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Purpose: Aging causes substantial changes in the intraocular lens, which leads to a reduction in chromatic perception. We aimed to measure the ocular light dispersion component in relation to the reduction in color vision by aging. Methods: Intraocular straylight was quantified psychophysically by C-Quant for light dispersion [Log(s)], reliability of the results (ESD), and psychometric sampling quality (Q). The Cambridge Color Test Trivector protocol measured the chromaticity thresholds for protan, deutan, and tritan color confusion axis in CIE 1976 u' v' units. We tested 224 subjects aged 24-68 years (106 men) with normal best-corrected visual acuity and without clinical evidence of cataracts. Results: A significant positive correlation was found between ocular dispersion of light and chromaticity thresholds for protan (r = 0.42; p < 0.001), deutan (r = 0.49; p < 0.001) and tritan (r = 0.51; p < 0.0001) color confusion axes with a moderate effect size (η2 = 0.39). However, a weak contribution of the logarithm of the straylight in predicting the chromaticity threshold for protan (b = 0.15; p = 0.025), deutan (b = 0.27; p = 0.001) and tritan (b = 0.21; p = 0.001) color confusion axes was verified in the regression coefficients. The other two measurement quality parameters estimated in the C-Quant were not correlated with chromaticity thresholds, suggesting that there are no problems with the quality of the measurement performed. Conclusion: An increase in ocular light dispersion that occurs physiologically with aging negatively impacts the chromaticity threshold in a similar manner across all three color confusion axes. The weak regression effects suggest that neural rather than optical processes were more related to the reduction in chromaticity in aging.

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The azo dyes, Yellow 5 (Y5), Red 2 (R2) and Blue 1 (B1), quantified in solutions and in mixtures of binary dyes, were studied by means of UV-Vis spectroscopy. In this work was used a CIE algorithm developed in Visual Basic for Applications (VBA). The CIE algorithm is based on the tristimulus chromaticity diagram, as an alternative to the shielding effect that arises in dye mixtures, and it can also be applied to complex quantification methods such as HPLC (High Performance Liquid Chromatography). The results obtained through of the algorithm, showed a higher accuracy from 97 to 99% in relation with similar UV-Vis quantification methods. In contrast, linear methods only managed to reach an accuracy from 78 to 98%. Additionally, the algorithm yielded significant similar values to the UHPLC reference method. The results showed that the method CIE algorithm was accessible and reliable to quantify binary mixtures of the dyes used which suggests the possibility to apply this method on other dyes, within the limits of quantification obtained in this study (0.076-24.56 mg/L) and the pH values from 2 to 10.

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BACKGROUND: The presence of quinolizidine alkaloids (QAs) in the species Lupinus mutabilis Sweet limits the expansion of its consumption and use, despite its high protein content. The objective of this research was therefore to determine the effect of two thermal treatments, aqueous (ATT) and saline (STT), on the QAs and total protein content, as well as on the texture (fracturability and hardness), visual perception attributes - hue (H*), luminosity (L*) and chromatism (C*) - and grain size in three lupin varieties (INIAP-450, INIAP-451, and Criollo). The water consumption required by each treatment was also measured. RESULTS: The debittering process with ATT helped to concentrate the total nitrogen by 560 g kg-1 and decreased the grain hardness to 2037 gf (grams of force) in the Criollo variety, while the chromatic parameters H* and C* increased in the three varieties. The STT treatment was more efficient than the ATT treatment in terms of the time required and the volume of water used to reduce the QAs to safe levels for consumption (2.5-3.5 g kg-1 ). The size of the grain increased to four times its original size; the luminosity L* decreased during cooking to a value of 41.49 in the Criollo variety and then increased to 57.42 during grain washing. CONCLUSIONS: The STT treatment is advisable for lupin debittering, although the extent of the effect was dependent on the variety. © 2020 Society of Chemical Industry.

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INTRODUCTION: The purpose of this study was to measure luminance contrast sensitivity and color vision thresholdfs in normal subjects using a blue light filter lens and transparent intraocular lens material. METHODS: Monocular luminance grating contrast sensitivity was measured with Psycho for Windows (version 2.36; Cambridge Research Systems) at 3.0, 6.0, 12.0, 20.0, and 30.0 cycles per degree of visual angle (cpd) in 15 normal subjects (eight female), with a mean age of 21.6 years (SD = 3.8 years). Chromatic discrimination was assessed with the Cambridge colour test (CCT) along the protan, deutan, and tritan color confusion axes. Both tests were performed in a darkened room under two situations: with a transparent lens and with blue light filter lens. Subjective impressions were taken by subjects regarding their visual experience under both conditions. RESULTS: No difference was found between the luminance contrast sensitivity measured with transparent and blue light filter. However, 13/15 (87%) of the subjects reported more comfortable vision with the blue filter. In the color vision test, tritan thresholds were significantly higher for the blue filter compared with the transparent filter (p = 0.003). For protan and deutan thresholds no differences were found. CONCLUSION: Blue-yellow color vision is impaired with the blue light filter, and no impairment occurs with the transparent filter. No significant differences in thresholds were found in the luminance contrast sensitivity comparing the blue light and transparent filters. The impact of short wavelength light filtering on intrinsically photosensitive retinal ganglion cells is also discussed.

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Introducción. La vitamina C es conocida por sus propiedades antioxidantes, y el color superficial es un importante atributo sensorial que incide en la compra final del consumidor. Objetivo. Determinar el efecto de los tratamientos térmicos sobre la concentración de vitamina C y el color superficial en guayaba (psidium guajava), mango (mangifera indica) y tomate de árbol (Solanum Betaceum Cav). Materiales y métodos. 120 g de muestras cortados homogéneamente en triplicado se sometieron a los tratamientos de cocción con agua (92 °C durante 10 minutos), vapor saturado (92 °C durante 10 minutos), microonda (760 W durante dos minutos), y horno (250 °C durante 10 minutos); finalizado el tratamiento de calor las muestras se enfriaron rápidamente y se procedió a determinar los propiedades fisicoquímicas de pH, acidez, sólidos solubles, concentración de vitamina C, y las coordenadas colorimétricas CIE L*a*b*. Resultados. Después de los tratamientos térmicos, el método de calor con horno registró la mayor reducción de vitamina C en los frutos de guayaba mientras que la cocción con vapor y microonda no afectó la concentración inicial de este micronutriente. Por otra parte los tratamientos de calor no afectaron el color superficial de los frutos de mango; por el contrario, en guayaba se reduce significativamente el valor de L*, y en tomate de árbol todas las variables de color son afectadas significativamente. Conclusión. El método de cocción con microonda fue el tratamiento que menos afectó la concentración final de la vitamina C en las muestras analizadas.

Introduction. Vitamin C is known for its antioxidant properties and the surface color is an important sensory attribute that affects their purchase by the final consumer. Objective. To determine the effect of thermal treatments on the concentration of vitamin C and the surface color in guava (Psidium guajava), mango (Mangifera indica) and tree tomatoes (Solanum Betaceum Cav). Materials and methods. 120 g of samples in triplicate and homogeneously cut, underwent baking treatments with water (92 ° C for 10 minutes), saturated steam (92 ° C for 10 minutes), microwave (760 W for two minutes) and oven (250 ° C for 10 minutes). Once the heat treatment was completed, the samples were cooled rapidly and the physicochemical properties of pH, acidity, soluble solids, vitamin C concentration and CIELab colorimetric coordinates were determined. Results. After the thermal treatments were performed, the oven heat method registered the largest vitamin C reduction in the guavas, while the cooking with steam and microwave did not affect the original concentration of this micronutrient. On the other hand, the heat treatments did not affect the superficial color of the mangos. In guavas the value of L*, was significantly reduced and in tree tomatoes all of the color variables were significantly affected. Conclusion. The method microwave cooking was the treatment less affected the final concentration of vitamin.

Introdução. A vitamina C é conhecida por suas propriedades antioxidantes, e a cor superficial é um importante atributo sensorial que incide na compra final do consumidor. Objetivo. Determinar o efeito dos tratamentos térmicos sobre a concentração de vitamina C e a cor superficial na goiaba (Psidium guajava), manga (Mangifera indica) e tomate de árvore ou Tamarilho (Solanum Betaceum Cav). Materiais e métodos. 120 g de amostras cortados homogeneamente em triplicado se submeteram aos tratamentos de cocção com água (92 °C durante 10 minutos), vapor saturado (92 °C durante 10 minutos), microonda (760 W durante dois minutos), e forno (250 °C durante 10 minutos); finalizado o tratamento de calor as amostras se enfriaram rapidamente e se procedeu a determinar os propriedades físico-químicas de pH, acidez, sólidos solúveis, concentração de vitamina C, e as coordenadas colorimétricas CIElab. Resultados. Depois dos tratamentos térmicos, o método de calor com forno registrou a maior redução de vitamina C nos frutos de goiaba enquanto que a cocção com vapor e microonda não afetou a concentração inicial deste micronutriente. Por outra parte os tratamentos de calor não afetaram a cor superficial dos frutos de manga; pelo contrário, na goiaba se reduz significativamente o valor de L*, e no tomate de árvore todas as variáveis de cor são afetadas significativamente. Conclusão. O método de cocção com microonda foi o tratamento que menos afetou a concentração final da vitamina C nas amostras analisadas.

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In congenital color blindness the red-green discrimination is impaired resulting in an increased confusion between those colors with yellow. Our post-receptoral physiological mechanisms are organized in two pathways for color perception, a red-green (protanopic and deuteranopic) and a blue-yellow (tritanopic). We argue that the discrimination losses in the yellow area in congenital color vision deficiency subjects could generate a subtle loss of discriminability in the tritanopic channel considering discrepancies with yellow perception. We measured color discrimination thresholds for blue and yellow of tritanopic channel in congenital color deficiency subjects. Chromaticity thresholds were measured around a white background (0.1977 u', 0.4689 v' in the CIE 1976) consisting of a blue-white and white-yellow thresholds in a tritanopic color confusion line of 21 congenital colorblindness subjects (mean age = 27.7; SD = 5.6 years; 14 deuteranomalous and 7 protanomalous) and of 82 (mean age = 25.1; SD = 3.7 years) normal color vision subjects. Significant increase in the whole tritanopic axis was found for both deuteranomalous and protanomalous subjects compared to controls for the blue-white (F 2,100 = 18.80; p < 0.0001) and white-yellow (F 2,100 = 22.10; p < 0.0001) thresholds. A Principal Component Analysis (PCA) found a weighting toward to the yellow thresholds induced by deuteranomalous subjects. In conclusion, the discrimination in the tritanopic color confusion axis is significantly reduced in congenital color vision deficiency compared to normal subjects. Since yellow discrimination was impaired the balance of the blue-yellow channels is impaired justifying the increased thresholds found for blue-white discrimination. The weighting toward the yellow region of the color space with the deuteranomalous contributing to that perceptual distortion is discussed in terms of physiological mechanisms.