Physical, Chemical, and Microbial Changes during

Fermentation of Bungkil: A Traditional Snack Originated from

Banyumas, Central Java

Umi Purwandari, Zeilina R. Pangestika, Jamilah, Rakhmawati and M. Fuad Fauzul Muktamar

Department of Agroindustrial Technology, University of Trunojoyo Madura, PO Box 2 Bangkalan, East Java, Indonesia

Keywords: Coconut, Fermentation, Traditional Food.

Abstract: Bungkil is a traditional snack or side dish made from by-product of traditional process of coconut oil making

process, originated from Banyumas and Kebumen regencies, Central Java. We interviewed a bungkil maker

for bungkil making process, in the area of production,. The process includes washing mature coconut kernel,

soaking in water for three days, draining, and first fermentation by wrapping in layers of banana leaf for three

days, draining, grating, second fermentation by wrapping grated coconut in layers of banana leaf for two days,

and sun-drying and oil separation. The by product is the cake, which is called ‘bungkil’. The cake is mixed

with spices, oval or round shaped, and then fried in coconut oil. It is then ready for consumption. We analysed

pH, water activity, and microbial count during fermentation. Results showed that final pH, and water activity

were 7.50, 0.88, respectively. Microbial concentration in fresh coconut was 9.84x10

cfu/mL, at the end of

soaking was 4.42x10

cfu/mL, and at the end of sun-drying was 2.74x10

cfu/mL.

1 INTRODUCTION

There is a rising demand towards traditional food in

international market, which has to be responded by

food industry (Vanhonacker 2013, Kwon 2015).

Recently, consumers highly valued traditional

character in food, and in the same time also required

safety, proper labelling, and availability and easy to

access product in the market (Vanhonacker 2013).

Apart from consumers’ better appreciation to ethnic

foods, traditional food is closely related to utilization

of local produce, local knowledge and technology

(Kwon 2015, Renna 2015), thus support food

security. One of the ancient methods to preserve food

is fermentation where growth of spoilage

microorganisms is inhibited by other beneficial

microorganisms (Kwon 2015). The role of fermented

traditional food in balancing availability of food

sources was also highlighted (Anal 2019). This

process is now well-known as a method having health

supporting effect. There are wide range of traditional

fermented products reported previously (Anal 2019),

however we did not encounter any of them made from

coconut meat fermentation.

However, we found a traditional fermented

coconut meat product in Indonesia. It is called

‘bungkil’ which is originated from Banyumas and

Kebumen, two regencies in southern part of Central

Java. Bungkil may be considered as by-product of

traditional fermentation for coconut oil extraction.

Fermentation is very cheap and easy method for

coconut oil making process (Iskandar 2009), which

can utilize wide range of microorganism including

yeasts (Iskandar 2009), and lactobacilli (Agarwal and

Bosco 2017). Although the process is more suitable

for small enterprise (Iskandar 2009), it is time

consuming and the quality of product was considered

inferior due to poor colour and odor (Agarwal and

Bosco 2017). Bungkil is consumed as a snack or a

side dish to be eaten with rice. Recently, this product

is rarely found in local market. Bungkil makers now

made it based on individual request of consumer.

Unlike a well-known forbidden fermented coconut

product in the area called ‘tempe bongkrek’

(bongkrek tempeh) which can pose fatal poisoning

(Anwar et al. 2017), there is no report on bungkil

poisoning. Therefore, it is important to conduct

preliminary study on fermentation process of bungkil.

In this work, we collected information of bungkil

making process, and subsequently studied some

chemical and microbial profile during fermentation.

Purwandari, U., Pangestika, Z., Jamilah, ., Rakhmawati, . and Muktamar, M.

Physical, Chemical, and Microbial Changes during Fermentation of Bungkil: A Traditional Snack Originated from Banyumas, Central Java.

DOI: 10.5220/0009979400002833

In Proceedings of the 2nd SEAFAST International Seminar (2nd SIS 2019) - Facing Future Challenges: Sustainable Food Safety, Quality and Nutrition, pages 89-92

ISBN: 978-989-758-466-4

2 METHODOLOGY

2.1 Stages of Process of Making

Bungkil

We interviewed a ‘bungkil’ maker and previously a’

bungkil’ seller lived in Cilacap, called Ibu Sagem.

After identifying stages of process, we carried out

bungkil fermentation in the laboratory, and decided

stages of process where samples would be collected.

All samples were taken from two separate

experiments, with two data readings in each

parameter in every experiment.

2.2 pH

pH was determined using standard method where

solid sample was grounded using pestle and mortar,

and then diluted using distilled water. Solid was

separated by filtration using Whatman paper no.40.

Determination of pH of filtrate was carried out using

pH-meter (PH 1120X, Mattler Toledo, China).

2.3 Water Activity

Water activity of sample was determined using an

Aw-meter (Hygropalm, Rotronic, Bassersdorf). As

much as 2 gram sample was put inside sample

chamber which was then closed with the lid to start

the reading.

2.4 Microbial Count, Macroscopical,

and Microscopical Observation of

Colonies

A serial dilution was performed for each sample taken

from each stage of process. Then, one milliliter of

suspension was aseptically transferred and spread

evenly onto surface of a plate count agar (Oxoid

CM0325).

3 RESULT AND DISCUSSION

The process of making ‘bungkil’ was described by

Ibu Sagem, and it consisted of several stages. It

started from fresh coconut meat which is washed, and

then soaked in well water or mixed of water with

coconut juice (approximately 1:1, v/v). The soaking

stage took three days at room temperature. After that,

the coconut chunks were drained, and put into a

bamboo basket lined with two or three layers of

banana leaves. The top of the coconut was covered

with two layers of banana leaves. It was left for three

days. This process was called ‘emplep’ or ‘empep’.

After that, coconut chunks were drained and grated.

The grated coconut went into another three-days

‘emplep’ process in a bamboo basket lined with

banana leaves. After that, for four days, grated

coconut was sun-dried during day time, and put into

bamboo basket for ‘emplep’ process during night. At

the end of four days, grated coconut has been very

soft and oily. The oil was separated by hand pressing

of grated coconut wrapped in cheese cloth. The oil

was collected, while the cake was then mixed with

spices (shallot, garlic, chilli, salt, sugar, and

galangal). The mixture was then shaped, and deep

fried in coconut oil previously collected from the

process.

Chemical and microbial changes during stages of

process was presented in Table 1. During ‘emplep’ or

fermentation process, acidity as expressed in pH

reduced from 7 to around 6. It was expected that lactic

acid bacteria may utilize simple sugar of coconut

meat to produce acid during the process. The final

product, however, showed higher pH than that of

fresh coconut. This may due to the formation of basic

substances resulted from protein degradation, such as

ammonia.

Water activity was high during the process, but

reduced to 0.88 after drying. Even after drying, high

water activity was expected, since coconut meat

became very soft and moist during fermentation. The

presence of oil in the product may hinder water

evaporation. High water activity during ’emplep’

facilitated growth of bacteria to increase from 9.84 ×

cfu/mL to 4.42 ×10

during soaking and 2.74 ×

after drying. We did not identify colonies to

species level, however there was apparently change

in types of microorganism during fermentation.

Colonies isolated from fresh coconut meat was

mostly white and cocci with around 3.3

μm diameter.

During soaking there were orange colonies of

streptobacilli cells, and white colonies of cocci. These

colonies were also isolated from the final product.

As bungkil making process is basically a

fermentation of coconut to produce coconut oil, it

differs from other familiar process where

fermentation was applied to coconut milk (Iskandar

2009) rather than coconut meat. Therefore, chemical

and microbial changes in bungkil fermentation may

not as fast as that in coconut milk fermentation. Final

pH of coconut oil produced by coconut milk

fermentation was 6 (Iskandar, 2009), while the solid

part (locally called as “blondo”) was 4.5 (Iskandar,

2009). The lowest pH in bungkil fermentation was

5.7, slightly lower than that of oil (Iskandar, 2009),

2nd SIS 2019 - SEAFAST International Seminar

Table 1: Acidity, water activity, and microbial count of during processing of ‘bungkil’.

Stages of process pH Water

activity

Microbial count

(cell/mL)

Microbial

characteristics

Fresh coconut meat 7.32 0.93

9.84 × 10

White, shiny colonies;

cocci, 3.3

μm diameter

Soaking 6.50 0.97

4.42 × 10

Orange colonies,

streptobacilli 4-5

μm in

length

White colonies, cocci 4

μm in diameter

White colonies, cocci,

11.3

μm in diameter

Coconut chunks

fermentation

6.63 0.97 Not analysed

Grated coconut fermentation 5.76 0.95 Not analysed

Coconut cake after drying 7.50 0.88

2.74 × 10

White colonies, cocci,

2.1

μm

Orange colonies,

streptococci, 4.5

μm in

length

but more basic than solid part of coconut milk

(Iskandar 2009). There was an increase of pH during

final of bungkil process after drying, to reach 7.5.

Therefore, bungkil process may be categorized as

alkaline fermentation (Anal 2019), where bacilli may

be predominated (Anal 2019). Lypolitic and

proteolytic activities during bungkil fermentation was

likely to produce basic substances such as ammonia.

Micrococci, which is characterized by small

diameter cell (0.5-3

μm), were isolated in several

coconut-based product, such as dried grated coconut

(Kinderlerer and Clark 1986), coconut milk (Suryani

et al. 2014), fresh coconut (Su’i et al. 2015), coconut

water (Salunkhe and Kadam 1995), and copra

(Salunkhe and Kadam 1995). Coconut meat was a

rich medium for growth of contaminating

microorganism (Umesha and Nrayanaswamy 2016),

as compared to coconut water (Umesha and

Narayanaswamy 2016). Although micrococci maybe

considered as spoilage bacteria which can be

inhibited by lactic acid bacteria (Gollop et al. 2006),

they showed growth stimulation effect to lactic acid

bacteria (Nath and Wagner 1973b) by inhibition of

hydrogen peroxide production (Nath and Wagner

1973a).

During bungkil fermentation, lactic acid bacteria

growth is expected, as indicated by reduced pH.

Lactic acid bacteria was reported to grow during

coconut milk spontaneous fermentation (Suryani et

al. 2014, Agarwal and Bosco 2017). Suitability of

coconut meat for lactic acid bacteria growth is also

shown by production coconut milk kefir employing

Lactobacillus spp. (Lakshmi and Pramela 2018).

Lactic acid bacteria are abundant in tropical

environment, including some species of lactobacilli,

Leuconostoc sp., Weisella sp. and Lactococcus lactis

(Khota et al. 2016).

4 CONCLUSION

Bungkil making process involved acidic fermentation

in early stage and basic fermentation in the later stage,

by cocci and streptobaccilli.

Physical, Chemical, and Microbial Changes during Fermentation of Bungkil: A Traditional Snack Originated from Banyumas, Central Java

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2nd SIS 2019 - SEAFAST International Seminar