scholarly journals Effect of Esterification Conditions on the Physicochemical Properties of Phosphorylated Potato Starch

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2548
Author(s):  
Jacek Rożnowski ◽  
Lesław Juszczak ◽  
Barbara Szwaja ◽  
Izabela Przetaczek-Rożnowska
Keyword(s):  
Phosphorus Content ◽  
Potato Starch ◽  
Principal Component ◽  
Dry Weight ◽  
Color Difference ◽  
Color Changes ◽  
Loop Area ◽  
Modified Starches ◽  
Hysteresis Loop Area ◽  
Total Color Difference

The aim of this study was to evaluate the effect of the temperature (15 or 45 °C) and the duration (15–120 min) of the modification process on the selected physicochemical, thermal, and rheological properties of phosphorylated potato starch. The modified starches contained 93.6–98.2 mg P/100 g (dry weight basis, d.w.b.). Phosphorylation caused color changes with a total color difference between the starches below 0.55, but these changes were less than those that were recognizable by the human eye. The thermal analysis showed two opposite processes appearing during the modification: the loosening of the structure (dominant among starches obtained at 15 °C) and the strengthening of the structure (dominant among starches obtained at 45 °C). The higher phosphorylation temperature reduced native starch recovery from 140% to 87–116% and increased the hysteresis loop area from −169 to 1040. All of the pastes made from the modified starches showed a weaker tendency for retrogradation (during 21 days of storage) than native starches. The results of the regression analysis conducted between the properties of the starch pastes obtained at 45 °C indicated that the modification time appeared to be a better indicator of the rate of modification progress than the phosphorus content. The PCA (principal component analysis) results made it possible to distinguish starch phosphates obtained at 15 °C from those obtained at 45 °C and those from natural starch.

Subjective Sensation of Color Differences – Determination of Thresholds Depending on Color Tones and Resolution

2015 ◽  
Vol 21 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Christian Brischke ◽  
Tanja Borcharding ◽  
Uta Mengel
Keyword(s):  
Color Space ◽  
Color Difference ◽  
Threshold Values ◽  
Color Tone ◽  
Color Changes ◽  
Art Objects ◽  
Color Differences ◽  
Subjective Sensation ◽  
Total Color Difference

Abstract Colors are frequently defined by three points on the L*a*b* coordinates of the CIELAB color space, and the distance between two colors can be expressed as the total color difference ΔE. In particular with respect to reproducibility of print media color differences are an important parameter, as well as for car finishes and textile dyes. Color changes are also the result of ageing and weathering which is an issue for art objects and in the building and restoration sector. However, the subjective perceptibility of color differences depends on numerous factors and general thresholds are difficult to define. This study aimed therefore on defining tolerance levels for color changes in dependence of color tones and color tone combinations as well as their resolution. In total 30 test persons evaluated samples, which had been painted with acrylic artist colors with defined color differences (ΔE = 0–7). The test subjects realized color differences already at ΔE = 1–4 for the highest resolution. Threshold values have been identified for different tones as well as the effect of interdependencies between tones and the level of color heterogeneity between adjacent areas.

Evaluation of Microwave and Ozone Disinfections on the Color Characteristics of Iranian Export Raisins Through an Image Processing Technique

2019 ◽  
Vol 82 (12) ◽  
pp. 2080-2087
Author(s):  
REZA SADEGHI ◽  
ESMAEEL SEYEDABADI ◽  
RAHIL MIRABI MOGHADDAM
Keyword(s):  
Image Processing ◽  
Color Difference ◽  
Processing Technique ◽  
Image Processing Technique ◽  
Storage Pests ◽  
Color Changes ◽  
Color Characteristics ◽  
Hue Angle ◽  
Total Color Difference ◽  
Ozone Treatments

ABSTRACT Raisins are one of the most important Iranian export products but are threatened by various storage pests. Because of the disadvantages of fumigants, we evaluated alternative microwave and ozone methods for their disinfection and the side effects on raisin qualities. To perform microwave disinfection, the studied raisin samples were exposed to microwave powers of 450, 720, and 900 W for 20, 30, 40, and 50 s. Also, ozone treatments included various combinations of ozone concentrations (2, 3, and 5 ppm) and exposure times (15, 30, 45, 60, and 90 min). An image processing technique was implemented to determine the color changes of raisins in terms of lightness, redness, yellowness, total color difference, chroma, and hue angle. The results revealed that increasing the microwave power and exposure time might lead to further changes of the previously mentioned color characteristics. Compared with the microwave treatments, ozone treatments had fewer effects on those features. Generally, microwave and ozone methods could successfully disinfect Oryzaephilus surinamensis in raisins, with acceptable changes in all the color characteristics. Hence, the previously mentioned methods are proposed as alternative chemical fumigants. HIGHLIGHTS

scholarly journals Chemical, morphological, rheological and thermal properties of Solanum lycocarpum phosphorylated starches

Revista CERES ◽  
2014 ◽  
Vol 61 (4) ◽  
pp. 458-466 ◽  
Author(s):  
Diego Palmiro Ramirez Ascheri ◽  
Luciane Dias Pereira ◽  
Suely Miranda Cavalcante Bastos
Keyword(s):  
Phosphorus Content ◽  
Cold Water ◽  
Sodium Tripolyphosphate ◽  
Raw Materials ◽  
Principal Component ◽  
Physicochemical Characteristics ◽  
Native Starch ◽  
Modified Starches ◽  
Pasting Temperature ◽  
Water Swelling

The increasing need for starches with specific characteristics makes it important to study unconventional starches and their modifications in order to meet consumer demands. The aim of this work was to study physicochemical characteristics of native starch and phosphate starch of S. lycocarpum. Native starch was phosphated with sodium tripolyphosphate (5-11%) added with stirring. Chemical composition, morphology, density, binding ability to cold water, swelling power and solubility index, turbidity and syneresis, rheological and calorimetric properties were determined. Phosphorus was not detected in the native sample, but the phosphating process produced modified starches with phosphorus contents of 0.015, 0.092 and 0.397%, with the capacity of absorbing more water, either cold or hot. Rheological data showed the strong influence of phosphorus content on viscosity of phosphate starch, with lower pasting temperature and peak viscosity higher than those of native starch. Enthalpy was negatively correlated with the phosphorus content, requiring 9.7; 8.5; 8.1 and 6.4 kJ g-1 of energy for the transition from the amorphous to the crystalline state for the starch granules with phosphorus contents of 0; 0.015; 0.092 and 0.397%, respectively. Cluster analysis and principal component analysis showed that starches with 0.015 and 0.092% phosphorus have similar characteristics and are different from the others. Our results show that the characteristics of phosphate modified S. lycocarpum starch have optimal conditions to meet the demands of raw materials, which require greater consistency in stickiness, combined with low rates of retrogradation and syneresis.

Color changes of ash wood (Fraxinus excelsior L.) caused by thermal modification in air and steam

2021 ◽  
Vol 116 ◽  
pp. 21-27
Author(s):  
Jakub Gawron ◽  
Monika Marchwicka
Keyword(s):  
Color Space ◽  
Color Difference ◽  
Thermal Modification ◽  
Fraxinus Excelsior ◽  
Space Model ◽  
Color Changes ◽  
Cielab Color Space ◽  
Before And After ◽  
Total Color Difference ◽  
Cielab Color

Color changes of ash wood (Fraxinus excelsior L.) caused by thermal modification in air and steam. Ash wood samples of 20x20x30 mm were subjected to thermal modification in different conditions. The thermal modification was conducted in air at 190 °C and in steam at 160 °C. For both environments modification lasted 2, 6 and 10 hours. Samples color parameters were measured before and after thermal modification on the basis of the mathematical CIELab color space model. Changes in all parameters (L, a and b) were observed, the highest in lightness (L) - darker color. The total color difference (ΔE) and chromaticity change (ΔC) were calculated for all samples. The highest value of ΔE was obtained for wood modified in the air at 190 °C for 10 h. The highest value of ΔC was obtained for wood modified in steam at 160 °C for 10 h. However, the value obtained for wood modified in the air at 190 °C for 10 h were only slightly lower.

scholarly journals The Influence of Drying Temperature on Color Change of Hornbeam and Maple Wood Used as Surface and Inner Layers of Wood Composites

2021 ◽  
Vol 11 (22) ◽  
pp. 10673
Author(s):  
Ivan Klement ◽  
Peter Vilkovský ◽  
Tatiana Vilkovská ◽  
Kazimierz A. Orłowski ◽  
Jacek Barański ◽  
...  
Keyword(s):  
High Temperature ◽  
Color Change ◽  
Color Difference ◽  
Wood Composites ◽  
Drying Temperature ◽  
Color Coordinates ◽  
Color Changes ◽  
Hot Air ◽  
Two Phases ◽  
Total Color Difference

The thermal treatment of wood changes its structure due to the degradation of wood polymers (cellulose, hemicellulose and lignin), so the physical properties of wood are either improved or degraded. Color changes apply not only to natural wood, but also to such wood composites for which some amount of glue is used in their construction (e.g., plywood, blockboard or laminboard). This article is focused on the analysis of hornbeam and field maple wood color changes influenced by drying temperature. Two types of drying modes were used: hot-air mode where the temperature of the drying environment was 60 °C, and high-temperature mode with a drying temperature of 120 °C. The drying mode was divided into two phases depending on the moisture content of the wood. The compared woods had similar values of color coordinates at the beginning of drying. During hot-air drying, the largest changes in color coordinates occurred during the first 24 h. The total color difference between the color at the end and the beginning of drying was 7.3 for hornbeam and 11.1 for maple. The overall color difference between the compared woods was minimal. During high-temperature drying (120 °C), the color changes of the dried woods were more pronounced. In the case of maple wood, there was a very significant change in color and the value of ΔE* was twice as high as for hornbeam. The total color difference between the color at the end and at the beginning of drying was 8.7 for hornbeam and 18.9 for maple.

scholarly journals Physicochemical properties of vacuum packaged snake fruits in the presence of olive leave extract

Food Research ◽  
2020 ◽  
Vol 4 (S1) ◽  
pp. 250-255
Author(s):  
A.N. Al-Baarri ◽  
F.P. Lestari ◽  
H.M. Wahda ◽  
Widayat ◽  
A.M. Legowo
Keyword(s):  
Physicochemical Properties ◽  
Room Temperature ◽  
Color Difference ◽  
Vacuum Packaging ◽  
Ambient Conditions ◽  
Olive Leaves ◽  
Color Changes ◽  
Fresh Cut ◽  
Total Dissolved Solid ◽  
Total Color Difference

This research was done to investigate the effectiveness of the presence of olive leaf extract in vacuum packaging in maintaining the physicochemical properties of fresh-cut snake fruit under ambient temperature. The snake fruits were vacuum packaged in the presence of 3% (v/w) olive leave extract (OLE) and stored in room temperature for 8 days of storage. The physicochemical properties including color changes, firmness, and total dissolved solid (TDS) were observed. The results indicated that addition olive leaves extract in vacuum packaging gave the best result by inhibiting color changes by declining in total color difference by 10.88, BI 5.08, absorbance 2.750 Ǻ declining in hardness by 14.61% and lowest TDS level. As an alternative method of storing fresh-cut snake fruit under ambient conditions, vacuum packaging containing olive leave extract can be used.

scholarly journals Drying of Steaming Maple Timber in Drying Kilns, While Preserving the Color Acquired by the Wood Steaming Process

2020 ◽  
Vol 328 ◽  
pp. 04004
Author(s):  
Ladislav Dzurenda
Keyword(s):  
Color Space ◽  
Free Water ◽  
Color Difference ◽  
Thermal Processes ◽  
Drying Process ◽  
Negative Aspect ◽  
Drying Time ◽  
Color Changes ◽  
The Difference ◽  
Total Color Difference

The paper presents a mode for drying steaming maple timber of thickness h = 38 mm from moisture W1 = 50 % to W2 = 10 %, while preserving the color of wood obtained by the steaming process. The drying process is divided into two parts. Evaporation of free water from wet wood at drying medium temperatures td = 35 - 40 °C and evaporation of water from wood below the hygroscopicity limit W ≤ 25 % at drying medium temperatures td = 70 - 80 °C. Total color difference ΔE* determined by the difference in values on the CIE L*a*b* color space coordinates dried by the proposed mode for steaming maple timber and the reference values ΔE* = 1.03. According to the categorization of wood color changes in thermal processes by work (Cividini et al. (2007), this change belongs to the category of small color changes. A negative aspect of this drying mode is the approx. 25 % increase in timber drying time.

scholarly journals Tooth discoloration induced by apical plugs with hydraulic calcium silicate-based cements in teeth with open apices—a 2-year in vitro study

2021 ◽  
Author(s):  
Ralf Krug ◽  
C. Ortmann ◽  
S. Reich ◽  
B. Hahn ◽  
G. Krastl ◽  
...  
Keyword(s):  
Calcium Silicate ◽  
In Vitro Study ◽  
Color Difference ◽  
Blood Contamination ◽  
Tooth Color ◽  
Color Changes ◽  
Gutta Percha ◽  
Tooth Discoloration ◽  
Post Hoc

Abstract Objectives To assess tooth discoloration induced by different hydraulic calcium silicate-based cements (HCSCs), including effects of blood and placement method. Materials and methods Eighty bovine teeth cut to a length of 18 mm (crown 8 mm, root 10 mm) were randomly assigned to 10 groups (n = 8), receiving orthograde apical plug treatment (APT). Apical plugs were 4 mm in length and made of ProRoot MTA (Dentsply), Medcem MTA (Medcem), TotalFill BC RRM Fast Set Putty (Brasseler), or Medcem Medical Portland Cement (Medcem) plus bismuth oxide (Bi2O3) with and without bovine blood. Further, orthograde (with or without preoperative adhesive coronal dentin sealing) and retrograde APT were compared. Teeth were obturated with gutta-percha and sealer, sealed with composite and stored in distilled water. Tooth color was measured on apical plug, gutta-percha/sealer, and crown surface before treatment versus 24 h, 1, 3, 6, 12, and 24 months after treatment by spectrophotometry. Color difference (ΔE) values were calculated and analyzed by Shapiro–Wilk test, ANOVA with post hoc tests, Friedman test, t test, and post hoc tests with Bonferroni correction (α = .05). Results Tooth discoloration occurred in all groups with no significant differences between HCSCs (p > .05). After 24 months, color changes were prominent on roots but insignificant on crowns. Blood contamination induced a significantly decreased luminescence (p < .05). Blood had a stronger impact on tooth color than Bi2O3. No relevant effects of retrograde placement (p > .05) or preoperative dentin sealing (p > .05) were detected. Conclusions Apical plugs of the tested HCSCs cause discoloration of bovine roots, but not discoloration of bovine tooth crowns within a 24-month period. Clinical relevance APT should be performed carefully while avoiding direct contact with the coronal dentin, and in that case no aesthetic impairments occur.

scholarly journals Quality stability and sensory attributes of apple juice processed by thermosonication, pulsed electric field and thermal processing

2016 ◽  
Vol 23 (3) ◽  
pp. 265-276 ◽  
Author(s):  
Alifdalino Sulaiman ◽  
Mohammed Farid ◽  
Filipa VM Silva
Keyword(s):  
Antioxidant Activity ◽  
Electric Field ◽  
Sensory Analysis ◽  
Thermal Processing ◽  
Apple Juice ◽  
Treatment Time ◽  
Pulsed Electric Field ◽  
Color Difference ◽  
Soluble Solids ◽  
Total Color Difference

Worldwide, apple juice is the second most popular juice, after orange juice. It is susceptible to enzymatic browning spoilage by polyphenoloxidase, an endogenous enzyme. In this study, Royal Gala apple juice was treated by thermosonication (TS: 1.3 W/mL, 58 ℃, 10 min), pulsed electric field (PEF: 24.8 kV/cm, 60 pulses, 169 µs treatment time, 53.8 ℃) and heat (75 ℃, 20 min) and stored at 3.0 ℃ and 20.0 ℃ for 30 days. A sensory analysis was carried out after processing. The polyphenoloxidase activity, antioxidant activity and total color difference of the apple juice were determined before and after processing and during storage. The sensory analysis revealed that thermosonication and pulsed electric field juices tasted differently from the thermally treated juice. Apart from the pulsed electric field apple juice stored at room temperature, the processed juice was stable during storage, since the pH and soluble solids remained constant and fermentation was not observed. Polyphenoloxidase did not reactivate during storage. Along storage, the juices’ antioxidant activity decreased and total color difference increased (up to 6.8). While the antioxidant activity increased from 86 to 103% with thermosonication and was retained after pulsed electric field, thermal processing reduced it to 67%. The processing increased the total color difference slightly. No differences in the total color difference of the juices processed by the three methods were registered after storage. Thermosonication and pulsed electric field could possibly be a better alternative to thermal preservation of apple juice, but refrigerated storage is recommended for pulsed electric field apple juice.

scholarly journals The efficacy of different seed priming agents for promoting sorghum germination under salt stress

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245505
Author(s):  
Xiaofei Chen ◽  
Ruidong Zhang ◽  
Yifan Xing ◽  
Bing Jiang ◽  
Bang Li ◽  
...  
Keyword(s):  
Salt Stress ◽  
Seed Germination ◽  
Germination Rate ◽  
Principal Component ◽  
Dry Weight ◽  
Seed Priming ◽  
Nacl Stress ◽  
Future Research ◽  
Fresh Weight ◽  
Positive Effects

Sorghum [Sorghum bicolor (L.) Moench] seed germination is sensitive to salinity, and seed priming is an effective method for alleviating the negative effects of salt stress on seed germination. However, few studies have compared the effects of different priming agents on sorghum germination under salt stress. In this study, we quantified the effects of priming with distilled water (HP), sodium chloride (NaCl), potassium chloride (KCl), calcium chloride (CaCl2), and polyethylene glycol (PEG) on sorghum seed germination under 150 mM NaCl stress. The germination potential, germination rate, germination index, vigor index, root length, shoot length, root fresh weight, shoot fresh weight, root dry weight, and shoot dry weight were significantly reduced by salt stress. Different priming treatments alleviated the germination inhibition caused by salt stress to varying degrees, and 50 mM CaCl2 was the most effective treatment. In addition, the mitigation effect of priming was stronger on root traits than on shoot traits. Mitigation efficacy was closely related to both the type of agent and the concentration of the solution. Principal component analysis showed that all concentrations of CaCl2 had higher scores and were clearly distinguished from other treatments based on their positive effects on all germination traits. The effects of the other agents varied with concentration. The priming treatments were divided into three categories based on their priming efficacy, and the 50, 100, and 150 mM CaCl2 treatments were placed in the first category. The 150 mM KCl, 10% PEG, HP, 150 mM NaCl, 30% PEG, and 50 mM KCl treatments were placed in the second category, and the 100 mM NaCl, 100 mM KCl, 20% PEG, and 50 mM NaCl treatments were least effective and were placed in the third category. Choosing appropriate priming agents and methods for future research and applications can ensure that crop seeds germinate healthily under saline conditions.

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