Small Color Changes Research Articles

Plasma-Activated Water Combined with Chitosan–Oregano Essential Oil Coating to Prolong the Shelf Life of Carp Fillets

This study aimed to investigate the effects of plasma-activated water (PAW) combined with a chitosan–oregano essential oil (CS-OEO) coating on the physicochemical, microbiological, and sensory attributes of carp fillets during chilled storage. Fresh carp fillets were immersed in sterile deionized water, PAW, CS-OEO, and PAW+CS-OEO, respectively, and stored at 4 °C for 10 d. The results showed that plasma-activated water combined with chitosan–oregano essential oil could effectively inhibit the microbial growth in carp fillets during chilled storage. At 10 d storage, the total viable count of carp fillets treated with PAW+CS-OEO decreased by 2.87 log10 CFU/g when compared to the control. The lowest pH values were found in the carp fillet samples after the PAW+CS-OEO treatment; as well, the carp fillet samples after the PAW+CS-OEO treatment showed the lowest total volatile basic nitrogen, thiobarbituric acid reactive substance values, and K values. In addition, the carp fillets in the PAW+CS-OEO treatment group showed the smallest color changes and the highest scores in sensory properties during chilled storage. This study provides a basis for the potential application of plasma-activated water combined with chitosan–oregano essential oil in the preservation of carp fillets and contributes to developing a new food packaging.

In situ study of the effect of endogenous and exogenous agents on color stability, hardness, and surface roughness of an elastomer for facial prostheses.

To evaluate in situ the influence of sweat, oil, sunscreen, and disinfectant solution on the color stability, hardness, and roughness of elastomer for facial prostheses. Standardized and intrinsically pigmented specimens remained in contact with human skin from the same person for 30days, considering exposures (n=36 per group), absent of exposition (Control, C); sweat and oiliness contact (SO); sweat and oiliness associated with sunscreen (SOS); 0.12% chlorhexidine digluconate immersion (CD0.12%); and all agents exposed (SOSCD). The main variables were color change (CIELab and National Standard Bureau system, NBS), Shore A hardness, and surface roughness, measured at baseline and 30days. Qualitative analyses were performed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The data were analyzed by Kruskal-Wallis tests (color) and two-way ANOVA (hardness and roughness) with Sidak post-test (α=0.05). CD0.12% (1.54±0.49) and SOSCD (2.10±1.03) had similar effects and caused the smallest color changes, considered mild and noticeable (NBS), respectively. SOS promoted the greatest color change (6.99±1.43, NBS: large) and hardness (17.97±0.56); SOS promoted intermediate roughness (3.48±1.05) between SOSCD (2.25±0.53), and two similar groups: C (4.46±0.95), and CD0.12% (4.39±1.26). The qualitative analysis showed an irregular, dense, dry, and whitish layer on the surface of the specimens exposed to sunscreen, which was reduced when in contact with 0.12% chlorhexidine digluconate. Endogenous and exogenous factors are capable of altering elastomer properties. The 0.12% chlorhexidine digluconate minimized the changes caused by sweat, oil, and sunscreen.

Recognising small colour changes with unsupervised learning, comparison of methods

Colour differentiation is crucial in machine learning and computer vision. It is often used when identifying items and objects based on distinct colours. While common colours like blue, red, green, and yellow are easily distinguishable, some applications require recognising subtle colour variations. Such demands arise in sectors like agriculture, printing, healthcare, and packaging. This research employs prevalent unsupervised learning techniques to detect printed colours on paper, focusing on CMYK ink (saturation) levels necessary for recognition against a white background. The aim is to assess whether unsupervised clustering can identify colours within QR-Codes. One use-case for this research is usage of functional inks, ones that change colour based on environmental factors. Within QR-Codes they serve as low-cost IoT sensors. Results of this research indicate that K-means, C-means, Gaussian Mixture Model (GMM), Hierarchical clustering, and Spectral clustering perform well in recognising colour differences when CMYK saturation is 20% or higher in at least one channel. K-means stands out when saturation drops below 10%, although its accuracy diminishes significantly, especially for yellow or magenta channels. A saturation of at least 10% in one CMYK channel is needed for reliable colour detection using unsupervised learning. To handle ink densities below 5%, further research or alternative unsupervised methods may be necessary.

Análise de cor em sementes de urucum (Bixa orellana L.)

Abstract Brazil has emerged as the world's largest producer of annatto seeds (Bixa orellana L.). Fortunately, the increase in national production has been accompanied by an improvement in the quality of this raw material. Annatto is a typical crop of small producers who usually use their empirical knowledge to evaluate the quality of the crop. Thefore, the visual observation of the color of annatto seeds has been considered a quality standard by many producers. To evaluate the scientific evidence, the present study evaluated annatto seeds from 51 accessions of the germplasm bank of the Agronomic Institute (Instituto Agronômico de Campinas - IAC) to determine a possible correlation between the pigment’s contents and the color of annatto seeds as well as the influence of humidity on this correlation. The correlations between the concentrations of pigments, humidity, lipids, and color (L*, a*, b*) were also evaluated. The color was evaluated using a colorimeter with measurements of the CIE L*, a*, b* scale. Only the correlation between the variables moisture and lipids was considered strong through the simple correlation, while the variables bixin content and coordinate a* presented a significant correlation while eliminating the effect of moisture (partial correlation). Thus, a correlation between the red color and the bixin concentration of annatto seeds was observed even though it was a weak correlation. In turn, the color difference (ΔEab) between the samples with higher and lower bixin contents was only 1.44. This difference indicates that large variations in the bixin concentrations may lead to small color changes in the annatto seeds, impairing the use of this criterion for quality control of these seeds.

The role of color in transsaccadic object correspondence.

With each saccade, visual information is disrupted, and the visual system is tasked with establishing object correspondence between the presaccadic and postsaccadic representations of the saccade target. There is substantial evidence that the visual system consults spatiotemporal continuity when determining object correspondence across saccades. The evidence for surface feature continuity, however, is mixed. Surface features that are integral to the saccade target object's identity (e.g., shape and contrast polarity) are informative of object continuity, but features that may only imply the state of the object (e.g., orientation) are ignored. The present study tested whether color information is consulted to determine transsaccadic object continuity. We used two variations of the intrasaccadic target displacement task. In Experiments 1 and 2, participants reported the direction of the target displacement. In Experiments 3 and 4, they instead reported whether they detected any target movement. In all experiments, we manipulated the saccade target's continuity by removing it briefly (i.e., blanking) and by changing its color. We found that large color changes can disrupt stability and increase sensitivity to displacements for both direction and movement reports, although not as strongly as long blank durations (250 ms). Interestingly, even smaller color changes, but not blanking, reduced response biases. These results indicate that disrupting surface feature continuity may impact the process of transsaccadic object correspondence more strongly than spatiotemporal disruptions by both increasing the sensitivity and decreasing the response bias.

Evaluation of the effects of whitening toothpaste containing nanohydroxyapatite on surface roughness and color change in restorative materials.

The effects of whitening toothpastes containing nanohydroxyapatite on the surfaces of restorative materials are not well known. This study evaluated the changes in surface roughness and color of coffee-stained restorative materials after brushing with nanohydroxyapatite and other whitening toothpastes. Disc-shaped specimens were formed using microhybrid, nanohybrid, and supra-nano-filled composite (n = 30) and stained with a coffee solution. A brushing simulation was applied with toothpastes containing nanohydroxyapatite (Dentiste Plus White), perlite (Signal White System) and hydrogen peroxide (Colgate Optic White) for 7, 15, and 30 days. Color and surface roughness measurements were taken before and after brushing. Color change (∆E00) was calculated using the CIEDE2000 system. Supra-nano-filled composite-Dentiste Plus White, supra-nano-filled composite-Colgate Optic White, and nanohybrid composite-Signal White System were the groups with the greatest color change observed on the 7th, 15th, and 30th days, respectively. The smallest color change was seen in the microhybrid composite-Signal White System, microhybrid composite-Dentiste Plus White, and nanohybrid composite-Dentiste Plus White groups on the 7th, 15th, and 30th days, respectively. No significant surface roughness changes were observed in the nanohybrid composite-Dentiste Plus White, supra-nano-filled composite-Colgate Optic White, supra-nano-filled composite-Dentiste Plus White, or supra-nano-filled composite-Signal White System groups. Whitening toothpaste containing nanohydroxyapatite provided a high degree of color change in the short term and did not create significant surface roughness in nanohybrid or supra-nano-filled composites.

PIHA: Detection method using perceptual image hashing against query-based adversarial attacks

As a representative adversarial example generation method in a black-box scenario, query-based adversarial attack has recently been highlighted due to its high attack success rate and feasibility. To provide the robustness against query-based adversarial attacks, the state-of-the-art defense methods use similarity of queries. Among them, two state-of-the-art defense methods have shown the good performance in the number of detected attack queries: (1) Stateful Detection; and (2) Blacklight. In this paper, we first propose two simple but effective mitigation strategies(i.e., parallelization and brightness adjustment) to show how to mitigate the robustness of the state-of-the-art defense methods. Next, we propose a new defense method, which uses the concept of perceptual hashing. Given a query image, the proposed defense method generates a hash sequence using a perceptual image hashing scheme, called PIHA, and compares the hash sequence with those of previous queries to detect query-based adversarial attacks. Here, a hash sequence has invariance to small perturbations and color changes when detecting query-based adversarial attacks. From the experimental results under various conditions, we show that the proposed defense method provides good robustness against well-known query-based adversarial attacks without or with mitigation strategies applied.

Color Stability of Nanoparticles-Modified Dental Resin-Based Composites

To evaluate the effect of beverages (coffee, tea, Cola-Cola, and mineral water) on the color stability of resin-based composite (RBC) materials modified with different nanoparticles (NPs). The specimens (70/beverage) were fabricated from light-cured RBCs and divided according to NPs into four groups: one control, unmodified (N0); and three experimental—ZrO2 (Zr), TiO2 (Ti), and SiO2 (Si) groups. Each experimental group was further subdivided into two subgroups according to NP concentrations: 3 wt.% and 7 wt.% (n = 10). A spectrophotometer was used to assess the color change (∆E) before and after six months of immersion. Data were analyzed and compared using one-way-ANOVA followed by Bonferroni’s post-hoc test (α = 0.05) and subsequently ∆E value conversion to National Bureau of Standards (NBS) units. The modified light-cured RBCs with ZrO2, TiO2, and SiO2 demonstrated smaller color changes after immersion in the beverages than the unmodified group (p < 0.001). Zr groups showed the lowest ΔE, followed by Ti and Si groups; a 3% concentration resulted in a lower mean ΔE than the 7% concentration. NBS findings showed that coffee and tea produced marked unacceptable color changes (NBS units were >3), and Coca-Cola resulted in noticeable color changes (NBS units between 1.5 and 3), while water produced slight color changes (NBS ≤ 1). Modification of RBCs with both concentrations of ZrO2, as well as 3% of TiO2 and SiO2, may improve its color stability. Based on NBS results, RBCs immersed in mineral water and Coca-Cola showed clinically acceptable color changes, while those immersed in coffee and tea were clinically unacceptable.

Ultrasonic assisted far infrared drying characteristics and energy consumption of ginger slices.

Three drying methods, including far infrared drying, infrared convection drying, and ultrasonic pretreatment assisted far infrared drying, were adopted in the drying of ginger slices. The effects of main parameters (ultrasonic pretreatment power and time, far infrared temperature and power, sample thickness, infrared convection temperature) on the drying kinetics, energy consumption, and color change were investigated and discussed in detail. The results showed that the drying process of ginger slices was controlled by falling rate period. For far infrared drying, the drying rate increased with the increase of infrared temperature and decrease of sample thickness, while the infrared power had no obvious effect on the drying process. The infrared convection drying showed the fastest drying rate and the smallest color change, however, the energy consumption was the highest. For ultrasonic pretreatment assisted far infrared drying, an appropriate ultrasonic pretreatment time and power would promote the far infrared drying process and the energy consumption was only slightly increased. However, the color change was relatively large. The ultrasound technology showed its greatest potential to enhance the drying rate at the early stage of drying and increasing ultrasonic power was more effective than prolonging the pretreatment time in promoting far infrared drying.

The Effect of UV Irradiation on the Stability of Coated Fir Wood Samples

Abstract The aim of the paper consists in assessing the protection of fir wood samples against UV degradation by using polyacrylates and titanium dioxide as absorber. The irradiation was achieved for 648 hours, considered as about 2 years of weathering. Colorimetric, water absorption, and mechanical investigations were performed on samples before and after irradiation. The structural changes were evidenced by FTIR spectroscopy. Small changes in color for coated wood samples are observed after maximum 648 h of UV treatment, with the best results obtained for the specimen covered with Paraloid B72-TiO2. Higher compressive strengths were observed for the polymer-TiO2 coatings, in correlation with a smaller water absorption capacity of the studied samples. FTIR revealed shifted peaks with increased intensities as proof of structural changes produced by irradiation of lignin and polyacrylates. The results highlight that Paraloid B72 and Paraloid B67 mixed with TiO2 can be used as efficient UV protective coatings for fir wood.

Effect of simulated brushing and disinfection on the surface roughness and color stability of CAD-CAM denture base materials

PurposeTo evaluate the effect of simulated brushing and chemical disinfection on the surface roughness and color stability of CAD-CAM denture base materials and to compare with those of a heat-cured denture base material. Material and methodsDisk-shaped specimens (Ø 10mm × 2 mm) were prepared from 3 CAD-CAM denture base resins (AvaDent, Ava; Merz M-PM, Merz; Polident d.o.o, Poli) and a heat-cured polymethylmethacrylate resin (Promolux, Conv) (n = 30). After polishing, baseline surface roughness (Ra) and color coordinates were measured. The measurements were repeated after 20000 cycles of simulated brushing, and the specimens were divided into 3 groups according to disinfection protocol (distilled water, 1% sodium hypochlorite (NaOCl), and effervescent tablet) (n = 10). After 9 cleaning cycles over a period of 20 days, Ra and color coordinates were remeasured. Color differences (ΔE00) were calculated by using CIEDE2000 formula. One-way analysis of variance (ANOVA) and pairwise t-tests were used to analyze Ra and ΔE00 data, while repeated measures ANOVA test was used to compare baseline, after brush, and after disinfection Ra values (α = 0.05). ResultsBrushing did not affect the Ra values of tested materials (P ≥ .08). Both before and after brushing, Merz and Conv had higher Ra values than Poli and Ava (P < .001). Among disinfectants, effervescent tablet led to the lowest Ra for Merz (P = .003) and the highest Ra for Poli (P ≤ .039). Only NaOCl resulted in significant differences among the Ra of materials (P < .001), as Merz and Conv had higher Ra values than Poli (P ≤ .002). Repeated measures ANOVA revealed that effervescent tablet disinfection of Merz led to lower Ra values than those of baseline and after brushing (P ≤ .042). After brushing, Ava and Conv had higher ΔE00 values compared with Merz and Poli (P ≤ .015). When compared with other disinfection protocols, effervescent tablet led to higher ΔE00 values for Merz and Poli (P < .001). Significant differences were observed among materials when NaOCl was used; Conv had higher ΔE00 values than Ava and Merz (P = .004). ConclusionsBrushing did not increase the surface roughness of materials. Disinfection protocol's effect on the surface roughness varied. The effect of brushing on the color of materials varied; color of Ava and Conv was affected from brushing more than the other materials. Color stability of materials varied depending on the disinfection protocol. Effervescent tablet caused higher color change with Merz and Poli compared with other disinfectants. NaOCl led to small color change for Poli, Ava, and Merz materials.

Color changes of esthetic elastomeric ligatures due to exogenic pigmentation

Vytautas Sabataitis1, Vilija Berlin2 1Institute of Odontology, Medical Faculty, Vilnius University, Vilnius, Lithuania 2Vilnius University Hospital Zalgiris Clinic, Vilnius, Lithuania Abstract Backround and aim of the work: a contemporary patient seeks to achieve the most aesthetically pleasing orthodontic treatment therefore chooses colorless elastic ligatures instead of metal ligatures. However, elastic ligatures tend to change their color due to food colorings and impair esthetics. Aim of this study is to evaluate and compare in vitro color change due to staining solutions of the most frequently used aesthetic orthodontic elastic ligatures offered by different companies in Lithuanian market. Materials and Methods: fourteen different types ligatures were immersed for 72 hours in four different solutions: distilled water (control), coffee, black tee, and wine. Ligatures’ color change was measured with spectrophotometer and evaluated by the Commission Internationale d’Éclairage color system and National Bureau of Standards units Results: Coffee was the most staining solution. Color change of all ligatures were from 4,32 (appreciable) to 24,71 (change to another color). Statistically significant and the smallest color change was observed in these ligatures: “Tooth” (GC), “Tooth” (America Orthodontics) and “Clear” (3M) with “Pearl” (American Orthodontics). The biggest color change was observed in “Clear” (American Orthodontics), “Clear” (GC), “Clear” (Ormco) and “Tooth” (Ormco) ligatures after the immersion. In group of all “Clear” ligatures only elastic ligatures by 3M showed statistically significant smallest colour alteration (p<0,01). Conclusion: all tested elastic orthodontic ligatures change their color after immersion in staining solutions and the color alteration is perceptible by human eye. Statistically significant color change between different types of ligatures was found. Keywords: Easthetic orthodontic, orthodontic appliances, Orthodontic ligatures.

Ultrasound-assisted convective drying of white mushrooms (Agaricus bisporus)

In this study, white mushrooms were dried in a laboratory hybrid dryer, equipped with an airborne ultrasound system. The effects of ultrasound power of 100 and 200 W combined with hot air at two temperatures of 50 and 70 °C were analyzed. The drying processes were assessed in terms of kinetics (drying rate and time), specific energy consumption, and product quality (relative color change, water activity, total polyphenol content, and visual appearance). Moreover, based on the approximation of the experimental data the effective diffusion coefficients were estimated. It was found that the application of ultrasound improved the kinetics of convective drying (increased the drying rate and reduced the time of drying) without compromising the quality of the products obtained. After ultrasound-assisted drying the mushroom samples were characterized by smaller color changes, higher phenolic content, and softer peel. The results obtained from the approximation of the experimental data also confirmed the positive effect of ultrasound on the drying process. For the ultrasonically assisted processes, both the effective diffusion and the mass transfer coefficients were higher. Taking into account the more favorable results it was stated that the higher the ultrasound power and air temperature, the better the drying performance.

Violet LED in Bleaching Non-Vital Teeth: a Case Series

Objetive: The main of this study was to clinically evaluate the effectiveness of violet LED in bleaching non-vital teeth. Case series: three clinical cases were selected (1, 2 and 3), which showed changes in the colour of specific teeth to shades A2, C4 and B3, respectively. Bleaching was performed over three sessions (one session/week). Each session consisted of 20 applications of violet LED for 60 s, with a 30 s interval between them. After bleaching using violet LED, 35% hydrogen peroxide was applied for 15 min in clinical cases 2 and 3, with continuous irradiation with the violet LED in the last 5 min. The dental bleaching using violet LED resulted in teeth with shades A1, C3 and C2 in clinical cases 1, 2 and 3, respectively. The application of 35% hydrogen peroxide with the violet LED further changed the teeth to shades A2 and C1 in clinical cases 2 and 3, respectively. Conclusions: the protocol used in this case series showed that whitening with a violet LED alone should be restricted to cases requiring small colour changes.

Opalescence and color stability of composite resins: an in vitro longitudinal study.

This study aims to evaluate the opalescence (OP) and color stability of composite resins over a period of 180days and to compare composite resins' OP with enamel's OP. Twenty human enamel specimens (5.0 × 0.3mm) and 9 specimens (10.0 × 1.0mm) of 10 colors of 4 different composite resins (3M ESPE, FGM, Ivoclar-Vivadent, Miscerium) and one brand of adhesive (3M ESPE) were made. The results were obtained by measuring the reflectance and transmittance spectra in the visible region. After baseline measurement, composites and adhesive were analyzed after 2, 7, 30, 60, 120, and 180days. The Lab color coordinates were used in the calculations of the OP parameter and color differences in the CIELab and CIEDE2000 methods. The data were analyzed statistically. The materials tested showed variation and an increase in OP over time. The OP found for enamel was 18.06 ± 2.99, and some resins showed higher results. There was a strong correlation between the coordinate b*T and the OP over time. Enamel Plus was the only one material that presented no color changes during all periods in both color analyses. Filtek Z350 XT, AT, and BT did not show differences in any time when analyzed by CIELAB. The OP of most composite resins changed during the period of 180days and was different from the OP of tooth enamel. In general, composites demonstrated small color changes over the period tested, being this characteristic material dependent. Natural teeth present different optical properties. Composite resins restorations should present properties similar to natural teeth and it is important that characteristics like color and opalescence remain stable over time.

Hygroscopicity and Ultraviolet (UV) Deterioration Characteristics of Finished Woods

This study investigated the hygroscopicity and UV deterioration characteristics of 3 domestic and 4 imported woods using natural oil, stain, and varnish paints. In terms of hygroscopicity, it was found that the hygroscopicity of the painted wood was lower than that of the unpainted wood, and that as the number of coatings increased, the hygroscopicity decreased. In terms of anti-absorption, oil-based chemical paints showed higher resistance than water-based paints, and natural oils showed results comparable to oil-based paints. As for the UV deterioration, the amount of color change of the painted wood was lower than that of the unpainted wood, and there was no significant difference according to the number of times of painting. The amount of color change was found to be low in oil-based paints and hardwoods. Through this study, we confirmed effective moisture blocking and small color changes during painting using paints, and it is believed that wood can be protected from internal and external defects through selective and efficient painting based on data for excellent painting performance.

Mode for hot air drying of alder blanks that retain the colour acquired during the steaming process

Mode for hot air drying of alder blanks that retain the colour acquired during the steaming process. The paper presents a hot-air mode for drying steamed alder in the form of blanks with dimensions: 38x100x800 mm from the initial moisture content W1 ≈ 50 % to the final moisture content W2 = 10%, while maintaining the colour of wood obtained in the process of steaming with saturated water steam. The drying process is divided into two parts: (I) evaporation of free water from wet wood at drying medium temperatures td = 35 - 40 °C and relative air humidity φ = 70 – 60%, when there are no chemical changes in the lignin-saccharide complex of alder wood manifested by a change in colour; (II) evaporation of bound water from alder wood below the hygroscopicity limit is performed at temperatures td = 60 - 80 °C. The color coordinates of steamed alder wood after drying by a given mode in the CIE L* a* b* colour space are: L* = 62.5 ± 1.7; a* = 13.1 ± 0.8; b* = 18.5 ± 0.9. Total colour difference ∆E = 1.6. According to the categorization of wood color changes in thermal processes of wood , this change belongs to small (insignificant) color changes.

Non-fluorine surface modification of acetylated birch for improved water repellence

Abstract In this work, a non-fluorinated surface treatment, i.e., hydrophobized silicone nanofilaments, was applied on both birch and acetylated birch wood samples via a gas-phase based reaction. A superhydrophobic behavior was observed on both the surface-modified samples as revealed by the static water contact angles (CAs) greater than 160°, also valid for samples prepared with the shortest reaction time of 1 h. The dynamic wettability behavior of the samples was studied by a multicycle Wilhelmy plate method. The surface-modified acetylated birch exhibited a pronounced enhanced water resistance, resulting in very low water uptake of 3 ± 1 wt% after 100 cycles, which was not only about 29 and 5 times lower than that of the non-surface-modified birch and acetylated birch, respectively, but also three times lower than that of the surface-modified birch. Moreover, the aesthetic appearance of the acetylated wood was maintained as the surface modification only resulted in a small color change. This work shows the potential of preparing super water-repellent wood by non-fluorinated surface modification.

Infant heart-rate measurement and oxygen desaturation detection with a digital video camera using imaging photoplethysmography.

To assess the feasibility of using an ordinary digital video camera to measure heart rate and detect oxygen desaturations in healthy infants. Heart rate and oxygen saturation were measured with a video camera by detecting small color changes in 28 infants' foreheads and compared with standard pulse oximetry measures. Multivariable regression examined the relationship between infant characteristics and heart-rate measurement precision. The average bias of camera heart-rate measures was -4.2 beats per minute (BPM) and 95% limits of agreement were ±43.8 BPM. Desaturations detected by camera were 75% sensitive (15/20) and had a positive predictive value of 20% (15/74). Lower birth-weight was independently correlated with more precise heart-rate measures (8.05 BPM per kg, [95% CI 0.764-15.3]). A digital video camera provides accurate but imprecise measures of infant heart rate and may provide a rough screening tool for oxygen desaturations.

Energy and Quality Aspects of Freeze-Drying Preceded by Traditional and Novel Pre-Treatment Methods as Exemplified by Red Bell Pepper

Freeze-drying is one of the most expensive and most energy intensive processes applied in food technology. Therefore, there have been significant efforts to reduce the freeze-drying time and decrease its energy consumption. The aim of this work was to analyze the effect of pulsed electric field (PEF), ultrasound (US), and hybrid treatment (PEF-US) and compare them with the effect of blanching (BL) on the freeze-drying kinetics, energy consumption, greenhouse gasses emission, and physical quality of the product. The freeze-drying process was applied to red bell peppers after pretreatment operations. Results showed that application of BL, PEF, US, or PEF-US reduces freeze-drying time and decreases energy consumption. Among the tested methods, the combination of PEF performed at 1 kJ/kg and US was the most effective in reduction of greenhouse gas emission. BL samples exhibited the highest porosity, but from a statistical point of view, most of the PEF-US treated materials did not differ from it. The smallest color changes were noted for US pre-treated bell peppers (ΔE = 9.4), whereas BL, PEF, and PEF-US material was characterized by ΔE of 15.2–28.5. Performed research indicates the application of pre-treatment may improve the sustainability of freeze-drying process and quality of freeze-dried bell pepper.