Effect of Steaming Treatment on Physical Properties
and Shelf Life of Hae-Kuen
Kanyawi Kolakul, Panadda Nonthanum and Wiramsri Sriphochanart
Faculty of Agro-Industry, King Mongkut’s Institute of Technology Ladkrabang, Ladkrabang, Bangkok, Thailand
Keywords: Physical Properties, Sensory Evaluation, Shelf-life, Shrimp Roll, Steaming Treatment.
Abstract: This research aimed to extend the shelf life of Hae-Kuen, Thai traditional shrimp roll, by effect of steaming
temperature (80 and 85C) and steaming time (5 and 10 minutes) on microbial contents, textural properties
and sensory evaluation. Results of the study showed that the microbial contents of steaming Hae-Kuen were
decrease as compared with the control sample (without steaming). While the initial microbial content of the
control sample was 6.410
7
CFU/g, there are steamed at 80C for 5 and 10 minutes had the microbial levels
of 5.310
2
and 2.310
2
CFU/g, respectively. The microbial contents decreased to 4.710
2
and 1.710
2
CFU/g
as higher steaming temperature (85C) was used for 5 and 10 minutes, respectively. Being stored at 4C,
microorganisms detected from unsteamed Hae-Kuen increased to the level of 7.7×10
6
CFU/g. which was
higher than the Community Product Standards Agency Criteria, at day 3. While, the microbial contents of
Hae-Kuen steamed at 80 and 85C for 5 and 10 minutes were in the range of 10 to 95 CFU/g after storing for
15 days. The texture profile analysis showed that all steamed Hae-Kuen samples had higher values of
hardness, springiness, cohesiveness and chewiness when compared to the control sample.
1 INTRODUCTION
Hae-Kuen or shrimp roll is the famous Chinese dish
in Thailand. It is made from shrimp and pork fat
mixed with corn flour, egg and seasoning, and
crushed or pounded until sticky, then wrapped with
bean curd skin into long and round pieces. The Hae-
Kuen is fried and served with plum sauce. Nowadays,
many Thai-Chinese style restaurants classified in the
appetizer menu. The restaurants prepared and stored
it in refrigerator as uncooked product. Unfortunately,
the shelf life of uncooked limited predominantly
because of spoilage contamination. Microorganism
content of uncooked was higher than 10
6
CFU/g after
3 days which was higher than the Community Product
Standards Agency criteria. Spoilage of Hae-Kuen is
mostly accompanied with physical properties
changes including souring, slimy meat juice exudates
and swelling (Purwanto et al, 2017).
It is important to improve Hae-Kuen to meet the
Community Product Standards Agency criteria and
maintenance of the quality characteristics of Hae-
Kuen. Therefore, the aim of this research was to
extend the shelf life by steaming treatment. An effect
of steaming temperatures at 80 and 85 C and
steaming times including 5 and 10 minutes on
microorganism content and physical properties of
Hae-Kuen were evaluated. Sensory test and shelf life
were also conducted.
2 MATERIALS AND METHODS
2.1 Preparation of Shrimp Roll,
Hae-Kuen
The Hae-Kuen ingredients comprised as following:
ground shrimp (80.91%), salt (2.1%), pepper
(0.81%), wheat flour (8.09%) and egg (8.09%). The
120 g of mixture were thoroughly mixed and wrapped
with bean curd sheet into 5 cm diameter and 15 cm
length. Each piece of Hae-Kuen was then packed in a
heat resistant nylon laminate bag in vacuum
condition.
2.2 Effect of Steaming Treatment
The Hea-Kuen samples were divided into five
separated batches, (1) no steaming treatment
(control), steaming at (2) 80 C 5 min, (3 80 C 10
Kolakul, K., Nonthanum, P. and Sriphochanart, W.
Effect of Steaming Treatment on Physical Properties and Shelf life of Hae-Kuen.
DOI: 10.5220/0009984000002964
In Proceedings of the 16th ASEAN Food Conference (16th AFC 2019) - Outlook and Opportunities of Food Technology and Culinary for Tourism Industry, pages 251-255
ISBN: 978-989-758-467-1
Copyright
c
 2022 by SCITEPRESS – Science and Technology Publications, Lda. All rights reserved
251

min, (4) 85 C 5 min, and (5) 85 C 10 min. The
samples was steaming in the temperature control
batch (MEMMERT Model: WNB series, Germany)
at 80 C and 85 C which measured at the middle of
sample. The sample were incubated for 5 and 10 min
and cooled down immediately. The collected samples
were kepts at 4 C until analysis.
2.2.1 Microbiological Analysis
After removing the outer plastic casing, a 25-gram of
Hae-Kuen samples were aseptically transferred to a
sterile plastic bag containing 225 mL of Butterfield s
phosphate sterile (0.1% w/v) solution and agitated
vigorously for one minute. Tenfold dilution series of
the sample solutions were prepared using sterile
peptone solution and 1 mL of each dilution was pour
plated on selective agar plates in triplicate.
The total viable count (TVC) was determined on
plate count agar (PCA) incubated at 35 C for 48 h
and yeast and mold on yeast malt agar (YM)
incubated at 35 C for 72-96 h. Bacterial counts were
expressed as colony-forming units per gram of
sample (CFU/g) The mean  standard deviation of the
count will be calculated by using three replicates for
each culture time S. aureus were analyzed according
to ISO 6888-1:1999/Amd 1:2003 by adding 1 ml of
suspension to Baird-Parker agar for 3 plates by
separating 0.3, 0.3 and 0.4 ml. respectively (make
a duplicate). Spread suspension in each plate and
incubated at 37 C for 22  2 h. Marked the typical
colonies which were black or gray color and
surrounding with opaque zone Then continued
incubated at 37 C for 22  2 h, marked all new
typical colonies and atypical colonies which were
black or gray color without opaque zone, recorded
number of all colonies. Selected 5 colonies in each
typical and atypical colonies to confirm coagulase
test. Selected colonies were inoculated to Brain -
heart infusion broth (BHI) and incubated at 37 C for
24  2 h. 0.1 ml culture was transferred to 0.3 ml of
rabbit plasma and incubated at 37 C for 6 h for clot
formation. Detection of E. coli in samples was done
according to BAM Chap. 4 (2002) by making at least
3 serial dilutions, inoculated 1 ml from each dilution
into 3 lauryl tryptose (LST) tubes for a 3 tubes MPN,
incubated at 35  0.5 C for 22 h and observed for the
presence of gas, the positive tubes were producing
gas. Transferred one loop of each suspension to a tube
of EC broth, incubated at 44.5 C for 24 + 2 h and
observed for the presence of gas, the positive tubes
were producing gas. One loop of culture was streaked
on Eosin Methylene Blue Agar) EMB  incubated at
35  0.5 C for 21  3 h. Characteristics of E. coli
colonies were dark purple colonies, with or without
a green metallic sheen. Transferred up to 5 suspicious
colonies from each EMB plate to PCA slants,
incubated at 35  05°C for 21  3 h and use for further
testing (IMViC test, Gram test and also reinoculated
back into LST to confirm gas production
C.perfringens were tested according to ISO
7937:2004 by adding 1 ml into petri dish, adding SC
agar and mixing with rotation overlay 10 ml of
Perfringens Agar and incubated at 37 °C for 20  2 h
in an anaerobic atmosphere. The colonies were then
inoculated into Fluid Thiogly-collate Medium at
37 °C for 21  3 h in an anaerobic atmosphere.
For confirmation, the culture was inoculated to
lactose sulphite medium at 46°C aerobic atmosphere
in a water bath for 21  3 h.
2.2.2 Physical Analysis
Moisture Content of Hae-Kuen sample was
determined according to AOAC methods (2002) with
the analytical No. 35.1.13.
Water activity was determined by water activity
analyzer (AQUALAB Model 4TE, Decagon Devices,
Inc., USA).
Texture profile analysis (TPA) was measured by
TA.XT-plus Texture Analyzer (Stable Micro System,
UK). Each Hae-Kuen was cut into 3 cm diameter x
3 cm length pieces and fried before texture
measurement. Five replicates were carried out with an
aluminium compression platen (50 mm diameter)
with a head speed of strain 5 mm/sec. Two 50 %
compression deformations were done with an interval
of 5 sec between them. The characteristics of
hardness, springiness, cohesiveness, gumminess and
chewiness were determined.
2.3 Shelf Life Analysis
The Hae-Kuen samples from the selected condition
were stored in refrigerator at 4  1°C. Samples were
taken at 0, 3, 6, 9, 12, and 15 days following the start
of incubation. Microbial content was determined in
total viable count as descripted in microbiological
analysis.
2.4 Sensory Analysis
Rating for preference tests were performed by 30
trained panellists to compare between (1) unsteamed
and (2) steamed Hea-Kuen at 80 C for 5 min, and (3)
steamed Hea-Kuen at 80 C for 10 min. All sample
were fried before serving. The 5 hedonic scale was
carried out to evaluate the taste attributes including
16th AFC 2019 - ASEAN Food Conference
252

appearance, color, aroma, taste and overall
preference.
2.5 Statistical Analysis
A completely randomized design (CRD) was used as
experimental design. Analyses were done in
triplicate. The data was statistical analyzed using
one–way analysis of variance (ANOVA) by SPSS
program. The Duncan’s Multiple Range test at 5%
level of significance was applied for all statistical
analyses and the statistical significance of differences
among mean values was established at (p< 0.05). The
data were expressed as mean  SD (standard
deviation).
3 RESULTS AND DISCUSSIONS
3.1 Microbial Profiles of Unsteamed
Hae-Kuen
Samples were collected from 3 restaurants and
analyzed for pathogenic microorganisms according to
the guideline. After 3 days of production, the
microbial results observed that the growth of E. coli
yeast and molds increased as shown in Table 1.
Table 1: Microbial profiles of unsteamed Hae-Kuen.
Microbial
Initial
Day 3
Total Plate Count
(TPC)
(CFU/g)
6.37x10
8
±3.27x10
7
7.77x10
8
±5.40
x10
7
C. perfringens
(Per 0.1 g)
Not Detected
Not Detected
E. coli
(MPN/g)
˂3.0
8.87 ±12
S. aureus
(Per 0.1 g)
Not Detected
Not Detected
Salmonella spp.
(Per 25 g)
Not Detected
Not Detected
Yeasts and Mold
(CFU/g)
1.2110
3
±7.7110
2
7.4210
3
±1.0
10
4
The initial amount of TPC and yeast and mold
were found at 6.37x10
8
± 3.27 x10
7
CFU/g and
1.21x10
3
± 7.71x10
2
CFU/g, respectively. After 3
days, the amount of TPC and yeast and mold
increased to 7.77x10
8
± 5.40 x10
7
CFU/g and
7.42x10
3
± 1.0 x10
4
CFU/g, respectively.
Additionally, E. coli was observed at 8.87 ± 12
MPN/g after 3 days. C. perfringens, S. aureus and
Salmonella spp. were not detected. Kanatt et al.
(2006) also reported that E. coli were usually found
in shrimps and their products. Therefore, one of the
important characteristics of both the shrimp and
shrimp product is that, if processed properties, they
receive a cook that is sufficiency to inactivate
negative cells of bacteria that are pathogenic to
humans Buchanan, 1991.
3.2 Effect of Steaming Temperature
and Steaming Time on Microbial
Content
Hae-Kuen samples were then steamed at 80 C and
85 C for 10 min. Microbial contents of steamed Hae-
Kuen were determined as TPC. The results as shown
in Table 2. As time increased, the microbial content
decreased in both Hae-Kuen samples.
The Hae-Kuen sample steamed at 80 C for 5 and
10 minutes had the microbial levels of 53 CFU/g and
23 CFU/g, respectively. The microbial content of
Hae-Kuen sample steamed at 85 C was lower than
that of Hae-Kuen sample steamed at 80 C. The
microbial content of Hae-Kuen steamed at 85 C
decreased from 4.4510
3
CFU/g to 48 CFU/g and 18
CFU/g at 5 and 10 minutes, respectively. Therefore,
the steaming temperature and time can decrease
microbial contents in Hae-Kuen product. The TPC of
steamed Hae-Kuen samples met the Office of
Community Product Standards (2003) which state
that the survival of microorganisms shall not exceed
110
3
CFU/g sample. The previous study found that
TPC of chicken drumsticks cooked for 2 min at 70C
reduced from 10
7
CFU/g to < 10 CFU/g (Can and
Haran, 2015)
Table 2: Effect of steaming treatment on microbial content
of Hae-Kuen.
Time
(minutes)
Total Plate Count (CFU/g)
80 ˚C
85 ˚C
0
7.1510
4
±4.95 10
2
4.4510
3
±7.7810
2
1
1.23 10
4
±1.2210
4
5.4510
3
±1.4910
3
2
1.06 10
4
±1.20 10
3
1.07 10
2
±95
3
3.9010
3
±3.90 10
3
83±4
4
93±1.10 10
2
43±18
5
53±60
48±32
10
23±
18±11
The heat of steam causes microbial cells to change
their condition as follows; resulting in hardening and
settling of proteins (protein coagulation) within the
cell, resulting in breakage and degradation of genetic
material, both ribonucleic acid (RNA) and
deoxyribonucleic acid (Deoxyribonucleic Acid,
Effect of Steaming Treatment on Physical Properties and Shelf life of Hae-Kuen
253

DNA) as well as destroying the membrane of the
microbes causing microbial cells to be destroyed
(Office of Community Product Standards, 2003)
3.3 Physical Characteristics of
Hae-Kuen Samples
Five Hae-Kuen samples were analyzed for physical
characteristics including moisture content, water
activity and texture.
3.3.1 Moisture Content
Moisture content of Hae-Kuen samples steamed at 80
C and 85 C was not different which ranged from
70.95–71.57% (as presented in Table 3). Control
(unsteamed Hae-Kuen) had the highest moisture
content at 75.06%. Water in the product was
dehydrated by steaming condition. Heat is supplied
by steam or heated fluid through a heat exchanger to
decrease the moisture in sample (Audibert, 2019).
Table 3: The moisture content and water activity of Hae-
Kuen.
Sample
Moisture
Content (%)
Water Activity (a
w
)
Control
75.06 ± 0.528
a
0.9593 ± .00389
b
Sample No.1
(80°C, 5 min)
71.57 ± 0.450
b
0.9650 ± .00289
a
Sample No.2
(80°C, 10 min)
71.14 ± 0.153
b
0.9647 ± .00092
a
Sample No.3
(85°C, 5 min)
70.95 ± 0.346
b
0.9643 ± .00105
a
Sample No.4
(85°C, 10 min)
70.91 ± 0.157
b
0.9618 ± .00338
ab
Mean values in the same column with mean in the same row with
different lowercase letters are significantly different (p<0.05).
3.3.2 Water Activity (a
w
)
The water activity (a
w
) of all steamed Hea-Kuen
products were approximately at 0.9618-0.9650 as
shown in Table 3.
3.3.3 Textural Properties
Textual profiles as shown in Table 4 revealed that all
steamed Hae-Kuen samples had significantly higher
hardness, springiness, cohesiveness and chewiness
values than control (unsteamed Hae-Kuen) (p< 0.05).
It was found that Gumminess, Chewiness,
Hardness and Springiness values of Hae-Kuen
steamed at 85 C for 5 and 10 min were not different.
On the other hand, the values of Hardness,
cohesiveness and Gumminess obtained from Hae-
Table 4: Texture profiles of Hae-Kuen samples.
Sample
Hardness
(kg)
Springiness
(mm/mm
)
Cohesiveness
(mm/mm
)
Gumminess
(mm/mm
)
Chewiness
(kg/mm)
Control
3895±
407.752
b
3338±
377.627
b
5975±
696.443
c
0.651±
0.015
a
0.851±
0.038
b
Sample
No.1
(80°C,
5min)
4490±
910.984
b
4589±
1240.371
a
7803±
1065.680
b
0.592±
0.044
bc
0.901±
0.021
a
Sample
No.2
(80°C,
10min)
6331±
736.627
a
5702±
768.750
a
10,140±
1302.780
a
0.623±
0.026
ab
0.907±
0.013
a
Sample
No.3
(85°C,
5min)
6098±
1919.689
a
4725±
1314.354
a
10,064±
2365.910
a
0.573±
0.049
c
0.894±
0.016
a
Sample
No.4
(85°C,
10min)
5048±
495.780
ab
4588±
433.500
a
8,791±
404.915
ab
0.570±
0.032
c
0.906±
0.009
a
Values are expressed as mean ± standard deviation. Means within
a column with different superscript lowercase letters are
significantly different (p < 0.05)
Kuen steamed at 80 C for 5 and 10 min were
significantly difference (p< 0.05). Springiness values
were not different among steamed Hae-Kuen
samples.
3.4 Shelf Life of Hae-Kuen
Five Hae-Kuen samples were stored at 4 ± 1 C and
taken every 3 days until 15 days for microbial
analysis as TPC. The results are presented in Table 5.
Unsteamed Hae-Kuen had higher microbial content
(7.7×10
6
CFU/g) than the Community Product
Standards Agency Criteria (2013), at day 3. On the
other hand, the microbial content of Hae-Kuen
steamed at 80 and 85 C for 5 and 10 minutes were in
the range of 10 to 95 CFU/g after storing for 15 days.
Table 5: Microbial content of Hae-Kuen samples during
storage at 4 C.
Day
Total Plate Count (CFU/g)
Sample No.1
(80°C,
5 min)
Sample No.2
(80°C,
10 min)
Sample No.3
(85°C,
5 min)
Sample No.4
(85°C,
10 min)
0
˂10
aa
˂10
aa
˂10
aa
˂10
aa
3
˂10
aa
˂10
aa
˂10
aa
˂10
aa
6
5.210
2ab
5.210
2ab
8.410
2ab
2.910
2ab
9
3.010
2 aa
1.410
2 aa
80
aa
25
aa
12
1.910
2aa
75
aa
30
aa
35
aa
15
95
aa
˂10
aa
˂10
aa
45
aa
16th AFC 2019 - ASEAN Food Conference
254

The descriptive data of the Hae-Kuen samples
indicated that changes occurred in product
characteristics during storage. At day 3, the unsteamed
Hae-Kuen had slime on the surface and sour taste,
while the steamed Hae-Kuen samples were not have.
Assessments of the taste of the product varied
significantly (p<0.01) with storage time (Can and
Haran, 2015). The results of the present study indicate
that it can be stored for 42 days at 2°C and present
acceptable sensory quality.
3.5 Sensory Profiles
Hae-Kuen steamed at 80
o
C for 5 and 10 min and the
control sample were then tasted for the acceptance in
appearance, color, aroma, taste and overall liking.
The Hae-Kuen samples were presented to 30 trained
panellists. The result of the sensory test is presented
in Table 6. The appearance, color, aroma and taste
scores were not statistically significant among Hae-
Kuen samples.
Table 6: Sensory evaluation.
Sample
Appearance
Color
Aroma
Taste
Overall
Control
4.031±
0.782
a
3.906±
0.777
a
3.906±
0.837
a
3.813±
0.693
a
4.063±
0.670
a
Sample
No.1
(80°C,
5min)
3.687±
0.693
a
3.875±
0.707
a
3.844±
0.847
a
3.750±
0.803
a
3.688±
0.896
ab
Sample
No.2
(80°C,
10min)
3.781±
0.706
a
3.594±
0.875
a
3.531±
0.950
a
3.594±
1.011
a
3.469±
1.106
a
a
Mean values in the same column with mean in the same row with different
lowercase letters are significantly different (p < 0.05).
The sensory evaluation also revealed that Hae-
Kuen steamed at 80 C for both 5 and 10 min received
the overall liking scores similar to the control sample.
It indicated that the steamed Hae-Kuen had
acceptable sensory quality similar to the traditional
Hae-Kuen.
4 CONCLUSIONS
This study indicated that unsteamed Hae-Kuen was an
unsafe and risky for consumption without further
cooking. The results showed that effect of steaming at
80 C and 85 C for 5 and 10 min could decrease
microbial content of Hae-Kuen and maintain product
properties. For safety improvement of Hae-Kuen
product, the processing method should examine. The
using of temperature and time for steaming conditions
can control good hygienic practice. It is important to
prevent cross-contamination during raw material
preparation, processing, storage, product distribution
and transportation or cross contamination for extend
shelf-life of Hae-Kuen. There are useful to extend the
shelf life of product that can apply to production
process in restaurant and to reduce the foodborne
illnesses.
ACKNOWLEDGEMENTS
We are obliged to a Thai Chinese restaurant that
participated in this study. This work is in part
supported the presentation expense by King
Mongkut’s Institute of Technology Ladkrabang,
Bangkok.
REFERENCES
Association of Official Analytical Chemists (AOAC)
2000. Official Methods of Analysis. 16th ed. AOAC
International, Arlington, Virginia, USA.
Audibert, F. 2019. Leading Industrial and non-industrial
Processes. [online] Science Direct. Available at:
https://www.sciencedirect.com/topics/earth-and-plane
tary-sciences/dehydration.
Buchanan, R. 1991. Microbiological criteria for cooked, ready-
to-eat shrimp and crabmeat. Food Technology, 45(4),
pp.157–160.
Can, Ö. and Harun, F. 2015. Shelf Life of Chicken Meat Balls
Submitted to Sous Vide Treatment. Brazilian Journal of
Poultry Science, 17(2), pp.137–144.
International organization for standardization. 1999.
Microbiology of food and animal feeding stuffs-horizontal
method for the enumeration of coagulanse-possitive
Staphylo- coccus (Staphylococcus aureus and other
species). 2th ed. ISO, Genewa, Switzerland.
International organization for standardization. 2004.
Microbiology of food and animal feeding stuffs-horizontal
method for the enumeration of Clostridium perfringens-
colony-count-technique. 3th ed. ISO, Genewa,
Switzerland.
Kanatt, S.R., Chawla, S.P., Chander, R. and Sharma, A. 2006.
Development of shelf-stable, ready-to-eat (RTE) shrimps
(Penaeus indicus) using 𝛾-radiation as one of the
hurdles. LWT, 39(6), pp.621–626.
Office of communities product standard. 2003. Standard of
communities product, Hae-kuen. Office of communities
product standard.
Purwanto, F.H., Kurnia, Y.F. and Purwati, E. 2017.
Microbiological quality and safety of meatball sold in
Payakumbuh city, West Sumatra, Indonesia. Journal of
nutrition and food engineering. 11(4), pp.337-341.
U.S. Food and Drug Administration. 2002. Bacteriological
Analytical Manual Chapter 4 Enumeration
of Escherichia coli and the Coliform Bacteria. [online]
FDA. Available at: https://www.fda.gov/food/ laboratory-
methods-food/bam-4-enumeration-escheri chia-coli-and-
coliform-bacteria.
Effect of Steaming Treatment on Physical Properties and Shelf life of Hae-Kuen
255