Project Title: IntelliPlasti-pH: Development of pH

Sensitive Bioplastics Using Yam

(Dioscorea luzonensis) and Taro
(Colocasia esculenta) Starch with
Bougainvillea glabra Extract
Project Category: Applied Science (Team)
Proponent: Maria Alenor L. Jandulong
Gavriele N. Melendez
Gie Ann S. Lumalang
Grade Level: 10
Project Adviser: Jhon Mark P. Mercene
School: Bangbang National High School
School Address: Brgy. Bangbang, Gasan, Marinduque

CONTENTS;
I. Research Plan
II. ISEF Forms
 Checklist for Adult Sponsor Form (1)
 Student Checklist (1A)
 Approval Form (1B)
III. LOGBOOK
IV. Research Paper
V. Abstract
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

RESEARCH PLAN
Rationale
The food packaging industry has long relied on conventional materials, particularly
single-use plastics, which have emerged as significant contributors to environmental pollution.
These materials saturate the entire food supply chain, from production facilities to supermarkets
and restaurants, raising pressing concerns about their ecological impact. Plastics, in particular,
exhibit extremely long degradation periods, with half-lives ranging from 2 years to over 2500
years, resulting in a considerable ecological footprint that threatens both terrestrial and marine
ecosystems (Jamieson et al., 2019). The imbalance between the production and recycling of
packaging materials intensifies this issue. For instance, data from the European Union indicate
that plastic packaging accounted for over 15 million tons in 2019, reflecting a staggering 26%
increase compared to 2009 (PlasticsEurope, 2019). This alarming trend poses a significant
environmental crisis, as improper disposal of plastic waste contributes to landfills, waterways,
and ocean pollution, severely impacting wildlife and ecosystems.
Moreover, as societal awareness of food quality and safety has evolved with
technological advancements and rising living standards, consumers are increasingly concerned
about the origins and preservation of their food. The demand for safe, fresh, and natural foods is
growing, yet various environmental factors—including microbial growth, light exposure,
temperature fluctuations, oxygen levels, and relative humidity—significantly affect food quality.
The proliferation of microorganisms is the leading cause of food spoilage and deterioration.
Presently, an increasing number of consumers seek valid information about food quality during
storage, desiring simple, fast, and reliable ways to monitor freshness. This shift has prompted
significant interest in intelligent packaging and antimicrobial packaging technologies, which
possess the capability to monitor food quality and extend shelf life (Mlalila et al., 2018).
However, the existing solutions often depend on synthetic materials that perpetuate the very
pollution problems they aim to resolve.
Intelligent packaging offers real-time monitoring of changes in food quality during
storage, relying on the interaction between the packaging material and the food, as well as its
immediate environment (Musso et al., 2019). One innovative approach in this realm is
colorimetric pH indicator packaging, which responds to changes in pH caused by food spoilage
or environmental fluctuations, displaying noticeable color alterations. Since microbial growth
can lead to pH changes in food (Narwade et al., 2019), implementing a pH indicator packaging
system allows for effective monitoring and visual communication of food quality through the
color changes of the packaging material itself. A promising candidate for such applications is
anthocyanin, a natural water-soluble pigment derived from plants. Anthocyanins are known to
exhibit color changes in response to different pH levels, making them particularly suitable for
use in intelligent packaging solutions (Wang et al., 2018).
In this context, this study leverages local agricultural resources, focusing on the starches
derived from Ulabi (Dioscorea luzonensis) and Taro (Colocasia esculenta). Yam (Dioscorea
luzonensis) is an edible wild root crop that thrives in the wilds of Northern Luzon without the
need for fertilizers and pesticides. Valued for its starchy and glutinous texture, it is commonly
consumed as a vegetable. Taro (Colocasia esculenta) is another vital plant, providing a

2
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

significant source of starch, with its corms containing 70–80% starch by dry weight. This starch
has diverse applications, including use in the food, pharmaceutical, and cosmetic industries.
Additionally, this study utilizes Bougainvillea glabra extract, commonly known as "Paper
Flower." This natural indicator is easy to extract and readily available. Herbal indicators,
including those derived from Bougainvillea, have been evaluated for their performance in weak
acid-strong base titrations, showing well-marked color changes at specific pH intervals (9 to 10).
Despite advancements in intelligent packaging technologies, a notable research gap
persists concerning the development of sustainable and biodegradable alternatives that utilize
natural materials. Many existing solutions continue to rely heavily on synthetic components,
which perpetuate the environmental challenges they aim to alleviate. Furthermore, there is a
pressing need for comprehensive studies that explore the potential of local agricultural resources
to create effective bioplastics that comply with food safety and preservation requirements. The
growing concern regarding the migration of hazardous compounds from conventional packaging
further underscores the need for innovative solutions. Traditional smart packaging systems often
involve the use of petroleum-based materials that pose health risks due to chemical leaching into
food products, leading to serious health and environmental concerns (Halonen et al., 2020). This
necessitates a shift towards natural alternatives that can safely interact with food without
compromising safety or quality.
In light of these challenges, researchers are increasingly exploring the use of natural
compounds in food packaging as a promising avenue for innovation (Ma et al., 2018). The
present study, titled "IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using Ulabi
(Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch with Bougainvillea glabra Extract
for Intelligent Packaging," aims to create sustainable and biodegradable packaging solutions. By
harnessing the potential of pH-sensitive bioplastics, this research seeks to enhance food safety
while minimizing environmental impact, thereby providing a viable alternative to conventional
packaging materials.
The significance of this study extends beyond environmental sustainability; it also
addresses the pressing concerns surrounding food safety. By utilizing locally sourced materials
such as Ulabi and Taro starches, the research supports agricultural economies while reducing
reliance on petroleum-based plastics. Moreover, the findings could pave the way for future
innovations in intelligent packaging, leading to safer food products and a reduction in plastic. As
the demand for eco-friendly solutions continues to grow, the outcomes of this project have the
potential to reshape the landscape of food packaging, offering a model for future innovations that
align with sustainability goals and consumer expectations. Ultimately, the IntelliPlasti-pH
initiative represents a crucial step towards a more sustainable and health-conscious approach to
food packaging, bridging the gap between environmental responsibility and consumer needs.
Statement of the Problem
The primary lens of this research is to develop and test pH-sensitive bioplastics using
locally sourced Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) starches, combined
with Bougainvillea glabra extract as a natural pH indicator.

3
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

1. How do varying proportions of Yam and Taro starches affect the tensile strength, water
absorption, biodegradability, and solubility of the synthesized IntelliPlasti-pH bioplastic
films?
2. How does IntelliPlasti-pH respond to based and acid solutions?
3. What combination of bioplastics produces the most durable and biodegradable material,
considering factors such as tensile strength, water absorption, biodegradability, solubility,
and pH responsiveness?
Research Methods
Materials and equipment
To create the IntelliPlasti-pH bioplastic, the required materials and equipment include
Taro (Colocasia esculenta), Yam (Dioscorea luzonensis), bougainvillea-extracted water, and
glycerin.
General Procedure
Collection of Materials
Taro (Colocasia esculenta) and Yam (Dioscorea luzonensis) will be sourced from a local
store in Gasan and authenticated. These will then be chopped into small pieces and ground to
produce starch, which will be stored at an appropriate room temperature.
Glycerin will be procured from the online platform Shopee, carefully observed upon
arrival, and preserved for use in bioplastic production.
Bougainvillea (Bougainvillea glabra caryophyllales) will be collected from the school
garden in Bangbang, Gasan, Marinduque. The bougainvillea flowers will be separated from the
leaves, and the collected flowers will be set aside for later use.
Preparation of boiling ingredients
The Taro (Colocasia esculenta) and Yam (Dioscorea luzonensis) starch will be boiled in a
beaker. Once boiling, the bougainvillea water extract will be added to the starch mixture, and the
solution will be continuously stirred. When the mixture reaches a thick consistency, glycerin will
be incorporated and mixed thoroughly. The prepared mixture will then be poured into a flat
casting mold and left to dry in sunlight. Once fully dried, the bioplastic will be stored in the
laboratory until testing.
Testing Procedure
To determine if the bioplastic meets required standards, it will undergo several tests.
First, a tensile test will be conducted to assess its tensile strength. Following this, a water
absorption test will be performed by placing the bioplastic in a beaker containing 10 mL of water
to observe if it absorbs moisture. Next, the bioplastic will undergo a biodegradability test, where
it will be buried in a beaker filled with soil to evaluate its ability to biodegrade. Finally, an
acid/base indicator test will be conducted to observe any color changes, indicating interaction
with acidic or basic environments.

4
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

Bibliography
Chayavanich, K., Thiraphibundet, P., and Imyim, A. (2020). Biocompatible film sensors
containing red radish extract for meat spoilage observation. Spectrochim. Acta A. 226,
117601. doi: 10.1016/j.saa.2019.117601
Jamieson, A. J., Brooks, L. S. R., Reid, W. D. K., Piertney, S. B., Narayanaswamy, B. E., and
Halonen N, Pálvölgyi PS, Bassani A, Fiorentini C, Nair R, Spigno G and Kordas K
(2020) Bio-Based Smart Materials for Food Packaging and Sensors – A Review. Front.
Mater. 7:82. doi: 10.3389/fmats.2020.00082
Linley, T. D. (2019). Microplastics and synthetic particles ingested by deep-sea amphipods in six
of the deepest marine ecosystems on Earth. Roy. Soc. Open Sci. 6, :180667. doi:
10.1098/rsos.180667
Ma, Y., Li, L., and Wang, Y. (2018). Development of PLA-PHB-based biodegradable active
packaging and its application to salmon. Packag. Technol. Sci. 31, 739–746. doi:
10.1002/pts.2408
Machado, P. G., Walter, A., and Cunha, M. (2016). Bio−based propylene production in a
sugarcane biorefinery: a techno−economic evaluation for Brazilian conditions. Biofuel.
Bioprod. Bior. 10, 623–633. doi: 10.1002/bbb.1674
Mlalila, N., Hilonga, A., Swai, H., Devlieghere, F., and Ragaert, P. (2018). Antimicrobial
packaging based on starch, poly (3-hydroxybutyrate) and poly (lactic-co-glycolide)
materials and application challenges. Trends Food Sci. Tech. 74, 1–11. doi:
10.1016/j.tifs.2018.01.015
Musso, Y. S., Salgado, P. R., and Mauri, A. N. (2019). Smart gelatin films prepared using red
cabbage (Brassica oleracea L.) extracts as solvent. Food Hydrocoll.oid. 89, 674–681.
doi: 10.1016/j.foodhyd.2018.11.036
Narwade, V. N., Anjum, S. R., Kokol, V., and Khairnar, R. S. (2019). Ammonia-sensing ability of
differently structured hydroxyapatite blended cellulose nanofibril composite
films. Cellulose 26, 3325–3337. doi: 10.1007/s10570-019-02299-y
PlasticsEurope. (2019). Plastics – The Facts 2019. Available online
at: https://www.plasticseurope.org/application/files/1115/7236/4388/
FINAL_web_version_Plastics_the_facts2019_14102019.pdf
Pereira, P. F., and Andrade, C. T. (2017). Optimized pH-responsive film based on a eutectic
mixture-plasticized chitosan. Carbohyd. Polym. 165, 238–246. doi:
10.1016/j.carbpol.2017.02.047
Wang, L. F., and Rhim, J. W. (2018). Grapefruit seed extract incorporated antimicrobial LDPE
and PLA films: effect of type of polymer matrix. LWT- Food Sci. Technol. 74, 338–345.
doi: 10.1016/j.lwt.2016.07.066

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 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

6
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

7
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

8
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

PROJ
ECT
DATA
LOG
BOO
K
9
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

10
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

11
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

12
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

13
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

14
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

15
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

16
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

17
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

DATA
COL
LEC
TION

18
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

19
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

20
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

21
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

22
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

23
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

24
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

25
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using Yam (Dioscorea luzonensis)

and Taro (Colocasia esculenta) Starch with Bougainvillea glabra Extract

Maria Alenor L. Jandulong

Gavriele N. Melendez
Gie Ann S. Lumalang
Researchers

Jhon Mark P. Mercene

Research Adviser

BANGBANG NATIONAL HIGH SCHOOL

Gasan District

26
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

TABLE OF CONTENTS
ABSTRACT …………………………………………………………………………….…..27

INTRODUCTION…………………………………………….……………………………..28

METHODOLOGY………………………………………………………………………..…32

RESULTS……………………………………………………………………………….……36

CONCLUSION……………………………………………………………………………….45

ACKNOWLEDGEMENTS…………………………………………………..……………..46

REFERENCES………………………………………………………………………………..47

APPENDICES
Appendix A (Process Flowchart)……………………………………………………50
Appendix B (Testing Procedure)…………………………………………………….51
Appendix C (Raw Data)…………………………………………………….……….52

27
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

ABSTRACT

This research explores the development of pH-sensitive bioplastics using locally sourced
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) starches, combined with
Bougainvillea glabra extract as a natural pH indicator. The study aimed to assess how varying
proportions of these starches affect the tensile strength, water absorption, biodegradability,
solubility, and pH responsiveness of the bioplastic films. The results showed that starch
composition significantly influenced the mechanical and environmental properties of the
materials. Notably, the bioplastics exhibited distinct color changes in response to acidic and basic
solutions, indicating their pH sensitivity, which is useful for applications requiring environmental
responsiveness. Bioplastics D and C emerged as the most balanced materials in terms of
durability and biodegradability. D demonstrated high tensile strength and moderate resistance to
solvents, making it suitable for applications that require structural integrity, while C offered
excellent biodegradability and stability in wet conditions, making it ideal for moisture-prone
environments. Both materials are promising candidates for industries seeking to balance
performance with environmental sustainability, with the choice between them depending on the
specific needs for tensile strength or moisture resistance. This study highlights the potential of
locally sourced, pH-sensitive bioplastics as sustainable alternatives for various industrial
applications.
Keywords: pH-sensitive, bioplastics, Yam starch, Taro starch, biodegradability

28
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

INTRODUCTION

The food packaging industry has long relied on conventional materials, particularly

single-use plastics, which have emerged as significant contributors to environmental pollution.

These materials saturate the entire food supply chain, from production facilities to supermarkets

and restaurants, raising pressing concerns about their ecological impact. Plastics, in particular,

exhibit extremely long degradation periods, with half-lives ranging from 2 years to over 2500

years, resulting in a considerable ecological footprint that threatens both terrestrial and marine

ecosystems (Jamieson et al., 2019). The imbalance between the production and recycling of

packaging materials intensifies this issue. For instance, data from the European Union indicate

that plastic packaging accounted for over 15 million tons in 2019, reflecting a staggering 26%

increase compared to 2009 (PlasticsEurope, 2019). This alarming trend poses a significant

environmental crisis, as improper disposal of plastic waste contributes to landfills, waterways,

and ocean pollution, severely impacting wildlife and ecosystems.

Moreover, as societal awareness of food quality and safety has evolved with

technological advancements and rising living standards, consumers are increasingly concerned

about the origins and preservation of their food. The demand for safe, fresh, and natural foods is

growing, yet various environmental factors—including microbial growth, light exposure,

temperature fluctuations, oxygen levels, and relative humidity—significantly affect food quality.

The proliferation of microorganisms is the leading cause of food spoilage and deterioration.

Presently, an increasing number of consumers seek valid information about food quality during

storage, desiring simple, fast, and reliable ways to monitor freshness. This shift has prompted

significant interest in intelligent packaging and antimicrobial packaging technologies, which

29
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

possess the capability to monitor food quality and extend shelf life (Mlalila et al., 2018).

However, the existing solutions often depend on synthetic materials that perpetuate the very

pollution problems they aim to resolve.

Intelligent packaging offers real-time monitoring of changes in food quality during

storage, relying on the interaction between the packaging material and the food, as well as its

immediate environment (Musso et al., 2019). One innovative approach in this realm is

colorimetric pH indicator packaging, which responds to changes in pH caused by food spoilage

or environmental fluctuations, displaying noticeable color alterations. Since microbial growth

can lead to pH changes in food (Narwade et al., 2019), implementing a pH indicator packaging

system allows for effective monitoring and visual communication of food quality through the

color changes of the packaging material itself. A promising candidate for such applications is

anthocyanin, a natural water-soluble pigment derived from plants. Anthocyanins are known to

exhibit color changes in response to different pH levels, making them particularly suitable for

use in intelligent packaging solutions (Wang et al., 2018).

In this context, this study leverages local agricultural resources, focusing on the starches

derived from Ulabi (Dioscorea luzonensis) and Taro (Colocasia esculenta). Yam (Dioscorea

luzonensis) is an edible wild root crop that thrives in the wilds of Northern Luzon without the

need for fertilizers and pesticides. Valued for its starchy and glutinous texture, it is commonly

consumed as a vegetable. Taro (Colocasia esculenta) is another vital plant, providing a

significant source of starch, with its corms containing 70–80% starch by dry weight. This starch

has diverse applications, including use in the food, pharmaceutical, and cosmetic industries.

Additionally, this study utilizes Bougainvillea glabra extract, commonly known as "Paper

Flower." This natural indicator is easy to extract and readily available. Herbal indicators,

30
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

including those derived from Bougainvillea, have been evaluated for their performance in weak

acid-strong base titrations, showing well-marked color changes at specific pH intervals (9 to 10).

Despite advancements in intelligent packaging technologies, a notable research gap

persists concerning the development of sustainable and biodegradable alternatives that utilize

natural materials. Many existing solutions continue to rely heavily on synthetic components,

which perpetuate the environmental challenges they aim to alleviate. Furthermore, there is a

pressing need for comprehensive studies that explore the potential of local agricultural resources

to create effective bioplastics that comply with food safety and preservation requirements.

The growing concern regarding the migration of hazardous compounds from

conventional packaging further underscores the need for innovative solutions. Traditional smart

packaging systems often involve the use of petroleum-based materials that pose health risks due

to chemical leaching into food products, leading to serious health and environmental concerns

(Halonen et al., 2020). This necessitates a shift towards natural alternatives that can safely

interact with food without compromising safety or quality.

In light of these challenges, researchers are increasingly exploring the use of natural

compounds in food packaging as a promising avenue for innovation (Ma et al., 2018). The

present study, titled "IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using Ulabi

(Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch with Bougainvillea glabra Extract

for Intelligent Packaging," aims to create sustainable and biodegradable packaging solutions. By

harnessing the potential of pH-sensitive bioplastics, this research seeks to enhance food safety

while minimizing environmental impact, thereby providing a viable alternative to conventional

packaging materials.

31
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

The significance of this study extends beyond environmental sustainability; it also

addresses the pressing concerns surrounding food safety. By utilizing locally sourced materials

such as Ulabi and Taro starches, the research supports agricultural economies while reducing

reliance on petroleum-based plastics. Moreover, the findings could pave the way for future

innovations in intelligent packaging, leading to safer food products and a reduction in plastic. As

the demand for eco-friendly solutions continues to grow, the outcomes of this project have the

potential to reshape the landscape of food packaging, offering a model for future innovations that

align with sustainability goals and consumer expectations. Ultimately, the IntelliPlasti-pH

initiative represents a crucial step towards a more sustainable and health-conscious approach to

food packaging, bridging the gap between environmental responsibility and consumer needs.

32
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

METHODOLOGY

Flowchart of the study

Prepare the ingredients/ Chop the Yam and Taro into

Boil the bougainvillea to
materials to be needed to small pieces and grind it to
produce extract.
make the bioplastic. produce starch.

Pour the gelatin powder into

the bougainvillea extract, After boiling, add the starch. Stir it until it thickens.
then mix it continuously.

Add the glycerin and mix it Mold it on a flat casting Dry it using the heat of the
in continuous way. molds. sun.

Testing the bioplastic ing 5

ways: tensil, water Recording/Tabulating/ Analysis and Interpretation
absorption, biodegradability, Interpreting of Observed
acid-base indicator, pH Results of Results
sentivity, Load test.

Materials and Equipment

33
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

The primary raw materials used in the study included starch sourced from Yam

(Dioscorea luzonensis) and Taro (Colocasia esculenta), both known for their high starch content

and local availability. Bougainvillea glabra flower extract served as the natural pH indicator due

to its colorimetric properties, enabling visual changes in response to pH variations. Essential

equipment for this study included beakers for mixing and preparing starch solutions, a retort

stand for load testing the bioplastic films, spring balances for measuring applied force, test tubes

for conducting solubility tests in various solvents, a sensitive electronic balance for accurate

weight measurement, a water bath to maintain consistent temperatures during film preparation,

and soil samples for biodegradability tests. A pH meter was also utilized for precise measurement

of pH levels in solutions.

Preparation of pH-sensitive Bioplastic

The preparation of IntelliPlasti-pH commenced with the extraction of starch from fresh

Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) tubers. These tubers were

thoroughly washed, peeled, and cut into small pieces before boiling and blending to form a

slurry. This slurry was then filtered to separate the starch from fibrous materials. The collected

starch was dried in an oven at 40–50°C until it reached a constant weight.

In a beaker, the dried starch was mixed in a predetermined ratio with Bougainvillea

glabra flower extract, glycerin, and distilled water. The addition of glycerin served as a

plasticizer, enhancing the flexibility and durability of the bioplastic. Five different setups were

created, as shown in the table below, to evaluate the effects of varying amounts of Yam and Taro:

Table 1 Bioplastic Set-Up Configurations with Varying Proportions of Yam and Taro Starch
Amount of
Amount of Amount of Bougainvillea Number of
Set-Up Glycerin
Ulabe (g) Taro (g) glabra flower Days of Drying
extract

34
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

A 30 g 0g 20 mL 120 mL 2 days
B 0g 30 g 20 mL 120 mL 2 days
C 15 g 15 g 20 mL 120 mL 2 days
D 10 g 20 g 20 mL 120 mL 2 days
E 20 g 10 g 20 mL 120 mL 2 days

The mixtures for each setup were gradually heated while stirring to facilitate

gelatinization, resulting in homogeneous gels. Once thickened, the mixtures were poured into flat

casting molds and allowed to cool at room temperature, where they solidified into bioplastic

films. After solidification, the films were carefully removed from the molds and sundried for two

days to further enhance their properties and reduce moisture content. Finally, the films were

stored in a cool, dry place to prevent moisture absorption before further testing.

Characterization of the synthesized IntelliPlasti-pH

Load test was conducted by suspending a rectangular piece of the bioplastic film (2 cm ×

6 cm) horizontally on a retort stand, ensuring it was supported at both ends, 3.5 cm apart. A

spring balance was attached at the midpoint of the film, and weights were added incrementally

until the film broke. The breaking point was recorded and repeated for three replicates to ensure

accuracy. Tensile strength was calculated using the formula

Weigℎt Load (N )
Tensile Strengℎt =
Area of cross section of bioplastic (m¿ ¿ 2)¿

For the water absorption test, a sample measuring 1 cm × 2 cm was weighed to determine

its initial weight, submerged in 60 mL of distilled water at room temperature for 24 hours, then

weighed again after wiping off excess water to obtain the final weight. Water uptake was

calculated using the formula

Final weigℎt ( g ) − Initial weigℎt ( g )

WA ( % ) = x 100
Initial weigℎt ( g )

35
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

To assess biodegradability, a pre-weighed piece of bioplastic was buried in a beaker

containing soil at a depth of 5 cm. Water was sprinkled on the soil to facilitate bacterial and

enzymatic activity, promoting the degradation of the bioplastic. This setup was left undisturbed

for 15 days, with weight measurements taken every five days to monitor degradation and record

weight loss.

The solubility test involved cutting the bioplastics into small pieces and placing them in

separate test tubes containing distilled. The samples were observed for any changes in solubility,

including dissolution or swelling, to indicate the persistence of the bioplastic materials in

different chemical environments.

To evaluate the pH sensitivity of IntelliPlasti-pH, bioplastic samples were immersed in

solutions of varying pH levels, including acidic (pH < 7), neutral (pH = 7), and basic (pH > 7)

environments for a specified period (e.g., 24 hours). Color changes of the bioplastics were

monitored visually, and the pH levels were measured before and after immersion using a pH

meter.

36
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

RESULTS AND DISCUSSION

The tensile strength data gathered for the various IntelliPlasti-pH bioplastic formulations

underscores the impact of different Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta)

starch ratios on the material's structural properties.

45
40
40 37.5 38.33 39.17
35 36.25
35 31.67
31.25
30.83
30 27.5
25.83 26.67
25 21.67
21.25
20.83
20
15
10
5
0
A B C D E

Trial 1 Tensile Strength (N/m²) Trial 2 Tensile Strength (N/m²)

Average Tensile Strength

Figure 2 Tensile Strength of IntelliPlasti-pH Bioplastics with

Varying Ratios of Yam and Taro Starch

Notably, Set-Up D, which combined 10 g of Yam and 20 g of Taro, exhibited the highest

tensile strength, averaging 46,000 N/m². This indicates that a higher proportion of Taro starch,

when paired with a smaller amount of Yam, results in a stronger, more resilient bioplastic film,

likely due to the complementary structural characteristics of the two starches. Conversely, Set-

Up B, composed exclusively of Taro starch (30 g), yielded the lowest tensile strength, with an

37
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

average of 21,250 N/m², suggesting that pure Taro starch lacks sufficient cross-linking or rigidity

for applications requiring high tensile strength. Set-Up A, which utilized 30 g of pure Yam

starch, achieved a moderate tensile strength of 26,667 N/m², indicating that while Yam can

produce a functional bioplastic on its own, it does not reach the strength levels achieved in

blends. Set-Up C, with an equal ratio of Yam and Taro (15 g each), achieved a tensile strength of

33,334 N/m², demonstrating a balanced yet moderately strong structure. This suggests that while

both starch sources contribute to tensile strength, a balanced mix does not maximize this

property as effectively as the optimal blend seen in Set-Up D. These findings point to the

formulation in Set-Up D as the most promising for applications in intelligent packaging, where a

strong, durable bioplastic is essential for withstanding physical stresses.

100
90 86
80.5
80 75 72.34
70 60.78 61.22
54.94 58 56.76
60 53.69
49.1 49.19 46.15
50 41.18
40.38
40
30
20
10
0
A B C D E

Trial 1 Water Absorption (%) Trial 2 Water Absorption (%)

Average

Figure 3 Water uptake of IntelliPlasti-pH Bioplastics with

Varying Ratios of Yam and Taro Starch
The water absorption test results highlight differences in moisture resistance across the

various bioplastic set-ups, influenced by the proportions of Yam and Taro starch used. Set-Up A

exhibited the highest average water absorption at 80.5%, indicating a high susceptibility to

moisture. This setup, containing 30 g of Yam starch only, suggests that Yam starch alone

produces a bioplastic that is more hydrophilic, likely due to its molecular structure and the

38
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

absence of Taro starch, which could improve water resistance. Conversely, Set-Up D, which

included 10 g of Yam and 20 g of Taro starch, showed a moderately high water absorption rate at

56.76%. Despite being the strongest bioplastic in terms of tensile strength, this composition still

allowed for significant water uptake, indicating that while Taro starch enhances strength, the

ratio used here still enables notable moisture absorption. Set-Up B, with 30 g of Taro starch only,

had a lower average water absorption of 54.94%, suggesting that Taro starch alone might offer

better moisture resistance than Yam starch alone. However, it does not achieve the same level of

resistance as certain starch combinations. Set-Up E, composed of 20 g of Yam and 10 g of Taro

starch, achieved an average water absorption rate of 53.69%, suggesting a balanced yet moderate

resistance to moisture uptake, slightly better than Yam-only compositions. The most notable

performance was observed in Set-Up C, with an equal blend of 15 g of Yam and 15 g of Taro

starch, achieving the lowest average water absorption at 49.19%. This equal ratio appears to

provide an optimal balance, reducing hydrophilicity and limiting water absorption while

maintaining structural integrity.

Set-Up C demonstrated the best moisture resistance, making it the most suitable for

applications where exposure to moisture is a concern. In contrast, Set-Up A showed the highest

water absorption rate, indicating that bioplastics composed primarily of Yam starch are more

prone to moisture uptake. This data suggests that combining Yam and Taro starch in balanced

proportions can significantly improve the water resistance of the resulting bioplastic.

39
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

6
1.09
5
1.12 0.91
4
0.89 E
1.08 0.68
3 D
0.9 C
0.6 0.52
1.15 B
2 0.98 0.62 0.43 A
0.73 0.44
1 1.1 0.58
0.93
0.68 0.53
0
Initial Weight Weight on Day 5 Weight on Day Weight on Day
10 15

Figure 4 Water uptake of IntelliPlasti-pH Bioplastics with

Varying Ratios of Yam and Taro Starch

Sample A demonstrated the highest degree of biodegradation, with a weight loss of

51.82% by Day 15, indicating that it is highly susceptible to microbial and enzymatic activity,

leading to efficient breakdown into simpler compounds. Sample B followed closely, with a

weight loss of approximately 49.57%. In contrast, Sample D exhibited the lowest weight loss at

approximately 38.39%, suggesting that it may possess properties that hinder degradation or that

it was less accessible to microbial action compared to the other samples.

The differences in weight loss percentages also highlight the importance of formulation

in determining the biodegradability of these bioplastics. Sample B, with a weight loss of 49.57%,

performed similarly to Sample A, suggesting that it also contains components that support

biodegradation. This suggests that certain combinations or concentrations of materials within the

bioplastics can enhance degradation rates. Conversely, Sample C, which lost 40.74% of its

weight by Day 15, indicates moderate biodegradability, which may be attributed to its

composition being less optimal for microbial attack compared to the more rapidly degrading

40
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

samples. the data emphasizes that the combination of materials within bioplastic formulations

significantly impacts their biodegradation profiles.

Table 2 Dissolution Behavior of Bioplastics in Water, Ethyl Alcohol, and Acetic Acid

Set-Up Water Ethyl Alcohol Acetic Acid

A Completely dissolved Slight softening, partial Dissolved completely
edges dissolve
B Dissolved entirely Noticeable softening, edges Completely dissolved
frayed
C Dissolved completely Moderate dissolution at Completely dissolved
edges
D Dissolved entirely Softened and partial Completely dissolved
dissolution
E Dissolved entirely Partially dissolved with Completely dissolved
fraying

In water, all setups (A through E) exhibited complete dissolution, indicating that the

bioplastics are highly hydrophilic. This property suggests that these materials may be prone to

rapid degradation in aquatic environments, which could be advantageous for applications

requiring biodegradability but raises concerns about their stability in moisture-rich conditions.

The complete dissolution in water highlights the need to consider the intended use of these

bioplastics, especially in products that may encounter wet environments.

When exposed to ethyl alcohol, a notable difference emerged among the samples. Set-Up

A demonstrated slight softening with partial edge dissolution, while Set-Up B experienced

noticeable softening and frayed edges, indicating that this formulation may have lower resistance

to alcohol. Set-Up C showed moderate dissolution at the edges, suggesting some vulnerability to

ethyl alcohol but less than that of Set-Up B. Set-Up D exhibited complete dissolution alongside

softening, highlighting a complete lack of resistance to this solvent. Finally, Set-Up E showed

partial dissolution with fraying, indicating some resistance but still significant vulnerability.

41
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

These differences suggest that the chemical composition of each bioplastic affects its interaction

with alcohol, which could be critical for applications where exposure to alcoholic substances is

likely.

In acetic acid, all setups dissolved completely, indicating a high susceptibility to this

solvent as well. The complete dissolution across all samples suggests that the chemical bonds or

structures within the bioplastics are compromised in the presence of acetic acid, highlighting a

potential weakness in environments where acidic conditions may occur. This characteristic

should be carefully evaluated when considering the use of these bioplastics in food packaging or

other applications involving acidic substances.

Table 3 Sensitivity of Developed IntelliPlasti-pH Film to pH Changes

Set-Up Water Sodium Hypochlorite Vinegar

42
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

The pH-sensitive bioplastics exhibited distinct color changes when exposed to different

solutions, indicating varying levels of pH responsiveness. In Set-up A, the plastic appeared clear

in water, yellow in Sodium Hypochlorite (Zonrox), and light violet in vinegar. This suggests that

the bioplastic in Set-up A demonstrated significant color changes in response to acidic and

alkaline environments, with a notable shift to yellow in the basic solution and light violet in the

acidic solution.

In Set-up B, the plastic maintained a clear appearance in water but turned brown in

Zonrox and pink in vinegar. The brown color in Zonrox suggests a less pronounced reaction to

alkalinity compared to Set-up A, while the pink color in vinegar indicates a moderate response to

acidity.

In Set-up C, the plastic was clear in water, turned green in Zonrox, and light pink in

vinegar. The green color in Zonrox suggests a moderate response to alkalinity, while the light

pink color in vinegar demonstrates a relatively mild reaction to acidity.

In Set-up D, the plastic was clear in water, dark green in Zonrox, and light red in vinegar.

The dark green color in Zonrox and light red color in vinegar indicate a stronger pH sensitivity,

43
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

with more significant changes compared to the previous setups, especially in response to both

alkaline and acidic solutions.

In Set-up E, the plastic remained clear in water, light green in Zonrox, and orange in

vinegar. This setup showed moderate pH sensitivity, with lighter color changes compared to Set-

up D. The light green color in Zonrox and orange color in vinegar demonstrate the bioplastic's

response to both pH extremes, but with a less intense shift than Set-up D.

The results show that varying the proportions of Ulabi and Taro starches significantly

affects the pH sensitivity of the bioplastics. Each setup exhibited different levels of

responsiveness to changes in pH, with color shifts indicating the degree of pH sensitivity in the

bioplastics. These findings suggest that the formulation of the bioplastic, including the starch

ratio, plays a key role in its ability to change color based on pH variations, which could be

beneficial for intelligent packaging applications.

Table 4 Comparison of Bioplastic Combinations Based on Durability, Biodegradability, and

pH responsiveness

Water Biodegradability
Set- Tensile Dissolution
Absorption Rate (after 15 pH Responsiveness
Up Strength Behavior
days)
Fully dissolves in water Clear in water, yellow in
A 26.67 80.50 51.8 and acetic acid, slightly Zonrox, and light violet in
softens in ethyl alcohol. vinegar.
Fully dissolves in water
Clear in water, brown in
and acetic acid, softens
B 21.25 54.94 49.6 with frayed edges in
Zonrox, and pink in
vinegar.
ethyl alcohol.
Fully dissolves in water,
Clear in water, green in
moderately dissolves in
C 36.250 49.19 59.3 ethyl alcohol, fully
Zonrox, and light pink in
vinegar.
dissolves in acetic acid.
Fully dissolves in water Clear in water, dark green
D 39.17 56.76 61.6 and acetic acid, softens in Zonrox, and light red in
in ethyl alcohol. vinegar.
Fully dissolves in water
Clear in water, light green
and acetic acid, partially
E 31.25 53.69 52.3 dissolves with fraying in
in Zonrox, and orange in
vinegar.
ethyl alcohol.

44
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

Bioplastics D and C emerge as the most balanced materials when evaluating both

durability and biodegradability. D stands out for its highest tensile strength (39.17), which

suggests superior resistance to mechanical stress and, therefore, greater durability. This makes it

a strong candidate for applications that require materials to maintain their structural integrity

under load. Additionally, D boasts the highest biodegradability rate (61.6) after 15 days,

indicating it will break down more quickly in natural environments, contributing to its

sustainability. Its dissolution behavior is also noteworthy, as it fully dissolves in water and acetic

acid, while it only softens in ethyl alcohol, suggesting a reasonable degree of stability in different

environmental conditions. Moreover, D shows pH responsiveness, changing color in response to

different pH levels, which could be advantageous in certain applications where the material’s

response to environmental conditions is relevant.

On the other hand, C offers a different set of advantages. While it has a slightly lower

tensile strength than D (36.25), it is still relatively durable, making it suitable for less demanding

applications where moderate strength is sufficient. C shines in its biodegradability, with a rate of

59.3 after 15 days, which is close to D’s rate, meaning it will degrade quickly in the

environment. Additionally, C has the lowest water absorption (49.19), meaning it is more

resistant to water-induced degradation compared to other bioplastics. This makes it a more stable

option in moist or wet conditions, where materials with high water absorption may weaken or

degrade more quickly. The dissolution behavior of C indicates that it is fully soluble in water and

acetic acid, and dissolves moderately in ethyl alcohol, offering a balance between

biodegradability and material integrity.

45
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

CONCLUSION

This research focused on developing pH-sensitive bioplastics using locally sourced Yam

and Taro starches, along with Bougainvillea glabra extract as a natural pH indicator, to evaluate

their performance in terms of tensile strength, water absorption, biodegradability, solubility, and

pH responsiveness. The results highlighted the unique pH sensitivity of the bioplastics, with the

materials exhibiting clear and distinct color changes when exposed to acidic and basic solutions.

Bioplastics D and C emerged as the most balanced in terms of durability and environmental

sustainability. D offered high tensile strength and moderate resistance to solvents, making it

46
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

suitable for applications requiring structural integrity, while C demonstrated excellent

biodegradability and stability in wet conditions. Both bioplastics are promising candidates for

industries seeking to combine pH responsiveness with material durability, with the choice

between them depending on whether the application prioritizes tensile strength or moisture

resistance.

47
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

ACKNOWLEDGEMENT

The researchers would like to express their heartfelt gratitude to the individuals who
provided invaluable guidance and support throughout the completion of this project. Their
assistance made this work possible.
First and foremost, we give thanks to our Almighty God for granting us knowledge,
wisdom, strength, confidence, and courage to pursue this study.
We extend our deepest appreciation to our parents for their unwavering support,
encouragement, financial assistance, and lifelong inspiration.
We are profoundly grateful to Mr. Jhon Mark P. Mercene, our Research Adviser, for his
insightful suggestions, guidance, and constructive feedback throughout the research process.
Our sincere thanks also go to Mr. Edson R. Sapungan, our Statistician, for his expertise in
assisting with the analysis and computation of the data.
We would like to acknowledge Mr. Gueller Dee V. Salazar, our Adult Sponsor, for his
generous financial support.
Lastly, we are thankful to our classmates for their wholehearted encouragement and
motivation, which kept us inspired and focused.
We also wish to thank everyone who contributed, in any way, to the successful
completion of this research study.

48
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

REFERENCES

Chayavanich, K., Thiraphibundet, P., and Imyim, A. (2020). Biocompatible film sensors
containing red radish extract for meat spoilage observation. Spectrochim. Acta A. 226,
117601. doi: 10.1016/j.saa.2019.117601
Jamieson, A. J., Brooks, L. S. R., Reid, W. D. K., Piertney, S. B., Narayanaswamy, B. E., and
Halonen N, Pálvölgyi PS, Bassani A, Fiorentini C, Nair R, Spigno G and Kordas K
(2020) Bio-Based Smart Materials for Food Packaging and Sensors – A Review. Front.
Mater. 7:82. doi: 10.3389/fmats.2020.00082
Linley, T. D. (2019). Microplastics and synthetic particles ingested by deep-sea amphipods in six
of the deepest marine ecosystems on Earth. Roy. Soc. Open Sci. 6, :180667. doi:
10.1098/rsos.180667
Ma, Y., Li, L., and Wang, Y. (2018). Development of PLA-PHB-based biodegradable active
packaging and its application to salmon. Packag. Technol. Sci. 31, 739–746. doi:
10.1002/pts.2408
Machado, P. G., Walter, A., and Cunha, M. (2016). Bio−based propylene production in a
sugarcane biorefinery: a techno−economic evaluation for Brazilian conditions. Biofuel.
Bioprod. Bior. 10, 623–633. doi: 10.1002/bbb.1674
Mlalila, N., Hilonga, A., Swai, H., Devlieghere, F., and Ragaert, P. (2018). Antimicrobial
packaging based on starch, poly (3-hydroxybutyrate) and poly (lactic-co-glycolide)
materials and application challenges. Trends Food Sci. Tech. 74, 1–11. doi:
10.1016/j.tifs.2018.01.015
Musso, Y. S., Salgado, P. R., and Mauri, A. N. (2019). Smart gelatin films prepared using red
cabbage (Brassica oleracea L.) extracts as solvent. Food Hydrocoll.oid. 89, 674–681.
doi: 10.1016/j.foodhyd.2018.11.036
Narwade, V. N., Anjum, S. R., Kokol, V., and Khairnar, R. S. (2019). Ammonia-sensing ability of
differently structured hydroxyapatite blended cellulose nanofibril composite
films. Cellulose 26, 3325–3337. doi: 10.1007/s10570-019-02299-y
PlasticsEurope. (2019). Plastics – The Facts 2019. Available online
at: https://www.plasticseurope.org/application/files/1115/7236/4388/
FINAL_web_version_Plastics_the_facts2019_14102019.pdf
Pereira, P. F., and Andrade, C. T. (2017). Optimized pH-responsive film based on a eutectic
mixture-plasticized chitosan. Carbohyd. Polym. 165, 238–246. doi:
10.1016/j.carbpol.2017.02.047
Wang, L. F., and Rhim, J. W. (2018). Grapefruit seed extract incorporated antimicrobial LDPE
and PLA films: effect of type of polymer matrix. LWT- Food Sci. Technol. 74, 338–345.
doi: 10.1016/j.lwt.2016.07.066

49
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

APPENDIX A
Flowchart

Chop the Yam and

Taro into small
pieces and grind it to
produce starch.

Prepare the ingredients/ Boil the bougainvillea to

materials to be needed produce extract.
to make the bioplastic.

Mold it on a flat casting

molds.
Add the glycerin and
mix it in continuous way After boiling, add the
starch

50
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

APPENDIX B
Testing Procedures

BIODEGRADABILITY WATER ABSORPTION

ACID-BASE
INDICATOR

51
 IntelliPlasti-pH: Development of pH-Sensitive Bioplastics Using
Yam (Dioscorea luzonensis) and Taro (Colocasia esculenta) Starch
with Bougainvillea glabra Extract

APPENDIX C

Raw Data

Tensile Strength

Trial 1 Trial 2
Cross- Average
Set- Trial 1 Trial 2 Tensile Tensile
sectional Area Tensile
Up Force (N) Force (N) Strength Strength
(m²) Strength
(N/m²) (N/m²)
A 3.1 3.3 0.00012 25.83 27.50 26.67
B 2.5 2.6 0.00012 20.83 21.67 21.25
C 4.2 4.5 0.00012 35.0 37.5 36.250
D 4.6 4.8 0.00012 38.33 40.0 39.17
E 3.7 3.8 0.00012 30.83 31.67 31.25

Water Absorption

Trial 1 Trial 2
Initial Final Water Initial Final Water Average
Set-
Weight Weight Absorption Weight Weight Absorption (%)
Up
(g) (g) (%) (g) (g) (%)
A 0.50 0.93 86.0 0.48 0.84 75.0 80.50
B 0.51 0.82 60.78 0.51 0.76 49.10 54.94
C 0.52 0.73 40.38 0.50 0.79 58.0 49.19
D 0.51 0.72 41.18 0.47 0.81 72.34 56.76
E 0.49 0.79 61.22 0.52 0.76 46.15 53.69

Biodegradability

Set- Initial Weight on Weight on Weight on

Biodegradability
Up Weight Day 5 Day 10 Day 15
A 1.10 0.93 0.68 0.53 51.8
B 1.15 0.98 0.73 0.58 49.6
C 1.08 0.90 0.62 0.44 59.3
D 1.12 0.89 0.60 0.43 61.6
E 1.09 0.91 0.68 0.52 52.3
Solubility Test

Set-Up Water Ethyl Alcohol Acetic Acid

52