Digital Colorimeter Research Articles

Design and investigation of a digital photocolorimeter

In this study, a digital photocolorimeter was developed based on a detector matched with an intrinsic operational color space and a set of optical filters. The color space M2′N2′P2′ with properties similar to the curves of the CIE XYZ 1931 system was used. Software was developed for processing of black-and-white images to operate the digital colorimeter. The image processing algorithm in the CIE LAB system is explained and the experimental procedure for determining the color coordinates of samples in the M2′N2′P2′ color space using X1X2Y1Z1 detectors is described herein. The color difference between green, yellow–green, and yellow optical filters was determined for an objective assessment of the quality of the developed system. Subsequently, an analysis of the experimental values was performed, and our system exhibited satisfactory results. The possible applications of the developed photocolorimeter are also proposed.

Comparative assessment of the antimicrobial efficacy of chitosan, ethylenediaminetetraacetic acid, sodium hypochlorite and chlorhexidine against enterococcus faecalis at different irrigant temperatures: An in vitro study

Aim: To evaluate and compare the antimicrobial efficacy of Chitosan, Ethylenediaminetetraacetic acid, Sodium Hypochlorite and Chlorhexidine against Enterococcus faecalis at room temperature of the irrigant, at warm temperature (60o Celsius) of the irrigant and after intracanal heating (180o Celsius) of the irrigant. Materials and method: A total of 120 extracted single-rooted teeth were infected for 21 days with E. faecalis after instrumentation with Pro Taper system. Before irrigation procedure, dentinal shavings were collected in 1 ml of sterile broth and incubated. The optical density of each broth was measured using digital colorimeter and initial readings were recorded. Samples were then divided into five groups of 24 teeth in each group– Group A: Sodium hypochlorite irrigation, Group B: EDTA irrigation, Group C: Chitosan irrigation, Group D: Chlorhexidine irrigation, Group E: Saline irrigation. Each group was further divided into three subgroups – (I) Room temperature of irrigant (II) Warm temperature of irrigant (III) Intracanal heating of irrigant. After irrigation, dentinal shavings were collected and optical density recorded. The values were analysed statistically with Student’s t test and analysis of variance followed by Post-Hoc Bonferroni’s correction test; p-value < 0.05 was considered to be statistically significant. Results: The post irrigation optical densities in all the groups were significantly lower than pre irrigation values. Sodium hypochlorite and Chlorhexidine demonstrated better antimicrobial efficacy followed by Chitosan and EDTA, whereas the least efficacy was shown by Saline which was the control group. Differences in optical density using different irrigants were found to be higher by intracanal heating of irrigants followed by warm irrigation and room temperature irrigation (p

Zootechnical performance, biochemical response, and chromaticity in Pacific white shrimp (Litopenaeus vannamei) (Boone, 1931) after the inclusion of lyophilized açaí (Euterpe oleracea) in the diet

Functional foods have molecules that promote health benefits beyond their nutritional qualities. In this context, the zootechnical performance, color, and biochemical responses of Pacific white shrimp (Litopenaeus vannamei) fed with different levels of acai (Euterpe oleracea), a fruit with unique antioxidant characteristics, were observed. Four diets with different levels of inclusion of lyophilized acai (0.0%, 2.5%, 5.0%, and 10.0% W/W) were administered to shrimps reared in biofloc technology (BFT) systems. After 43 days, the zootechnical parameters (weight gain, feed conversion ratio, and specific growth rate) and coloration in fresh and cooked shrimps were measured, and the L*, a*, and b* parameters were estimated with a digital colorimeter. Survival and growth performances were not affected by acai inclusion in diets. Acai inclusion modulates the flavonoid content in the gills of L. vannamei and in the bioflocs of the rearing BFT system. As in the diet of 10.0% acai, performed with a total replacement of fish oil without affecting growth, we propose the use of acai as a vegetal oil source for shrimp feeding in BFT systems. Acai also induced the reddish color in fresh and cooked L. vannamei, an influential factor in their commercial value.

Основы построения цифрового спектрофотоколориметра для работы с объектами сложной формы

Основы построения цифрового спектрофотоколориметра для работы с объектами сложной формы

Measuring Human Water Needs.

Water connects the environment, culture, and biology, yet only recently has it emerged as a major focus for research in human biology. To facilitate such research, we describe methods to measure biological, environmental, and perceptual indicators of human water needs. This toolkit provides an overview of methods for assessing different dimensions of human water need, both well‐established and newly‐developed. These include: (a) markers of hydration (eg, urine specific gravity, doubly labeled water) important for measuring the impacts of water need on human biological functioning; (b) methods for measuring water quality (eg, digital colorimeter, membrane filtration) essential for understanding the health risks associated with exposure to microbiological, organic, metal, inorganic nonmental, and other contaminants; and (c) assessments of household water insecurity status that track aspects of unmet water needs (eg, inadequate water service, unaffordability, and experiences of water insecurity) that are directly relevant to human health and biology. Together, these methods can advance new research about the role of water in human biology and health, including the ways that insufficient, unsafe, or insecure water produces negative biological and health outcomes.

Associations between pigments, antioxidant activity and coloring of blackberry fruits (Rubus sp.) and jellies through storage

The objective of this study was to investigate the relations between the amount of anthocyanins, carotenoids and the antioxidant activity measured by the FRAP and TEAC methods. Furthermore, pigments and the coloration of blackberry harvested fruits were measured at 3 different collection points then fruits stored in refrigerated environment and the jelly made from them, preserved in hermetically sealed glasses, without contact with light and temperature of 25ºC. In order to investigate the relations between the study variables (content of anthocyanins and carotenoids, antioxidant activity and coloration using digital colorimeter), Pearson’s correlation analysis was adopted, which indicates the existence of a positive or negative relation between two variables. The α = 5% (correlation coefficient) was used to verify the significance of the correlation. The Mahalanobis (D2) generalized distance for the clustering analysis by the mean linkage method between group of blackberry fruits and jellies was applied. Furthermore, the cophenetic correlation coefficient and multivariate analysis using major components were applied to verify the grouping of different responses of harvesting points of fresh blackberry fruit in natura and jellies. The results showed that there was correlation between the content of anthocyanins and carotenoids in fruits (0.99*) and between the same parameters in jellies. However, this behavior was not clearly observed between the pigments and the antioxidant activity. There was a positive correlation between the factors involved in the coloring of chroma fruits ‘L’, ‘a’, ‘b’ and ºHue in fruits and jellies. Blackberry jellies presented as good sources of anthocyanins and carotenoids.

Cassava Varieties Trichome Density Influence the Infestation of Vatiga illudens (Hemiptera: Tingidae)

The objective of this study was to evaluate the infestation of Vatiga illudens in cassava varieties and to correlate its infestation with the physical and morphological parameters of resistance. The experiments were conducted in the 2014/2015 and 2016/2017 seasons, out in a randomized complete block design with nine treatments and five replicates. Nymphs and adults of V. illudens were evaluated on the abaxial surface of 16 leaves of the middle third of the plant. The density of trichomes was quantified with the use of electron micrographs, and the roughness of the epicuticular wax was assigned to the leaves of the shoot and the apical third. The color components L*, a*, b*, were measured with a portable digital colorimeter. The cultivars IAC 90 and Santa Helena demonstrated the smallest infestations in the 2014/2015 season and maintained low infestation in the 2016/2017 season. The varieties Baianinha, IAC 576-70 and Catarina-Branca, maintained high infestations in the both seasons. The density of trichomes of the middle third of the plants correlated negatively to the V. illudens infestation for the two seasons. The higher density on trichomes, negatively affects the infestation of V. illudens in cassava varieties, characterizing as a specific resistance factor to this species.

Influence of salivary PH in color stability of different flowable resins: In vitro study

Objective: To determine the color stability of two types of flow composites immersed in artificial saliva with three different pH values, using Vita Easy-shade digital colorimeter. Materials and methods : An experimental, comparative and in vitro study is proposed using 90 discs made from two fluid resin markings of 10mm diameter and 1mm thickness, light-cured using the same lamp, after being immersed in distilled water and made a first registration color using Easy-shade digital colorimeter, the samples were divided into three groups and in turn into three subgroups, becoming submerged in artificial saliva with different pH of 5, 6 and 7 respectively for 7 days, making a new color taking by digital colorimeter, later the samples were submerged in beet juice as a pigmenting agent for 24 hours, after this period they were washed to eliminate pigment residues and made a third color take. Results : Greater color change occurred in the discs that were subjected to artificial saliva with pH 5 (p = 0.000), the minor color changes occurred in the discs that were immersed in artificial saliva with pH 7. Conclusions : The pH salivary 5 or acid, caused greater change in color without significant difference between the materials tested.

Distillers dried grains with solubles from corn in diet of japanese quails

The objective of this study was to evaluate different inclusion levels of distillers dried grains with solubles (DDGS) from corn in the diet of quails. A total of 210 japanese quails (Coturnix coturnix japonica) were distributed in a completely randomized design of five treatments and six replicates, with seven quails per experimental unit. The treatments used were: control feed; inclusion of 5, 10, 15 and 20% of DDGS. The variables assessed were: feed intake, feed conversion per dozen and egg mass, egg production, egg weight, specific gravity, yolk color and economic analysis. Data were analyzed by regression model and Dunnett’s test at 5% probability. For individual feed intake, laying rate, and feed conversion per egg mass, specific gravity and yolk color by color fan, there was effect caused by inclusion of DDGS (p &lt; 0.05), but the other variables did not show significant difference. By Dunnett’s test, for feed intake, feed conversion per egg mass, specific gravity and digital colorimeter’s L parameter, there was effect (p &lt; 0.05). As for economic analysis, DDGS presented low cost. It can be concluded that DDGS can be used in feed at a 20% level without impairing the performance and quality of quails eggs.

INFLUENCE OF FOOD BY-PRODUCTS ON THE COLOR OF BAKERY PRODUCTS

The aim of this paper is to analyze the effect of replacing part of wheat flour (4, 8, 16, 24 and 32% for cookies and 4, 6, 8 and 10% for sponge cake) and to measure influence on the color of the cookies and the sponge cake with apple skin powder and grape pomace powder, respectively. The cookies were produced according to the AACC 10-50D method with some modifications, and the sponge cake was produced according to the method presented by Velioğlu et al., 2017 with some modifications. Digital image analysis and colorimeter were used to determine the colour change of the samples. Results show that by increasing food by-products (apple skin powder and grape pomace powder), the colour difference between the control sample and other samples was bigger. The colour of the sample measured by digital image analysis covers the entire sample and is more representative and more objective regarding colour measurement.

Use of a shade guide to test the perception and prevalence of natural tooth colour in people of Nepal

Background: Recent advances in colour matching have been driven by the market demand for high-quality esthetic restorations. Improved shade guides, availability of shade-taking devices and research in the area of human colour vision have improved the potential of clinicians to achieve excellent colour matched restorations. A thorough understanding of appearance attributes of natural teeth is required along with these new tools to maximize shade matching results.&#x0D; Aims and Objectives: The aim of the present investigation is to determine tooth shade among the people of Nepal.&#x0D; Materials and Methods: In the present study, shade of cervical, middle and incisal third of the facial surface of natural maxillary central incisor was measured with digital colorimeter, VITA Easy shade Advance 4.0. It is an optical reading device that can assess the wavelengths reflected back to its sensors. Lighting in operatory does not affect the shade measurement. It is extremely accurate. The limitation of study was its small sample size.&#x0D; Result: The shade obtained in the cervical third of tooth is 1M2 (37.33%), in the middle 1M1 (32.88%), and in the incisal third 2M1 (37.33%). Value 1 indicates lighter tooth colour and colour saturation is up to 2.&#x0D; Conclusion: It was concluded that the most prevalent shade in cervical third was 1M2, middle third was 1M1 and incisal third was 2M1.

Rapid Low-Cost Determination of Lead(II) in Cassava by an iPod-Based Digital Imaging Colorimeter

An iPod-based digital image colorimeter was developed for the determination of lead(II) in cassava. The method is based on the color values of a lead(II) solution following its reaction with dithizone. Lead(II) from cassava was extracted using an ultraviolet-digestion unit followed by the color-forming reaction and image capture using the ColorConc application operated on an iPod touch. The concentration was predicted by comparing the color values with those collected in a database. The time needed for complete digestion was 30 min. The determined concentrations of lead(II) were from 0.10 to 1.00 µg mL−1. The limits of detection and quantitation were 0.0120 and 0.0399 µg mL−1, respectively. The recovery values were 105 ± 7.07% and 109 ± 6.61% at 0.2 µg mL−1 and 0.4 µg mL−1 lead(II) (n = 5). The reported method was demonstrated to be simple, accurate, rapid, precise, and low cost.

Effect of whitening toothpaste on the discoloration level of stained conventional glass ionomer cement

Staining is not unique to natural enamel and may also occur on the restorative material, such as conventional glass ionomer cement (GIC). This study identified the effect of whitening toothpaste on the discoloration level of conventional GIC. In total, 24 GIC specimens were immersed in coffee and then brushed with one of the four commercially available. The specimens were brushed for various durations (1, 2, and 4 weeks), and changes in discoloration were assessed using a digital colorimeter (VITA Easy Shade). Significant changes (p<0.05) in brightness were observed after the first and fourth week of brushing. However, not all toothpaste caused significant color changes. This study provides evidence that some whitening toothpaste can decrease the discoloration level of stained conventional GIC.

Demonstration of physical phenomenas and scavenging activity from d-psicose and methionine maillard reaction products

Maillard reaction has been well understood as a non-enzymatic reaction between reducing sugars and amino acids to generate the Maillard reaction products (MRPs). This study is aimed to demonstrate the browning intensity, color development, spectra measurements, scavenging activity, and the correlation between browning intensity and scavenging activity of the MRPs generated from D-Psicose and Methionine (Psi-Met) at 50℃. The browning intensity of MRPs was investigated based on the absorbance using spectrophotometer at 420 nm, the color development was observed using digital colorimeter to gained L*a*b* value then calculated as browning index, the spectra development was analyzed using spectrophotometer at 190 - 750 nm, and the scavenging activity was determined with ABTS method using spectrophotometer at 734 nm. The browning intensity, color development, and scavenging activity were improved along with the increase in heating process. Based on spectra analysis, MRPs from Psi-Met was initially detected at 21 h and Psi at 24 h of heating treatment, which indicating that Psi-Met have faster and better reaction than Psi during heating process. Positive non-linear and significant correlation between browning intensity and scavenging activity were assigned. This finding may provide beneficial information of D-psicose and MRPs to the next scientific research and to the food industries which applies MRPs in their products.

Comparative Evaluation of Antimicrobial Efficacy of Neem, Miswak, Propolis, and Sodium Hypochlorite against Enterococcus faecalis using EndoVac

ABSTRACTAimTo compare the antimicrobial efficacy of herbal irrigants neem, miswak, propolis with sodium hypochlorite using conventional needle irrigation and EndoVac irrigation system againstEnterococcus faecalis.Materials and methodsA total of 120 extracted single-rooted mandibular premolar teeth were infected for 21 days withE. faecalisafter instrumentation with ProTaper system. Before irrigation procedure, dentinal shavings were collected in 1 mL of sterile broth and incubated. The optical density of each broth was measured using digital colorimeter and initial readings were recorded. Samples were then divided into four groups of 30 teeth each – Group I: Sodium hypochlorite irrigation, group II: Neem irrigation, group III: Miswak irrigation, group IV: propolis irrigation. Each group was further divided into two subgroups – (a) EndoVac irrigation (b) conventional needle irrigation. After irrigation, dentinal shavings were collected and optical density recorded. The values were analyzed statistically with Student's t test and analysis of variance followed by Tukey's honest significant difference test; p-value &lt; 0.05 was considered to be statistically significant.ResultsThe postirrigation optical densities in all the groups were significantly lower than preirrigation values. Sodium hypochlorite demonstrated better antimicrobial efficacy followed by propolis, neem, and miswak. Differences in optical density values for all irrigants are higher in EndoVac (p &lt; 0.0001) compared with needle (p = 0.0009) group, but it failed to reach statistical significance.ConclusionSodium hypochlorite proved to be a better irrigant followed by propolis, neem, and miswak. EndoVac irrigation system was more effective for elimination ofE. faecalisthan needle irrigation group.How to cite this articleDaga P, Asrani H, Farista S, Mishra P. Comparative Evaluation of Antimicrobial Efficacy of Neem, Miswak, Propolis, and Sodium Hypochlorite againstEnterococcus faecalisusing EndoVac. Int J Prosthodont Restor Dent 2017;7(2):60-65.

The prevalence of natural tooth colors in the people of North India

Aims and Objectives: Tooth color is a major factor with regard to dental esthetics. Restorative dentistry has evolved from its previous dentist driven to patient driven service and patient opinion plays an important role in selecting the treatment plan. Whitening teeth and smile designing for esthetic purpose is currently fashionable. Selection of appropriate tooth shade for edentulous patients is an important part of teeth replacement. Most patients prefer having lighter shades. However ultimate objective of esthetic dentistry is to create a beautiful smile, with teeth of pleasing inherent proportions to one another and color in harmony with gingiva, lips and face of the patient. Proper shade selection has a positive impact on the patient's acceptance of the treatment. The present study was designed to measure the tooth colors in a particular age group of North Indian population. There is enough data to support the use of objective methods of measuring shade and dentists are shifting to these newer technologies but subjective methods of shade selection are still popular as the digital devices are expensive. Materials and Methods: In the present study, shade of cervical, middle and incisal third of the facial surface of natural maxillary central incisor was measured with digital colorimeter, VITA Easyshade® Advance 4.0. It is an optical reading device that can assess the wavelengths reflected back to its sensors. Lighting in operatory does not affect the shade measurement. It is extremely accurate. The limitation of study was its small sample size. Conclusion: It was concluded that the most prevalent shade in cervical third was 1M2, middle third was 1M1 and incisal third was 2M1.

A Study on Possibility of Clinical Application for Color Measurements of Shade Guides Using an Intraoral Digital Scanner.

To assess if color measurement with intraoral scanner correlates with digital colorimeter and to evaluate the possibility of application of a digital scanner for shade selection. The L*a*b* values of the five shade tabs (A1, A2, A3, A3.5, and A4) were obtained with an intraoral scanner (TRIOS Pod) and a colorimeter (ShadeEye). Both devices were calibrated according to the manufacturer's instructions before measurements. Color measurement values were compared with paired t-test, and a Pearson's correlation analysis was performed to evaluate the relationship of two methods. The L*a*b* values of the colorimeter were significantly different from those of the digital scanner (p < 0.001). The L* and b* values of both methods were strongly correlated with each other (both p < 0.05). The device repeatability in both methods were reported to be excellent (p < 0.05). Within the limitations of this study, color measurements with digital intraoral scanners and computer-assisted image analysis were in accordance with those of the colorimeter with respect to L* and b* values; however, all the coordinates of shade tabs were significantly different between two methods. The digital intraoral scanner may not be used as the primary method of color selection in clinical practices, considering significant differences in color parameters with colorimeter. The scanner's capability in shade selection should be further evaluated.

Estimating chlorophyll content from Eucalyptus dunnii leaves by reflectance values

This study aimed to estimate photosynthetic pigments contents from leaves of Eucalyptus dunni Maiden based on values of reflectance spectra of red, green and blue colors obtained with a digital color analyzer. We collected fifty leaves from the lower third of the crown of twenty trees including young as well as mature leaves. From each leaf an area of 14 cm2 of the leaf blade was cut in which we measured reflectance values on the red, green and blue spectra with a portable digital colorimeter, obtained relative index of chlorophyll with a SPAD – 502 and determined the content of the chlorophyll a, b, and a + b by classic method of solvent extraction. We submitted the data to multiple linear regression and nonlinear analysis at 5% of error probability. It was evaluated the occurrence of multicollinearity. The negative exponential model resulted in good fit when data from red spectrum was used for chlorophyll a, green spectrum for chlorophyll b and a + b, making possible correlation coefficients between the estimated values and the extracted above 0.85. Except for the chlorophyll a content, the accuracy in estimates of photosynthetic pigments were higher than estimated by the chlorophyll meter, even with linearity between methods. Therefore, it is possible to estimate photosynthetic pigments on E. dunni leaves through values of red and green wavelengths from a digital color analyser.

Physiological maturity of seeds and colorimetry of the fruits of Allophylus edulis [(A. St.-Hil., A. Juss. &amp; Cambess.) Hieron. ex Niederl.

Abstract This study aimed to determine the physiological maturity of A. edulis seeds, check if this is achieved in the same maturation stage, regardless of the collection region and, colorimetry of the fruit can be indicative of the time of harvest. Fruits were harvested in three counties of the western region of Paraná and visually classified into five ripening stages according to the color of the pericarp with the help of a digital colorimeter. Analyzed seed variables included morphological characteristics, germination and vigor. The experiment was conducted in a completely randomized design with four replications. The maximum dry matter accumulation of seeds was reached when the fruits reached the color orange. With the advance of the ripening process, red color fruits had seeds with lesser moisture content, coinciding with the maximum germination percentage and speed, besides generating seedlings with larger size and biomass accumulation. The green spectrum allowed to discriminate maturity from different places of harvest. A. edulis seeds with physiological maturity should be harvested when fruits present the red color, independent of the harvesting region or, with reflectance values between 28.0 and 49.2 nm in the green range of the color spectrum.

Effec t of Freeze-Thaw Cycles on Lipid Oxidation and Myowater in Broiler Chickens

The present study was carried out to investigate the influence of freezing-thawing cycles (0, 2, 4 and 6) on lipid oxidation and myowater contents and distribution. Nine replicates of chicken breast meat samples were used for each cycle. Lipid oxidation was determined by measuring peroxide value, and malondialdehyde (MDA) concentrations, which reflect thiobarbituric acid reactive substance (TBARS). Color was determined with a digital colorimeter. Muscle moisture contents were determined by drip loss and thawing loss, water holding capacity, and nuclear magnetic resonance (NMR). The results showed that, as the number of freeze-thaw cycles increased, meat redness decreased and MDA and peroxide values increased. Drip loss and thawing loss tended to decreasing as the number of freeze-thaw cycles increased. Water holding capacity also decreased as a function of increasing freeze-thaw cycles. NMR relaxometry profile showed freeze-thaw cycles change the water distribution of meat subjected to multiple freeze-thaw cycles. In conclusion, multiple freezing and thawing rate (6 cycles) increased lipid oxidation, decreased myowater, and impaired the color of chicken meat.