an innovative approach to increase the production of specific compounds for use as nutraceuticals or as ingredients in the design of functional foods. In this review a comprehensive study of various techniques for extraction of bioactive components citing successful research work have been discussed. Further, their efficient utilization in development of nutraceutical products, health benefits, bioprocess development and value addition of food waste resources has also been discussed.

Section: Subcritical Water Extractionmentioning

confidence: 99%

Food waste: a potential bioresource for extraction of nutraceuticals and bioactive compounds

Yadav

et al. 2017

Bioresour. Bioprocess.

351

148

“…Currently research in appropriate methodologies for the extraction of NEP is a priority topic because of the economic advantages of the use of ARs. Some examples of research on the best conditions for the extraction of NEP from ARs are those for the use of cocoa by-products, which involve extractions assisted by ultrasound [20,35], thermic treatment [59,60], hydrodynamic cavitation [35], pressurized liquids [50], pulsed electric field [61], subcritical water hydrolysis [62], and solid fermentation [63]. There are also reports on detailed chemical studies of the NEP structure thanks to modern analytical instrumentation, such as liquid chromatography (LC) coupled to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), electrospray/ionization time-of-flight mass spectrometry (ESI-TOF-MS), LC Â LC coupled to tandem mass spectrometry, pyrolysis/gas chromatography/mass spectrometry (Py/GC/MS), and nuclear magnetic resonance (NMR), which has been key to making detailed chemical studies of high-molecular-weight polyphenols [36,[64][65][66].…”

Section: Non-extractable Polyphenols (Nep)mentioning

confidence: 99%

Antioxidant Compounds from Agro-Industrial Residue

Hernández-Carlos¹,

Santos-Sánchez²,

Salas-Coronado³

et al. 2019

Antioxidants

Agro-industrial residues are a potential source of antioxidant compounds, which in general are phenolic compounds with a large chemical variability. The structure and the complexity of the phenolic compounds (polyphenols) determine their antioxidant capacity, pretreatments, and extraction methods. This chapter gives an overview of the chemical complexity of the phenolic compounds found in extractable and non-extractable fractions of agro-industrial residues, and representative compounds that are present in such residues are shown. Moreover, extraction methods described in this review showed the use of nonconventional technologies and chemical, enzymatic, or thermic treatments, useful to transform non-extractable polyphenols (NEP) to extractable polyphenol (EP) and then apply the EP extraction methods and recover antioxidants.

“…The water in subcritical state is at a temperature range of 100 to 374 °C using pressures higher than the vapor pressure avoiding the phase change. In turn, under supercritical conditions, the temperature conditions are higher than those of its critical point (critical temperature of 374.15 °C and 22.1 MPa) Mayanga-Torres et al, 2017). Under these conditions, water is a highly reactive solvent, and this is due to such interesting changes in its properties (namely density, dielectric constant, ionization constant and viscosity) due to the progressive increase in temperature and pressure (Brunner, 2009;Kruse and Dahmen, 2015;Kruse and Dinjus, 2007;Möller et al, 2011;Yu et al, 2007) which are appropriate for effective hydrothermal biomass processing.…”

Section: Subcritical and Supercritical Water Processingmentioning

confidence: 99%

A review of research trends in the enhancement of biomass-to-hydrogen conversion

et al. 2018

Different types of biomass are being examined for their optimum hydrogen production potentials and actual hydrogen yields in different experimental setups and through different chemical synthetic routes. In this review, the observations emanating from research findings on the assessment of hydrogen synthesis kinetics during fermentation and gasification of different types of biomass substrates have been concisely surveyed from selected publications. This review revisits the recent progress reported in biomass-based hydrogen synthesis in the 2 associated disciplines of microbial cell immobilization, bioreactor design and analysis, ultrasound-assisted, microwave-assisted and ionic liquid-assisted biomass pretreatments, development of new microbial strains, integrated production schemes, applications of nanocatalysis, subcritical and supercritical water processing, use of algae-based substrates and lastly inhibitor detoxification. The main observations from this review are that cell immobilization assists in optimizing the biomass fermentation performance by enhancing bead size, providing for adequate cell loading and improving mass transfer; there are novel and more potent bacterial and fungal strains which improve the fermentation process and impact on hydrogen yields positively; application of microwave irradiation and sonication and the use of ionic liquids in biomass pretreatment bring about enhanced delignification, and that supercritical water biomass processing and dosing with metal-based nanoparticles also assist in enhancing the kinetics of hydrogen synthesis. The research areas discussed in this work and their respective impacts on hydrogen synthesis from biomass are arguably standalone. Thence, further work is still required to explore the possibilities and techno-economic implications of combining these areas for developing robust and integrated biomass-to-hydrogen synthetic schemes.