Canrea Journal: Food Technology, Nutritions, and Culinary, 2022; 5 (2): 139–150 OPEN ACCESS

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Type of the Paper (Article)

Effect of yeast concentration and fermentation time on the
characteristics of tuak from coconut sap
Ida Bagus Wayan Gunam1,2*, Thobie E. B. Kaban1 and Ni Putu Suwariani1,2

1 Department of Agroindustrial Technology, Faculty of Agricultural Technology, Udayana

University, Bukit Jimbaran, Badung-Bali 80361, Indonesia
2 Laboratory of Bioindustry, Faculty of Agricultural Technology, Udayana University,

Denpasar-Bali 80234, Indonesia

Article History
Abstract Received February 16, 2022
Tuak is a traditional fermented drink made from the sap of the Palmae family Accepted November 7, 2022
that is favored by rural communities. The quality of tuak varies greatly and Published December 2, 2022
depends on the type of microbe that contaminates the sap raw material. This
research aimed to get the best yeast concentration and fermentation time,
Keyword
to get the best characteristics of tuak from coconut sap. The first factor was
yeast concentration (0, 2, 4, 6, and 8%). The second factor was fermentation
Coconut sap, Yeast,
time (24, 48, 72, 96, and 120 hours). The research was grouped based on the Fermentation time,
processing time and got 50 units of the samples. The experiment was carried Tuak.
out at room temperature (±30°C). The parameter of this research was
sensory evaluation test, alcohol content, pH, total dissolved solids, and total
sugar. The data of this research were analyzed with analysis of variance,
followed by the Duncan’s test. The results showed that yeast concentration
4% w/v and fermentation time of 72 hours produced the best characteristics
of tuak from coconut sap with the characteristics of sensory test for the
alcohol flavor was between like to really like (4.30), the sour flavour was
neutral to like (3.59), the sweet flavour was like to really like (4.85), and
overall acceptance was like to really like (4.95) with alcohol content (9.38%),
pH (4.2), total dissolved solids (7.52 mg/L) and total sugar (1.54%). The
addition of starter culture can speed up the fermentation process and at the
same time improve the quality of tuak from coconut sap.

1. Introduction
Coconut plants (Cocos nucifera L.) are natural resources with great potential in
Indonesia. Every part of the coconut palm can be utilized by humans in some way (1). One
part of the coconut plant that can be used is the sap. The clear liquid that comes out of
coconut flowers whose shoots have not yet opened is the main source of coconut sap.
Coconut sap is tapped from the inflorescences of coconut trees that have not yet bloomed
and are ripe. Tapping of coconut sap is done by cutting the inflorescence heads (2–4). Xia et
al. (1) and Trisnamurti (5) reported that good quality and fresh coconut sap has a sweet taste,
smells good, colorless, pH ranges from 6–7, has high nutrition, and is easy to digest. The
composition of the sap of a plant species is influenced by several factors, including plant
variety, plant age, plant health, soil conditions, climate, fertilization, and irrigation. Likewise,
each plant has a different composition of sap and generally consists of water, sucrose,
reducing sugar, other organic materials, and inorganic materials. The water in the sap is the
largest part, which is between 75–90%. Sucrose is the largest part of solids ranging from

* Correspondence: Ida Bagus Wayan Gunam ibwgunam@unud.ac.id 139

ISSN 2621-9468 Online, DOI 10.20956/canrea.v5i2.599

 Canrea Journal: Food Technology, Nutritions, and Culinary, 2022; 5(2): 139–150

12.30–17.40% (3). While Hebbar et al. (6) reported that the total sugar of fresh coconut sap
(Coconut inflorescence sap) ranged from 9.2–16.2%. Reducing sugars are between 0.50–
1.00% and the rest are organic and inorganic compounds. Reducing sugars may consist of
hexose, glucose, and fructose, as well as very low amounts of mannose. Organic matter
consists of carbohydrates (excluding sugars), proteins, organic acids, amino acids, dyes, and
fats. Inorganic materials consist of mineral salts (7).
Fresh coconut sap is usually consumed as juice by local people in Southeast Asia and is
also used as a raw material for producing sugar, alcoholic beverages, vinegar, and acetic acid
(8,9). The milky white fermented sap is sold as an alcoholic beverage called 'toddy' or 'palm
wine'; it is referred to as ‘tuba’ in the Philippines and ‘tuak’ in Indonesia (10). Tuak is a
traditional drink produced from the fermentation of Palmae family sap (11–13). Tuak contains
4% alcohol (3,14). This product when distilled can produce arak, with an alcohol content
ranging from 20–40% (15). The better the quality of the tuak, the better the arak produced.
Fermentation is influenced by temperature, pH, fermentation time, oxygen content,
type and concentration of yeast (16). Indonesian people generally produce tuak using
ingredients that come from nature and are fermented spontaneously without the use of
starter cultures, such as dry yeast. The quality and yield of tuak can be increased by
fermenting coconut sap with added yeast. Yeast is a microbe that can trigger or initiate
fermentation in the processing of certain foodstuffs. The yeast that is often used in the
process of making alcoholic beverages is Saccharomyces cerevisiae (17), and this microbe is
naturally dominant in sap (12). These microbes will convert glucose on a substrate into CO 2
and ethanol. This microbe grows well at 25-30oC with a maximum growth temperature of 35-
40oC. It is necessary to pay attention to the concentration of yeast in the manufacture of tuak.
If the concentration is too little, it will reduce the speed of fermentation because there is little
mass that will decompose glucose into ethanol, whereas if it is too much, more substrate will
be needed because there is not enough substrate (18). Likewise with the fermentation time,
the longer the fermentation time, the higher the ethanol content produced. However, if the
fermentation time is too long, the ethanol that has been produced will be converted by
bacteria into acetic acid (19). For this reason, it is necessary to research the concentration of
yeast and fermentation time to produce the best characteristics of tuak from coconut sap.

2. Material and Methods

2.1. Materials
The materials used in this study were: coconut sap obtained from Jungutan Village,
Karangasem Bali, Indonesia. The sap used is the sap that has just been taken down from a
coconut tree and is stored in a sterile container. Saccharomyces cerevisiae ATCC 9763 was
obtained from the Bogor Agricultural Institute Culture Collection (IPBCC). Materials for media
manufacture: CaCl2.2H2O (Pudak Scientific brand), MgSO4.7H2O (KgaA brand), K2HPO4 (KgaA
brand), KH2PO4 (KgaA brand), NaHCO3 (KgaA brand), NaCl (KgaA brand), peptone and yeast
extract (Himedia brand), glucose (Brataco brand), distilled water and materials for analysis
were obtained from the Laboratory of Bioindustry, Agroindustrial Technology Study Program,
Faculty of Agricultural Technology, Udayana University.

2.2. Experiment Design

The experiment design used was a factorial Randomized Block Design (RBD) consisting
of two factors. The first factor was the concentration of yeast which consisted of 0, 2, 4, 6,

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and 8% (v/v). The second factor is the fermentation time which consists of 24, 48, 72, 96, and
120 hours. All treatments were grouped into two groups based on the processing time so that
50 experimental units were obtained.

2.3. Preparation of Media, Culture, and Coconut Sap Fermentation

Cultures of S. cerevisiae were taken from culture stock, then rejuvenated on PDA media.
After growing, 2-3 oses were taken to be re-grown in 50 mL of media containing yeast extract,
peptone, and glucose (YPG). YPG media was prepared by taking 5 g/L yeast extract, 5 g/L
peptone, and 10 g/L glucose dissolved in 50 mL distilled water and then sterilized at 121°C for
15 minutes. Cultures of S. cerevisiae were transferred aseptically into YPG media which had
been cooled and incubated at 30°C for 24 hours and shaken at 100 rpm (20,21). After
multiplication of yeast cells, then centrifuged at 5000 rpm at 4°C, then the pellet cells were
washed with saline solution twice and finally the cell concentration was adjusted to OD660 5
before being used in the fermentation of coconut sap.
Sample preparation includes material preparation, i.e. freshly harvested coconut sap in
a sterile container in a closed condition. The composition of fresh coconut sap before
fermentation includes 8.11% total sugar, 2.75% reducing sugar, 14.07% total dissolved solids
Brix, 0.06% total protein, 84.89% water content, 0.44 ash content, and pH 4.82. The sap is put
into one container and then pasteurized at 72°C for 15 minutes, then used as a fermentation
medium in the next stage.
The fermentation media was prepared by pouring 400 mL of sap into a bottle with a
volume of 500 mL, then the yeast culture of S. cerevisiae was inoculated with a concentration
of 0, 2, 4, 6, and 8% (v/v). The bottle that already contains the media and culture is closed,
the bottle cap is given a hose as a distributor of CO 2 gas produced from the fermentation
process, and the other end of the hose is placed in a 4% sodium metabisulfite solution.
The fermentation process was carried out for five days at room temperature (±30oC) at
the Bioindustry Laboratory of the Faculty of Agricultural Technology (22). Observations were
made daily, i.e. sensory tests, alcohol content, pH, and total dissolved solids.

2.4. Sensory Evaluation

Sensory evaluation was carried out to know the level of preference of the panelists for
a food product. The acceptability of a product was always determined by the consumer of
point of view (23). A total of 20 people were used as trained panelists to conduct sensory
tests on tuak products from coconut sap. This sensory evaluation includes a hedonic test to
assess the acceptability of product quality attributes such as aroma (alcohol, sour and sweet),
color, taste, and overall acceptance of the tuak. The scores used are: 5 = really like, 4 = like, 3
= neutral, 2 = less like, and 1 = very dislike. The test was continued with a preference test by
giving a score of 1 to the sample that had poor quality (very dislike) to a score of 5 for the best
quality (really like) (24).

2.5. Alcohol Level Test

The alcohol produced during fermentation was determined using an alcoholmeter. The
distillate resulting from the distillation of tuak as much as 100 mL was used as a sample, then
the alcoholmeter was dipped into the distillate. The immersed boundary on the surface of
the distillate indicates the alcohol content of the sample being tested (25).

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2.6. Measurement of pH
The measurement of degree of acidity was determined using a pH meter. The pH meter
electrode was inserted into each tuak sample solution. Measurement of pH was carried out
on each sample at the same time every day (26,27).

2.7. Total Dissolved Solids

The measurement of total dissolved solids uses a refractometer and before being used,
calibration was carried out using distilled water first. A total of 1 drop of the sample was put
in the prism of the refractometer and the amount of dissolved solids content is expressed as
°Brix. The value shown on the instrument was recorded and observations were made on the
process before fermentation and after fermentation for each treatment variation. The
difference between observations before and after fermentation in each treatment variation
was compared (28).

2.8. Data Analysis

The data of psychochemical analysis were analyzed with analysis of variance using the
SPSS application. If a treatment has a significant effect, then Duncan's test was performed.
Sensory evaluations were analyzed using quantitative description.

3. Results and Discussion

3.1. Sensory Evaluation
3.1.1. Alcohol Aroma Sensory Evaluation
The analysis of variance showed that the interaction between yeast concentration and
fermentation time had a very significant effect (P < 0.01) on the aroma of alcohol of tuak from
coconut sap. The average value of the sensory test for the aroma of tuak from coconut sap
can be seen in Table 1.

Table 1. The average value of sensory evaluation of the aroma of tuak from coconut sap.
Concentration Fermentation time (hours)
starter culture
(%, v/v) 24 48 72 96 120
0 4.60 ± 0.070ab 4.73 ± 0.035ab 4.82 ± 0.035ab 4.22 ± 0.035b 4.17 ± 0.035b
2 4.83 ± 0.035ab 4.93 ± 0.035a 4.05 ± 0.070bc 4.55 ± 0.070ab 4.30 ± 0.070ab
4 4.95 ± 0.070a 4.17 ± 0.035b 4.30 ± 0.070ab 4.52 ± 0.035da 4.47 ± 0.035ab
6 4.18 ± 0.035b
4.38 ± 0.035 b
4.55 ± 0.070 ab
3.87 ± 0.035 c
3.60 ± 0.000c
8 3.88 ± 0.035c 3.97 ± 0.035bc 4.10 ± 0.070b 3.57 ± 0.106c 3.36 ± 0.160d
Different letters behind the mean value indicate a very significant difference at the 5% error level (p < 0.05).

Based on Table 1, the average value of sensory evaluation of the aroma of alcohol
ranged from 3.36 (neutral-like) to 4.95 (really like). Tuak from coconut sap treated with 8%
yeast concentration and 120 hours of fermentation time had a neutral or normal preference
level and tuak from coconut sap with 4% yeast concentration and 48 hours of fermentation
time had a very favorable level of preference (4.17±0.035) and not different from 2% yeast
treatment and 24 hours fermentation time (4.93±0.035). The alcohol aroma of tuak from
coconut sap is influenced by the yeast concentration and fermentation duration.

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3.1.2. Sour Aroma Sensory Evaluation Test

The analysis of variance showed that the interaction between yeast concentration and
fermentation time had a very significant effect (P < 0.01) on the sour aroma of tuak from
coconut sap. The average value of the sensory evaluation of the aroma of tuak from coconut
sap can be seen in Table 2.
Table 2. The average value of sensory evaluation of sour tuak aroma from coconut sap.
Concentration Fermentation time (hours)
starter culture
(% v/v) 24 48 72 96 120
0 3.57 ± 0.042ab 3.7 ± 0.070aa 3.67 ± 0.035ab 3.21± 0.049b 3.05 ± 0.035bc
ab ab a ab
2 3.67 ± 0.035 3.82 ± 0.035 3.95 ± 0.007 3.51 ± 0.091 3.17 ± 0.106bc
4 3.80 ± 0.070ab 3.87 ± 0.035ab 3.95 ± 0.000a 3.55 ± 0.106ab 3.20 ± 0.045b
6 3.25 ± 0.063b 3.42 ± 0.035ab 3.06 ± 0.084ab 2.47 ± 0.035c 3.02 ± 0.035bc
c c c c
8 2.89 ± 0.077 2.95 ± 0.035 2.85 ± 0.007 2.50 ± 0.070 2.59 ± 0.318c
Different letters behind the mean value indicate a very significant difference at the 5% error level (p < 0.05).

The average value of the panelists' preference for the sour aroma of coconut sap ranged
from 2.47 (less like-neutral) to 3.95 (like). Tuak from coconut sap treated with yeast
concentration of 6% and fermentation time of 96 hours had a dislike level of preference, while
the treatment with yeast concentration of 4% and fermentation time of 72 hours had a
preference level of 3.95 (like) and was not different from the treatment with yeast 2% and 72
hours of fermentation.

3.1.3. Sweet Aroma Sensory Evaluation

The analysis of variance showed that the interaction between yeast concentration and
fermentation time had a very significant effect (P < 0.01) on the sweet aroma of tuak from
coconut sap. The average value of the sensory evaluation of the sweet aroma of coconut sap
can be seen in Table 3.
Table 3. The average value of sensory evaluation of the sweet aroma of palm wine from coconut sap.
Concentration Fermentation time (hours)
starter culture
(%, v/v) 24 48 72 96 120
0 3.93 ± 0.021bc 4.12 ± 0.035bc 4.24 ± 0.055b 4.35 ± 0.0353b 3.79 ± 0.014bc
2 4.37 ± 0.035b 4.65 ± 0.141bb 4.63 ± 0.021ab 4.70 ± 0.077ab 4.21 ± 0.049b
4 4.50 ± 0.070ab 4.74 ± 0.056ba 4.85 ± 0.035a 4.57 ± 0.035b 4.29 ± 0.014b
6 3.57 ± 0.035 c
3.85 ± 0.035 bc
3.92 ± 0.035 ac
3.37 ± 0.098 cd
3.14 ± 0.056d
8 3.45 ± 0.035c 3.51 ± 0.070c 3.67 ± 0.106c 3.14 ± 0.056d 2.85 ± 0.033d
Different letters behind the mean value indicate a very significant difference at the 5% error level (p < 0.05).

Based on Table 3, the average sensory test value for the sweet aroma of tuak from
coconut sap ranges from 2.85 (neutral) to 4.85 (really like). Tuak from coconut sap treated
with 8% yeast concentration and fermentation time of 120 hours had a neutral or ordinary
preference level (2.85) and tuak from coconut sap with 4% yeast treatment and 72 hours
fermentation time had a very high preference level (4.85). Panelists on the sensory test of the
sweet aroma of tuak from coconut sap preferred tuak with 4% yeast concentration treatment
and 72 hours of fermentation.

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3.1.4. Overall Acceptance Sensory Evaluation

Based on Figure 1, the average sensory evaluation value of the overall acceptance of
tuak from coconut sap ranged from 3.13 (neutral-like) to 4.95 (really like). Tuak from coconut
sap treated with yeast concentration of 8% and fermentation time of 120 hours had a
preference level of 3.13 (neutral-like). Tuak from coconut sap with yeast treatment of 4% and
fermentation time of 72 hours had a preference level of 4.95 (really like). Panelists on the
sensory test of the overall acceptance of tuak from coconut sap preferred tuak with 4% yeast
concentration treatment and 72 hours of fermentation.
6
0 2 4 6 8

4
Sensory Analysis

0
24 48 72 96 120

Fermentation Time (h)

Figure 1. Sensory evaluation of the overall acceptance of tuak at different
concentrations of yeast during fermentation.

3.2. Physicochemical Analysis

3.2.1. Alcohol Level
In Figure 2 it can be seen that the concentration of 8% starter culture with a
fermentation time of 120 hours produced tuak with the highest alcohol content of 10.37%,
but it was not significantly different from the starter culture treatment of 4% and the
fermentation time of 72 hours (9.38%), starter culture 6% and fermentation time 72 hours
(9.81%), starter culture 8% and fermentation time 72 hours (9.87%) and 96 hours (9.88%).
While the starter culture concentration of 2% with 24 hours of fermentation resulted in the
lowest average value of 3.88% alcohol content. This indicates that the higher the yeast
concentration and the longer the fermentation time will increase the alcohol content of the
tuak produced. This change can occur because yeast can break down glucose into alcohol and
carbon dioxide. S. cerevisiae can form two molecules of ethanol and carbon dioxide from one
glucose molecule. Fermentation time affects the alcohol content of tuak, longer the
fermentation time, the higher the alcohol content will be. Similar results have been reported
by Asngad et al. (29), the longer the fermentation process and the more doses of yeast given,
the higher the alcohol content in papaya peel fermentation. The longer the fermentation, the
more glucose is converted into alcohol, so the resulting alcohol content is higher (30).

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12

10
Ethanol Content (%)
8

2 0 2 4 6 8

0
24 48 72 96 120

Fermentation Time (h)

Figure 2. Changes in the alcohol content of tuak with different concentrations
of yeast during fermentation.

3.2.2. pH
The analysis of variance showed that the yeast concentration treatment and
fermentation time had a very significant effect (P < 0.01) on the pH of tuak from coconut sap.
The average pH value of tuak can be seen in Table 4.
Table 4. The average pH value of tuak from coconut sap at different starter concentrations during
storage.
Concentration Fermentation time (hour)
starter culture
(%, v/v) 24 48 72 96 120
0 4.9 ± 0.070a 4.4 ± 0.141ab 3.9 ± 0.000b 3.8 ± 0.000bc 4.0 ± 0.144b
2 4.2 ± 0.212ab 3.9 ± 0.070b 3.9 ± 0.000b 3.8 ± 0.144bc 3.6 ± 0.000c
ab ab ab b
4 4.2 ± 0.212 4.2 ± 0.000 4.2 ± 0.000 4.0 ± 0.070 4.1 ± 0.000ab
6 4.1 ± 0.070ab 4.2 ± 0.000ab 4.2 ± 0.000ab 4.1 ± 0.070ab 4.2 ± 0.141ab
8 4.1 ± 0.000ab 4.2 ± 0.000ab 4.2 ± 0.000ab 4.2 ± 0.140ab 4.2 ± 0.000ab
Different letters behind the mean value indicate a very significant difference at the 5% error level (P < 0.05).

Table 4 shows a decrease in the pH value with the increasing yeast concentration and
the longer the fermentation time. The decrease in the pH of tuak from coconut sap was
caused by fermentation products in the form of alcohol and carbon dioxide and the
metabolism of S. cerevisiae. The formed CO2 gas will react with water molecules to form
H2CO3 as a carbonation reaction characterized by the formation by gas bubbles. H2CO3 will
give an acidic atmosphere to tuak products so that tuak from coconut sap has a low pH (31).
The study of Taherzadeh et al. (32) added that acetic acid can diffuse through cell membranes
by lowering the internal pH. Thus, when the pH is low (acid), the enzyme activity will be
inhibited so that the ability of microbes to break down sugar into bioethanol is lower. In
addition, the presence of oxygen will also oxidize lactic acid so that the pH of the medium will
decrease (33).

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3.2.3. Total Dissolved Solids Content

The analysis of variance showed that the yeast concentration and fermentation time
had a very significant effect (P < 0.01) on the total solids of tuak from coconut sap. The
average value of the total dissolved solids content of tuak can be seen in Table 5.
Table 5. Average value of total dissolved solids content of coconut sap tuak (mg/L).
Concentration Fermentation time (hour)
starter culture
(%, v/v) 24 48 72 96 120
0 14.01 ± 0.000a 14.12 ± 0.000a 14.00 ± 0.000a 13.06 ± 0.000a 14.03 ± 0.000a
2 8.04 ± 0.000cd 9.00 ± 0.006bc 9.12 ± 0.000bc 9.97 ± 0.000b 9.21 ± 0.000bc
4 6.50 ± 0.707d 8.34 ± 0.000c 7.52 ± 0.707cd 8.06 ± 0.000cd 7.53 ± 0.707cd
6 6.06 ± 1.414de 7.29 ± 0.000d 7.47 ± 0.770cd 7.00 ± 0.000d 7.50 ± 0.707cd
8 5.00 ± 1.414 e
6.50 ± 0.711 d
6.50 ± 0.704 d
6.55 ± 0.707 d
6.50 ± 0.707d
Different letters behind the mean value indicate a very significant difference at the 5% error level (P < 0.05).

During the fermentation process, sugar will be metabolized by S. cerevisiae into alcohol
and CO2, so that the total dissolved solids become low. Sintasari (34) reported that the low
total dissolved solids were thought to be because, during the fermentation process, sugar
which was the dominant solid component in the medium was metabolized by yeast into
alcohol, and CO2 was then utilized by acidic bacteria as a carbon source so that the total
dissolved solids became low. Mulyawanti et al. (35) reported that the decrease in total
dissolved solids during storage is due to the sugar contained will experience changes to
alcohol, aldehydes, and amino acids. The remnants of organic acids, sucrose, and lactose
dissolved in water will be counted as total dissolved solids (34). The decrease in total dissolved
solids was also caused by the activity of yeast in breaking down sugar to produce alcohol
during the fermentation process. Yeasts need substrates and nutrients for their survival.
Substrate and nutrients will be reduced, causing the total amount of dissolved solids in the
medium to be reduced (36). At an initial pH of 4.5 total dissolved solids were lowest at the
end of fermentation, but with the highest total ethanol. According to research by Mulyawanti
et al. (35), during the fermentation process, there was a decrease in total dissolved solids,
due to the activity of yeast and bacteria in the sap. The lower the total dissolved solids content
at the end of the fermentation, the better and the higher the ethanol produced, on the
contrary, the higher the total solids content, the lower the ethanol produced and the less
good quality of palm wine.

3.2.4. Total Sugar

The results of variance showed that the interaction between yeast concentration and
fermentation time had a very significant effect (P < 0.01) on the total palm sugar from coconut
sap. The average value of total sugar from coconut sap can be seen in Table 6.

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Table 6. The average value of the total sugar of tuak from coconut sap (%).
Concentration Fermentation time (hours)
starter culture
(%, v/v) 24 48 72 96 120
0 8.53 ± 0.028a 8.13 ± 0.007ab 7.56 ± 0.084ab 7.15 ± 0.063ab 6.94 ± 0.036b
2 6.20 ± 0.035 bc
4.15 ± 0.056 c
1.73 ± 0.035 d
0.46 ± 0.014 e
0.19 ± 0.007e
4 6.00 ± 0.021bc 3.57 ± 0.011c 1.54 ± 0.033de 0.35 ± 0.007e 0.16 ± 0.007e
bc c de e
6 5.69 ± 0.120 3.11 ± 0.014 1.52 ± 0.063 0.27 ± 0.014 0.14 ± 0.014e
8 5.22 ± 0.022bc 3.21 ± 0.267c 1.25 ± 0.021de 0.24 ± 0.021e 0.15 ± 0.007e
Different letters behind the mean value indicate a very significant difference at the 5% error level (p < 0.05).

In Table 6 it can be seen that the highest total sugar was obtained from the treatment
with 0% yeast concentration and 24-hour fermentation time, i.e., 8.53 ± 0.028%. The lowest
total sugar was obtained from the treatment with a 6% yeast concentration and 120 hours of
fermentation time, i.e., 0.14 ± 0.014%. At the time of increasing the concentration of yeast
and fermentation time resulted in a decrease in total sugar. This decrease in total sugar was
due to the use of glucose by S. cerevisiae for metabolism. Pandiselvam et al. (37) reported
that during fermentation there was a rapid decrease in total sugar at room temperature
compared to under refrigerated conditions. S. cerevisiae has a high ability to ferment glucose,
fructose, galactose, maltose and has resistance in the environment at relatively high alcohol
levels and is resistant to other microbes. S. cerevisiae is a genus of yeast that can convert
glucose into ethanol and CO2. During fermentation, sugar will be consumed as a carbon
source and converted into alcohol and CO2 due to yeast activity (15).

4. Conclusions
From the results of the study, it can be concluded as follows: the interaction between
yeast concentration treatment and fermentation time has a very significant effect on sensory
tests, alcohol content, pH, total dissolved solids, and total palm sugar from coconut sap. The
characteristics of the best tuak from coconut sap were obtained from the treatment of 4%
yeast concentration and 72 hours of fermentation time producing characteristics based on
the results of sensory evaluation, i.e. the panelists' preference level for alcohol aroma 4.30
(between like-really like), sour aroma 3.95 (like), sweet aroma 4.85 (really like), and overall
acceptance was 4.95 (really like), with physicochemical characteristics, i.e. alcohol content
(9.38%), pH (4.2), total solids (7.52 mg /L) and total dissolved sugar (1.54%).

Acknowledgements
The project was financially supported by the Institute for Research and Community
Services of Udayana University, under Unggulan Udayana Research Grand No. B/20-
217/UN14.4. A/LT/2020, March 10, 2020.

Author Contributions
I.B.W.G. and N.P.S. were responsible for experiments design and coordinating all the
research processes; T.E.B.K. performed the experiments and analyzed the data; I.B.W.G. dan
T.E.B.K. wrote the paper.

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Funding
This is research received no external funding.

Institutional Review Board Statement

Available data are presented in the manuscript.

Data Availability Statement

Not applicable.

Conflicts of Interest
Authors may declare no conflict of interest.

References
1. Xia Q, Li R, Zhao S, Chen W, Chen H, Xin B, et al. Chemical composition changes of post-
harvest coconut inflorescence sap during natural fermentation. African J Biotechnol.
2011;10(66):14999–5005.
2. Ouoba LII, Diawara B, Jespersen L, Jakobsen M. Antimicrobial activity of Bacillus subtilis
and Bacillus pumilus during the fermentation of African locust bean (Parkia biglobosa)
for Soumbala production. J Appl Microbiol. 2007;102(4):963–70.
3. Swamy GMS. Coconut neera production and processing in Karnataka. Indian Coconut
J. 2013;
4. Hebbar KB, Pandiselvam R, Manikantan MR, Arivalagan M, Beegum S, Chowdappa P.
Palm sap—Quality profiles, fermentation chemistry, and preservation methods. Sugar
Tech. 2018;20(6):621–34.
5. Trisnamurti RH, Sutrisno ET, Fatimah D. Perubahan kenaikan titik didih dan panas jenis
larutan pada pembuatan gula semut aren (Arenga pinnata). Bul IPT. 1999;5:36–40.
6. Hebbar KB, Arivalagan M, Pavithra KC, Roy TK, Gopal M, Shivashankara KS, et al.
Nutritional profiling of coconut (Cocos nucifera L.) inflorescence sap collected using
novel coco-sap chiller method and its value added products. J Food Meas Charact.
2020;14(5):2703–12.
7. Gautara S. Dasar pengolahan gula. Bogor: IPB University; 2005.
8. Purnomo H. Sugar components of coconut sugar in Indonesia. ASEAN Food J.
1992;7(4):200–1.
9. Kurniawan T, Kustiningsih I, Firdaus MA. Palm sap sources, characteristics, and
utilization in Indonesia. J Food Nutr Res. 2020;6(9):590–6.
10. Fan L, Hansen LT. Handbook of plant-based fermented food and beverage technology.
New York: CRC Press; 2012.
11. Chandrasekhar V, Amulya V, Rani VS, Prakash TJ, Ranjani AS, Gayathri C. Evaluation of
biocompatibility of a new root canal irrigant Q Mix TM 2 in 1-An in vivo study. J Conserv
Dent JCD. 2013;16(1):36–40.
12. Hariharan B, Singaravadivel K, Alagusundaram K. Identification of volatile compounds
in coconut toddy by GC-MS-assisted with different solvent system. J Microb Biochem
Technol. 2014;6(1):017–23.
13. Ahangangoda Arachchige MS, Yoshida S, Toyama H. Thermo-and salt-tolerant
Saccharomyces cerevisiae strains isolated from fermenting coconut toddy from Sri
148
 Canrea Journal: Food Technology, Nutritions, and Culinary, 2022; 5(2): 139–150

Lanka. Biotechnol Biotechnol Equip. 2019;33(1):937–44.

14. Ilyas S. Evaluasi kualitas spermatozoa dan jumlah turunan mencit (Mus musculus L.)(F1)
setelah pemberian tuak. Pros SEMIRATA 2013. 2013;1(1).
15. Neves MA das, Kimura T, Shimizu N, Shiiba K. Production of alcohol by simultaneous
saccharification and fermentation of low-grade wheat flour. Brazilian Arch Biol
Technol. 2006;49:481–90.
16. Periadnadi P, Sari DK, Nurmiati N. Isolasi dan keberadaan khamir potensial
pemfermentasi nira aren (Arenga pinnata Merr.) dari dataran rendah dan dataran
tinggi di sumatera barat. Bioeksperimen J Penelit Biol. 2018;4(1):29–36.
17. Walker. Evaluasi empiris jenis inovasi dan karakteristik organizasi-nasional dan
lingkungan: menuju kerangka konfigurasi. J Penelit Adm Publik dan Teor.
2016;18(4):591–615.
18. Umam MS. Pengaruh konsentrasi ragi roti (Saccharomyces cerevisiae) dan waktu
fermentasi terhadap kadar bioetanol nira siwalan (Borassus flabellifer L.). J Sains dan
Teknol Univ Islam Negeri. 2018;7(5):110–108.
19. Sofyan H, Soekarto. Pemanfaatan buah pepaya untuk dijadikan yoghurt fruit. J Agrina.
2016;1(1):31–9.
20. Arnata IW, Gunam IBW, Anggreni A, Wijaya IMM, Sartika D. Utilization of solid tapioca
waste for bioethanol production by co-fermentation of baker’s and tapai yeast. In: IOP
Conference Series: Earth and Environmental Science. IOP Publishing; 2021. p. 12058.
21. Gunam IBW, Dewi IAPK, Antara NS, Anggreni AAMD, Setiyo Y. Bioethanol production
from sugarcane bagasse by Saccharomyces cerevisiae ATCC 9763 immobilized in Na-
alginate. IOP Conf Ser Earth Environ Sci [Internet]. 2021;824(1):12054. Available from:
https://dx.doi.org/10.1088/1755-1315/824/1/012054
22. Simbolon NC, Wijaya IMM, Gunam IBW. Isolasi dan karakterisasi khamir potensial
penghasil bioetanol dari industri arak di Karangasem Bali. J Rekayasa dan Manaj
Agroindustri. 2018;6(4):316–26.
23. Mahendradatta M, Alri UM, Bilang M, Tawali AB. Utilization of black rice (Oryza sativa
L. indica) extract in making sarabba as functional drink. Canrea J Food Technol Nutr
Culin J. 2021;4(2):75–82.
24. Cuarto PM, Magsino RF. Develpoment of young coconut (Cocos nucifera) wine. Asia
Pacific J Multidiscip Res. 2017;5(2).
25. Wijaya I, Arthawan I, Sari AN. Potensi nira kelapa sebagai bahan baku bioetanol. J Bumi
Lestari. 2012;12(1):85–92.
26. Aryasa IWT, Artini NPR, Vidika A. DPR, Hendrayana IMD. Kadar alkohol pada minuman
tuak desa sanda kecamatan pupuan kabupaten tabanan bali menggunakan metode
kromatografi gas. J Ilm Medicam. 2020;5(1):33–8.
27. Asghar MT, Yusof YA, Mokhtar MN, Ya’acob ME, Mohd. Ghazali H, Chang LS, et al.
Coconut (Cocos nucifera L.) sap as a potential source of sugar: Antioxidant and
nutritional properties. Food Sci Nutr. 2020;8(4):1777–87.
28. Magwaza LS, Opara UL. Analytical methods for determination of sugars and sweetness
of horticultural products—A review. Sci Hortic (Amsterdam). 2015;184:179–92.
29. Asngad A, Laksono PB. Uji kadar serat, karbohidrat, dan sifat organoleptik pada
Pembuatan tempe dari bahan dasar kacang merah (Vigna umbellate) dengan
penambahan bekatul. J Penelit Sains Teknol. 2011;12(1):23–36.
30. Nasrun N, Jalaluddin J, Mahfuddhah M. Pengaruh jumlah ragi dan waktu fermentasi

149
 Canrea Journal: Food Technology, Nutritions, and Culinary, 2022; 5(2): 139–150

terhadap kadar bioetanol yang dihasilkan dari fermentasi kulit pepaya. J Teknol Kim
Unimal. 2017;4(2):1–10.
31. Bottei R. Where’s the carbon in carbonated beverages. Int Chem Environ Eng.
2006;8(2):121–132.
32. Taherzadeh MJ, Karimi K. Acid-based hydrolysis processes for ethanol from
lignocellulosic materials: a review. BioResources. 2007;2(3):472–99.
33. Hawusiwa ES, Wardani AK, Ningtyas DW. Pengaruh konsentrasi pasta singkong
(Manihot esculenta) dan lama fermentasi pada proses pembuatan minuman wine
singkong [In press Januari 2015]. J Pangan dan Agroindustri. 2015;3(1):147–55.
34. Sintasari RA, Kusnadi J, Ningtyas DW. Pengaruh penambahan konsentrasi susu skim
dan sukrosa terhadap karakterisik minuman probiotik sari beras merah [in press juli
2014]. J pangan dan Agroindustri. 2014;2(3):65–75.
35. Mulyawanti I, Setyawan N, Syah ANA, Risfaheri R. Evaluasi mutu kimia, fisika dan
mikrobiologi nira aren (Arenga pinnata) selama penyimpanan. Agritech. 2011;31(4).
36. Fiecher. Food microbiologi. McGraw-Hill Publishing Co. New Delhi: McGraw-Hill
Publishing Co; 1982.
37. Pandiselvam R, Manikantan MR, Binu SM, Ramesh S V, Beegum S, Gopal M, et al.
Reaction kinetics of physico-chemical attributes in coconut inflorescence sap during
fermentation. J Food Sci Technol. 2021;58(9):3589–97.

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