| 11. |
- Gouveia, Sandra C., et al.
(författare)
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Artemisia annua L. : Essential oil and acetone extract composition and antioxidant capacity
- 2013
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Ingår i: Industrial crops and products (Print). - : Elsevier. - 0926-6690 .- 1872-633X. ; 45, s. 170-181
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Tidskriftsartikel (refereegranskat)abstract
- Aerial parts of Artemisia annua growth in three different locations of Madeira Archipelago were studied. The essential oil composition was established by GC-MS and the main components were mono- and sesquiterpenes; artemisia ketone was not detected. The presence of phenolic compounds in the acetone extracts was investigated by HPLC-DAD-ESI/MSn and a diversified phenolic profile of 40 hydrocinnamic acid derivatives and glycosylated flavonoids was found. A few compounds were reported for the first time in Artemisia annua. The antioxidant capacity of essential oils and extracts were measured by three different in vitro assays. For the essential oils, a very good antioxidant response was found and the extracts also showed a good antioxidant capacity, in particular as antiradical scavengers. (C) 2012 Elsevier B.V. All rights reserved.
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| 12. |
- Hernández, Ena, et al.
(författare)
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Dilute sulphuric acid pretreatment and enzymatic hydrolysis of Moringa oleifera empty pods
- 2013
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Ingår i: Industrial crops and products (Print). - : Elsevier. - 0926-6690 .- 1872-633X. ; 44, s. 227-231
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Tidskriftsartikel (refereegranskat)abstract
- In this work, dilute sulphuric acid prehydrolysis of residual empty pods of Moringa oleifera fruits was investigated as pretreatment for enzymatic hydrolysis of cellulose. In experiments performed at 130–190 °C for 10–30 min, corresponding to a severity range between log Ro = 1.9 and log Ro = 4.2, the effect of pretreatment conditions on the recovery of polysaccharides and on the enzymatic convertibility of cellulose was evaluated. Overall cellulose recovery was above 95% in the pretreatments performed at 130 and 160 °C, and between 87 and 90% in the pretreatments at 190 °C, while xylan recovery in the most severe pretreatments was only 24.7–50.2%. The highest sugar concentration in the acid prehydrolysates (15.0 g/L) was obtained in the pretreatment performed at 160 °C and 20 min. The formation of degradation products was low at mild pretreatment conditions, but it increased with the severity. Furfural concentration reached 4.04 g/L at log Ro = 3.1 and decreased again with a further increase of the pretreatment severity. HMF, formic acid and levulinic acid were formed only in the most severe pretreatments. The pretreatment was effective for improving the enzymatic hydrolysis of cellulose, and the highest conversion (84.3%) was achieved in the material pretreated at mid severity (log Ro = 3.1).
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| 13. |
- Jonoobi, Mehdi, et al.
(författare)
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Producing low-cost cellulose nanofiber from sludge as new source of raw materials
- 2012
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Ingår i: Industrial crops and products (Print). - : Elsevier BV. - 0926-6690 .- 1872-633X. ; 40:1, s. 232-238
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to isolate cellulose nanofibers by ultrafine grinding, from sludge (residue from dissolving cellulose production) and cellulose (dissolving cellulose) and to characterize their properties. The mechanical fibrillation was found to be more energy efficient at low rotor speed (1440) and was estimated to be 1.7 and 1.3 kWh/kg for cellulose (CF) and sludge fibers (SF), respectively. Sludge (SNF) and cellulose (CNF) nanofibers had diameter less than 100 nm, as measured from transmission electron microscopy images. The specific surface area ranged from approximately 84 to 112 m2/g for CNF and SNF respectively. The apparent networks density increased with fibrillation, being approximately 330 and 370 for CF and SF while 907 and 986 kg/m3 for the corresponding nanosized ones. The scanning electron microscopy (SEM) study exhibited considerably smoother surfaces for the nanofiber networks compared to microsized. Fibrillation to nanosized fibers had positive impact on modulus and strength of both raw materials and the improvement was more significant for sludge, indicating more efficient fibrillation. The study showed that the isolation of nanofibers from sludge could be considered an economic, energy efficient and viable alternative to generate value-added product from cellulose sludge while minimizing the sludge disposal issues.
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| 14. |
- Khosravi, Sara, et al.
(författare)
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Protein-based adhesives for particleboards
- 2010
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Ingår i: Industrial crops and products (Print). - : Elsevier BV. - 0926-6690 .- 1872-633X. ; 32:3, s. 275-283
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to elucidate the possibilities of using soy protein isolate (SPI) and wheat gluten (WG) as binders for particleboards. One-layer particleboards were produced in laboratory scale. Parameters regarding the formulation of the adhesive and the gluing process were investigated, while the press parameters were kept constant. The considered factors were: the use of protein as a dispersion and/or as a dry protein powder, the temperature during the preparation of the dispersion, the time for preparing the dispersion, the storage time of dispersion prior to gluing, and the use of dried core particles or green particles. The board properties evaluated were: internal bond (IB), thickness swelling (TS) and water absorption (ABS). The results were statistically evaluated and SIMCA-P+ software was employed as a multivariate analyzing tool. The results show that protein adhesives can work as adhesive for particleboard. The results also reveal that it is preferable to use the dispersion as a binder rather than the dry protein. Furthermore, in the case of the SPI, the time for preparing the dispersion is a significant parameter: it appears that longer dispersion time results in enhanced board properties. According to the results, the temperature during the preparation does not seem to have any impact on the gluing properties of the SPI dispersions. On the other hand, in the case of WG dispersions, the temperature has an impact on the properties of the adhesive, favouring lower temperature, while the time is insignificant. Additionally, if the dispersion has been stored for more than 1 day before it is used, it results in boards with poorer mechanical and water resistance properties. The utilization of the green chips, instead of the dried core particles, is clearly a disadvantage, especially regarding the water resistance of the particleboards. It appears that SPI is superior to WG when it comes to the water resistance as well as the mechanical properties of the boards. However, it is not possible to compare these two proteins explicitly, since SPI contains a higher percentage of protein. Additionally, WG contains more starch, which is known to give poorer water resistance properties.
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| 15. |
- Khosravi, Sara, et al.
(författare)
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Protein-based adhesives for particleboards - effect of application process
- 2011
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Ingår i: Industrial crops and products (Print). - : Elsevier BV. - 0926-6690 .- 1872-633X. ; 34:3, s. 1509-1515
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Tidskriftsartikel (refereegranskat)abstract
- The main purpose of this study was to investigate wheat gluten (WG) dispersions as adhesives for particleboard. The effect of the dispersion concentration and two application methods were studied. When application method 1 was employed all the dispersion was added to the particles in one step, the particles were dried after the gluing. When using application method 2, the dispersion was added in two steps with drying of the glued chips between the first and the second addition of the dispersion. The amount of dry wheat gluten on dry particles was kept constant for all the experiments as was the pressing conditions. The performance of the wheat gluten dispersions were evaluated based on the following board properties: internal bond (IB), thickness swelling (TS) and water absorption (ABS). The experiments were conducted according to a factorial screening design and SIMCA-P+ was employed as a multivariate analyzing tool. The results reveal that application method 2 seems to be beneficial. Furthermore, it appears as, regarding the IB of the boards, the preferable dispersion concentration depends on the employed application method. When application method 1 is used a higher concentration seems to be better, in contrast for application method 2 a lower concentration of the dispersion may be beneficial. The improved properties obtained using application method 2 is proposed to be due to a more optimal penetration of the dispersion into the wood particles.
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| 16. |
- Korkut, Süleyman, et al.
(författare)
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Effect of thermal modification on the properties of narrow-leaved ash and chestnut
- 2012
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Ingår i: Industrial crops and products (Print). - : Elsevier BV. - 0926-6690 .- 1872-633X. ; 35:1, s. 287-294
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Tidskriftsartikel (refereegranskat)abstract
- The concept of thermal modification has evolved from a challenging research program to commercial reality in several European countries in recent years. The aim of this study is to determine the change of various physical properties (oven-dry density, air-dry density, weight loss, swelling and anti-swelling efficiency (ASE)), compression strength parallel to grain, colour difference (ΔE), glossiness and surface roughness of narrow-leaved ash (Fraxinus angustifolia Vahl.) and chestnut (Castanea sativa Mill.) woods after heat treatment under different temperatures and durations. For this study two different temperatures (160°C and 180°C) and two different durations (2h and 4h) were considered. A stylus method was employed to evaluate the surface characteristics of the samples. Roughness measurements by the stylus method were made in the direction perpendicular to the fiber. Four main roughness parameters which are mean arithmetic deviation of profile (Ra), mean peak-to-valley height (Rz), root mean square roughness (Rq), and maximum roughness (Ry) obtained from the surface of wood were used to evaluate the effect of heat treatment on the surface characteristics of the specimens. The properties studied were significantly different (p=0.05) at two temperatures and two durations of heat treatment. Based on the findings of this study, the results showed that oven-dry density, air-dry density, swelling, compression strength parallel to grain and surface roughness decreases with increasing heat treatment temperature and time.
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| 17. |
- Li, Shu-Ming, et al.
(författare)
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Microwave-assisted method for the synthesis of cellulose-based composites and their thermal transformation to Mn2O3
- 2013
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Ingår i: Industrial crops and products (Print). - : Elsevier BV. - 0926-6690 .- 1872-633X. ; 43, s. 751-756
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate the synthesis of inorganic materials using cellulose as a template by thermal treatment of the precursor. Cellulose-based composites have been successfully fabricated by an efficient microwave-assisted method. The influences of heating time on the phases and shape of the precursor were investigated. Mn2O3 materials were obtained by thermal treatment of the precursor at 600 degrees C for 3 h in air. The morphology of cellulose composites was preserved after thermal transformation to form Mn2O3. The products were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectrometry (FTIR), energy-dispersive X-ray spectra (EDS). scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential thermal analysis (DTA). A rapid microwave-assisted method with the thermal post-treatment provides a promising route for the fabrication of inorganic materials using natural polymer as a template.
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| 18. |
- Li, Xue-Yuan, et al.
(författare)
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Highly efficient in vitro regeneration of the industrial oilseed crop Crambe abyssinica
- 2011
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Ingår i: Industrial Crops and Products. - : Elsevier BV. - 0926-6690 .- 1872-633X. ; 33, s. 170-175
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Tidskriftsartikel (refereegranskat)abstract
- A highly efficient regeneration protocol for oilseed crop Crambe abyssinica has been developed using hypocotyls as explants in this study. Crambe is a potential engineering oilseed crop for industrial purposes as it contains 55-60% erucic acid in its oil and, more importantly, it does not outcross with any food oil seed crops. However, the low regeneration frequency with the currently available protocols is still a limiting factor for genetic modification of Crambe. In this study, we investigated the effects of N-source, C-source, AgNO(3), cultural conditions as well as the concentration and combination of plant growth regulators (PGR) on the regeneration frequency of C. abyssinica. The results showed that all these factors, especially the N-source and PGR concentrations and combinations, played an important role in shoot regeneration. Among all the factors tested, the combination of using hypocotyls from C. abyssinica cv. galactica, the Lepiovre basal medium supplemented with 16 g l(-1) glucose, 0.5 g l(-1) AgNO(3), 2.2 mg l(-1) thidiazuron (TDZ), 0.5 mg l(-1) alpha-naphthaleneacetic acid (NAA), 2.5 g l(-1) Gelrite, seeds germinated in dark for 3 days and explants cultured in light, gave the best regeneration frequency (over 95%). The results also suggest that reducing the content of NH(4)(+) or keeping a suitable NO(3)(-)/NH(4)(+). ratio in the regeneration medium would be crucial to Crambe shoot regeneration. (C) 2010 Elsevier B.V. All rights reserved.
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| 19. |
- Mathew, Aji P., et al.
(författare)
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Process scale up and characterization of wood cellulose nanocrystals hydrolysed using bioethanol pilot plant
- 2014
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Ingår i: Industrial crops and products (Print). - : Elsevier BV. - 0926-6690 .- 1872-633X. ; 58, s. 212-219
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Tidskriftsartikel (refereegranskat)abstract
- The paper discusses the isolation of cellulose nanocrystals (CNCBE) from wood resources by integrating the processing with pilot-scale bioethanol processing unit. The nanocrystals were isolated from cellulose obtained by acid pretreatment of wood chips in a bioethanol pilot-scale facility, followed by a series of chemical processes and subsequent homogenization using a lab-scale homogenizer. The isolated nanocrystals had diameters of 5-15 nm, cellulose I crystalline structure and formed a thick semi-transparent gel at low concentration (2 wt%). XPS data showed that these nanocrystals had predominantly O=C-O surface groups which also contributed to its high negative zeta potential. Casted CNCBE films showed excellent mechanical performance (200 MPa of strength, 16 GPa of modulus) and transparency and were also found to be cytocompatible. The developed process route resulted in high-quality nanocellulose crystals with a yield of 600 g/day.
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| 20. |
- Matsakas, Leonidas, et al.
(författare)
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Use of dried sweet sorghum for the efficient production of lipids by the yeast Lipomyces starkeyi CBS 1807
- 2014
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Ingår i: Industrial crops and products (Print). - : Elsevier BV. - 0926-6690 .- 1872-633X. ; 62, s. 367-372
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Tidskriftsartikel (refereegranskat)abstract
- The ability of the oleaginous yeast Lipomyces starkeyi to efficiently produce lipids when cultivated on saccharified sweet sorghum stalks juice was evaluated. Initially the production of lipids using synthetic media mimicking sweet sorghum stalks has been studied and optimized concerning the nitrogen source and the C:N ratio. Under optimum conditions (yeast extract as nitrogen source and C:N ratio of 190) the lipid production reached 5.81 g/L with a lipid content of 47.3% (w/w) from a mixture of sucrose, glucose and fructose, mimicking the sugar composition of sorghum. When cultivated on sweet sorghum stalks juice, it was observed that no external nitrogen addition was necessary which could result in substantial decrease of the initial C:N ratio. Moreover a distinct saccharification process prior to yeast cultivation improved the lipid production yield as it resulted in an increase of the C:N ratio. The highest lipid production, which was 6.40 g/L with a lipid content of 29.5% (w/w), was obtained when juice from saccharified sweet sorghum stalks at an initial sorghum content of 12% (w/w) was used as feedstock.
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