scholarly journals The Colour of Tropical Woods Influenced by Brown Rot

Forests ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 322 ◽  
Author(s):  
Zuzana Vidholdová ◽  
Ladislav Reinprecht
Keyword(s):  
Brown Rot ◽  
Colour Difference ◽  
Weight Losses ◽  
Before And After ◽  
Colour Parameters ◽  
Colour System ◽  
Colour Saturation ◽  
Tropical Woods ◽  
Intentional Attack ◽  
Yellow Tint

Interesting aesthetic properties of tropical woods, like surface texture and colour, are rarely impaired due to weathering, rotting and other degradation processes. This study analyses the colour of 21 tropical woods before and after six weeks of intentional attack by the brown-rot fungus Coniophora puteana. The CIEL*a*b* colour system was applied for measuring the lightness, redness and yellowness, and from these parameters the hue tone angle and colour saturation were calculated. Lighter tropical woods tended to appear a less red and a more yellow, and had a greater hue tone angle. However, for the original woods was not found dependence between the lightness and colour saturation. Tropical woods at attack by C. puteana lost a weight from 0.08% to 6.48%. The lightest and moderately light species—like okoumé, iroko, ovengol and sapelli—significantly darkened, while the darkest species—wengé and ipé—significantly lightened. The majority of tropical woods obtained a brighter shade of yellow, typically wengé, okoumé and blue gum, while some of them also a brighter shade of green, typically sapelli, padouk and macaranduba. C. puteana specifically affected the hue tone angle and colour saturation of tested tropical woods, but without an apparent changing the tendency of these colour parameters to lightness. The total colour difference of tested tropical woods significantly increased in connection with changes of their lightness (ΔE*ab = 5.92 − 0.50·ΔL*; R2 = 0.37), but it was not influenced by the red and yellow tint changes, and weight losses.

Colour stability of surface finishes on thermally modified beech wood

2021 ◽  
Vol 114 ◽  
pp. 116-124
Author(s):  
Gabriela Slabejová ◽  
MÁRIA ŠMIDRIAKOVÁ
Keyword(s):  
Surface Finish ◽  
Beech Wood ◽  
Surface Finishing ◽  
Colour Stability ◽  
Colour Difference ◽  
Surface Finishes ◽  
Before And After ◽  
Thermally Modified Wood ◽  
Wood Surfaces ◽  
Modified Wood

Colour stability of surface finishes on thermally modified beech wood. The paper deals with the influence of the type of transparent surface finish on the change of colour of the surfaces of native beech wood and thermally modified wood. At the same time, the colour stability of three surface finishes on the surfaces of native and thermally modified beech wood was monitored. Beech wood was thermally modified at temperature of 125 °C for 6 hours. The thermal treatment was performed in a pressure autoclave APDZ 240, by the company Sundermann s.r.o in Banská Štiavnica. Three various types of surface finishes (synthetic, wax-oil, water-based) were applied onto the wood surfaces. The colour of the surfaces of native wood and thermally modified wood was measured in the system CIELab before and after surface finishing; the coordinates L*, a*, b*, C*ab and h*ab were measured. From the coordinates measured before and after surface finishing, the differences were calculated and then the colour difference ∆E* was calculated. Subsequently, the test specimens with the surface finishes were exposed to natural sunlight, behind glass in the interior for 60 days. The surface colour was measured at specified time of the exposure (10, 20, 30, 60 days). The results showed that the colour of the wood surfaces changed after application of the individual surface finishes; and the colour difference reached a change visible with a medium quality filter up to a high colour difference. The wax-oil surface finish caused a high colour difference on native wood and on thermally modified wood as well. On native beech wood, the lowest colour difference after exposure to sunlight was noticeable on the synthetic surface finish. On the surface of wood thermally modified, after exposure to sunlight, the lowest colour difference was noticeable on the surface with no surface finish.

Levels of Polychlorinated Biphenyls and Pesticides in Bluefish Before and After Cooking

1989 ◽  
Vol 72 (3) ◽  
pp. 501-503
Author(s):  
William J Trotter ◽  
Paul E Corneliussen ◽  
Ronald R Laski ◽  
Joseph J Vannelli
Keyword(s):  
Polychlorinated Biphenyls ◽  
Moisture Loss ◽  
Aroclor 1254 ◽  
Weight Losses ◽  
Before And After

Abstract Similar levels of polychlorinated biphenyls (PCBs), pesticides, and fat were found in 20 correlated uncooked and cooked (baked) bluefish fillets. Fillets averaged 2.5 ppm PCBs as Aroclor 1254 (whole basis) before cooking; after cooking, with the oil drippings and skin discarded, the average PCB level was 2.7 ppm. Although PCBs, lipophilic pesticides, and fat were lost along with oil drippings and skin that were discarded after cooking, the moisture loss in the fillets during cooking compensated for these weight losses almost completely. After the fillets were cooked and the oil drippings and skin were discarded, the PCB content of the fillets was 27% lower on the average.

scholarly journals Usefulness of selected methods of colour change measurement for pork quality assessment

2011 ◽  
Vol 29 (No. 3) ◽  
pp. 212-218 ◽  
Author(s):  
T. Karamucki ◽  
J. Gardzielewska ◽  
A. Rybarczyk ◽  
M. Jakubowska ◽  
W. Natalczyk-Szymkowska
Keyword(s):  
Quality Assessment ◽  
Meat Quality ◽  
Colour Change ◽  
Industrial Process ◽  
Chemical Components ◽  
Pork Quality ◽  
Before And After ◽  
Longissimus Lumborum ◽  
Colour Parameters ◽  
Meat Colour

A few selected methods of the meat colour change determination were compared with regard to their usefulness in the assessment of the quality of minced pork. The study was carried out on 128 samples of the muscle longissimus lumborum, taken from 128 carcasses weighing 70&ndash;105 kg (equal number of both sexes &ndash; 64), obtained from pigs slaughtered in an industrial process line. The relationships were determined between the meat quality traits (concentrations of basic chemical components in the meat, colour, sensory analysis of wateriness and firmness, WHC and pH<sub>u</sub>), and the changes in colour parameters measured in CIELAB and CIELCh scales, total colour change (&Delta;E*), and the changes determined by Karamucki using the modified Kortz method. It was found that the most useful method for the quality assessment was the Kortz method modified by Karamucki, used to determine the stability of the meat colour (expressed as % colour change) and based on the measurements of absorbance at wavelengths 580 nm and 630 nm, before and after the change of colour. Out of the meat colour parameters, the most useful for assessing the meat quality were the changes in redness (a*) &ndash; CIELAB scale, and hue angle h&ordm; &ndash; CIELCh scale. The changes in colour determined by the aforementioned methods were a better indicator of the pork quality than the total colour change (&Delta;E*).

Artificial weathering of tropical woods. Part 2: Color change

Holzforschung ◽  
2004 ◽  
Vol 58 (5) ◽  
pp. 558-565 ◽  
Author(s):  
Masanori Kishino ◽  
Takato Nakano
Keyword(s):  
Diffuse Reflectance ◽  
Color Change ◽  
Reflectance Spectra ◽  
Acacia Auriculiformis ◽  
Eucalyptus Marginata ◽  
Artificial Weathering ◽  
Diffuse Reflectance Spectra ◽  
Before And After ◽  
The Difference ◽  
Tropical Woods

Abstract This paper describes the change in diffuse reflectance Fourier transform infrared (DRIFT) and ultraviolet-visible (UV-Vis) diffuse reflectance spectra of the following eight tropical woods during artificial weathering up to 600 h in relation to their color changes, especially to yellowing: Amnurana acreana, Acacia auriculiformis, Dipterocarpus spp., Eucalyptus marginata, Eucalyptus robusta, Shorea spp. and Tabebuia spp. with relatively high and low specific gravity. For A. acreana, A. auriculiformis, Dipterocarpus spp. and both Tabebuia spp., Δb* (yellowing) increased with exposure up to 50 h, and decreased above 50 h. For E. marginata, E. robusta and Shorea spp., on the other hand, both Δa* (shift to red) and Δb* decreased with increased exposure time. For woods in which Δb* increased, the Δb* showed a positive dependence on the difference in relative intensity ratio of a band at 1740 cm–1 to that at 2900 cm–1 (ΔD1740/D2900) in DRIFT spectra of specimens before and after exposure. This result indicated that the increased band at 1740 cm–1 played a significant role in the increased Δb*. Then again, also for woods in which Δb* decreased, the ΔD1740/D2900 increased, but was not related to the Db*. The ΔD1740/D2900 for woods in which Δb* decreased had a positive relationship to the difference in remission function at 410 nm (ΔF(R∞)410) in UV-Vis diffuse reflectance spectra for specimens before and after exposure, while woods in which Δb* increased were independent of the ΔF(R∞)410. Therefore, it is suggested that woods in which Δb* increased and decreased differ from one another in the contribution to the increase in the band at 1740 cm–1, resulting in either an increase or decrease of Δb*.

Influence of roasting temperature on physicochemical properties of different coffees

1998 ◽  
Vol 4 (1) ◽  
pp. 59-66 ◽  
Author(s):  
M.D. Ortolá ◽  
L. Londoño ◽  
C.L. Gutiérrez ◽  
A. Chiralt
Keyword(s):  
Quality Parameters ◽  
Soluble Solids ◽  
Volume Increase ◽  
Weight Losses ◽  
Before And After ◽  
Different Temperatures ◽  
Roasting Temperature ◽  
The Mean ◽  
Colour Development ◽  
Different Origins

Arabica and robusta coffees from different origins were characterized before and after roasting at different temperatures (between 220 and 295°C). Samples were roasted (dark roast) until they attained the same colour. Colour development of the ground samples was measured throughout using CIE L*a*b* co-ordinates. The roasting temperature did not affect final weight loss and moisture content of the different coffees significantly, but slight differences were detected in the mean weight losses for the different coffees. Roasting temperature affected bulk and bean densities, grain volume increase, and soluble solids and acidity of coffee extracts. Robusta coffees were less sensitive to the bean volume increase, but showed a stronger temperature effect on the content of soluble solids and in the acidity of the aqueous extract, which can benefit its quality parameters.

Effect of pectin coating on colour and quality of dehydrated pineapple during storage

2016 ◽  
Vol 35 (2) ◽  
Author(s):  
C. S. Saini ◽  
H. K. Sharma
Keyword(s):  
Colour Change ◽  
Quality Parameters ◽  
Colour Difference ◽  
Rehydration Ratio ◽  
Browning Index ◽  
Reaction Rate Constants ◽  
Evaluation Scores ◽  
Colour Parameters ◽  
Predicted Values

The effect of storage on the colour and quality parameters of uncoated and pectin coated dehydrated pineapple samples were studied during storage. The dehydrated pineapple samples were packed in aluminium foil pouches and stored at 30 ± 1°C and 75% RH. The colour change was determined using <italic>L*, a*, b*</italic>, hue, total colour difference and browning index values. The kinetics of changes in colour parameters was determined using zero-order and first-order reaction kinetics. Non-linear regression of experimental data was done to obtain the reaction rate constants. <italic>L*, b*</italic>, and hue values decreased, while <italic>a*</italic>, total colour difference and browning index increased during storage in both coated and uncoated samples. Both the models were found to describe the data of colour parameters adequately. The correlation coefficient value of most of the colour parameters was more than 0.95 indicating good agreement between experimental and model predicted values. The browning was more observed in uncoated samples than coated samples, which increased in the later stages of storage. Rehydration ratio decreased, while moisture content increased with storage. The sensory evaluation scores of coated samples remained acceptable for longer period than uncoated samples.

Decay susceptibility of Amazon wood species from Brazil against white rot and brown rot decay fungi 10th EWLP, Stockholm, Sweden, August 25–28, 2008

Holzforschung ◽  
2009 ◽  
Vol 63 (6) ◽  
Author(s):  
Jane Silveira Carneiro ◽  
Luciano Emmert ◽  
Gerson H. Sternadt ◽  
Julio César Mendes ◽  
Getúlio F. Almeida
Keyword(s):  
Wood Species ◽  
Wood Decay ◽  
Brown Rot ◽  
White Rot ◽  
Natural Resistance ◽  
Decay Fungi ◽  
Pycnoporus Sanguineus ◽  
Hymenaea Courbaril ◽  
Weight Losses ◽  
Resistant Species

Abstract A total of 28 tropical Amazon woods – many of them rarely used – from Tapajós National Forest, Pará state, Brazil, were tested for their natural resistance against the decay fungi: Ganoderma applanatum, Trametes versicolor, Pycnoporus sanguineus, Meruliporia incrassata, and Gloeophyllum trabeum. The wood resistance classification was made according to the ASTM D 2017-81 method. High variability on susceptibility to wood decay fungi was found. Their mean weight losses varied from 0.6% to 45.6%. Highly resistant species include: Astronium gracile, Bagassa guianensis, Caryocar villosum, Claricia racemosa, Diplotropis purpurea, Dipteryx odorata, Hymenaea courbaril, Manilkara huberi, Mezilaurus itauba, Sextonia rubra, Tabebuia incana, and Vatairea paraensis. The following wood species are less durable: Brosimum parinarioides, Jacaranda copaia, Laetia procera, Pouteria pachycarpa, Virola caducifolia, and Trattinnickia rhoifolia. Meruliporia incrassata caused extensive weight losses in most of the investigated Amazon wood species.

scholarly journals Effect of exterior wood coatings on the durability of cross-laminated timber against mold and decay fungi

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 8420-8433
Author(s):  
Gabrielly S. Bobadilha ◽  
C. Elizabeth Stokes ◽  
Grant Kirker ◽  
Sheikh Ali Ahmed ◽  
Katie M. Ohno ◽  
...  
Keyword(s):  
Brown Rot ◽  
Acrylic Resin ◽  
Water Repellency ◽  
The United States ◽  
Mold Growth ◽  
Decay Fungi ◽  
Cross Laminated Timber ◽  
Dimensional Changes ◽  
Weight Losses ◽  
Rhizopus Sp

Cross-laminated timber (CLT) is increasingly used in building construction worldwide. Durability of CLT against fungal attack has yet to be fully explored. Water intrusion in mass timber can yield dimensional changes and microbial growth. This study evaluated the performance of CLT coated with various water- and solvent-based stains commercially available in the United States. Twelve coatings were tested for moisture excluding effectiveness, water repellency effectiveness, volumetric swelling, and anti-swelling efficiency. Only five coatings repelled water, limiting dimensional changes. A modified version of AWPA E10-16 (2016) was performed to evaluate decay of the coated CLT samples. Weight losses were recorded after 18 weeks’ exposure to the brown-rot decay fungus Gloeophyllum trabeum. In accelerated mold testing, coated CLT samples were grown in chambers containing spores of Aspergillus sp., Rhizopus sp., and Penicillium sp. for 29 d and assessed visually for mold growth. In both tests, coating C (transparent, water-based, alkyd/acrylic resin) performed the best among the tested coatings. Mold growth was completely prevented, and weight loss caused by G. trabeum was approximately 1.33%. Although coating C prevented decay for 18 weeks, coatings are not intended to protect against decay fungi. However, they may offer short-term protection during transport, storage, and construction.

scholarly journals 355 Effect of UV-C on Ripening and Postharvest Quality of Peaches

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 504D-504 ◽  
Author(s):  
Robert C. Ebel ◽  
Floyd M. Woods ◽  
Dave Himelrick
Keyword(s):  
Fruit Quality ◽  
Skin Color ◽  
Storage Temperature ◽  
Brown Rot ◽  
Soluble Solids ◽  
Postharvest Quality ◽  
Before And After ◽  
And Storage ◽  
Uv C

Brown rot of peaches is one of the most devastating diseases that can occur before and after harvest. There has been extensive research that has shown that ultraviolet light (UV-C) kills the fungus that causes brown rot. However, it is has not been determined whether UV-C will also change ripening and fruit quality. We applied UV-C to `Loring' peaches that were harvested 10 days before normal harvest. We intentionally picked the fruit early because we wanted to make sure the fruit had not entered the climacteric. The fruit were treated with UV-C and ethylene, skin color, firmness, and soluble solids were measured. We also held fruit at three storage temperatures to determine whether there may be an interaction between UV-C treatment and storage temperature. Ethylene was slightly higher for UV-C treated fruit at 70 °F (20 °C) and 55 °F (12 °C), but not at 40 °F (4 °C). However, there was very little effect on firmness and soluble solids. There was a slight delay in development of red blush. UV-C had little effect on ripening and peach fruit quality.

scholarly journals Egg Morphometry and Eggshell Quality in Ring-Necked Pheasants Kept in Cages / Budowa jaja i jakość skorupy u bażantów obrożnych utrzymywanych w klatkach

2013 ◽  
Vol 13 (3) ◽  
pp. 531-541 ◽  
Author(s):  
Sebastian Nowaczewski ◽  
Tomasz Szablewski ◽  
Renata Cegielska-Radziejewska ◽  
Helena Kontecka
Keyword(s):  
Shape Index ◽  
Yellow Colour ◽  
Shell Quality ◽  
Percentage Points ◽  
Egg Shape ◽  
Colour Parameters ◽  
Colour Saturation ◽  
Eggshell Colour ◽  
Egg Shell

Abstract The aim of the study was to evaluate the morphometry and shell quality of eggs laid by pheasants kept in cages, and also to analyse the dependence between egg shell colour parameters, its quality and morphometric characteristics. Four groups of 15 eggs (60 eggs), each classified according to their eggshell colours, i.e. blue, light brown, dark brown and olive, were examined. The eggs did not differ significantly between each other in their mean weight and olive-coloured eggs had a higher shape index (about 8.91 percentage points) than blue eggs. Blue and light brown coloured eggs had thinner shells than the dark brown eggs (by 33.57 and 27.97 μm, respectively). Blue eggs had the lightest shells (L* = 67.97) and the highest proportion of green colour in their shells since the a* parameter value for blue eggs was negative. A significant positive correlation was observed between the egg shape and the shell colour saturation (C*) and the proportion of yellow colour (b*) in it. In addition, a negative correlation was found between lightness in eggshell colour, its thickness and the egg shape (r = from -0.338* to -0.480**). In comparison with the data obtained from the literature concerning the quality of eggs laid by pheasants kept in aviaries and eggs laid by birds kept in cages, the eggs were described as having similar weights and morphometries along with greater shell thicknesses. Furthermore, our study confirmed that pheasant eggs with blue and light brown colour have poorer shell quality, a fact which has been shown already in earlier research. However, this fact is related to the lightness of the shell pigment rather than its colour.

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