HAL Project# MU07018 (April 30, 2009) Post-harvest Vitamin D Enrichment of Fresh Mushroom Robert Beelman and Michael Kalaras Department of Food Science Penn State University U.S. Mushroom Council Australian Mushroom Growers Association

Hal Project # MU07018 Robert Beelman 404 Food Science Building University Park, PA 16802 Email: [email protected] Phone: 814-863-2964 Michael Kalaras The purpose of this project was to determine the factors influencing the production of vitamin D2 in fresh mushrooms using pulsed UV light. The effect of dose of irradiation, distance from the lamp, weight of mushrooms treated, treatment of sliced and whole mushrooms and brown and white button mushrooms were examined. The shelf life effect were also determined including retention of vitamin D2 during storage and the effects on color and appearance as well as microbial population. Funding Sources: U.S. Mushroom Council Australian Mushroom Growers Association July 13, 2009

Contents

Media Summary Technical Summary Introduction Materials and Methods Results and Discussion Recommendations Technology Transfer References Appendix

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Media Summary Previous research demonstrated that pulsed UV light treatment of mushrooms can increase the Vitamin D2 content well over 100% Daily Value (DV) in an 84 g serving of sliced fresh mushrooms in under one second of exposure. This study was conducted to determine methods needed to optimize pulsed UV light treatment and to study the potential factors influencing the amount of vitamin D2 produced. The effects of this process on the shelf life of fresh mushrooms and their quality attributes, as well as the retention of Vitamin D2 were evaluated. Both white and brown button mushrooms were treated sliced and whole for one second. It was determined that sliced mushrooms produce significantly more Vitamin D2 than whole (692% DV/serving and 380% DV/serving, for sliced and whole respectively). White button mushrooms produced slightly more Vitamin D2 than browns but differences were not statistically significant. The results indicate that with increasing exposure to pulsed UV light the Vitamin D2 content increased dramatically but after 4 seconds of exposure the Vitamin D2 produced leveled off around 1700% DV. The shelf life and quality attributes of the treated mushrooms were not adversely affected. After 3 days in cold storage the Vitamin D2 content of mushrooms treated for one second decreased from an initial level of 729% DV to 555% DV and then remained steady for 8 days.

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Technical Summary Vitamin D deficiency is a significant problem and as such more dietary sources are needed. The use of UV irradiation of fresh mushrooms has been previously shown to increase the Vitamin D2 content but is problematic because of the long exposure times required and browning of white button mushrooms. For this reason, the use of pulsed UV light irradiation can be utilized to rapidly increase the Vitamin D2 content of fresh mushrooms. In this study, the use of pulsed UV light to increase the Vitamin D2 content of fresh mushrooms was studied to determine the effects of various factors on production. This included, dose of irradiation, volume of mushrooms treated, distance from the lamp, whether the mushrooms are sliced or whole, and differences between brown and white button mushrooms. A shelf life study was also conducted to determine the effects on quality attributes such as color, appearance and weight loss as well as possible microbial reduction. Importantly, the stability of the Vitamin D2 produced after treatment was evaluated during storage. Brown and white button mushrooms were treated sliced and whole for one second and it was determined that sliced mushrooms produce significantly more (643 and 692% DV/serving, for brown and white respectively) Vitamin D2 than whole (300 and 380% DV/serving, for brown and white respectively). White buttons produce slightly higher levels than brown buttons but the differences were not statistically different. It was determined that vitamin D increased dramatically with time of UV exposure but after about 4 seconds of exposure to pulsed UV light the Vitamin D2 of fresh white button mushrooms leveled off around 1700% DV/serving. Sliced button mushrooms were found to produce more Vitamin D2 than whole mushrooms. In the shelf life portion of the study, after one second of exposure the Vitamin D2 content of sliced fresh white button mushrooms was 729% DV/serving but decreased to 555% DV/serving after three days storage at 3°C and remained steady through 11 days of storage. There were no adverse effects on quality attributes after pulsed UV light treatment. Pulsed UV light technology was shown to be capable of producing mushrooms with high levels of Vitamin D2 in a very short period of time and with no negative effects on quality. However, Vitamin D2 levels in fresh mushrooms declined about 24% after 3 days of cold storage and then remained stable for eight days.

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Introduction Vitamin D deficiency is an ever-increasing problem in human nutrition and health. Current research suggests it affects much more than the classic diseases of rickets in children and osteomalacia in adults resulting from inadequate bone mineralization (NIH, 2008). Links to vitamin D deficiency and diseases such as cardiovascular disease (Wang et al., 2008) and cancer (Lappe et al., 2007) have been documented. Other diseases with links to vitamin D deficiency include hypertension, stroke, diabetes, multiple sclerosis, rheumatoid arthritis, inflammatory bowel disease, periodontal disease, macular degeneration, mental illness, propensity to fall and chronic pain (Cannell et al., 2008). The main source of vitamin D is through exposure to sunlight and the subsequent conversion of cholesterol in the skin to vitamin D3 (cholecalciferol). People with limited sun exposure are the most at risk for vitamin D deficiency. Further compounding the problem, with the use of a sunscreen with a SPF of 8, the ability to produce vitamin D is reduced by 95% (Matsuoka et al., 1987). There are many other groups at risk for vitamin D deficiency including infants who are exclusively breastfed, older adults, obese individuals, individuals with dark skin and individuals with fat malabsorption (NIH, 2008). There are limited options beyond sun exposure and vitamin supplements for individuals to obtain vitamin D from the diet. Foods containing vitamin D naturally include fatty fish (such as salmon and mackerel), eggs, and beef liver. Fortified foods include milk and orange juice and some cereals. Mushrooms, however, are another option. Studies have shown that some wild mushrooms have naturally occurring levels of vitamin D2 in the range of (2.91-58.7 µg/100g fresh weight) (Matilla et al., 1994; Teichmann et al., 2007; Matilla et al., 2002). Vitamin D2 content of mushrooms can also be enhanced through the use of UV light irradiation (Mau et al., 1998; Jasinghe and Perera, 2005; Jasinghe and Perera 2006; Jasinghe et al., 2007; Teichmann et al., 2007; Ko et al. 2008; Roberts et al., 2008; Koyyalamudi et al., 2009). The use of continuous UV irradiation to increase the vitamin D2 content has shown some limitations however. The exposure time (minutes to hours) to generate adequate amounts of vitamin D2 may be too long to be practical for commercially produced mushrooms. Studies have also shown browning of white button mushrooms with UV treatment (Mau et al., 1998; Teichmann et al., 2007; Koyyalamudi et al., 2009), which is a negative quality attribute. Pulsed UV light is a technology that uses a broad spectrum (100-800 nm) lamp along with high intensity pulses, delivering energy at a high peak power in a short amount of time. According to one manufacturer (Xenon Corporation, 2008) the lamps come close to duplicating sunlight. Compared to continuous UV light systems, the time for the same amount of UV light irradiation is much shorter. The use of such a system for vitamin D2 enrichment could prove to be more beneficial for commercial use due to the decreased exposure times and potential for higher throughput. Previous research conducted in our laboratory (Beelman and Kalaras, 2008) demonstrated that pulsed UV light, using a Xenon! C-type lamp, could be used to rapidly produce vitamin D2 in fresh mushrooms. Another study (Kalaras and Beelman, 2008), completed prior to the current study, demonstrated that pulsed UV light using a Xenon!

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B-type lamp could produce upwards of 800% of the Daily Value of vitamin D in one serving of fresh mushrooms with one second of exposure. The current study was conducted to determine methods needed to optimize pulsed UV light treatment using the B-type lamp to produce significant amounts of vitamin D2 in fresh mushrooms after short exposure times and to study the potential factors influencing the amount of vitamin D2 produced. A dose/response study was also conducted to determine if generation of vitamin D2 would reach a maximum level at some point. The effects of this process on the shelf life of fresh mushrooms and their quality attributes were evaluated. The retention of the vitamin D2 produced by this process during postharvest storage was also determined. Materials and Methods Mushrooms were obtained from the Penn State Mushroom Test and Demonstration Facility (MTDF) on the day of harvest and treated the same day. All mushrooms were protected from extraneous light exposure throughout the experiments. A Steripulse®- XL 3000 (Xenon Corporation, Woburn, MA) was used with a Btype lamp for pulsed UV light exposure. The lamp sits 5.8 cm from a quartz window. The system generated 505 Joules per pulse. At 3.18 cm from the quartz window the broadband energy was 0.873 J/cm2 per pulse. The system generates 3 pulses per second. All experiments consisted of 3 replications of each treatment. Dose/Response Study To determine the dose/response of pulsed UV light treatment to vitamin D2 production in fresh mushrooms, white button mushrooms (Agaricus bisporus) were sliced and weighed into 150g lots in polystyrene containers. The mushrooms were randomly treated in increments of 3 pulses from 0 to 18, at a distance of 3.18 cm from the quartz window. This was done to simulate treatment in a commercial package. Sliced and Whole, Brown and White White and brown button mushrooms were treated as described in the dose response study with 3 pulses either as whole mushrooms or sliced. Package Weight and Distance From Lamp White button mushrooms were weighed into 150 and 230g lots to determine the effect of the amount of mushrooms treated in a package on vitamin D2 generation. 150 g packages of white button mushrooms were also treated at 3.18 and 6.36 cm from the quartz window to determine if distance effects vitamin D2 conversion. Shelf Life White button mushrooms were sliced and treated in 150 g lots with either 0 or 3 pulses of pulsed UV Light. Mushrooms were stored at 3°C after treatment.

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Vitamin D2 Retention Samples were taken during storage at days 0, 3, 6, and 11 and tested for vitamin D2 content. Microbiological Testing After treatment mushrooms were tested on day 0 and day 11 of the shelf life study for effects on the microbiological flora. 150 g of mushrooms were placed in a Waring LB10S laboratory blender and diluted 1:1 with buffered peptone water (BPW) and blended for 30 seconds. After serial dilution with BPW samples were plated on Standard Methods Agar and DRBC agar for analysis of aerobic plate count and yeasts and molds, respectively. The inoculated plates were incubated at 25°C for 48-92 h after which colonies were enumerated. Quality Three markers of quality were tested to determine any difference between pulsed UV light treated mushrooms and untreated mushrooms. Weight loss, whiteness and visual appearance were measured at days 0, 3, 6 and 11 of storage at 3°C. To determine weight loss, weight over the course of storage was monitored and percent weight loss was calculated using weight at day 0 as the standard. Whiteness was measured using a Minolta Chromameter to measure L-value (n=20). Visual appearance was assessed by the use of digital photographs, which were taken in controlled conditions each day to ensure lighting was the same among all photos. Vitamin D2 Analysis Samples were frozen and subsequently freeze-dried directly following treatment or after x days of storage depending on the experiment. The freeze dried mushrroms were ground into powder and sent to Medallion Labs (Minneapolis, MN) for Vitamin D2 analysis. Vitamin D2 values are presented based on the % DV (Adequate Intake of 400 IU for adults over 50) in a serving (84g) of fresh mushrooms. Results are also reported as IU/100 g fresh weight in table 1. Statistics For each experiment the mean of three replicates for each treatment was calculated and ANOVA and Tukey’s Test were performed to determine significant difference (p = 0.05)

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Results and Discussion Dose/Response Study Data from the dose/response study (Figure 1 and table 1) shows the vitamin D2 content of sliced white button mushrooms increased with increasing exposure to pulsed UV light but leveled off after 12 pulses (4 s). The vitamin D2 content of mushrooms treated with 12 pulses and 18 pulses are not significantly different. The data suggest that since the vitamin D2 levels off around 1700% DV/serving this could provide a built in safety factor to reduce the possibility of producing potentially toxic levels of vitamin D2.

Figure 1. Vitamin D2 content of sliced fresh white button (Agaricus bisporus) mushrooms treated with pulsed UV light in increments of 3 pulses (3 pulses = 1 s exposure time). Error bars represent standard deviation. Lower case letters that are the same are not significantly different (p=0.05).

Sliced and Whole, Brown and White Untreated samples of brown and white button mushrooms (figure 2) contained low levels of naturally occurring Vitamin D2 (0.80% DV/ serving in brown buttons and 1.66% DV in white buttons). The sliced mushrooms of both types produced the highest amounts of Vitamin D2 generation (about 2 fold higher) compared to mushrooms treated whole. White button mushrooms produced slightly higher amounts of Vitamin D2 when treated both sliced and whole, although levels were not significantly different.

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Figure 2. Vitamin D2 content of sliced fresh white and brown button (Agaricus bisporus) mushrooms treated with pulsed UV light (3 pulses = 1 s exposure time, control mushrooms received 0 pulses) in either sliced or whole form. Error bars represent standard deviation. Lower case letters that are the same are not significantly different (p=0.05).

Package Weight and Distance From Lamp Sliced white buttons mushrooms treated in a full 8 oz package (230 g) and the same containing 150 g showed that an increased volume of mushrooms leads to a decrease of about 40% in the generation of Vitamin D2 (figure 3). Increasing the distance to 6.36 cm (double the distance of 3.18 cm used in all previous experiments) from the window did not result in a significant effect on vitamin D2 production (figure 4). The results of the dose response study show that with increasing treatment there is not a linear trend with regards to amount of Vitamin D2 generated. The level of vitamin D2 appears to level off around 1700% DV. Coupled with the data on the package weight, it is can be seen that the Vitamin D2 content can be controlled through various factors to assure the desired amount is generated. Distance from the lamp, although not shown to be a factor in this study, is also an important variable to consider when creating a treatment regimen for fresh mushrooms. As the distance from the lamp increases the dose of irradiation will decrease as shown by Koyyalamudi et al. (2009). It was also seen that different types of mushrooms even of the same species could vary in their Vitamin D2 generation. The white and brown button mushrooms used in this study contained small but not statistically significant differences in vitamin D2 content. This is most likely due to either differences in the ergosterol content of the mushroom and/or the pigmentation of the brown mushrooms reducing the effects of the UV light. Much like in humans, darker pigmentation may block UV irradiation resulting in less Vitamin D2 generation (Clemens et al., 1982). When mushrooms are sliced the gill tissue is exposed. Jasinghe (2004) showed that ergosterol is concentrated differently in the 8

various tissues of a mushroom; most notably it is more concentrated in the gills. Thus, slicing mushrooms exposes the most ergosterol rich tissue allowing more efficient Vitamin D2 generation can occur.

Figure 3. Vitamin D2 content of sliced fresh white button (Agaricus bisporus) mushrooms treated in two different weight packages with pulsed UV light (3 pulses = 1 s exposure time). Error bars represent standard deviation. Lower case letters that are the same are not significantly different (p=0.05).

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Figure 4. Vitamin D2 content of sliced fresh white button (Agaricus bisporus) mushrooms treated with pulsed UV light (3 pulses = 1 s exposure time) at two distances from the quartz window of the pulsed UV light system. Error bars represent standard deviation. Lower case letters that are the same are not significantly different (p=0.05).

Vitamin D2 Retention Vitamin D2 decreased significantly during postharvest storage at 3°C (figure 5) from Day 0 (729% DV) to Day 3 (555% DV) but remained stable through days 6 and 11. This amounted to a decrease of about 24% from initial levels. The retention of Vitamin D2 in fresh mushrooms is of particular interest, mainly regarding the conflict of information up to this point. Previous studies disagree on the stability of Vitamin D2 in mushrooms during storage. Roberts et al. (2008) showed a significant decrease (40-50%) in Vitamin D2 content after 2 days of storage at 2°C. Hu (2009) also found the levels decreased (22-48%) after 3 days of storage at 2-5°C, however data also showed that the levels then subsequently increased after 7 days. Koyyalamudi et al. (2009) reported no change in Vitamin D2 levels over time, although no data was given. The current study showed that after an initial decrease from 729% DV directly following treatment to 555% DV after 3 days of storage at 3°C, the levels remain steady through 11 days of storage. This illustrates that, in order to achieve a Vitamin D content in fresh mushrooms that meet regulations for vitamin content claims, the initial decrease (~24%) would need to be accounted for in the treatment scheme.

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Figure 5. Vitamin D2 content of sliced fresh white button (Agaricus bisporus) mushrooms treated with pulsed UV light (3 pulses = 1 s exposure time) and stored for up to 11 days at 3°C. Error bars represent standard deviation. Lower case letters that are the same are not significantly different (p=0.05).

Microbiological Testing When treated with 3 pulses of light the initial levels of aerobic plate count (figure 6) and yeasts and molds (figure 7) were not significantly different from untreated mushrooms at day 0 or after 11 days of storage at 3°C. In this shelf life study, it was shown that the short irradiation time to increase Vitamin D2 content was not sufficient to significantly change the microbiological population. Much longer treatment times are necessary to reduce microbial load (Chikthimmah and Beelman, 2006). Thus, if longer exposure times are employed as a method for microbial inactivation on fresh mushrooms, pulsed UV light may produce undesirable quality attributes, such as increased browning.

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Figure 6. Total aerobic plate counts of pulsed UV treated (3 pulses) and untreated sliced white button (Agaricus bisporus) mushrooms directly following treatment and after 11 days of storage at 3°C. Error bars represent standard deviation. Lower case letters that are the same are not significantly different (p=0.05).

Figure 7. Yeast and mold counts of pulsed UV treated (3 pulses) and untreated sliced white button (Agaricus bisporus) mushrooms directly following treatment and after 11 days of storage at 3°C. Error bars represent standard deviation. Lower case letters that are the same are not significantly different (p=0.05).

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Quality Evaluation of quality attributes indicated there were no significant differences between treated and untreated mushrooms. Figure 8 shows no significant difference in weight loss at any day during storage between treated and untreated mushrooms although a trend of less weight change in the treated mushrooms was observed. The L-values measured to describe whiteness of the mushrooms shows no significant difference in treated and untreated mushrooms on any day measured during storage (figure 9), however on day 11 both treated and untreated mushrooms are significantly less white than their whiteness on day 0. Figure 10 supports the observation that there is no difference in color between treated and untreated mushrooms on each day measured during storage. However, a change in appearance can be seen by day 6 (figure 10c). If mushrooms enriched in Vitamin D2 were negatively impacted in terms of quality there may be a significant issue with consumer acceptance. Treated and untreated mushrooms did not vary over the shelf life compared to each other in weight loss, color change and visual appearance. Thus, no negative effects on quality were introduced with Vitamin D2 enrichment of sliced white button mushrooms.

Figure 8. % Weight change in pulsed UV treated sliced fresh white button (Agaricus bisporus) mushrooms from initial weight (150 g) after storage at 3°C for up to 11 days. Error bars represent standard deviation. Lower case letters that are the same are not significantly different (p=0.05).

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Figure 9. Whiteness (L-value) of untreated and pulsed UV light treated sliced fresh white button (Agaricus bisporus) mushrooms. An L-value of 100 = white and 0= black). Error bars represent standard deviation. Lower case letters that are the same are not significantly different (p=0.05).

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Figure 10. Photograph of sliced fresh white button mushrooms after storage at 3°C for 0 days (a), 3 days (b) 6 days (c) and 11 days (d). The top row of each quadrant are untreated, the bottom row was treated with 3 pulses of pulsed UV light.

This study illustrates the complexity and breadth of factors that must be taken into consideration when developing a treatment regimen for vitamin D2 enrichment of fresh mushrooms. The results demonstrate that the desired vitamin D2 content of fresh mushrooms can be achieved through proper control of these factors including; dose of irradiation, volume of mushrooms treated, whether the mushrooms are sliced or whole, and the variety of mushroom treated and consideration of the retention of vitamin D2 during storage. Results of the dose/response study should help reduce concerns by regulatory agencies about the possibility of producing excessive amounts of vitamin D2 using this technology.

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Recommendations This study confirmed that the use of pulsed UV light treatment could be a more practical and efficient method compared to previous studies involving continuous UV light treatment. It should be noted that in this study, the mushrooms were treated in commercial packages filled with 150 g (less than a full package) using a Xenon" B-type lamp. Our results showed that if the package was full the vitamin D2 content was reduced by ~40%. Thus, the vitamin D2 will most likely vary if treated in any other fashion (i.e. as single layer on a conveyor belt). The retention of vitamin D2 is also important and should be taken into account for labeling and regulatory concerns. Following is an example calculation for the final vitamin D2 content in a package of fresh mushrooms using the parameters outlined in this study. A full commercial package (230g) of sliced white button mushrooms is treated at a distance of 3.18 cm from the quartz window of the system with 3 pulses of pulsed UV light. The estimated vitamin D2 content would be 447% DV/ 84 g serving (or 1984 IU/100 g fresh weight) directly following treatment. After storage for 3 days at 3°C the vitamin D2 content would decrease by approximately 24% to about 340% DV/ 84 g serving (1500 IU/100 g fresh weight). The results presented from this study should serve as guidance for development of a treatment regimen to increase the vitamin D2 content of fresh mushrooms on a commercial basis under varied circumstances. Technology Transfer The results from this study will be submitted for publication in a peer reviewed scientific journal and be included as part of the author’s PhD thesis. In addition, the data will be presented at the 2009 Penn State Mushroom Industry Conference in Avondale, PA on September 22. This will aide those in the industry in understanding the fundamental principles governing the enrichment of fresh mushrooms with vitamin D2 and allow them to develop treatment regimens to meet their needs.

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References Beelman RB, & Kalaras MD. 2008. Provisional patent application: 61/047,268. Cannell JJ, Hollis BW, Zasloff M, & Heaney RP. Diagnosis and treatment of vitamin D deficiency. Expert opinion on pharmacotherapy 9(1):107-18 (2008). Chikthimmah N, & Beelman RB. 2006. Microbial spoilage of fresh mushrooms. In: Sapers GM, Gorney JR, & Yousef AE. Micro.biology of Fruits and Vegetables. Boca Raton, FL: Taylor and Francis. p 135-158. Clemens TL, Henderson SL, Adams JS, Holick MF. 1982. Increased skin pigment reduces the capacity of skin to synthesize vitamin D3. Lancet. 1:74–6. Hu, X. 2009. Commercialization preparedness studies of UVB light treated mushrooms. Mushroom News 57(3): 12-13,16-18. Jasinghe VJ & Perera CO. 2005. Distribution of ergosterol in different tissues of mushrooms and its effect on the conversion of ergosterol to vitamin D2 by UV irradiation. Food Chem. 92(3):541-546. Jasinghe VJ & Perera CO. 2006. Ultraviolet irradiation: The generator of Vitamin D2 in edible mushrooms. Food Chem. 95(4):638-643. Jasinghe VJ, Perera CO, & Sablani SS. 2007. Kinetics of the conversion of ergosterol in edible mushrooms. Journal of Food Engineering 79(3):864-869. Kalaras MD, & Beelman RB. 2008. Vitamin D2 enrichment in fresh mushrooms using pulsed UV light. Available online at: foodscience.psu.edu/directory/rbb6/VitaminD Enrichment.pdf. Ko JA, Lee BH, Lee JS, & Park HJ. 2008. Effect of UV-B exposure on the concentration of vitamin D2 in sliced shiitake sushroom (Lentinus edodes) and white button mushroom (Agaricus bisporus). J. Agric. Food Chem. 56(10):3671-3674 Koyyalamudi SR, Jeong SC, Song CH, Cho KY, & Pang G. 2009. Vitamin D2 formation and bioavailability from Agaricus bisporus button mushrooms treated with ultraviolet irradiation. J. Agric. Food Chem. 57(8):3351-3355. Lappe JM, Travers-Gustafson D, Davies KM, Recker RR, & Heaney RP. 2007. Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial. Am. J. Clin. Nutr. 85(6):1586-1591. Matsuoka LY, Ide L, Wortsman J, MacLaughlin J, & Holick MF. 1987. Sunscreens suppress cutaneous vitamin D3 synthesis. J. Clin. Endocrinol. Metab. 64:1165–1168.

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Matilla PH, Piironen VI, Uusi-Rauva EJ, & Koivistoninen PE. Vitamin D Contents in Edible Mushrooms. J. Agric. Food Chem 1994 42: 2449-2453. Mattila P, Lampi A-M, Ronkainen R, Toivo J, & Piironen V. 2002. Sterol and vitamin D2 contents in some wild and cultivated mushrooms. Food Chem. 76(3):293-298. Mau JL, Chen PR, & Yang JH. 1998. Ultraviolet Irradiation Increased Vitamin D2 Content in Edible Mushrooms. J. Agric. Food Chem. 46(12):5269-5272. NIH. (2004, 2008). "Dietary Supplement Fact Sheet: Vitamin D." 2009, from http://ods.od.nih.gov/factsheets/vitamind.asp. Roberts JS, Teichert A, McHugh TA. 2008. Vitamin D2 formation from post-harvest UVB treatment of mushrooms (Agaricus bisporus) and retention during storage. J. Agric. Food Chem. 56(12):4541-4544 Teichmann A, Dutta PC, Staffas A, & Jagerstad M. 2007. Sterol and vitamin D2 concentrations in cultivated and wild grown mushrooms: Effects of UV irradiation. LWT - Food Science and Technology 40(5):815-822. Wang TJ, Pencina MJ, Booth SL, Jacques PF, Ingelsson E, Lanier K, Benjamin EJ, D’Agostino RB, Wolf M, & Vasan RS. 2008. Vitamin D deficiency and risk of cardiovascular disease. Circulation 117: 503-511. Xenon Corporation. 2008. Vitamin D system. Available online at: http://www.xenoncorp.com/Images/Vitamin_D_System2.pdf

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Table 1. Vitamin D2 content of mushrooms from all experiments from this study. Data are means of three replications ± standard deviation.

Other Factors

Vitamin D2 Content (%DV/ 84 g Serving)

Vitamin D2 Content (IU/100 g FW)

N/A N/A N/A N/A N/A N/A