Nutrient content and nutrient retention
of selected mushrooms
D.B. Haytowitz. Nutrient Data Laboratory, Beltsville Human Nutrition Research Center,
USDA-ARS, Beltsville, MD
Abstract
Abstract
In 2004 Americans consumed 2.6 pounds per capita of fresh
mushrooms. While the white button mushroom remains a
frequent component of many recipes, other varieties such as
shiitake, enoki, maitake, oyster, portabella, and shiitake are also
growing in popularity. To improve and expand the data in the
USDA National Nutrient Database for Standard Reference, the
Mushroom Council and USDA undertook the sampling and
analyses of these mushrooms.
Mushroom samples were collected from retail outlets in 12 cities
in the US. These were then combined into 4 random composites
by type and analyzed under existing contracts and cooperative
agreements managed by USDA’s Nutrient Data Lab (NDL). All
mushrooms were analyzed raw. White mushrooms were also
analyzed stir-fried and microwaved, so that retention factors could
be developed and used to calculate cooked values for other
mushroom varieties.
Results of this study show that mushrooms are a good source of
several nutrients. These include total dietary fiber, which ranges
from 1.4 g/100g in the white variety to 2.8 g/100g in enoki.
Potassium ranged from 204 mg/100g in maiitake to 359 mg/100g
in both enoki and white. Niacin ranged from 2.8 mg/100g in white
to 7.0 mg/100g in enoki. Enoki contained 52 μg/100g of folate,
while other mushrooms contained lower amounts. All minerals
and vitamins were well retained (most at 100%) during cooking.
Some losses of sodium (due to leaching) and folate and vitamin
B6, which are more heat labile, were observed.
These new values for mushrooms enabled USDA to update and
expand the data on mushrooms in its databases, which are
available on its web site: www.ars.usda.gov/nutrientdata. The
Mushroom Council was also able to use the data to promote
mushrooms to the public and to provide information on the
nutrient content of mushrooms to its members.
.
Introduction
Introduction
In 2003 Americans consumed 2.6 pounds per capita of
mushrooms. While the white button mushroom remains a
frequent component of many recipes, other varieties such as
enoki, oyster, and maitake are also growing in popularity. To
improve and expand the data in the USDA National Nutrient
Database for Standard Reference, the Mushroom Council and
USDA undertook the sampling and analyses of these mushrooms.
Agricultural
Research
Service
References
References
Murphy, E.W., P.E. Criner, and B.C. Gray. 1975. Comparison of methods for
determining retentions of nutrients in cooked foods. Journal of Agriculture
and Food Chemistry 23:1153.
Pehrsson P.R, Haytowitz D.B., Holden J.M. 2003. The USDA’s National
Food and Nutrient Analysis Program: Update 2002. J. Food Comp. Anal.
16(3): 331-341.
Perry, C.P., Beckler, D.G., Pehrsson, P.R., Holden, J.M. 2001. A National
Sampling Plan for Obtaining Food Products for Nutrient Analysis.
Proceedings of the 2000 Joint Statistical Meetings, American Statistical
Association: Section on Survey Methodology. Indianapolis, IN. p. 267-72.
This project is supported by ARS, USDA , the Mushroom Council under
agreement #58-1235-5-121 and by NIH under Contract #Y1CN5010
Methods
Methods
This study used the infrastructure established by USDA’s Nutrient Data Laboratory (NDL)
for the National Food and Nutrient Analysis Program (NFNAP). NFNAP incorporates
prioritizing foods and nutrients for analysis, statistically valid sampling plans, qualified
analytical laboratories, and a rigorous quality control program. Samples of white, maitake,
oyster, and enoki mushrooms were collected from 12 retail outlets around the country.
Discussion
Discussion
Proximate and other components: The proximate composition of the raw
mushrooms was quite similar for all types (Table 1). Moisture ranged from
87.7 g/100 g in enoki to 92.18 g/100 g in white mushrooms. Protein ranged
from 1.94 g/100 g in maitake to 3.00g/100 g in white. The average fat
content for all mushrooms was approximately 0.3g/100 g. There is a
significant difference (P ≥0.05) between mushrooms for moisture and ash,
but no significant difference was observed for protein, fat, and
carbohydrates
The β-glucan content of mushrooms varied from 0.02 g/100 g in enoki to
0.79 g/100 g in oyster types. The ergosterol content varied from 37 mg/100
g in enoki to 59 mg/100 in maitake and white types. The ergosterol content
is of particular interest as it is precursor to vitamin D and recent research
sponsored by the Mushroom Council has shown significant amounts of
vitamin D can be produced in mushrooms by exposure to UVB light.
Minerals
: More variability was observed in the mineral content of
mushrooms (Table 2), with significant differences (p≤0.05) between
mushrooms for calcium, copper, iron, magnesium, manganese and
potassium. No observable differences were noted for phosphorus, sodium,
and zinc. All mushrooms provided a significant amount of copper ranging
from 0.1 mg/100 g for enoki to 0.3 mg/100g for white, compared to a RDA of
0.9 mg/day. Sodium values were low, but variable, ranging from 1 mg/100
g in maitake to15 mg/100 g in white.
Vitamins:
There is a significant difference (p≤0.05) between mushrooms for
niacin and folic acid, but no significant difference were observed for thiamin,
riboflavin, pantothenic acid, and vitamin B6 (Table 3). Mushrooms contain
significant amounts of niacin, ranging from 2.80 mg/100 g in white
mushrooms to 7.0 mg/100 g in enoki, compared to a RDA of 16 mg/day
(men and women, 19+). Folate is quite variable ranging from 19 μg/100 g in
white mushrooms to 52 μg/100 g in enoki, compared to a RDA of 400
μg/day (men and women, 19+).
Nutrient Retention:
Most nutrients were retained at the 100% level in both
stir-frying and cooking in a microwave oven (Table 4). Of the minerals,
sodium showed the lowest retention, 80% and 85% for stir-frying and
microwaving respectively. Sodium losses are typically due to leaching,
though neither cooking method is known to have high amounts of nutrient
losses due to leaching.
Folic acid retention during stir-frying (95%) was higher than that during
microwaving (65%). Conversely, vitamin B
6
was better retained during
microwaving (80%) than stir-frying (65%). Other B-vitamins exhibited 100%
retention under the cooking conditions used in this study.
These data have been aggregated with other acceptable data on
mushrooms obtained by NDL and released in the USDA National Nutrient
Database for Standard Reference, which is available on NDL’s web site:
http://www.ars.usda.gov/nutrientdata. For this reason, the values reported
in SR may be slightly different from those reported here.
a,b
means with the same letter are not significantly different (p≤0.05) between
types of mushrooms; Mean ± Standard error
Table 1. Proximate content of raw mushrooms (g/100 g, edible portion)
0.21±0.04
b
0.79±0.06
a
0.29
b
0.62
a
β-glucan
59±4.22695937±9.27Ergostrerol (mg/100
g)
1.452.102.702.8±0.21Dietary fiber
3.695.956.818.42Carbohydrate
(by difference)
0.79
b
0.77±0.02
b
0.52
b
0.91±0.08
a
Ash
0.34±0.060.33±0.040.200.28±0.08Fat
3.00±0.222.75±0.241.942.66±0.25Protein
92.18±0.48
b
90.20±0.52
b
90.53
b
87.73±0.51
a
Moisture
White (n=3)Oyster (n=3)Maitake (n=2)Enoki (n=3)
15±3.51613±0.35 (3)
Sodium
0.60 ±0.050.770.750.65 (2)Zinc
a,,b,c
means with the same letter are not significantly different (p≤0.05)
between types of mushrooms; Mean ± Standard error (number of samples)
Table 2. Mineral content of raw mushrooms (mg/100 g, edible portion)
358±15.7
a
324
a
204
b
359±19.8 (3)
a
Potassium
94±898
b
74105 (2)
Phosphorus
0.05±0.01
c
0.10
b
0.06
a
0.08 (3)
a
Manganese
10±0.42
b
15
a
10
b
16 (2)
a
Magnesium
0.22±0.05
b
0.91
a
0.30
b
1.15±0.09 (3)
a
Iron
0.30±0.01
a
0.12
a
0.25
b
0.11±0.02 (3)
a
Copper
4±0.89
a
1
b
1
b
0.4±0.13 (3)
a
Calcium
White (n=3)Oyster (n=2)Maitake (n=2)Enoki
a,,b,c
means with the same letter are not significantly different (p≤0.05) between
types of mushrooms; Mean ± Standard error (number of samples)
Table 3. Vitamin content of raw mushrooms (mg/100 g, edible portion)
19 (2)
b
6 (2)
c
29 (2)
b
52±2 (3)
a
Folic acid (μg/100 g)
0.05±0.005 (3)0.10 (2)0.05 (2)0.10±0.02 (4)Vitamin B6
1.36 (1)1.30 (1)0.27 (1)1.35 (1)Pantothenic acid
2.80±0.94 (4)
b
5.87±0.97 (3)
a
6.58 (2)
a
7.03±0.86 (4)
a
Niacin
0.22 (1)0.33 (1)0.24 (2)0.20±0.02 (3)Riboflavin
0.05±0.02 (4)0.17±0.04 (3)0.15 (2)0.22±0.07 (4)Thiamin
White Oyster Maitake Enoki
1
Stir-fried yield 90.69%, Moisture loss –9.58%, fat loss -0.09%
Microwave yield 81.98%, Moisture loss –16.64%, fat loss -0.03%
2
dashes denote nutrient not analyzed.
Table 4. Nutrient retention for cooked white mushrooms
1
1000.061000.100.05 Thiamin
19 16
0.05
1.96
5.35
0.43
0.7
17
488
126
0.06
14
0.33
0.4
6
Microwave
d
95
65
100
100
-
85
80
100
100
80
100
100
80
90
% Retention
20
0.04
1.45
3.99
-
2
0.57
12
395
105
0.05
11
0.25
0.29
4
Stir-fried
0.05
1.36
2.80
0.22
0.6
15
358
94
0.05
10
0.22
0.3
4
Raw
Folic acid
Vitamin B6
Pantothenic
acid
Niacin
Riboflavin
Zinc
Sodium
Potassium
Phosphorus
Manganese
Magnesium
Iron
Copper
Calcium
65
80
100
100
100
100
85
100
100
100
100
100
100
100
% Retention
Sampling:
• States where samples were procured were selected proportional to the state population
(US Census, 2000)
• Sample counties within states dispersed over the 48 conterminous states, were selected
proportional to the county population
• Sample Consolidated Metropolitan Statistical Areas (CMSAs) selected proportional to
CMSA population
• Retail outlets with over $2M sales were selected in 12 primary locations (Figure 1)
• Maitake mushrooms were not available in retail outlets identified in the sampling plan, so
samples were obtained from two growers; enoki mushrooms were not found in all of the
retail outlets, so additional samples were obtained from two growers.
Reference: (Perry et al, 2002).
Sample preparation:
• Shipped overnight to the Food Analysis Laboratory Control Center (FALCC) at Virginia
Polytechnic Institute and State University in Blacksburg, Virginia where composites were
prepared. Composites were analyzed for nutrients based on expected content and
priority. Therefore not all composites were analyzed for all nutrients.
• White mushrooms were stir-fried for six minutes over medium heat in a non-stick skillet.
No oil was added. White mushrooms were covered loosely with plastic wrap and
cooked in a microwave oven on high (100% power) for three minutes.
• Samples were packed under nitrogen and shipped frozen to qualified commercial
analytical labs under USDA contracts, for analysis.
Analysis Methods:
The methods used were those of AOAC international as follows:
• Protein was analyzed by Kjeldahl (990.03); fat by acid hydrolysis (954.02), moisture by
vacuum oven (934.01) and ash by gravimetric measurement (923.03).
• Dietary fiber was analyzed by the enzymatic-gravimetric method (991.43)
• Minerals were analyzed by ICP (984.27).
• Thiamin and riboflavin were analyzed by the fluorometric method (942.23 and 9700.65,
while niacin, pantothenic acid, and vitamin B6 were analyzed by microbiological methods
(944.13, 945.74 and 961.15); Folic acid was done by the enzymatic method (992.15).
• Ergosterol was determined by gas chromatography (Phillips et al, J Food Lipids 12
(2005) p. 124-140)
• β-glucan was determined by enzymatic spectrophotometric analysis (Megazyme
"Mushroom and Yeast Beta Glucan Assay Procedure“, 2005)
NDL’s quality control panel reviewed results from the labs for both the analytical samples
and the quality control materials included in the sample stream. Once approved, the data
were migrated into NDL’s Nutrient Databank System for processing.
True retention (TR) factors for the various nutrients were calculated by the method of
Murphy et al (1975).
% TR = (nutrient content per g of cooked food X g of food after cooking)
(nutrient content per g of raw food X g of food before cooking) X 100
This formula accounts for changes in weight, due to loss or gain of moisture or fat, as well
as nutrient losses during preparation.
White Oyster Enoki
Revised NFNAP County
Samples
