Utilization of sweet potato
as matrix for bioplastic
Custodio, Lil Jane G.
Diego, Marcel R.
Gavarra, Alwyne T.
Hernandez, Honjrow V.
Maagma, Krystal Anne S.
Traje, Florenz H.
Makato Integrated School
Grade-12 Curie (STEM)
Capstone Project
Second Semester
S.Y. 2024-2025
March 14, 2025
TABLE OF CONTENTS
Title page
Pages
Table of Contents………………………………………………………………………………… i
Acknowledgement……………………………………………………………………………….. ii
Abstract………………………………………………………………………………………….. iii
INTRODUCTION
Background of the Study…………………………………………………………………………..
Review of Related Literature………………………………………………………………………
Statement of the Problem
Significance of the Study
Hypothesis
Conceptual Framework
METHODOLOGY
Research Design
Data Collection Procedure
Scope and Delimitaton
Data Collecting Instruments
Data Analysis
Ethical Considerations
RESULTS AND DISCUSSIONS
Results and Analysis of Quantitative Data
Conclusion
Recommendation
APPENDICES
A1 (Budgetary Equipment)
A2 (Time Table for the Research)
A3 (Sample Data Gathering Test)
A4 (Observational journal)
ACKNOWLEDGEMENT
First of all, we, the researchers would like to thank the Almighty God for His enduring
grace, guidance, and protection that He has bestowed upon us during this capstone project.
We would also like to express our sincerest gratitude to our adviser, Mrs. Glezxell T.
Estacion for her continuous support in our research, for her patience, motivation, and immense
knowledge. Her guidance helped us throughout our research and writing of our thesis.
To our parents, as well as our siblings, who have continuously supported us financially,
mentally and spiritually to accomplish this study and for their guidance, encouragement and
inspiration to us throughout our lives, a very special thank you for your presence and constant
guidance to us.
Moreover, we would like to thank our fellow classmates and especially to our ‘barkadas’
for the stimulating discussions, for the sleepless nights we were working together for deadlines,
and for all the fun we had for a month.
We would like to express our sincerest gratefulness to our statistician, Ms. Donavie
Tumaca for her help and support to allow every result described in our research to be
accomplished.
To Mrs. Buena Majah Vanessa T. Bonus and Ms. Salvie Marie Fuentes, we would like
to thank you for providing us some valuable insights in the revision of our research paper.
In addition to our panelists, who gave suggestions and comments to improve our research,
we appreciate your patience and effort for making our research a success.
ABSTRACT
Envision a world where plastic decomposes naturally without causing harm to the
environment; this is where bioplastic comes into play. However, bioplastics encounter hurdles,
including high production costs and the limited availability of raw materials. As a result, this study
aimed to investigate the effectiveness of three types of sweet potatoes—purple, white, and
yellow—as potential raw materials for producing bioplastics. The bioplastic was synthesized using
sweet potato starch, vinegar, water, and glycerin. A total of 18 bioplastic samples were created,
and tests were conducted to assess their durability and water resistance. To evaluate durability, a
rock was dropped onto the bioplastic from three different heights: 5 inches, 10 inches, and 15
inches. Additionally, a ¼ teaspoon of water was placed on the surface to determine its ability to
retain it for one minute, thus testing its water resistance and potential degradation in water. The
results demonstrated that the bioplastic was both durable and water-resistant based on the
experiments conducted. Consequently, the three varieties of sweet potatoes present a promising
low-cost and abundant source of starch for bioplastic production.
INTRODUCTION
The global plastic crisis is escalating at an alarming rate. Based on Statista Research
Department (n.d.), the annual production had skyrocketed, reaching a staggering levels with over
400 million metric tons produced yearly. This rampant production has led to a deluge of plastic
waste. According to Mallos (2019), every year an additional of 11 million metric tons are already
present in marine environments.—it is equivalent to dumping one garbage truck full of plastics
into the ocean every minute. The same problem arising in the Philippines, with the international
study on plastic pollution showing that the Philippines is the world's leading contributor to plastic
pollution in the ocean, having an average of 3.30 kilograms (kg) per person per year (Cornales,
2024). Additionally, these escalating plastic waste are mainly caused by the improper disposal
methods and a throwaway mindset of the people, harming the valuable resources of both land and
water ecosystem (Heliyon, 2024). According to Yale Climate Connection (2019); oil, gas, and coal
are the fossil-fuel building blocks of plastics— the plastic originate as fossil fuels and emit
greenhouse gases. Also, the Ocean University of China (2022), discovered that microplastic
reduced the growth of microalgae and the efficiency of photosynthesis.
To address this issue, one possible solution is to use bioplastics. Bioplastics, are made from
renewable materials and have lower carbon footprint than traditional plastics. The often cited
advantages of bioplastic are reduced use of fossil fuel resources and faster decomposition.
Bioplastics are also less harmful and do not include bisphenol A (BPA), a hormone disruptor
commonly present in conventional plastics. (Morath, 2022) One possible source of bioplastic is
sweet potatoes (Ipomoea batatas). Sweet potato, locally known as “camote” and popularly known
as the poor man’s crop in the Philippines. It is a nutritious food primarily consumed as a staple and
vegetables. From a mere supplemental source of income to small farmers, sweet potato has become
a vital livelihood crop due to new and high market demand for sweet potato products such as flour,
confections, wine, and feedstuff. Furthermore, in 2019, Eastern Visayas remained the top sweet
potato producer with 98.95 thousand metric tons, sharing 18.8 percent of the total output
(Philippine Statistic Authority, 2019). Sweet potato starch contains a component that can be used
to create plastic, which plays an important role in our daily lives as it is found in a wide range of
products. Starch is a natural biopolymer primarily made up of two forms of glucose: amylose and
amylopectin. The benefits of using starch for plastic production include its renewable nature,
excellent oxygen barrier properties when dry, availability, affordability, and biodegradability (Tabil
et. al, 2007)
Sweet potato is widely known for its starch component, but its varieties has not been used
to explore their traits and compatibility as bioplastic. Studies from other researchers mainly
focuses in one variety, which has shown a good result in producing bioplastic. Although their
results are promising, the information about the compability and characteristics of other varieties
of sweet potato as bioplastic are still uninvestigated. This research aims to address this gap through
formulating bioplastic using the three varieties of sweet potato— characterized by their starch
components to make a fine and shaped bioplastic. By exploring the potential of this readily
available resource, this research aims to provide an eco-friendly solution to reduce the reliance in
fossil making and promote for sustainable future.
Research on bioplastics primarily benefits the environment, society, and industry. By
reducing the use of fossil fuels, it helps minimize environmental harm caused by plastic waste
accumulation and reduces greenhouse gas emissions (Geyer et al, 2017). It improves public health
by minimizing exposure to plastic-related contaminants and enhances the quality of life through a
more sustainable economy (Lithner et al, 2011). For the industry, it opens doors to innovative and
sustainable renewable resources, driving economic growth and offering businesses a competitive
advantage by enabling them to offer more environmentally friendly products (Shen et al, 2009).
Overall, this research aims to address crucial global challenges and fulfill societal needs for
sustainable solutions.
Although so much research has been done into sweet potato as bioplastic, the kind of
variety of sweet potato will be somewhat restricted. The study will focus on exploring the
possibility of sweet potato variety as bioplastic that will help in mitigation of the sustainable and
environmental solution. Three varieties of sweet potato will be tested , thus, this study assumes
that: (a) null hypothesis (Hо): There will be no significant differences in, solubility or durability
among bio-plastics made from purple (basco purple), yellow (sweet caroline white), and white
(jewel white) sweet potato starches; and (b) alternative hypothesis (H₁) There will be significant
differences in, solubility or durability among bio-plastics made from purple (basco purple), yellow
(sweet caroline white), and white (jewel white) sweet potato starches. This research aims to
determine the feasibility of using different varieties of sweet potato starch as polymer matrices,
contributing to the development of a more sustainable and eco-friendly alternative to conventional
plastics.
This research aims to provide valuable insight for environmental advocates on how sweet
potato bioplastic can contribute reducing plastic pollution and protecting the environment. It also
seek consumers to access to sustainable products, allowing them to make better choices that
benefits the environment. Additionally, it aims to serve as a resource for future researchers,
providing them with useful information to explore other natural materials for bioplastics.