Respiration Rate and Respiratory Quotient of Harvested Oyster Mushrooms at Different Storage Temperatures.

Respiration Rate and Respiratory Quotient of Harvested Oyster Mushrooms at
Different Storage Temperatures
By:
Gede Arda1, B. Rahardjo2 and Nursigit Bintoro2
1
Department Agricultural Engineering
Faculty of Agricultural Technology, Udayana University
Bali, Indonesia
2
Department of Food and Agricultural Engineering
Faculty of Agricultural Technology, University of Gadjah Mada,
Yogyakarta, Indonesia

Abstract
Temperature management on postharvest handling of fruits and vegetables has an important
role to preserve the product to prolong their sales appeal period or shelf life. Besides, availability
of gases around the product influences the product behavior also. The important aspects of the
related-physiological behaviors are respiration rate and respiratory quotient. Those provide the
initial information about the changes of gas composition in inner space of storage jar as well as
the sign of the shift of aerobic to anaerobic respiration occurred. Based on that issue, the aim of
this work is to study the physiological behaviors of Oyster mushroom on various temperature

storage and gas concentration. The object of study was Oyster mushrooms (Pleurotus ostreatus)
produced by the local farmers. Respiration rate was determined by closed or static system until
gas composition shows 1-2% of O2 and 20-21 % of CO2 under 5 0C, 15 0C and ambient storage
temperature. The result showed that respiration rate of Oyster mushroom was influenced by
storage temperature with activation energies of 2.33 kJ/mol and 2.08 kJ/mol for O2 consumption
and CO2 evolution respectively. Respiration rates resulted from this measurement were 55.45
mlO2/kg.h, 135.97 mlO2/kg.h, 318.97 mlO2/kg.h and 61.59 mlCO2/kg h, 165.34 mlCO2/kg h, 335.76
mlCO2/kg h for 5 0C, 15 0C and ambient storage temperatures respectively. In this work also was
found that Oyster mushrooms were not CO2 sensitive (tolerant of high CO2 concentration). The
value of respiratory quotients were not much different although the concentrations of CO2 reach
more than 15 %. Respiratory quotient of mushroom under 5 0C, 15 0C and ambient storage
temperatures were 1.11, 1.22 and 1.05 respectively.
Keywords: Oyster mushroom, Pleurotus ostreatus, respiration rate, respiratory quotient,
activation energy.

1

equilibrium condition reached when the
respiration rate, transfer of gas oxygen and
carbon dioxide were equal. Oxygen that

consumed by packed products was
compensated by oxygen permeating from
the surrounding atmosphere. In the same
way to oxygen, the carbon dioxide which
diffuses to surrounding atmosphere is
replaced by diffusion from product’s
tissues. On one hand, oxygen must be
available for respiration to avoid anaerobic
respiration during storage. On the other
hand, over supply of oxygen makes the
packaging has no benefit for prolonging
shelf life. The critical threshold of gas
concentration is considered to design the
magnitude of gas transfer of packaging
film (Beaudry et al., 1992).
The water vapor that produced from
respiration and transpiration continuously
adds the water vapor contained in jar’s
head space. Water vapor diffuses to
ambient environment with a certain

magnitude. Most of them condense on
product’s or packaging’s surface when
saturated water vapor pressure at certain
temperature is exceeded. This liquid water
encourages the microbial development and
reduces the diffusivity of packaging film.
Mushroom is one of the vegetables that
have short shelf life, only 3 days on
ambient temperature (Czapski and
Szudyga, 2000). Their dermal tissues have
no cuticle to protect them from physical
damages or microbial attack or water loss
(Martine et al., 2000). High moisture
content in their fruit body’s makes
mushrooms respire and transpire with high
rate. Mushroom need low temperature
storage (0 - 20C), low O2 concentration
and relatively high CO2 concentration as
well as high humidity (90-98%)
(Thompson et al, 2002).

Oyster
Mushroom
(Pleurotus
ostreatus) becomes commercial product
that is highly demanded nowadays in
Yogyakarta. Local farmer and seller pack
the mushroom with commercial plastic bag
which was available on traditional market.
It was needed physiological properties data

1. Introduction
Some agricultural produces are
perishable that characterized by their short
shelf life. Physical, chemical or biological
damages on product accelerate the
deterioration of products. The improper
management of storage conditions, i.e., too
warm or too cold for a certain product, is
another factor that increases physiological
deterioration. The shelf life of certain

products could be extended by applying
the proper packaging system also.
Temperature and humidity were essential
factors for fresh products shelf-lifeextension-efforts. Respiration rate which
indicates many metabolic activities of the
tissues as well as the rate of quality
degradation of stored products could be
suppressed through lowering the storage
temperature to slightly above the critical
temperature of certain product (Saltveit,
2004). The second factor that has great
influence on product quality is humidity.
Weight loss can be controlled by reducing
the gradient of water vapor pressure
(WVP) between product's surface and
surrounding atmosphere (Perkins et al,
2008). Losing 1-2 % of water of produce
can reduce sales appeal of produce of fresh
produce (Kader, 2002). Therefore, the
packaging system that can maintain the

oxygen and carbon dioxide at certain
concentration as well as humidity is
needed. The characteristics of packaging
system have strong relationship with
characteristics of packed product. It has
been proved that every product has their
own
unique
properties;
therefore,
designing of packaging system should be
based on those properties. The initial
knowledge that is important on designing
packaging system is respiration rate on
different temperature storage. Respiration
rate is main factor that changes the
composition of atmosphere dynamically
on jar’s head space. The gases
concentration inside jar’s head space is
always changing dynamically until the

equilibrium condition is obtained. This
2

Schiberle, 2009). So, three factors that
influence the activity of enzyme are
substrates concentration, pH and reaction
temperature. Heat is released during
respiration, 686 kcal or 2870 kJ heat is
released per 1 mole of glucose. Besides,
0.8-1 fraction of heat released is used to
heat the surrounding atmosphere or to
increase temperature of product (Ooraikul
and Stiles, 1991).

of Oyster mushroom, that were still rare, to
choice the right kind of bag plastic or to
design the proper packaging system.
Therefore, the aim of this work is to study
the physiological behaviors of Oyster
mushroom on several variations of

temperature storage and gas concentration.
2.

Theoretical Approach

2.1 Respiration
2.2 Respiratory quotient
Respiration
is
the
oxidative
breakdown of complex substrate normally
present in plant cells -such as starch,
sugars, and organic acids- to simpler
molecules such as CO2 and H2O.
Concomitant with this catabolic reaction is
the production of energy and intermediate
molecules that are required to sustain the
myriad of anabolic reactions essential for
the maintenance of cellular organization

and membrane integrity of living cells
(Kader and Saltveit, 2003). Oxygen which
is needed for oxidation must be available
in the course of respiration process.
Respiration on fresh produce located on
free atmosphere can be considered that
availability of oxygen is unlimited,
therefore availability of oxygen does not
inhibits the respiration. Otherwise,
limitation of oxygen availability on
surrounding atmosphere suppresses the
rate of respiration (Kader and Saltveit,
2003). Depletion of oxygen and
accumulation of carbon dioxide inhibit the
reaction on internal tissue. Respiration is
enzymatic reaction that has common
characteristic such as depend on substrate
concentration, pH, and temperature and of
course the concentration of enzyme that
catalyses the reaction (Metzler, 2002).

Enzyme needs pH range 5.5 to 7.5 to
perform optimum activity on reaction.
Besides, enzyme needs optimum reaction
temperature also (Kader and Saltveit,
2003). Enzyme can be inactivated if the
reaction temperature very low otherwise
enzyme will be denaturalized on too high
reaction temperature (Belitz, Grosch,

Respiratory quotient is defined as ratio
of production rate of CO2 to consumption
rate of O2. According to respiration
equation in which mole O2 consumed is
equal to mole of CO2 produced indicated
by coefficient of every species that involve
in reaction.
+6
(Ooraikul

6

+6

+

and Stiles, 1991).

From the definition it can be concluded
that the respiratory quotient is preferable
to evaluate the respiration. Increasing on
magnitude of respiratory quotient indicates
respiration is approaching to anaerobic
respiration or production rate of CO2 is
higher than consumption rate of O2. Kader
(2002) suggested that respiratory quotient
on aerobic respiration range between 0.8 to
1.3 and the exact value is depending on the
intrinsic properties of product and the
storage condition.
3.

Method

3.1 Sample preparation
Oyster mushroom was obtained from
UD. Agro Mandiri Yogyakarta located on
Pakem Village. It took about 45 minutes
travelled by motorcycle. Mushrooms were
harvested early in the morning, it was
about 5 o’clock, and then the harvested
mushrooms were spread on the floor
covered by paper to reduce the water
3

Respiration rate measured in this work
was not daily respiration development of
harvested mushrooms but respiration rate
at different gas composition. The gas
composition change occurred when
oxygen was consumed and carbon dioxide
was produced by product. The mushroom
stored
without
interruption
and
measurements were periodically conducted
during storage. Each data point in the
figures below was taken to be initial gas
composition for the next measurement.
Amount of measurement data
indicated the rate of gas composition
change inside the jar’s head space.
Amount of measurement data time by
period of measurement showed the
spending time for the head space to obtain
1% oxygen or 20% carbon dioxide level.
The lowest storage temperature, 5 0C,
spent 52 hours to obtain those levels. This
period was longer than period that
mushrooms spent at 15 0C with 18 hours
and 14 hours at room temperature.
Crossing point between O2 and CO2 curves
occur at near 10% level. This indicates that
mushrooms spend equal time to obtain the
half level of head space concentration and
also indicates that the ratio between O2
consumption rate and CO2 production rate
approaches 1.

which covers the mushroom’s surface.
Mushrooms were weighted before packed
into box. Mushroom then transported to
Operation Unit Laboratory of Agricultural
Technology Faculty of Gadjah Mada
University. The last step was storing the
mushrooms at 5 0C or 15 0C for 1 hour to
equilibrate the mushroom’s temperature
according to treatment temperature.
Three replications were prepared to
investigate the respiration rate on different
storage temperatures. The plastic jars 9
liters were used on this work. Two holes
were made on the lid of plastic jars to
facilitate the measurement of gas
concentration.
3.2 Respiration rate measurement
Mushrooms were weighted range
from 300 to 500 grams according to
storage temperature and then were placed
in 9 liters plastic jars. Paraffin wax was
used to cover the gap between the lid and
the body of the jar as well as at the hole at
its lid. The mass of mushroom used were
±500 grams, ± 400 grams and ±300 grams
for 5oC, 15oC and room temperature
respectively. Those masses differences
were intentionally used for avoiding small
gas concentration change on measurementtime-range in which was difficult to
measure due to lack of accuracy of
instruments. Gas compositions were
measured by Cosmotector XP-314 type
(Sensorex Oy, Finland)
for Oxygen
concentration and Cosmotector XP-318
type (Sensorex Oy, Finland) for CO2
concentration. The instruments have an
accuracy of 0.1%. Gas composition
measurements were taken every 4 hours, 3
hours and 2 hours for 50C, 150C and room
temperature respectively, until 1-2%
oxygen level was obtained.
4.

concentration(%v/v)

25
20
15
[O2]
10

[CO2]

5
0
0 1 2 3 4 5 6 th 7 8 9 10 11 12 13 14
n data

Figure 1. Gas concentration development at 50C
(data are taken every 4 hours)

Results and Discussion

4.1 Respiration rate

4

Oyster is grouped in vegetables with very
high respiration rate (Kader, 2002).

25

concentration (%)

20

4.2 Respiration and temperature
15

Data demonstrate that temperature had
major influence on Oyster mushroom
respiration rate. Air temperature is the
most important variable because it tends to
control flesh temperature of perishable
commodities (Thompson, 2002). Lowering
temperature to 150C and 50C could
suppress the consumption rate of O2 76.4%
and 95%, respectively. Slight different
effect occurred to production rate of CO2.
Lowering temperature to 150C and 50C
suppressed the production rate of CO2
50.7% and 81.7%, respectively. On the
other hand, gas composition has minor
effects on Oyster mushroom respiration
i.e, at room temperature respiration rate
decreases to 27.9%. All of this value was
calculated from the data taken at first
measurement of gas concentration. First
measurement was considered indicate the
influence of temperature alone. It was
different to next measurement which was
considered indicate the influence of
temperature and gas concentration. This
value is as great as respiration of broccoli.
Relative to held in the ambient air, the
reduction in respiration rate is about 28%
for broccoli heads in 2% O2 (Kader and
Saltveit, 2003).

[O2]

10

[CO2]
5
0
0

1

2

3 th
4
n data

5

6

7

Figure 2. Gas concentration development at 150C
(data are taken every 3 hours)

concentration (% v/v)

25
[CO2]
[O2]

20
15
10
5
0
0

1

2

3

4
5
nth data

6

7

8

Figure 3. Gas concentration development at room
temperature (data are taken every 2
hours)

Figure 1-3 show that rapid respiration
occurs at initial storage of mushrooms.
Abundant oxygen on head space and field
heat that still remain accelerate the
respiration. Respiration continuously
decreases when oxygen is getting thinner
and carbon dioxide getting thicker as well
as product temperature getting colder.
Oyster mushroom respires rapidly faster
than 60 ml O2/hr.kg, therefore mushroom

Table 1.Respiration rate on 50C, 150C and room temperature storage
replication

Consumption rate of O2

50C

1
2
3
average

55.82
56.94
53.59
55.45

(ml/hr.kg)
150C

135.97
135.97
135.97
135.97

Production rate of CO2

Respiratory Quotient
(RQ)

Room

5 0C

(ml/hr.kg)
150C

Room

5 0C

150C

Room

302.18
302.18
352.55
318.97

62.52
64.20
58.05
61.59

173.05
162.68
160.29
165.34

319.38
319.38
368.51
335.76

1.12
1.13
1.08
1.11

1.27
1.20
1.18
1.22

1.06
1.06
1.05
1.05

5

Ea (kJ/mol)
O2

CO2

2.33

2.09

Table. 2 Respiration rate at different O2 concentration
5 0C

n
[O2]
% (v/v)
1
2
3
4
5
6
7
8
9
10
11
12
13

21.00
15.95
14.00
11.90
10.25
9.55
7.75
6.50
5.50
4.70
3.85
3.05
2.30

150C
R02
mlO2/hr.kg
56.38
22.05
23.45
18.42
8.93
17.86
12.40
11.16
8.93
10.12
8.03
8.27
8.16

[O2]
% (v/v)
21.00
15.50
11.83
8.60
5.00
2.13

Columns of Table.2 showed the influence
of O2 concentration changes. But,
combination of temperature and gas
concentration changes gives the great
influence on mushroom respiration.

Room
R02
mlO2/hr.kg
135.97
90.64
79.93
89.00
70.87
8.65

[O2]
% (v/v)
21.00
18.47
15.83
13.30
9.83
7.40
5.57

R02
mlO2/hr.kg
318.97
323.47
296.72
419.70
281.08
228.55
230.03

changes, but was still in the aerobically
respiration range (Table 3). Give more
attentions on value on 50C and 150C, they
show that Oyster mushrooms was not
sensitive to O2 low level or CO2 high level.
Kader (2002) suggest that mushrooms are
one of vegetables that respire highly but
withstand to high level of CO2. Evaluation
on mushroom appearance that are stored at
50C and packed with plastic jar for 3 days
give the prove that they can preserve with
low temperature and low O2 concentration.
The excessive accumulation of CO2 (>
12%) inside the package can cause
physiological injuries to the produce,
which in the case of mushrooms, results in
severe browning (Nichols and Hammond,
1973; Lopez-Briones et al., 1992) is not
proven in this case. But authors suggest
that this fact need to be investigated
further, because this research is not
intended to prove or to refuse that fact.
Especially, the similar influences occur on
different species and different storage
conditions.

4.3 Respiratory quotient (RQ)
Respiratory quotient could be define
as the rate ratio of CO2 production to O2
consumption; CO2 and O2 could be
measured in moles or volumes depending
on the substrate being oxidized. RQ values
for fresh commodities range from 0.7 to
1.3 for aerobic respiration. When
carbohydrates are being aerobically
oxidized, the RQ is near 1, while it is < 1
for lipids, and > 1 for organic acids. Very
high RQ values usually indicate anaerobic
respiration in those tissues that produce
ethanol. In such tissues, a rapid change in
the RQ could be used as an indication of
the shift from aerobic to anaerobic
respiration (Saltveit, 2004). The value of
the RQ presented in Table 1. Although has
the various value at different temperature,
but the deviations is small. Those values
were calculated from initial respiration
where the surrounding atmosphere was
still rich in O2. Kader (2002) and Saltveit
(2004) suggest that aerobically respiration
on fresh produces stored at physiological
temperature range from 0.7 – 1.3.
Therefore, those values indicate that
respiration was aerobic. This conditions
continuously changes according to O2

4.4 Activation energy of respiration
Activation energy of respiration used
to predict the respiration rate on other
storage temperatures. Predictions of the
respiration rate of mushroom on different
storage temperature are conducted by
taking the 50C as reference temperature.
From figure below we can see that the
influence of temperature has linear pattern.
6

quotient. Oyster mushrooms show the
significant influence of temperature on its
respiration but less dependent on
atmospherically
gas
composition.
Combination of low temperature and low
oxygen give the great effects to mushroom
respiration and less effect on respiratory
changes. Predictions of the respiration rate
of mushrooms can be established
satisfyingly by applying the Arrhenius
equations.

The gradient of each linear equations come
from linearization represents the activation
energy and universal gas constant ratio
(Ea/R).
Table 3. Respiratory quotient on different
temperature and O2 composition*
5 0C

150C

Room

1.12
1.19
0.93
0.87
1.29
0.89
0.85
1.03
1.23
1.04
1.06
1.01
1.03

1.18
0.61
0.48
1.35
1.49
1.25

1.05
1.12
1.24
0.57
0.96
0.99
0.96

References
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and Lange, D.D. 1992. Modified
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Kader, A.A and Michael E. Saltveit.
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Physiology
and
nd
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Lopez-Briones, G., Varoquaux, P., C.
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mushroom
under
controlled
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treatment with citric acid or

*The O2 concentrations refers to Table 2

Applying the
Arrhenius’ law,
respiration rate of mushrooms along
physiological temperature can be counted.
= 0.28
.......(a)
= 0.25

.......(b),

Where subscript on parameter RR and T
represent value of respiration rate on
storage temperature T at condition 1
(reference) and storage temperature T will
be found. Equations (a) and (b) are the
predictive equation for O2 consumption
and CO2 production rate, respectively.
With the activation energy (Ea) are 2.33
kJ/mol and 2.08 kJ/mol for O2
consumption
and
CO2
evolution
respectively, prediction of respiration rate
of Mushroom Oyster at 50C to 30 0C is
easy to count. This Arrhenius equation
assists the engineer to design of packaging
system.
5.

Conclusions

The important physiological aspects
of postharvest handling of fruits and
vegetables are physiological behaviors
including respiration rate and respiratory
7

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Storage of Fruits, vegetables, florist
and
Nursery
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Modified Atmosphere Packaging of
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Resources. Publication 3311 USA.

8