Color Difference ΔE Research Articles

Myrrh Oleo‐Gum Resin as a Functional Additive in Pectin and κ‐Carrageenan Composite Films for Food Packaging

ABSTRACTMyrrh oleo‐gum‐resin (MOGR) is a natural substance that has a rich history of medicinal use due to its anti‐inflammatory, antimicrobial, and antioxidant properties. The present study reports on the fabrication and assessment of pectin and K‐carrageenan composite films infused with varying proportions (0.3%, 0.5%, and 0.7%) of MOGR. Morphological analysis of the film samples was conducted using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The results indicated that the introduction of MOGR led to a notable increase in surface roughness. The SEM micrographs of the films showed that the MOGR addition had an important effect on the microstructure of the film. The surface hydrophobicity of the MOGR‐loaded films increased, as confirmed by the rise in the contact angle. Moreover, there was an increase in the thickness (0.062 ± 0.004–0.095 ± 0.006 mm) and opacity (1.24 ± 0.07–9.41 ± 0.24) of the films with the addition of MOGR; however, tensile strength (7.30 ± 0.50–4.92 ± 0.34 MPa), elongation at break (32.41% ± 1.0%–29.70% ± 0.24%), and barrier properties decreased. Additionally, a rise in MOGR concentration corresponded to a rise in overall color difference ΔE (0.77 ± 0.03–5.09 ± 0.49) of the films. Notably, the incorporation of MOGR led to an increase in the antioxidant activity of the composite films, indicating potential applications in functional packaging materials.

Examination of weight loss and colour changes in Golden Delicious apples under light and dark storage conditions

AbstractThis study analyzed the impact of storing Golden Delicious apples at 3 °C with a relative humidity of 85 ± 5% in two environments, namely a darkroom (D03) and a lightroom (L03), on the fruit quality. The research evaluated weight loss (Δm) and color metrics (a*, b*, L*, ΔE, C*, hue angle). The number of apples used for each storage was 12. Weight loss was calculated by measuring the changes in mass during storage. Color differences (ΔE), chroma (C*), and hue angle were determined based on the L*a*b* scale values. Apples stored at 3 °C in D03 experienced a minimal percentage of weight loss of 7.02%. The results indicated that compared to the D03 storage, the L03 storage had a more significant increase in Δm and color variation. The non-destructive method of measuring color characteristics facilitates the assessment of the storage conditions for Golden Delicious apples.

Closed-Loop Recycling of 3D-Printed Wood–PLA Composite Parts: Effects on Mechanical and Structural Properties via Fused Filament Fabrication

This study investigated the closed-loop recycling of 3D-printed wood fiber (WF)-filled polylactic acid (PLA) composites via fused filament fabrication (FFF). The WF-PLA composites (WPCs) were extruded into WPC filaments (WPCfs) to produce FFF-printed WPC parts (WPCps). The printed WPCps were reprocessed three times via extrusion and 3D-printing processes. The tensile properties and impact strengths of the WPCfs and WPCps were determined. To further investigate the impact of closed-loop recycling on the surface morphology, crystallinity, and molecular weight of WPCfs, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and gel permeation chromatography (GPC), respectively, were used. After closed-loop recycling, the surface morphology of the WPCfs became smoother, and a decrease in the pore sizes was observed; however, the tensile properties (tensile strength and elongation at break) deteriorated. With increasing numbers of recycling iterations, the molecular weight of the PLA matrix decreased, while an increase in crystallinity was observed due to the recrystallization of the low-molecular-weight PLA molecules after recycling. According to the SEM images of the recycled WPCps, their layer heights were inconsistent, and the layers were rough and discontinuous. Additionally, the color difference (ΔE*) of the recycled WPCps significantly increased. Compared with those of the WPCps after recycling them only once, the tensile strength, elongation at break, and impact strength of the WPCps noticeably decreased after recycling them twice. Considering the changes in various properties of the WPCfs and WPCps, the FFF-printed WPC parts can be reprocessed only once through 3D printing.

Chromatic Adaption of Two Universal Composites: Spectrophotometric Analysis

Objective: The purpose of this study was to evaluate the chromatic adaptability and color stability of two different composite resins, Omnichroma and Estelite Bulk-Fill Flow, in Class V restorations at different times. Materials and methods: Standardized Class V cavities were prepared on the labial surface of 34 extracted intact and noncarious human permanent molars. The dental elements were randomly divided into two groups according to the resin composite material. Group 1 was restored with Omnichroma (Tokuyama Dental Corporation Inc., Tokyo, Japan) and Group 2 was restored with Estelite BulkFill Flow Universal (Tokuyama Dental Corporation Inc., Tokyo, Japan). Color properties were assessed using a spectrophotometer, SpectroShadeTM Micro (MHT Optic Research, Niederhasli, Switzerland), at baseline (T0), immediately after Class V restoration (T1), 24 h after restoration (T2) and after thermocycling (T3) (ISO/TS 11405, 2015 protocol). Color difference (ΔE) was analyzed with a Student’s t-test and a Wilcoxon–Mann–Whitney test to evaluate the differences, in terms of chromatic adaptability, between the two materials (inter-group analysis) while Kruskal–Wallis test e Two-way ANOVA statistical tests were used to evaluate the color stability of each material over time (intra-group analysis). Results: Regarding the inter-group analysis, there were no statistically significant differences between the two materials in all the comparisons: T0–T1 (p = 0.9025), T0–T2 (p = 0.2779), T0–T3 (p = 0.4694). Moreover, both groups showed an average ΔE > 2. In the intra-group analysis, no statistically significant differences were observed in either Group 1 (p = 0.954) or Group 2 (p = 0.8654). Conclusions: The in vitro color matching, assessed by spectrophotometry, of the two tested resin composites does not vary at different time intervals. Furthermore, even though both composites use different mechanisms to produce the color the human eye perceives, they show very similar chromatic adaptability.

Ultra-high-pressure homogenization in chicory root juice production

The demand for freshly squeezed natural fruit juices has increased in recent years, however their shelf life is quite short. Thermal processes applied to extend the shelf life of such products and increase their storage stability cause significant losses in color and other sensory properties, depending on the temperature applied. Therefore, the preference for high-pressure homogenization as an alternative to thermal processes is on the rise. We aimed to determine effects of ultra-high-pressure homogenization and production stages on some quality properties of chicory root juice. Ultra-high-pressure homogenization was applied at the pressure levels of 0 (Control), 50, 100, 150, and 200 MPA. The samples also included juice after homogenization with an ULTRA-TURRAX disperser and after a water bath. Ultra-high-pressure homogenization affected such quality characteristics of chicory root juice as total soluble solids (p < 0.01), pH (p < 0.01), L* (p < 0.01), a* (p < 0.01), b* (p < 0.01), a*/b* (p < 0.01), chroma (p < 0.01), hue angle (p < 0.01), and total color difference ΔE (p < 0.01). Higher levels of ultra-high-pressure homogenization pressure increased pH (p < 0.05), a* values (p < 0.05), and the a/b* ratio (p < 0.05) but reduced L* (p < 0.05), b* (p < 0.05), chroma (p < 0.05), and hue angle (p < 0.05) values of the juice samples. Thus, the use of ultra-high-pressure homogenization (100 and 200 MPa) contributed to improving the total soluble solids and redness values of chicory root juice. Our study showed that the ultra-high-pressure homogenization process improved the quality of chicory root juice.

Colorimetric chitosan/polyvinyl alcohol composite membrane incorporated with anthocyanins as pH indicator for monitoring fish freshness

AbstractDuring storage, food undergoes transformations, often producing volatile nitrogen compounds known as total volatile basic nitrogen (TVB‐N), which serves as an indicator of food freshness. In this study, chitosan (CTS) was blended with polyvinyl alcohol (PVA) and incorporated with anthocyanins (ACNs) to monitor the quality changes in fish fillets over different time intervals. The results demonstrated that the presence of PVA in the CTS membrane enhanced light transmittance and reduced water absorption due to the reinforcement of the membrane structure through chemical interactions. In the freshness monitoring experiments, the CTS/PVA membranes exhibited an improved value of total color difference (ΔE), facilitating better detection of pH changes of the surrounding environment. Moreover, the ΔE value of the CTS/PVA film was observed to be quite similar to the value at pH 9 after 24 h and at pH 11 after 36 h when the fish fillet was stored at 25°C. In contrast, the ΔE value of the CTS/PVA film closely matched the value at pH 11 after 96 h of storage at 4°C. Additionally, the correlation between the generated TVB‐N and the ΔE values indicated a higher correlation coefficient (R2) for the composite membranes compared to the pristine CTS or PVA membranes.

The colour stability of 3D-printed, non-invasive restorations after 24 months in vivo – esthetically pleasing or not?

ObjectivesThe aim of the present prospective study was to evaluate the colour stability of 3D-printed non-invasive restorations after 24 months in vivo. MethodsThe study included 29 patients, who received 3D-printed restorations made of a computer-aided design (CAD) / computer aided-manufacturing (CAM) hybrid material (n = 354). Restoration colour of 190 restorations was measured using a spectrophotometer. By applying the CIELAB system, *L (lightness), a* (red-green) and b* (blue-yellow) values were recorded. An evaluation of the colour differences (ΔE) after 6, 12 and 24 months was conducted. ResultsAnalysis of colour differences of 3D-printed restorations showed continuous discolouration of the restorations. After one year 34 % and after two years 18 % of the restorations were rated alpha or bravo, indicating no or hardly visible colour change. After two years, 54 % of the evaluated restorations yielded a colour difference with ΔE > 6.8 (delta). More than 82 % of the evaluated restorations showed values between ΔE 3.8 – 6.8 (charlie) and ΔE ˃ 6.8 (delta) after two years. Conclusions3D-printed non-invasive restorations showed an overall reduced colour stability after 24 months in vivo. Clinical SignificanceThe present study provides first clinical data regarding 3D-printed restorations. These restorations are recommended for a wearing time of about 6 months.

Visual colorimetric label for real-time monitoring of SO2 concentration change in grape and mango during storage

Sulfur dioxide (SO2) is widely utilized as a preservative in food transportation and storage, but excessive consumption poses health risks. This study presents a novel and efficient method for the real-time detection of SO2 using a sensor named TK, synthesized from triphenylamine and 2-cyanomethyl-1-methyl-quinolinium. The core mechanism involves the Michael addition reaction of the CC bond in TK with SO2, which disrupts the intramolecular charge transfer process, resulting in a significant color change and a blue shift in fluorescence emission. Methodologically, the sensor's response was quantified by the change in fluorescence intensity ratio (I425/I647) within a SO2 concentration range of 0–180 μM. The sensor exhibited high sensitivity and selectivity. For practical application, TK was incorporated into hydrophilic polyvinyl alcohol to create a smart label capable of visual colorimetry and fluorescence analysis. SO2 concentration changes were monitored by using this label, demonstrated by the color transition from burgundy red to colorless, yielding a maximum color difference (ΔE) of 73.6. The smart label was successfully used to monitor the quality of various grapes and mangoes during long-term storage, providing a reliable, equipment-independent method suitable for household use. The study offers a new tool for enhancing food safety and mitigating health risks associated with SO2 exposure.

Performance analysis of heat pump drying system combined with rotor dehumidification for low temperature drying of mango slices

In order to solve the problems of low drying efficiency and poor drying quality existing in the current closed heat pump drying system (CHPD), a closed carbon dioxide heat pump drying system (CHPRD) with the function of combining rotor dehumidification was designed. This study investigates the drying kinetics and quality characteristics of CHPRD in low-temperature drying processes using mango as the drying material through experimental studies and theoretical analysis. The experimental results showed that the drying rate of CHPRD increased by 29% and 17.8%, the moisture removal rate per unit energy (SMER) by 14.2% and 12.5%, and the coefficient of performance (COP) by 17.3% and 12.0%, respectively, compared with that of CHPD in the low-temperature drying process with loading amounts of 400 and 450 g, respectively. In terms of drying quality, the rehydration factor (Rf ) of CHPRD-dried mango slices increased by 6.0% and 5.0%, the ascorbic acid content increased by 15.0% and 14.4%, and the color difference (ΔE) was lower by 11.0% and 5.6%, respectively. These improvements indicate that CHPRD provides better drying kinetics and higher quality of dried material. Based on the experimental data, simulation fitting was conducted, revealing that the two-term model is the best mathematical model to simulate the drying characteristics of CHPRD for mango.

Replacement of native sugars of apples by isomaltulose in dual stages

The present study aimed to substitute the native sugars of apples for isomaltulose. In the first stage, native sugars were partially removed from the fruit tissue, and in the second stage, isomaltulose was incorporated. The use of ultrasound was evaluated at both process stages. Water loss (WL), solid gain (SG), water activity (aw), soluble solids content (°Brix), shrinkage (Sh), and color parameters (total color difference (ΔE), L* a*, b*, Cr*, and h°) were evaluated. The temperature of 35 °C stood out for its contribution to the mass transfer parameters (SG = 8.196%; WL = 21.699%—maximum values). There seems to be a threshold regarding the use of ultrasound in the process stages, indicating that its excessive use does not favor impregnation. The ideal process to promote the dehydration of apples and incorporation of the greatest amount of isomaltulose consisted of a treatment in which samples were immersed in water in the first stage, followed by impregnation of isomaltulose for 40 min assisted by ultrasound in the second stage. In addition, there was a significant reduction of aw (0.971 ± 0.001) and a slight change in color parameters (2.91 ± 0.45). Only concerning Sh (28.7 ± 3.6%), this treatment was not advantageous.Graphical

Activated carbon derived from Mahachanok mango seeds as a potential material to delay the ripening of mangoes

The mango processing industry in Thailand generates significant waste, with over 60 % consisting of mango seed. Mahachanok mango seeds, a by-product of mango processing, can be processed into highly porous activated carbon with potential application in agricultural and food preservation. This study investigated the potential of activated carbon derived from Mahachanok mango seeds on delaying the ripening of Nam Dok Mai mangoes. The activated carbon was prepared through a two steps process: biochar preparation followed by activation using KMnO4. The morphology of activated carbon was characterized by Fourier transform infrared (FT-IR) spectroscopy, Brunauer-Emmett-Teller (BET) surface area, and Scanning electron microscopy (SEM). The optimal carbonization temperature was determined, and the activated carbon was applied to mango storage. The mango ripening was assessed by measuring weight loss, total color difference (ΔE), firmness, total soluble solids (TSS), titratable acidity (TA), and TSS/TA ratio as a ripening level indicator. The optimal carbonization temperature was found to be 500 °C, yielding 25.47 % activated carbon with iodine number of 361.77 mg I2/g AC. The activated surface carbon contained hydroxyl and manganyl groups, with a BET-surface area of 0.649 m2/g. Mangoes stored with 10 g of synthesized activated carbon exhibited the best delay in ripening, extending the ripening process by five days compared to the control. On the 8th day of storage, mangoes became early ripe with firmness and TSS/TA values for 10 g of synthesized activated carbon were 0.467 N/mm and 22.35, respectively (p < 0.05). The TSS/TA ratio indicated that this treatment effectively maintained mango quality for up to 14 days of storage. Activated carbon derived from Mahachanok mango seed shows promising results in delaying mango ripening, especially when used at 10 g dosage. This approach utilized food processing waste to create a valuable product for post-harvest handling, potentially improving the freshness of exported fruit.

Fabrication and characterization of novel biodegradable films based on tomato seed mucilage and gelatin plasticized with polyol mixtures

This research evaluates the potential of tomato seed mucilage (TSM) –gelatin (Ge) in producing edible films. Edible films were made using various ratios of TSM to Ge (1:0, 0.33:0.66, 0.66:0.33, and 0:1). Moreover, the effects of including three types of plasticizers, namely, glycerol (Gly), sorbitol (Sor), and polyethylene glycol (PEG) were investigated. The findings indicated that adding Ge did not affect the thickness of the films (p>0.05). However, it significantly increased the tensile strength (TS) and Young's modulus while reducing the elongation at break (EB) (p˂0.05). A higher TSM ratio significantly increased total color difference (ΔE) and yellowness index while decreasing film lightness and whiteness index (WI) (p˂0.05). The contact angle significantly decreased with the TSM ratio increases and Ge decreases (p˂0.05). Moreover, this led to higher opacity, solubility, moisture content, oxygen permeability, water vapor permeability (WVP), swelling, and moisture absorption (p˂0.05). Adding a plasticizer had no effect on the films' opacity, contact angle, and thickness. The Gly-containing film featured the highest EB, solubility, moisture content, swelling, WVP, oxygen permeability, and moisture absorption. The Sor-containing film had the highest TS. TSM concentration was directly correlated with increased film heterogeneity and surface roughness. X-ray diffraction peaks became sharper by increasing TSM concentration and including PEG, while Gly inclusion produced ordered broad peaks.

Assessing the Aesthetic Performance of CAD/CAM Provisional Restorative Materials: A Spectrophotometric Analysis.

Achieving color match between natural teeth and restorative materials is crucial in dentistry. Factors such as the light source, brightness, and opacity influence tooth color, determined by light absorption and scattering within the material. Advances in CAD/CAM systems have enhanced prosthodontic treatments, particularly with new temporary materials, but data on their color stability and masking ability remains limited. However, data on the color stability and masking ability of these CAD/CAM materials is limited. Telio® CAD-Temp and VITA CAD-Temp® blocks were cut into slices and polished. Composite resin specimens were prepared using a custom-designed metal resin former and light-cured. Samples were paired randomly and assigned to experimental groups based on base type and thickness (n = 30). Samples were stored in a controlled environment for 24 h before color evaluation using an EasyShade® V spectrophotometer. Color difference (ΔE) was calculated using L*, a*, and b* values. Statistical analyses included the Shapiro-Wilk test, Levene's test, and three-way ANOVA, with post-hoc comparisons using the Bonferroni method (α = 0.05). ΔE was classified according to perceptibility (PT = 1.2) and acceptability (AT = 2.7) values.

The impact of various substrates, ceramic shades, and brands on the ultimate color and masking capacity of highly translucent monolithic zirconia: an in vitro study.

This study aimed to examine the impact of substrates, ceramic shades, and brands on the color and masking ability of highly translucent monolithic zirconia (HTMZ) using CIELab and CIEΔE2000 metrics. A total of 156 1-mm thick HTMZ disks in shades A1, A2, and A3 were produced using Dental Direkt and Kerox zirconia brands. Four 3-mm thick substrates (nickel-chromium alloy, non-precious gold alloy (NPG), zirconia shade A2, and resin composite shade A2) were prepared. HTMZ disks were overlaid on these substrates, and color measurements were taken with a spectrophotometer. Color differences (ΔE) were analyzed using CIELab and CIEΔE2000 formulas. The influence of brand, shade, substrate, and their interactions on ΔE values was assessed with a General Linear Model (GLM) and LSD pairwise comparison test. Spearman's correlation test examined the relationship between CIELab and CIEΔE2000 values. Results indicated that ΔEab was significantly influenced by substrate type and shade, while ΔE2000 was also affected by the ceramic brand. Mean color differences across ceramic-substrate groups were within clinically acceptable and perceptible ranges (clinically perceptible: ∆Eab ≥ 1.3 and ∆E2000 ≥ 0.8; clinically acceptable: 0.8 < ∆E2000 ≤ 1.8 and 1.3 < ∆Eab ≤ 2.7), except for NPG, which had ΔE values exceeding the perceptible range (ΔE2000: 1.1 ± 0.11 to 1.8 ± 0.31; ΔEab: 1.61 ± 0.15 to 2.16 ± 0.36). A significant correlation (r = 0.974, P < 0.001) was found between ΔEab and ΔE2000. Various ceramic brands and shades led to notable ΔE variations, yet average color differences within all ceramic-substrate groups remained clinically acceptable. Both ΔEab and ΔE2000 were reliable methods with a strong correlation for measuring color differences.

Discoloration Evaluation of Stone Cultural Heritage Based on Hyperspectral Imaging

ABSTRACT Discoloration poses a serious threat to stone cultural heritage, making accurate assessment crucial for its protection and repair. Current detection methods are limited by coverage, slow speed and direct contact with cultural heritage. To address these issues, a spectral index based on the correlation between spectral reflectance and brightness was developed to identify discoloration boundaries in stone cultural heritage. Color difference ΔE* was then calculated to assess the deterioration of sandstone cultural heritage such as Leshan Giant Buddha over recent years. The results show that a strong correlation between the spectral index and the color changes on the Buddha’s face, with the three-band index using 530, 550, and 555 nm showing the best results in identifying discoloration areas. Among the evaluation models, the Competitive Adaptive Reweighted Sampling-Support Vector Machine Regression (CARS-SVR) model effectively quantifies the degree of discoloration. Brightness (L*) shows the strongest response to black pollution on the Buddha’s face. Discoloration is divided into five levels, with severe discoloration concentrated in the nose area, consistent with field survey findings. This study demonstrates the feasibility of using hyperspectral technology for quantitative discoloration assessment in stone cultural heritage.

The development of environmentally friendly Pr/W Co-doped Bi2MoO6 green pigment with high near-infrared reflectivity

In this article, a green pigment Bi1.95-xPrxW0.05MoO6+δ (x = 0.1–0.5) co-doped with Pr and W was developed using high temperature solid-phase synthesis method. The microstructure, color performance, and optical characteristics of the novel pigment was analyzed using x-ray diffraction instrument (XRD), field-emission scanning electron microscopy (FESEM), L∗ a∗ b∗ color date, and ultraviolet–visible–near infrared light spectrophotometer. The results indicate that all the samples possess a monoclinic structure, characterized by the space group P21/c(14). Compared to Bi2-xPrxMoO6+δ doped solely with Pr6O11, the Pr/W co-doped Bi2MoO6 pigment demonstrates superior green coloration. The solar reflectance in the near-infrared region of all pigment samples exceeds 80 %, highest value reaches 92.82 %. In thermal insulation tests, the temperature difference between the Bi1.95-xPrxW0.05MoO6+δ pigment coating and a blank galvanized sheet reaches up to 10.3 °C after 60 min under infrared lamp irradiation. The color difference ΔE∗ of the pigment powder after immersion in acid and alkali solution and high-temperature calcination are less than 5, indicating good chemical stabilities in acidic, alkaline and high-temperature environments. To our knowledge, Bi1.95-xPrxW0.05MoO6+δ has the highest reflectivity among green pigments without toxic metals.

In Vitro Kinetic and Thermodynamic Staining Study of Three Energy Drinks on the Restorative Charisma Composite

Abstract Aim: The research utilized charisma composite resin, a dental restorative material known for its esthetic properties, with the chemical formula 2,2-bis[p(2-hydroxy-3-methacryloxy propoxyphenyl)] propane. The primary objective of the study was to examine the overall color change (ΔE*ab) of the charisma resin after it was subjected to three distinct energy drink solutions: Monster Energy Ultra-Sunrise, Wild Tiger, and Red Bull. Further we examined the effects of temperature and time on the staining interaction and overall color difference ΔE*ab on the surface of charisma restorative resin generated by three energy drink. Materials and Methods: A microfilled Charisma Classic composite resin was used in presented comparative study selected. The prepared 144 composite disk samples (subdivided n=48) with random allocation method were used for the three energy drinks to determine the effect of temperature and time over the course of 90 days. A metallic circulator mold was prepared. Every set of 48 specimens in the energy drink was heated in a water bath for 1, 7, 30, 60, and 90 days at four different temperatures This investigation spanned various time intervals, ranging from 1 to 90 days, and encompassed four temperature levels between 283 and 310 K. One-way ANOVA was used to evaluate the mean data for color change between the energy drinks, and Tukey’s post hoc test was used for multiple comparisons, with a significance level of P &lt; 0.05. Results: The study revealed that the rate of staining was most pronounced in the case of Wild Tiger, while it was comparatively lower for Monster Energy Ultra-Sunrise. These findings were established through an examination of the kinetic and thermodynamic behavior of surface color changes in micro-hybrid composites treated with the three energy drink solutions. Conclusions: The observed patterns aligned with the pseudo second-order model. It was observed that the Red Bull drink displayed a negative activation energy, resulting in a slower color change rate with increase in temperature. In contrast, endothermic, spontaneous, and regular staining activity was demonstrated throughout time by Monster Energy Ultra-Sunrise and Wild Tiger.

Anthocyanin modified by chondroitin sulphate and tannic acid improved the quality-indicating properties of gelatin-based intelligent film

A highly pH-responsive gelatin film incorporating purple cabbage anthocyanin (PCA) and chondroitin sulphate (CS)/tannic acid (TA) was developed. Co-pigmentation of PCA via CS/TA improved its photothermal stability and visibility of color change in gelatin film. The morphological and structural properties of CS-PCA and TA-PCA films revealed that a more stable network was formed as new hydrogen bonds were generated by the co-pigmentation. Meanwhile, the co-pigmentation improved film's mechanical and hydrophobic properties, expressed as higher tensile strength (16.65 and 17.97 Mpa) and lower water vapor permeability (1.45 and 1.41) in CS-PCA and TA-PCA films, compared to PCA film. CS-PCA and TA-PCA films showed distinct color transitions for chilled fish fillets during storage. Total color difference (ΔE) of CS-PCA and TA-PCA films correlated well with the deterioration indexes of total volatile base nitrogen (TVB-N). All the results provided a novel pH-sensitive intelligent packaging strategy by co-pigmenting CS/TA with PCA for freshness monitoring.

Impact of different pre-treatments and drying methods on the physicochemical properties, bioactive compounds and antioxidant activity of different tomato (Solanum lycopersicum) cultivars

A green pre-treatment approach, microwave (MW) and ultrasound (US), along with drying methods [hot air (HA) and freeze-drying (FD)], was assessed for colour properties, phenolics, carotenoid components and antioxidant activity DPPH, ABTS, FRAP assays of three tomato cultivars (Zzx171, Zzx162 and Zzx65). All three cultivars showed a reduced colour difference (ΔE) after US-FD. The US-FD method retained higher levels of total carotenoids, lutein, β-carotene, lycopene and antioxidant activity in all cultivars than other methods. While US-HA drying retained the highest level of total phenolic content, chlorogenic acid, 4-O-caffeoylquinic acid, rutin, protocatechuic acid and ABTS•+ scavenging activity in powders of all cultivars. ‘Zzx162’ is best suited for US-FD to produce tomato carotenoids-rich functional powder. Powders of ‘Zzx162’ showed the highest lycopene (14.40 mg/g), β-carotene (6.13 mg/g), and ABTS•+ scavenging activity (8.37 SC50 mg/mL). While ‘Zzx162’ with US-HA produced powders rich in chlorogenic acid (58.48 mg/100 g) and rutin (50.33 mg/100 g). These findings suggest that ultrasound pre-treatment is the preferred technology for developing functional tomato powder.

Effect of Melamine Formaldehyde Resin Encapsulated UV Acrylic Resin Primer Microcapsules on the Properties of UV Primer Coating.

Ultra-Violet (UV) coatings are widely adaptable of substrates and produce low emissions of volatile organic compounds. UV coatings can extend service life by adding self-healing microcapsules that restore integrity after sustaining damage. In this study, UV coating was used as a core material; microcapsules were produced and added to the UV coating to enhance its self-healing property, providing a good protection for both the UV coating and the substrate. UV primer microcapsules were prepared with UV primer as the core material and melamine formaldehyde resin as the wall material. The UV primer containing more than 98.0% solids content was mainly composed of epoxy acrylic resin, polyester acrylic resin, trihydroxy methacrylate, trimethyl methacrylate, and photo initiator. The preparation process of the UV primer microcapsules was optimized. Further, the UV coating was prepared with better UV primer microcapsules, and the effects of the UV primer microcapsules alongside the comprehensive properties of the coating were studied. The best preparation process for the UV primer microcapsules was as follows: the wall-core mass ratio was 1:0.50, Triton X-100 and Span-20 as emulsifiers with an HLB value of 10.04, the microcapsule reaction temperature was 70 °C, and the reaction time of the was 3.0 h. When the quantity of the UV primer microcapsules increased in the coating, color difference ΔE of the coating increased, gloss decreased, transmittance decreased, elongation at break increased and then decreased, roughness increased, and self-healing rate first increased and then decreased. When the addition of the UV primer microcapsules reached 2.0%, the color difference ΔE of the coating was 1.71, the gloss was 106.63 GU, the transmittance was 78.80%, the elongation at break was 3.62%, the roughness was 0.204 μm, and the self-healing rate was 28.56%, which were the best comprehensive properties of the UV primer. To improve the comprehensive properties of the UV coatings, the UV coatings were modified by a microcapsule technology, which gave the UV coatings a better self-healing property. The application range of microcapsules for the UV coatings was broadened. Based on the previous research of microcapsules in UV coatings, the results further refined the study of the effects of adding self-healing microcapsules to UV coatings using the UV coating itself as the core material.