Effect of Far-UVC Light (222 nm) on Spoilage Microbes and Shelf Life of Sweetpotatoes.

Current understanding of Martian regolith has advanced due to various rover explorations. Due to this, there are now several variants of Martian regolith that are chemically known and commercially available. These simulants are vital for panspermia models that suggest a transfer of simple life throughout the solar system via ejecta containing life from Mars when its surface was more favourable to host life. Bacteria that produce endospores are suitable candidates for these models as they have adequate protection from the harsh conditions of space. To assess this, the simple endospore former, Bacillus subtilis, was assessed for growth on several Martian regolith that represented different locations and epochs of Mars. This consisted of a conventional Martian regolith, a sulphur rich regolith, and a simulant of the Jezero crater which was thought to have once been flooded with water. We found that the sulphur rich regolith inhibited endospore formation, while the other two variants favoured endospore production. Interestingly, we also identified that pulsing of UVC in a simulation of endospores on rotational ejecta show that endospores break down faster with lower rotational frequency despite receiving the same UVC dose. Moreover, and most strikingly is that viable endospores after surviving UVC dosage displayed elevated expression of the DNA damage SOS response gene, RecA. Importantly, this study suggests that astrobiological approaches that utilise endospore viability as a benchmark for survival require reassessment as genomic integrity may be compromised.

Inactivation of infectious virus samples through UV irradiation for downstream analysis.

Ballast water is a major vector for the transport of aquatic non-indigenous species among ecosystems worldwide. To comply with the International Convention for the Control and Management of Ships' Ballast Water and Sediments, vessels on international voyages commonly rely on Ballast Water Management Systems (BWMS) to meet the D-2 performance standard, often using ultraviolet (UV) irradiation as a key disinfection step. UV-light-emitting diodes (UV-LEDs) offer a mercury-free UV source with long lifespan and flexibility in wavelength selection; compared to conventional lamps, they are smaller in size and require no warm-up time. Yet, their effects on larger planktonic organisms (≥50μm) remain poorly understood. Here, we tested the effect of UV-C-LED (λ=265nm) on larvae of the invasive European green crab Carcinus maenas, assessing mortality, immobility, and respiration under three UV-C doses (40, 120, and 200mJ·cm-2). All UV-C treatments significantly reduced larval motility and respiration relative to controls, leading to increased mortality over time. Larvae required comparatively high doses (120-200mJ·cm-2) to reach substantial inactivation, relative to doses reported for bacterial and phytoplanktonic fractions. These results provide species- and life stage-specific UV-C thresholds for the ≥50μm size class and demonstrate the value of combining behavioural, lethal and physiological endpoints when validating UV-LED-based BWMS.

There is a high risk of transfer of foodborne pathogens to the edible part of microgreens when seeds, irrigation water or soilless substrates are contaminated. Post-harvest sanitizer treatments are generally not preferred due to the fragility of microgreens. In this study, the effectiveness of post-harvest UV-C treatment was evaluated against Salmonella enterica, Shiga toxin-producing Escherichia coli O157:H7, and Listeria monocytogenes in sunflower and radish microgreens. Agricultural perlite soaked with plant nutrient solution was artificially contaminated with foodborne pathogens at a concentration of 105-106 CFU/g to serve as the soilless substrate. UV-C was applied to harvested microgreens uni- and bidirectionally with doubled exposure at varying distances (10, 20, and 30 cm) and exposure times (5, 10, 20, 30, 60, and 120 s). UV-C doses ranged from 0.03 to 2.07 kJ/m2, depending on treatment distance and exposure time. The survival of pathogens in treated microgreens was also determined at 4 °C for 14 days. The highest pathogen inhibition was achieved with bidirectional UV-C treatment at a 10 cm distance for 120 s (p < 0.05), yielding reductions of up to 3.1, 3.0, and 2.0 log CFU/g for S. enterica, E. coli O157:H7, and L. monocytogenes, respectively. Pathogen inhibition decreased significantly with increasing distance (p < 0.05). During subsequent refrigerated storage after UV-C treatment, pathogen populations increased by 0.3-1.7 log CFU/g. These results demonstrate that UV-C treatment can significantly reduce pathogen populations on microgreens as a post-harvest treatment strategy but cannot fully address food safety concerns about these immature seedlings.

PREDICTIVE MODELLING OF E. COLI DARK REGROWTH AFTER UVC-LED DISINFECTION IN DIFFERENT WATER MATRICES AND TEMPERATURES

ABSTRACT This study investigated the inactivation kinetics of the human norovirus GII.4 (HuNV GII.4) and hepatitis A virus (HAV) in artificially inoculated groundwater under Ultraviolet-C irradiation (0–240 mWs/cm2). Viral genome copies were quantified using RT-qPCR and PMA/RT-qPCR to evaluate the effects of the UV-C dose and to distinguish potentially infectious particles. For HuNV GII.4, the number of genome copies decreased from 4.11 to 1.99 log10 copies/μL by RT-qPCR, and from 4.11 to 1.69 log10 copies/μL following PMA treatment. The effect for HAV was similar, with reductions from 4.89 to 1.51 log10 copies/μL (RT-qPCR) and to 1.06 log10 copies/μL (PMA/RT-qPCR). Data fitting with the Weibull model revealed significantly higher D-values for HuNV GII.4 (57.51 mWs/cm2) compared with HAV (15.99 mWs/cm2), indicating that HuNV GII.4 was approximately 3.6-fold more resistant to UV-C irradiation. The PMA/RT-qPCR data supported this trend, with D-values of 38.62 mWs/cm2 for HuNV GII.4 and 11.12 mWs/cm2 for HAV. Overall, HuNV GII.4 demonstrated greater resistance to UV-C irradiation than HAV across both molecular detection methods. PMA treatment improved the accuracy of the viability assessment by weakening the signals from non-infectious particles, thus underscoring its utility for evaluating disinfection efficacy in water environments.

Mpox virus (MpoxV), an emerging zoonotic pathogen, has recently caused global concern due to increasing outbreaks beyond its traditional endemic regions. While transmission primarily occurs via close contact, fomites are also suspected of contributing. This study aims to evaluate the effectiveness of UV-C irradiation on MpoxV-contaminated surfaces. the virucidal activity of UV-C (254 nm) irradiation on MpoxV applied to plastic, glass, and stainless-steel surfaces was assessed. Using a viral stock of 2.49 × 105 TCID50/mL, the samples were exposed to increasing UV-C doses. Viral titers were quantified through TCID50 and plaque assays. A UV-C dose of 6.34 mJ/cm2 achieved a >2-log reduction of viral load, below the detection limit (31.6 TCID50/mL), on all tested surfaces. EC90 values were determined as 3.33 mJ/cm2 (plastic), 0.81 mJ/cm2 (stainless steel), and 1.98 mJ/cm2 (glass). No viable virus was detectable post-treatment at these doses on plastic and stainless steel while the titer was significantly reduced on glass. UV-C irradiation at low doses effectively inactivated MpoxV on various fomites. These findings support UV-C as a rapid and effective environmental disinfection strategy in healthcare and community settings to prevent indirect transmission of MpoxV.

Purpose The current work investigates the potential of exopolysaccharides (EPSs) and carotenoids produced from radioresistant bacteria as radioprotective agents. Materials and methods Twenty strains, isolated from gamma-irradiated roots of Cistanche violacea from Chott El-Djerid (Tunisia), were screened for EPSs and carotenoids production. The most EPS and carotenoids-producing bacterium was selected. The assessment of the impact of UVC-radiation dose effects on the synthesis of EPSs and carotenoids was investigated by response surface methodology (RSM). Both EPS and Carotenoids, from the strain CV6, were characterized by UV–Vis and Fourier transform infrared. The radioprotective potential of EPS and carotenoids on the survival of K. rosea CV6 following UVC dose was evaluated using the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay. Finally, in silico analyses of CV6’s genome were assessed to identify the mechanisms involved in UVC protection. Results It was demonstrated that UVC irradiation of Kocuria rosea CV6 generated high amounts of EPSs and a carotenoid-producing strain. The assessment of the impact of radiation dose effects on the synthesis of EPSs and carotenoids by RSM shows that strain CV6 exhibited particular resistance to UVC radiation. The characterization of EPSs revealed the presence of six particular functional groups using Fourier transform infrared spectra. Pigments produced by CV6 were classified as carotenoids based on their spectroscopic characteristics. Also, the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide survival assay demonstrated a positive correlation between the concentrations of EPSs and carotenoids and viability of the UV-sensitive strain, Escherichia coli DH5α, following exposure to UVC radiation. In addition, the whole-genome analysis of the CV6 strain identified seven biosynthetic gene clusters encoding secondary metabolites, including those involved in the synthesis of EPSs and carotenoids. Conclusion The present investigation demonstrated that EPSs and carotenoids, extracted from K. rosea CV6, are promising bioactive components that could be used in the protection against UVC radiation.

Ultrasound-assisted extraction using natural deep eutectic solvent of secondary metabolites from Tagetes erecta flowers irradiated with UVC light

&amp;lt;p&amp;gt;This study investigated the effects of three key factors, UV-C irradiation, storage time, and cutting effect, on the physicochemical properties of fresh-cut and whole plum tomatoes. UV-C irradiation was applied at three low radiation doses (0.22, 0.4 and 1.23 kJ/m&amp;amp;sup2;) appropriate for the ripening stage of the tomato. Tomatoes were subsequently stored at 5.9 &amp;amp;deg;C for four days (96 h). Mass loss analysis demonstrated significantly higher water loss in fresh-cut tomatoes (up to 12.39%) compared to whole tomatoes (max 2.65%) with UV-C treatment amplifying this effect, especially at higher UV-C doses. Colorimetric changes were more pronounced in fresh-cut samples, as indicated by the higher total colour difference (&amp;amp;Delta;E*=6.23 vs. 2.95 in whole tomatoes) and greater chroma (C*) reduction (11.6% vs. 4.4%) reflecting increased oxidative stress induced by tomato cutting and UV-C-exposure. Firmness decreased more in fresh-cut tomatoes (F|&amp;lt;sub&amp;gt;max&amp;lt;/sub&amp;gt; reduction up to 28.5%), although UV-C irradiation moderately preserved firmness in whole fruits. Respiration rate was higher in fresh-cut tomatoes, rising by 64% in fresh-cut controls compared to whole controls (5.21 vs. 3.17 mL CO₂&amp;amp;middot;kg⁻&amp;amp;sup1;&amp;amp;middot;h⁻&amp;amp;sup1;), and was further increased by UV-C exposure (up to 7.43 mL CO₂&amp;amp;middot;kg⁻&amp;amp;sup1;&amp;amp;middot;h⁻&amp;amp;sup1; at 1.23 kJ/m&amp;amp;sup2;), indicating enhanced metabolic stress. Additionally, soluble solids and titratable acidity responded to UV-C treatment, with more pronounced changes in fresh-cut tomatoes, suggesting metabolic changes. Ethylene production increased significantly in fresh-cut tomatoes, particularly at later storage times, contributing in accelerated ripening. Overall, UV-C irradiation demonstrated potential for extending shelf-life and preserving quality in whole tomatoes by limiting water loss and maintaining firmness and colour stability. However, in fresh-cut tomatoes, the benefits were UV-C dose-dependent and limited by increased susceptibility to oxidative stress and ripening. Optimization of UV-C dosage appears necessary to balance beneficial antimicrobial and shelf-life extension effects with the minimization of quality degradation in fresh-cut products.&amp;lt;/p&amp;gt;

Ultraviolet (UV) radiation is a significant environmental stressor for plant growth, stress responses and secondary metabolites. UV-B (280–315 nm) and UV-C (100–280 nm) wavelengths are particularly known to induce oxidative stress among the UV wavelenghts. The physiological and biochemical reactions of Portulaca oleracea with differing intensity of UV radiation are still uncertain. P. oleracea plants were exposed to UV-B and UV-C with measurements at 0, 200, 400 and 600 J.m⁻². Both UV-B and UV-C treatments reduced plant height, biomass, and leaf water potentially the largest reductions were under UV-C treatments in fact at 600 J.m⁻². Photosynthetic pigments such as chlorophyll a, chlorophyll b and carotenoids decreased with rising intensities of ultraviolet (UV). However, proline, malondialdehyde (MDA), phenols and flavonoids increased indicating more oxidative stress. Activities of the antioxidant enzymes catalase and peroxidase increased under increasing UV-C doses; the antioxidants increased with intense UV-C. Although UV-B and UV-C radiation produces physiological and biochemical effects that are dose-dependent in the greenhouse weed, P. oleracea, the exposure of plants to UV-C caused growth inhibition and decrease in pigments, but induced the defense mechanism against oxidative stress. Overall findings shed light on plant resilience to natural stress together mitigation measures for sustainable agro-ecosystem management amidst an increasing UV environment.

BackgroundVirtual reality (VR) headsets are increasingly used in health care settings for a variety of clinical indications, yet processes to ensure safe use between patients are not well-established. Centers vary in how these processes are performed. Most use disinfection wipes that require manual contact with VR devices for a specified dwell time to allow for sufficient pathogen killing, which may introduce manual error and device degradation over time. Ultraviolet-C light (UV-C) devices offer a no-touch, low-cost, and passive method to achieve pathogen killing without the harms of chemical contact-based disinfectants. The use of UV-C for disinfection has been studied for some medical devices but its efficacy for microbe killing on VR headsets is not well-established.ObjectiveThis study aims to determine the bactericidal efficacy of UV-C on VR headsets through quantifying UV-C irradiance and bacterial killing of 3 commercially available UV-C devices.MethodsThree commercially available, low-cost UV-C devices were tested for UV-C energy output at multiple positions, angles, and times across the devices’ zone of disinfection. The top and lens of a VR headset, the Meta Oculus Quest 2, were artificially inoculated with high quantities of 3 different strains of bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, and Staphylococcus epidermidis) and subjected to UV-C light according to each device’s manufacturer’s instructions for use. The primary outcome was the amount of bacterial killing after exposure to UV-C light.ResultsAll 3 UV-C devices produced a UV-C dose that ranged from 3.57 to 195.37 mJ/cm2, depending on proximity, angle, irradiance, and time the sensor received. At least 3-log10 killing of all 3 strains of bacteria was achieved for each of the tested UV-C devices; however, there was variability by organism with respect to UV-C device and VR headset location within the device, notably with the proximity of the bacteria to the bulb. S aureus and P aeruginosa were more readily killed than S epidermidis, with increased bacterial killing occurring with increased UV-C exposure doses. There was no experiment in which all bacteria were killed.ConclusionsUV-C dosage increased with exposure irradiance, time, proximity, and angle to the bulb for all 3 UV-C devices. Bacterial killing on the top and lens of a VR headset occurred in all 3 UV-C devices when run according to their manufacturer’s instructions for use, although full bacterial killing did not occur in any experiment. UV-C may be an effective method for microbial killing on VR equipment with low-level contamination.

The increase of African swine fever (ASF) outbreaks worldwide has raised concerns about the feeding of spray-dried porcine plasma (SDPP) to pigs. The processing of blood into SDPP should thus guarantee sufficient inactivation of ASF virus (ASFV) to render a safe product. The objective of this study was to evaluate (i) the required level of inactivation if blood of ASF-infected pigs would be processed into SDPP and fed to piglets, and (ii) the additional safety achieved if UV treatment is applied to plasma before spray-drying. A quantitative microbial risk assessment (QMRA) model was built to assess the infection probability (Pinf) of weaned piglets fed with SDPP produced from blood collected from a single ASF-infected herd. The inactivation of ASFV by UV treatment was quantified using a mobile, laboratory-scale “Cold Pasteurization” apparatus (Lyras inc, Aalborg, Denmark). Porcine plasma spiked with blood collected from pigs experimentally infected with ASFV was irradiated with different doses of UV-C and the log10 reduction factor (LRF) calculated. An average LRF of 2.2 was achieved by the highest dose of UV-C irradiation applied (~137 Joule/m2). QMRA model results indicate that an LRF of 5 needs to be achieved during processing to arrive at a median value of Pinf < 0.01, i.e., less than 1 out of 100 ASF-infected batches resulting in new infections. With an LRF of 8, also the 95th percentile value of Pinf is < 0.01. These results were compared to reported LRF values of spray-drying and dry storage of SDPP, which varied between 5.2 and 11.1. Applying UV-C irradiation as an additional step in SDPP production thus provides extra safety guarantees as the combined inactivation levels of spray-drying, dry storage and UV treatment are likely to result in an overall LRF ≥ 8, implying a very low risk of new ASF infections (median Pinf 7.3 × 10−6; 95th percentile 1.6 × 10−3). The QMRA model did not account for the probability that ASF-infected pigs are unintendedly processed into SDPP. This probability is low if SDPP is not sourced from pigs in ASF-infected areas, therewith further reducing the ASF infection risk of SDPP.

This study investigated the effect of different UV-C doses on physicochemical (pH, color, viscosity) and sensory properties, FFA, vitamin D3, cholesterol, fatty acid composition, and oxidative volatile compounds formation. The physicochemical properties (pH, viscosity, and color) of milk were significantly affected by the application of UV-C and different UV-C doses (p &lt; 0.05). The FFA of raw and pasteurized milk was determined as 0.053% and 0.10%, respectively. The FFA values significantly increased with the application of UV-C. The amount of cholesterol in UV-C-applied milk was in the range of 38.74-49.70 ppm. The cholesterol level was significantly reduced by the application effect of UV-C treatment at all dosages (p &lt; 0.05). The amount of vitamin D3 of raw and pasteurized milk was found as 90.91 mg kg-1 and 65.87 mg kg-1, respectively. The UV-C application at all dosages, with the exception of 98.4 J mL-1, significantly increased the amount of D3 (p &lt; 0.05). UV-C application caused a significant change in the composition of fatty acid composition and this change varied according to applied UV-C dosage. The carbon disulfide and aldehyde formation rate increased and the sensory quality reduced as the UV-C dose increased.

Numerous studies have demonstrated that ultraviolet radiation in the C wavelength range produced by light-emitting diodes (UVC-LEDs) is effective for disinfection (i.e., inactivation of vegetative bacteria and viruses). However, there are few efficacy data available to confirm its use as a sterilization technique (complete inactivation of bacterial spores). The present study evaluated the use of UVC-LED to achieve the sterilization of stainless-steel surfaces as a function of UVC dose and several other variables. Spores of Bacillus atrophaeus and two strains of Bacillus pumilus were used as indicator microorganisms. Results showed that the microorganism, spore loading, and inoculation method all affected whether complete inactivation was achieved. Under the tested conditions, sterilization of stainless-steel surfaces was achieved using UV-LED with doses that ranged from ∼4500 to 21,000 mJ/cm2, and if spore deposition was low enough to prevent clumping and subsequent shielding. We found that spore deposition in which sterilization was achieved ranged from 2.9 to 6.2 log10 colony-forming units/cm2 and depended primarily on the microorganism/strain. Shielding of UV radiation diminished efficacy and may have also occurred from the presence of foreign material.

UV-C irradiation is an innovative postharvest technique for increasing the safety of fruits and vegetables. This study investigated the effect of UV-C rays (UV-C1 = 0.26 KJ/m2; UV-C2 = 0.40 KJ/m2; UV-C3 = 0.67 KJ/m2; and UV-C4 = 1.34 KJ/m2) on the preservation of the antioxidants, hardness, and color of fresh green asparagus during storage. UV-C1 and UV-C2 significantly maintained higher total phenolic content (10.6%), total flavonoid content (36%), rutin (14.3%), quercetin (27.03%), kaempferol-3-O-rutinoside (21.25%), and antioxidant activity (DPPH 7.5%). Over three weeks of storage, quercetin, ferulic acid, and kaempferol 3-O-rutinoside increased, while rutin and caffeic acid decreased. Storage caused a significant change in the color and hardness of the control sample, but UV-C4 counteracted hardening for up to three weeks, and UV-C3 was the best dose for stabilizing color during storage. This study indicates that the choice of UV-C dose can be modulated based on the characteristics that are intended to be preserved in green asparagus, maintaining a balance between nutraceutical and hedonic characteristics. To maintain the maximum level of nutraceutical compounds over time, UV-C2 can be adopted, while to preserve texture and color, UV-C3 and UV-C4 are a better choice.

Blackcurrant is a notable superfruit in Europe, and its vitamin C content surpasses the well-known blueberry superfruit. However, due to its short shelf life during storage, consumption is mainly accounted by frozen berries, extracts, and concentrates. This study applied an intensity of 1.2 W/m2 UVC with different durations, including control (non-treated), UVC irradiation for 0.5 h (0.5 h treatment), UVC irradiation for 1 h (1 h treatment), and UVC pretreatment for 2 h (2 h treatment) to blackcurrant berries before storage. Fundamental physical (firmness and weight loss) and physicochemical characteristics (SSC, pH, and acids), microbial population changes, total phenolic content, antioxidant capacity, and specific phenolic compound changes were evaluated every five days over a twenty-day storage period. The results indicated that the longer the UVC pretreatment, the lower the water weight losses during storage. Meanwhile, the UVC pretreatment significantly affected the blackcurrant soluble solid content, resulting in higher soluble solid contents detected in the blackcurrants with the higher doses of UVC. For the mold population control, UVC effects were highly correlated with the pretreatment duration. However, UVC did not have a significant influence on the berry pH and acid contents, but the storage length slightly increased the pH and decreased the acids. At the same time, UVC pretreatment did not affect the berry firmness, polyphenols, ascorbic acid content, or antioxidant capacities, which were primarily influenced by the storage duration. The monophenolic compounds detected before and after storage indicated that more than one hour of UVC radiation influenced most of the phenolic contents largely before storage. The UVC pretreatment has also influenced some phenolic compounds. After storage, half an hour of UVC pretreatment increased cyanidin levels, and two hours of UVC pretreatment increased catechin and epicatechin levels. However, most of the compounds remained at similar amounts during storage in each treatment. Further research is needed to improve the UVC radiation time length or intensity or explore other technology combinations to optimize UVC pretreatments for blackcurrant storage.

The rapid perishability of Agaricus bisporus mushrooms presents a major challenge in post-harvest management due to microbial contamination, enzymatic browning, and lack of protective outer skin. This study aimed to optimize preservation parameters for microbial load reduction using Response Surface Methodology (RSM) with a Box-Behnken Design (BBD). Initially, a One-Factor-At-a-Time (OFAT) approach evaluated the effects of UV-C dose, gamma irradiation, storage time, temperature, and packaging thickness on microbial quality. Subsequently, BBD was applied to assess both individual and interactive effects of these variables. The results revealed that UV-C exposure at 254 nm and gamma irradiation at 2 kGy significantly reduced microbial load, particularly when combined with storage at 4 °C and packaging material of 40 µm thickness. The model yielded a significant F-value of 2.04 (p = 0.0468) with a non-significant lack-of-fit (p = 0.7906), indicating strong model adequacy. Validation trials under optimized conditions predicted microbial reduction of 1.2 log CFU/g, closely aligning with the experimental result of 1.3 log CFU/g (8.33% error). This confirms the robustness and predictive accuracy of the model. The findings are in agreement with earlier reports highlighting the efficacy of UV-C and gamma irradiation in microbial reduction without compromising mushroom quality. The developed RSM model provides a statistically sound and practical framework for enhancing mushroom shelf life and offers a scalable preservation strategy for fresh produce industries.

Vitamin D deficiency is a global health concern linked to various chronic diseases. Although food fortification is a promising solution, its implementation remains limited by processing losses, matrix inconsistency, and clean-label trends. Certain foods, including mushrooms and yeast-containing bakery products, naturally contain provitamin D2 (ergosterol), which can be photoconverted into vitamin D2 by ultraviolet (UV) light. While UV-based vitamin D2 enrichment has been extensively studied in mushrooms, its application in bread remains largely unexplored. This study investigated UV-C irradiation as a biofortification strategy for white and whole wheat bread, evaluating the effects of UV-C dose (0.50 and 2.00 kJ/m2) and dose rate (0.03 and 0.13 kJ/m2·min) on vitamin D2 content and bread quality attributes. Optimized UV-C parameters enabled a novel strategy to increase vitamin D2 content in bread without compromising the quality. UV-C treatments resulted in varying vitamin D2 levels in bread, depending on the dose and dose rate, whereas control bread did not contain any detectable vitamin D2. The highest vitamin D2 content was obtained when the 2.00 kJ/m2 dose was applied at 0.03 kJ/m2·min dose rate, although this treatment altered odor and taste. However, other treatments increased vitamin D2 without compromising the quality. The optimal treatment of 2.00 kJ/m2 dose at 0.13 kJ/m2·min dose rate achieved the best balance between vitamin D2 enrichment and sensory acceptability. Under the optimal conditions, a 14 g serving of UV-C treated white bread and a 15.5 g serving of whole wheat bread provided 27 and 37% of the recommended dietary allowance (RDA) for vitamin D, respectively. Thus, UV-treated bread represents a valuable and practical source of plant-based vitamin D for consumers, particularly for vegetarians or vegans.