Drying of Oyster Mushroom
Drying of Oyster Mushroom
Drying of Oyster Mushroom
INTRODUCTION
during drying (Deshpande and Tamhane,
Mushroom contains high quality 1981).
proteins, vitamins and minerals as compared
The optimum tefDperature for drying
to fruits and vegetables (Hemant Mohure, of sulphited mushroom was 600C to retain the
2(02). The mushroom is popular for its delicacy original colour and flavour (Dang and Singh
and flavour. It contains about 90% moisture, 1978). Mudahar and Bains (1982), suggested
. because of its high moisture and delicate nature that pre-treatment is necessary to check
cannot be stored for more than 24 hours at an discolouration during mushroom drying.
ambient temperature. After harvest, changes
In order to improve the shelf life of the
like browning, loss of moisture and texture
occurs. Production of mushroom in the world mushroom and thereby to introduce
at present is estimated to be around 5 million mushroom-based Agro-industries, the present
tones per annum and is increasing at the rate investigation was under taken to study the
of 7% per annum as compared to past years drying behavior of mushroom in various driers.
(Tewari and Meera Pandey, 2002). In India its
Oyster mushroom is highly suitable for
production is about 50,000 tonnes per annum cultivation in plains and even in hilly areas with
(Tewari, 2004).
.
more bio-efficiency (40~100 percent} and it
Since all the mushrooms produced requires wider cropping temperature. Oyster
cannot be marketed immediately, effective mushroom contains 89.8 % moisture, 2.9 %
preservation methods are necessary to improve pro~ein, 0.36 % fat, 5.3 % carbohydrates, 1 %
the shelf life. Among different drying methods fiber, 1 % ash and 33.9 Kilocalories of energy
like hot air drying, freeze drying, microwave value. Oyster mushroom known to have
drying and irradiation drying; hot air drying is vitamines like thiamine (0.5 mg/100 g fresh
mostly used for long-term storage of mushroom), riboflavin (0.5 mg/100 g fresh
mushroom. Hot air drying is comparatively mushroom) and niacin (10.9 mg/lOO 9 fresh
cheaper method and is employed on mushroom). Oyster mushroom is also having
commercial scale (Pruthi eta/, 1978). However, minerals like calcium (3.3 mg/100 g fresh
water blanching for 3 min .inactivates the mushroom), phosphorous (134.8 mg/100 g
polyphenoloxidase that causes browning fresh mushroom), Iron (1.5 mg/100 g fresh
1.COliege of Agriculture, OAS, GRVR; Bangalore-65, IndIa.
2.Department of Argil. Microbiology, UAS, GKVK, Bangalore-65, India.
80
Treatment
Solar Cabinet
Drying
Control
Blanching
0.5%KMS
1.0%KMS
1.5% KMS
Control
Blanching
0.5%KMS
1.0%KMS
1.5% KMS
Microwaveoven Drying
Cabinet Tray
Drying
Control
Blanching
0.5%KMS
1.0%KMS
1.5% KMS
Control
Blanching
0.5'YaJ<'MS
1.0% KMS
1.5% KMS
Control
Blanching
0.5%KMS
1.0% KMS
1.5% KMS
Temperature (OC)
40-70
40 2
55
60
70
Drying
Final moisture content, %
(wb)
time (min)
(db)
Drying
Ratio
360
480
390
420
480
95
110
110
8.81
8.71
8.93
8.96
9.05
8.61
8.35
8.81
8.10
8.01
8.20
8.23
8.30
8.02
7.71
8.09
10.00
7.04
10.73
1078
10.81
9.97
6.96
10.67
115
120
330
420
360
390
420
270
330
300
330
360
210
270
240
240
270
8.94
9.16
9.31
9.07
9.48
9.50
9.65
9.13
9.05
9.11
9.17
9.24
9.00
8.85
9.08
9.11
9.13
8.21
8.34
8.51
8.32
8.66
8.68
8.80
8.37
8.30
8.35
8.41
8.46
8.26
8.13
8.32
8.35
8.36
10.67
10.67
9.73
6.91
10.49
10.52
10.55
9.96
7.15
10.76
10.79
10.89
9.66
7.36
10.45
10.51
10.61
mushroom), Sodium, (83.7 mg/lOOg fresh (3) Soaking in 1.0% KMS Solution for 15 min
mushroom) and Fbtassium (373.3 mgl100'g fresh (4) Soaking in 1.5% KMS Solution for 15 min
mushroom) as given by Marimuthu'et aL, (1989). (5) Untreated mushroom served as control
The pre-treated mushroom samples were
MATERIAL AND METHODS
placed
on
a blotting paper to remove the unbound
Freshly harvested oyster mushroom
surface
moisture.
The control as well as the pre(PJeurotus florida) was cultivated during winter on
treated
samples
were
dried by three methods of
paddy strawsubstrate at the University ofAgricultural
drying
Viz.,
Solar
cabinet
drying, Microwave oven
Sciences, GKVK, Bangalore were procured. The
drying
and
cabinet
tray
drying.
mushroom with 90.56% moisture (wb) was sOrted
for good quality. The brown and affected portions
Moisture content of oyster mushroom was
of the Itnishroom were discarded. Quality determined as per the procedure given by AOAC
mushroom was sliced to12mm thickness (Pruthi et standards (1995). The pretreatment was followed
aI. 1978) and washed with potable water to remove as suggested by Sugunal et aI. (1995). The samples
dirt and foreign materials, so as to reduce the initial were dried in cabinet tray drier at 55, 60 and 7fJJC
microbfal load, and wven various pre-treatments, temperatures to a predetermined moisture level (8. Suchas,
9%Wb). Similarly the samples were dried in
(1) Blanching: It was done in boiling water for 3-4 microwave oven at a power level-I, hot air
min. Immediately, the blanched mushroom were temperature 4O2C. In solar cabinet drier the
samples were dried at 4O-700C. The dried samples
cooled under running tap water for 10 minutes.
(2) Soaking in 0.5% KMS Solution for 15 min in all the methods of drying were immediately
81
Microwaveoven Drying
Cabinet Tray
Drying
Treatment
Control
Blanching
0.5%KMS
1.0% KMS
1.5% KMS
Control
Blanching
0.5%KMS
1.0%KMS
1.5%KMS
Control
Blanching.
0.5%KMS
).O%KMS
1.5%KMS
Control
Blanching
0.5%KMS
1.0%KMS
1.5%KMS
Control
Blanching
0.5%KMS
1.0%KMS
1.5% KMS
Temperature (OC)
40-70
40-70
40-70
40-70
40-70
40 2
40 2
40 2
40 2
40 2
55
55
55
55
55
60
60
60
60
60
70
70
70
70
70
Rehydration
Ratio
3.41
3.20
3.75
3.82
3.87
3.46
3.42
3.88
4.91
4.95
3.91
3.68
4.72
4.81
4.93
3.98
3.76
4.90
4.93
5.2)
4.10
3.89
5.20
5.22
5.25
Organoleptic Characteristics
Colour
Texture
Flavour
2.8
2.0
3.0
3.2
3.0
2.0
2.2
3.4
3.8
3.6
3.0
2.2
3.2
3.6
3.4
3.2
2.6
3.6
4.0
3.4
3.0
2.0
3.2
3.4
3.2
2.2
2.0
2.8
3.0
3.0
2.0
2.0
3.4
3.6
3.4
2.8
2.0
3.2
3.4
3.2
2.6
2.0
3.6
3.8
3.4
2.6
2.0
3.0
3.2
3.0
2.4
2.4
3.2
3.4
3.0
2.2
2.6
3.6
3.8
3.6
2.4
2.8
3.4
3.6
3.2
2.6
2.8
3.4
4.0
3.6
2.2
2.8
3.2
3.2
3.0
packed in polyethylene bag and kept in desiccators judges was nur.lerical scores rating from 0 (very
to prevent further accumulation of moisture from poor) to 5 (extrerlieiy good) points as proposed by
the surroundings.
.
Amerine et al., (1965).
The rehydration ratio (ratio of sample
weight after maximum rehydration when immersed
in boiling water to the weight of dried sample taken
for rehydration) was determined as per the method
described by Pruthi et al. (1978). Rehydrayion ratio
at different time of immersion (10, 20 and 30
minutes) in boiling water was calculated as under
82
Table 2A;. Effect of pre-treatment and drying methods on rehydration of dried mushroom by
immersion in boiling water
Drying Method
Treatment
W2
RR
TIme (min)
20
W2
RR
7.85
7.33
7.98
8.18
8.28
8.30
7.80
8.10
10.70
10.75
7.90
7.80
11.05
11.13
11.75
8.13
8.08
11.28
11.40
12.10
8.43
8.35
11.43
11.48
11.53
3.14
2.93
3.19
3.27
3.31
3.32
3.12
3.24
4.28
4.30
3.16
3.12
4.42
4.45
4.70
3.25
3.23
4.51
4.56
4.84
3.37
3.34
4.57
4.59
4.61
8.23
7.95
8.90
9.05
9.23
8.43
i.30
9.25
11.90
12.05
8.93
8.40
11.70
11.80
12.18
9.33
8.80
11.90
11.95
12.80
9.38
8.85
12.05
12.13
12.23
10
Control
Blanching
0.5%KMS
1.0%KMS
1.5% KMS
Control
Blanching
0.5%KMS
1.0%KMS
1.5%KMS
Control
Blanching
O:5%KMS
1.0%KMS
1.5%KMS
Control
Blanching
0.5%KMS
1.0%KMS
1.5% KMS
Control
Blanching
0.5%KMS
1.0%KMS;
1.5%KMS
Solar Cabinet
.Drying
Temperature:
40-70"C
Microwaveoven drying
Power level-I
Temperature:
40 2C
Cabinet Tray
Drying at 55C
Cabinet Tray
Drying at 60C
Cabinet Tray
Drying at 70"C
1200
1100
1000
_ n___ 30
3.29
3.18
3.56
3.62
3.69
3.37
3.32
3.70
4.76
4.82
3.57
3.36
4.68
4.72
4.87
3.73
3.52
4.76
4.78
5.12
3.75
3.54
4.82
4.85
4.89.
W2
RR
8.53
8.00
9.38
9.55
9.68
8.65
8.56
9.70
12.28
12.38
9.78
9.20
11.80
12.03
12.33
9.95
9.40
12.25
12.33
13.03
10.30
9.73
13.00
13.05
13.13
3.41
3.20
3.75
3.82
3.87
3.46
3.42
3.88
4.91
4.95
3.91
3.68
4.72
4.81
4.93
3.98
3.76
4.90
4.93
5.21
4.10
3.89
5.20
5.22
5.25
i900
--
';/.800
.......-O.5%KMS
if
u 700
_ _ Blanching(3-4 min)
~I.O%KMS
c600
8~ 500
3400
o 300
.I!l
200
1~~
o
30
.=-~,
60
90
... ..
120 150 180 210 240 270 300 330 360 390 420 450 480 '51
Time (min)
Fig. I: Drying characteristics ofmushroom under solar cabinet dry ing at diflerent
pre -treatments
Drying Temperature: 40 2 C
Power Ievel-I
1200
1100
,-.
.J
1000
900
83
....-Control
_____ Blanching (3-4 min)
800
'<
-.-0.5% KMS
'i:
u
700
~I.O%K.MS
:5
~
600
500
::s
400
300
.;o
1.5%KMS
200
100
o
o
1200
I 1100
I
I~ 900
800
Drying Temperature: 55 C
1000 .
-+-Control
_____ Blanching (3-4 min)
C
til
700
'i: 600
8
~
:s
-.-0.5%KMS
500
,.i 400
~ 300
200
100 .
--~,----,.-~
...-....
0306090
~-,.
120 150
84
II
1100
1000
l:c
800
E
.,
E
0
u
700
.=
900
I~
~
I.
-+-Control
___ Blanching (3-4 min)
-.-050/0KMS
600
500
400
300
200
Vl
1.00/0KMS
100
0+
0
L -_ _
30
90
60
120
150
180
210
240
270
300
330
360
Time (min)
Fig. 4: Dry ing Characteristics of mushroom under cabinet tray drying (6O"C) at
different pre-treatments
..
_
--"--- ..
_-
r-~-----I
1100
--.
1000
:g900
-......'#.
I~
-+-Control
800
700
-.-O.50/0KMS
600
~1.O%KMS
500
t; 400
-il-1.50/0KMS
;:s
.!!2
300
'~ l__-
200
30
60
90
120
150
Time (min)
I:
180
210
_=- __=II
240
,,--------------
270
85
1200
1100
I
I
I' '"'
.0
I -0
.......
-+-Temperature: 55Cj
1000
900
i~ 800
c:
700
c:
600
500
400
300
200
i,
.8
<Il
1'-
l~
I
i
I
L
I~ 1--.--,----.---,--.-~~t,:;:;~~l;:;:;~=~~
o
30
60
90
120
150
180
210
240
270
300
330
Time (min)
Fig.6: Drying characteristics ofmushrom under cabinet tray drying at different
temperatures
86
.........
ratio of blan~hed samples. Similar results were pretreatment had highest sensory evaluation
obtained by Rama and Jacob Johan (2000) scores for colour, texture and flavour compared
and Kashibai et al. (1998).
to untreated and blanched samples (Table 2).
The rehydration ratios of the dried It is known that sulphuring or sulphiting (KMS)
samples under different drying methods for acts as a preservative and also prevents the
different periods of immersion time are presented enzyme catalyzed oxidative changes, inhibits
in Table 2A. From the table, it is observed that, microbial deterioration and withstands higher
the rehydration was almost complete within ten temperatures for drying. The texture of the
minutes of immersion in boiling water. During blanched samples were adversely affected, as
the rehydration process, the water turned brown it was very hard compared to KMS treated
and turbid in case of untreated and blanched samples, which might be due to blanching
samples. In case of KM$ pre-treated samples, it treatments. The quality of the dried
had an attractive yellow colour and remain~d mushrooms, which had no pretreatments, was
almost clear. Similar observation have been found to be undesirable, the texture was soft
made by Pruthi et aI., (1978).
and the product crumbled readily. Similar
Sensory evaluation
results were recorded by Deshpande and
Mushroom samples dried after KMS Tamhane (1981).
REFERENCES
Amerine, M.D.et al (1965). Principles ofSensory Evaluation ofFoods, Academic Press, London.
AOAC (1995): Official methcxls Q/Analysis ofAOAC international, 1995, (Edited by Patricia Cunniff), AOAC International
Publication, 16th Edition, Vol. II, Chapter 37, pp: 4.
Dang, RL. and Singh, RP., (1978), In: Indian Mushroom Science 1. First Symposium on Survey and Cultivation of edible
mushroom in India, held at Regional Research Laboratory, SrInagar, 1976, (Atal, C.K., Eds), pp: 215-223.
Deshpande, AG. and Tamhane, D.\/., (1981), J. Fd. Sci. Technol., 18 (3): 96-101.
Hemant Mahure, (2oo2),Agric Today, March 2002, pp: 42-43.
Kashibai, 5., (1998) Karnataka J. Agril. Sci., 11 765-769.
Marimuthu, 1.,(1998) In: Oyster Mushroom Production., Arst edn. Tamil Nadu Agril. Univ. Coimbatore.
Mudahar, G.S. and Bains, G.S., (1982),lndian. Fd. Packer. 36 (2): 19-27.
Pruthi, J.S.,(1978) Indian. Fd. Packer, 32 (2): 7-15.
Rama, \/. and Jacob John, P., (2000) Indian. Fd. Packer, 54 (1-6): 59-64.
Suguna, S., L.,(1995) J. Fd. Sci. Technol., 32 (4): 284-288.
Tewari, RP. and Meera Pandey, (2002) Hindu Survey of Indian Agriculture-2002, pp: 165-167.
Tewari, RP., (2004), The Hindu Survey of Indian Agriculture-2004. pp: 132-133.
Tulsidas,T. N., (1994) Combined convective and microwave drying of grapes. Ph. D. Thesis submitted to the faculty of
graduate studies and research of Mc Gill., Macdonald Campus, Canada H9X3V9.