Assessment of spoilage potential posed by Alicyclobacillus spp. in plant-based dairy beverages mixed with fruit juices during storage

The scope of the present study was to assess the spoilage potential of different Alicyclobacillus spp. in commercial pasteurized (ambient-stable) plant-based dairy beverages mixed with fruit juices at different inoculation levels and storage temperatures. Different products (Coconut and Berry‒CB; Almond, Mango, and Passionfruit‒AMP; Oat, Strawberry, and Banana‒OSB) were inoculated with 10 or 2x103 spores/mL of either Alicyclobacillus acidoterrestris or A. fastidiosus or A. acidocaldarius strain composites, while non‒inoculated samples served as controls. Samples inoculated with A. acidoterrestris and A. fastidiosus were stored at 30°C and 45°C, while in case of A. acidocaldarius storage took place at 50°C for 240 days. Gas composition, Alicyclobacillus spp. populations, total viable counts, pH, aw, color, and guaiacol off-taste were monitored. CB and AMP supported growth of A. acidoterrestris and A. fastidiosus, reaching populations of 4.0‒5.0 log CFU/mL. In OSB, populations of the latter species remained close to the initial inoculation levels during storage at 30°C, while at 45°C, the populations declined <1 CFU/mL. A. acidocaldarius growth was supported only in CB samples, reaching ca. 3.0 log CFU/mL at 50°C, regardless of initial inoculum size. Total color change was increased during storage, however the instrumentally recorded color changes were not macroscopically visible. Spoilage in terms of guaiacol off-taste, was identified only in CB and AMP samples inoculated with A. acidoterrestris after 60 days at 30°C and 45°C. Considering that these products are becoming increasingly popular and the scarcity of existing literature related to their spoilage by Alicyclobacillus spp., the contribution of the findings and data of present study are critical for assessing the significance of Alicyclobacillus spp. as a potential spoilage hazard in these products and thus, to assist in the design and implementation of effective mitigation strategies by the beverage industry.

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Changes of quality of rennets during storing

Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis ◽

10.11118/actaun201260060189 ◽

2012 ◽

Vol 60 (6) ◽

pp. 189-196

Author(s):

Monika Kozelková ◽

Miroslav Jůzl ◽

Táňa Lužová ◽

Květoslava Šustová ◽

Aneta Bubeníčková

Keyword(s):

Near Infrared ◽

Color Change ◽

Coagulation Time ◽

Time Activity ◽

Spectrophotometric Methods ◽

Color Changes ◽

Rennet Coagulation ◽

Total Color Change ◽

Instrumental Methods

This work deals about evaluation of qualitative parameters of rennets. During the six months storing of rennets were determined following qualitative parameters: pH, rennet coagulation time, activity (strange) of rennet and dose of rennet, and finally were used instrumental methods: Near infrared spectroscopy (NIR) for recognizing age of rennets and spectrophotometric methods of determining the color of rennets. The theory found in the references suggests, that the activity of rennet should decrease by an average of 1–2 % per month, but the results are showing, that are changing quality of rennets namely mostly activity (strange) of rennet, which was decreased by 33% per half year. In analysis of color of rennets weren’t observed major changes by the whole group. Some statistical differences were detected in the partial values L*a*b*, most advantageous were evaluation by rennet total color change during storage, which were higher than noticeable change in four samples. The least color changes (P > 0.05) were observed in microbial rennets, with no values observed (ΔEab < 2) that can be recognized even by the human eye when subjected to parallel comparison. It was found that the NIR analysis can be used to recognizing of rennets, which are different ages.

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Assessment of changes in color and color parameters of light-cured composite resin after alternative polymerization methods

European Journal of Dentistry ◽

10.1055/s-0039-1699004 ◽

2013 ◽

Vol 07 (01) ◽

pp. 110-116 ◽

Cited By ~ 4

Author(s):

Emine Sirin Karaarslan ◽

Bulbul Mehmet ◽

Ertas Ertan ◽

Mehmet Ata Cebe ◽

Aslihan Usumez

Keyword(s):

Composite Resin ◽

Color Change ◽

Color Difference ◽

Study Groups ◽

Color Parameters ◽

Color Changes ◽

Yellow Color ◽

Before And After ◽

Total Color Change

ABSTRACTObjective:To examine the amount of change in color and color parameters of a composite resin (Filtek P60) polymerized by five different polymerization methods.Methods: A Teflon mold (6mm in diameter, 2mm in height) was used to prepare the composite resin discs (n=10). G1: Polymerization with inlay oven; G2: Polymerization with HQTH and autoclave; G3: Polymerization with LED and autoclave; G4: Polymerization with HQTH; G5: Polymerization with LED. Colorimetric values of the specimens before and after polymerization were measured using a spectrophotometer. The CIE L*a*b color system was used for the determination of color difference. Analysis of variance (ANOVA) was used to analyze the data for significant differences. Tukey’s HSD test and paired two-tailed tests were used to perform multiple comparisons (α=.05).Results: There were no significant differences in total color change (ΔE*ab) among the polymerization groups (P>.05). However, the lowest color change (ΔE*ab) value was 3.3 in LED and autoclave; the highest color change (ΔE*ab) value was 4.6 in HQTH. For all groups, CIE L*, C*ab and a*values decreased after polymerization (P<.05). The highest Δb* and ΔC*ab values were observed in specimens polymerized in an inlay oven (P<.05).Conclusion: Composite resin material showed color changes above the clinically accepted value in all study groups (ΔE*ab≥3.3). All specimens became darker during investigation (ΔL*< 0). Specimens polymerized with inlay oven presented the highest Δb* values which means less yellow color in specimens. (Eur J Dent 2013;7:110-116)

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Color stability of esthetic coatings applied to nickel-titanium archwires

Revista de Odontologia da UNESP ◽

10.1590/1807-2577.02317 ◽

2017 ◽

Vol 46 (5) ◽

pp. 307-311

Author(s):

Marcus Vinicius Neiva Nunes do REGO ◽

Geórgia Wain Thi LAU ◽

Yago Carneiro ARAÚJO ◽

Rayssa Melo e SILVA

Keyword(s):

Epoxy Resin ◽

Color Change ◽

Color Stability ◽

Surface Characteristics ◽

Nickel Titanium ◽

Staining Solution ◽

Color Changes ◽

Significant Difference ◽

Total Color Change ◽

Coating Type

Abstract Introduction Color stability is an important feature to be considered when using esthetic coated archwires. Objective To evaluate color changes on the surface of esthetic nickel-titanium archwires coated with Teflon (Ortho Organizers, USA) or epoxy resin (Tecnident, Brazil) after immersion in staining solution. Material and method Twelve 20-mm-long wire segments were used for each type of coating, which were mounted as two test specimens with a width of 7 mm each. The buccal surface of the archwires was evaluated for fluorescence and color measurements both at baseline and after immersion in a staining solution for 21 days using the VITA Easyshade® Compact spectrophotometer (Model DEASYC220). Differences in total color change according to coating type were compared using an independent samples t-test (p<0.05). The surface characteristics of as-received coated archwires were assessed using scanning electron microscopy. Result Color changes were observed on the esthetic coatings, with a significant difference between the two brands analyzed. Surface analysis revealed flaws such as wear, pitting, elevations, lack of material, granulation, grooves, cracks, and lack of standardization in the coating process in all as-received archwires, but flaws were less evident in epoxy-resin coatings. Conclusion The two esthetic coatings did not show color stability, but Teflon coatings showed a more intense color change than epoxy-resin coatings.

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The Effects of Natural Weathering on Color Stability of Impregnated and Varnished Wood Materials

Advances in Materials Science and Engineering ◽

10.1155/2015/526570 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 7

Author(s):

Turkay Turkoglu ◽

Ergun Baysal ◽

Hilmi Toker

Keyword(s):

Scots Pine ◽

Color Change ◽

Color Stability ◽

The Other ◽

Natural Weathering ◽

Color Changes ◽

Oriental Beech ◽

Total Color Change ◽

Dark Color ◽

Copper Arsenate

The aim of this study was to investigate effects of natural weathering on color stability of Scots pine (Pinus sylvestrisL.) and Oriental beech (Fagus orientalisL.) impregnated with some chemicals [tanalith-E (TN-E), adolit-KD5 (AD-KD5), and chromated copper arsenate (CCA)] and then varnished [synthetic varnish (SV) and polyurethane varnish (PV)]. While applying varnish increased lightness, impregnation decreased lightness of the wood specimens before natural weathering. Natural weathering caused greenish, bluish, and dark color tones of the wood surface. Total color change was increased with increasing exposure times in natural weathering. Untreated (control) wood specimens exhibited higher color changes than the other wood specimens in all the stages of natural weathering. The total color changes of untreated Oriental beech specimens were less than untreated Scots pine specimens. The color stability of impregnated and varnished wood specimens gave better results than untreated and solely varnished wood specimens after natural weathering. The best color stability was obtained from both Oriental beech and Scots pine wood impregnated with TN-E before PV coating.

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Color changes of esthetic elastomeric ligatures evaluated with the Commission Internationale d'Éclairage color system

European Journal of Dentistry ◽

10.4103/ejd.ejd_355_17 ◽

2018 ◽

Vol 12 (03) ◽

pp. 428-433

Author(s):

Vanessa Dias da Silva ◽

Caroline Dias ◽

Leandro Berni Osório ◽

Paulo Ricardo Baccarin Matje ◽

Luciane Macedo de Menezes ◽

...

Keyword(s):

Statistical Difference ◽

Color Change ◽

Multiple Comparisons ◽

Color Changes ◽

Color Differences ◽

Color System ◽

Total Color Change ◽

Cie Color System ◽

Spearman’S Correlation

ABSTRACT Objective: The aim of this study was to assess and compare color changes in esthetic elastomeric ligatures after 30 days in situ using a spectrophotometer and the Commission Internationale d'Éclairage (CIE) color system. Materials and Methods: The sample comprised elastomeric ligatures of four color groups (n = 42): blue pearl (BP); colorless; white pearl (WP); and pearl. Four samples from each group were allocated in for quadrants of seven patients in a split-mouth model. Color measurements were performed with a spectrophotometer in the elastomeric ligatures as received (T0) and after 30 days in situ (T1). Variables L*, a*, and b* were compared between times (T1–T0) with Wilcoxon paired ranks; color changes were compared between groups with Kruskal–Wallis test; Dunn's test was used for multiple comparisons. Spearman's correlation was applied between CIELAB and CIEDE2000 calculations. Results: All groups showed color changes (T1–T0) in a* and b*, but only the Group BP had a change in L* (P < 0.01). Group C showed the greatest lightness decrease (ΔL = −2.49 ± 0.47) (P < 0.05), the smallest yellowing (Δb = 3.17 ± 0.88) (P < 0.05), and the smallest total color change (ΔE2000 = 3.19 ± 0.85), which had no statistical difference from Group WP (ΔE2000 = 3.36 ± 0.53). Correlation between ΔEab and ΔE2000 was moderate (r = 0.59; P < 0.01). Conclusions: Esthetic elastomeric ligatures became yellowish after 30 days in situ, and there were color differences between them.

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Color stability of an artificially aged nanofilled composite resin post-cured with different techniques

Journal of Dental Research Dental Clinics Dental Prospects ◽

10.34172/joddd.2021.010 ◽

2021 ◽

Vol 15 (1) ◽

pp. 53-58

Author(s):

Lais Sampaio Souza ◽

Tais Rocha Donato ◽

Gabriela Alves Cerqueira ◽

Andrea Nobrega Cavalcanti ◽

Paula Mathias

Keyword(s):

Composite Resin ◽

Color Change ◽

Physical And Mechanical Properties ◽

Color Stability ◽

Microwave Oven ◽

Composite Resins ◽

Distilled Water ◽

Color Analysis ◽

Color Changes ◽

Total Color Change

Background. Post-cured composite resins exhibit improvements in physical and mechanical properties due to additional polymerization conversion. However, the post-curing techniques might influence the color stability of composite resin materials. Thus, this study evaluated the color stability of a nanofilled composite resin (Filtek Z350 XT - 3M ESPE) subjected to different post-curing techniques. Methods. Sixty samples (color A2) were randomly allocated to six experimental groups (n=10): G1: photoactivation (P) (control); G2: P + microwave oven with distilled water; G3: P + microwave oven without distilled water; G4: P + conventional oven; G5: P + dry-heat sterilizer; G6: P + steam autoclave. All the groups were stored in distilled water for 60 days and immersed daily in 5 mL of a coffee solution for 3 minutes. The color readings (CIEL*a*b* system) were performed at two different time intervals, initially and after 60 days, in a reflectance spectrophotometer (UV-2600; Shimadzu). The colorimetric readings were performed using the Color Analysis software (CIEL*a*b* system). Results. Group G6 exhibited significantly low values of total color change (ΔE=13.16). The control (ΔE=15.32) and G5 (ΔE=15.49) groups exhibited intermediate values, with no difference between them. In turn, the groups in which the resin was heated in a microwave (G2 ΔE=18.55 and G3 ΔE=19.45) exhibited the most significant color changes (one-way ANOVA and Tukey test, P≤0.05). Conclusion. Steam autoclave post-polymerization increased the color stability of the nanofilled resin subjected to artificial aging and coffee immersion.

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Optimization of the effect of accelerated weathering conditions on wood surfaces via the Taguchi method

BioResources ◽

10.15376/biores.16.1.1642-1653 ◽

2021 ◽

Vol 16 (1) ◽

pp. 1642-1653

Author(s):

Rifat Kurt ◽

Ahmet Can

Keyword(s):

Taguchi Method ◽

Scots Pine ◽

Color Change ◽

Accelerated Weathering ◽

Color Changes ◽

Uv Irradiance ◽

Total Color Change ◽

Uv Lamps ◽

Wood Surfaces ◽

Cutting Direction

This study investigated the effect of accelerated weathering conditions on total color changes on Scots pine (Pinus sylvestris L.) and poplar (Populus x euroamericana) wood surfaces using the Taguchi method. The experiments, based on the L18 orthogonal array, were conducted separately for both tree species. The radial and tangential surfaces of wood specimens were subjected to an accelerated weathering process using 340 nm ultraviolet (UV) lamps and temperature conditions of 50 °C. The factors for the minimum color change were determined via the signal-to-noise (S/N) ratios of the four parameters thought to be effective on color change. These parameters were cutting direction (two levels), UV-irradiance, conditioning, and water (three levels each). The most important factor affecting the color change was then determined by analysis of variance (ANOVA) testing. The results showed that the maximum UV-irradiance (W/m2) had the largest effect on the total color change, while the cutting direction (radial and tangential) had the smallest effect. The factors that affected the total color change of the poplar and Scots pine wood specimens were the same. However, the analysis revealed that different application times had varying effects on the color change.

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Investigation of the selective color-changing mechanism of Dynastes tityus beetle (Coleoptera: Scarabaeidae)

Scientific Reports ◽

10.1038/s41598-020-80699-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jiyu Sun ◽

Wei Wu ◽

Limei Tian ◽

Wei Li ◽

Fang Zhang ◽

...

Keyword(s):

Focused Ion Beam ◽

Color Change ◽

Incidence Angle ◽

Ion Beam ◽

Three Dimensional ◽

Water Infiltration ◽

Photonic Materials ◽

Local Color ◽

Water Contact ◽

Color Changes

AbstractNot only does the Dynastes tityus beetle display a reversible color change controlled by differences in humidity, but also, the elytron scale can change color from yellow-green to deep-brown in specified shapes. The results obtained by focused ion beam-scanning electron microscopy (FIB-SEM), show that the epicuticle (EPI) is a permeable layer, and the exocuticle (EXO) is a three-dimensional photonic crystal. To investigate the mechanism of the reversible color change, experiments were conducted to determine the water contact angle, surface chemical composition, and optical reflectance, and the reflective spectrum was simulated. The water on the surface began to permeate into the elytron via the surface elemental composition and channels in the EPI. A structural unit (SU) in the EXO allows local color changes in varied shapes. The reflectance of both yellow-green and deep-brown elytra increases as the incidence angle increases from 0° to 60°. The microstructure and changes in the refractive index are the main factors that influence the process of reversible color change. According to the simulation, the lower reflectance causing the color change to deep-brown results from water infiltration, which increases light absorption. Meanwhile, the waxy layer has no effect on the reflection of light. This study lays the foundation to manufacture engineered photonic materials that undergo controllable changes in iridescent color.

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Characterization of Food Packaging Films with Blackcurrant Fruit Waste as a Source of Antioxidant and Color Sensing Intelligent Material

Molecules ◽

10.3390/molecules26092569 ◽

2021 ◽

Vol 26 (9) ◽

pp. 2569

Author(s):

Mia Kurek ◽

Nasreddine Benbettaieb ◽

Mario Ščetar ◽

Eliot Chaudy ◽

Maja Repajić ◽

...

Keyword(s):

Food Packaging ◽

Water Solubility ◽

Color Change ◽

Chitosan Film ◽

Water Vapor Permeability ◽

Vapor Permeability ◽

Color Changes ◽

Insoluble Particles ◽

Polymer Stability ◽

Food Packaging Films

Chitosan and pectin films were enriched with blackcurrant pomace powder (10 and 20% (w/w)), as bio-based material, to minimize food production losses and to increase the functional properties of produced films aimed at food coatings and wrappers. Water vapor permeability of active films increased up to 25%, moisture content for 27% in pectin-based ones, but water solubility was not significantly modified. Mechanical properties (tensile strength, elongation at break and Young’s modulus) were mainly decreased due to the residual insoluble particles present in blackcurrant waste. FTIR analysis showed no significant changes between the film samples. The degradation temperatures, determined by DSC, were reduced by 18 °C for chitosan-based samples and of 32 °C lower for the pectin-based samples with blackcurrant powder, indicating a disturbance in polymer stability. The antioxidant activity of active films was increased up to 30-fold. Lightness and redness of dry films significantly changed depending on the polymer type. Significant color changes, especially in chitosan film formulations, were observed after exposure to different pH buffers. This effect is further explored in formulations that were used as color change indicators for intelligent biopackaging.

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