MINISTRY OF EDUCATION AND TRAINING HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION GRADUATION THESIS FOOD TECHNOLOGY CHARACTERIZATION OF CHITOSAN FILMS CONTAINING BEESWAX AND THYMUS VULGARIS ESSENTIAL OIL FOR BANANA PRESERVATION LECTURER: NGUYEN VINH TIEN STUDENT: PHAM THI THUY GIANG LE HONG TU SKL012528 Ho Chi Minh City, January 2023 HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION FACULTY FOR HIGH QUALITY TRAINING DEPARTMENT OF FOOD TECHNOLOGY GRADUATION THESIS ID: 2024-19116050 CHARACTERIZATION OF CHITOSAN FILMS CONTAINING BEESWAX AND THYMUS VULGARIS ESSENTIAL OIL FOR BANANA PRESERVATION Advisor: Assoc. NGUYEN VINH TIEN Students: PHAM THI THUY GIANG - 19116050 LE HONG TU - 19116056 HO CHI MINH CITY – JANUARY 2024 i iii ACKNOWLEDGMENTS We would like to express our heartfelt appreciation to the individuals and organizations who have made significant contributions to our academic journey and the successful completion of our thesis. First and foremost, we extend our deepest gratitude to our advisor, Professor Assoc. Nguyen Vinh Tien, for his unwavering guidance, support, and encouragement throughout the process of writing our graduation thesis.
His expertise, patience, and willingness to go above and beyond have played a pivotal role in our growth as researchers and writers. We are particularly grateful for his insightful feedback, which challenged us to think critically and approach our work with rigor and dedication. We would also like to thank the Department of Food Technology, Faculty of Chemical and Food Technology, and Ho Chi Minh City University of Technology and Education for providing us with the necessary resources and support to conduct our graduation thesis. We are truly appreciative of the access to research facilities, the availability of academic resources, and the supportive environment created by the faculty and staff.
To all the individuals and organizations mentioned above, we are sincerely grateful for your contributions to our academic journey and the completion of our thesis. Your guidance, support, and encouragement have been invaluable, and we are deeply indebted to you for your role in our success. We recognize that errors are inevitable in our research, and we welcome constructive feedback from our esteemed teachers and friends to continuously improve and grow every day. iv v vi vii viii ix x xi xii xiii xiv xv xvi TABLE OF CONTENTS MISSION OF THESIS.
v ASSESSMENT FORM GRADUATION THESIS OF FOOD TECHNOLOGY ( FOR SUPER ADVISOR). vi ASSESSMENT FORM GRADUATION THESIS OF FOOD TECHNOLOGY ( FOR REVIEWER .viii ASSESSMENT FORM GRADUATION THESIS OF FOOD TECHNOLOGY ( FOR COMMITTEE MEMBER. xvi TABLE OF CONTENTS .xvii LIST OF FIGURES. xx LIST OF TABLES .xxi LIST OF ACRONYMS.
xxiii CHAPTER 1: INTRODUCTION .3 Subjects and research scope. Introduction of active packaging/ coatings. Active packaging/ coatings systems. Methods for incorporating bioactive compounds in packaging systems.
Edible packaging - films/ coatings. Active packaging/ coatings films materials. Chitin and chitosan. Overview of beeswax.
Properties and composition of beeswax. Beeswax-based coatings. Thymus vulgaris (Thyme) essential oil. Properties of thyme essential oil.
20 CHAPTER 3: MATERIALS AND RESEARCH METHODS .Materials, chemicals and equipments. Preparation chitosan solution. Chitosan and beeswax film. Chitosan and thyme essential oil film.
Film moisture – Solubility – Swelling degree. Film thickness, tensile strength and elongation. FTIR - fourier transform infrared spectroscopy. Absorption spectrum and light transmittance of the film.
Water vapor permeability. In vitro antifungal activity of the film. Method for isolation fungal culture. Method for assessment of antifungal activity of active films in in vitro mycelial growth.
Measurement of fruit firmness. Measurement of color bananas .37 CHAPTER 4: RESULTS AND DISCUSSION. Film moisture – Solubility – Swelling degree .2 Color measurement of films. Film thickness – Tensile strength – Elongation.
FTIR – fourier transform infrared spectroscopy. Absorption spectrum and light transmittance of the film. Water vapor transmission rate. In vitro antifungus activity of film.
Results of fungal culture isolation. Method for assessment of antifungal activity of active films. Effects of active film on the postharvest quality of bananas. The changes in the weight of bananas .2 The changes in firmness of bananas .3 The change in color of bananas.
63 CHAPTER 5: CONCLUSION AND RECOMMENDATIONS. 88 xix LIST OF FIGURES Figure 2. The diagram (Mol View et al. 2020) showcases the chemical structure of N- acetyl -D-glucosamine dẻived from shrimp shells.
A diagram is presented demonstrating the process of chitin deacetylation using alkaline solutions (Suyeon Kim et al. A chitosan film is depicted, which was created using a 1% (w/w) chitosan solution. The casting method was employed to form the film in a Petri dish, followed by a drying period of 2 days at room temperature. The image shows (a) natural beeswax; and (b) molecular structure of triacontanyl palmitate which is the main component of beeswax.
The structure of the main components of thyme essential oil. Research process diagram. Measure banana color at 3 points near the head, body, and tail regions. Moisture contents of films.
The swelling capacity of films. The solubility of films. 4 Color of CS, CSEO0.5, CSBW3, CSBW5, and CSBW7 films. Tensile strenth value of films.
Elongation at break value of films. The FTIR of films. Optical transmittance (% T) of film samples. Water vapor permeability of films.
(a) The fungal hyphae exhibit ongoing growth, infiltration, and infection of neighboring fruit tissues. (b) Fungal disease in bananas caused by the pathogen Lasiodiplodia theobromae, as observed in the PDA medium. Result of fungal strain isolation. The results of the antifungal activity of the active films include:.
The impact of eight coating film samples on the weight changes of bananas during the storage. The effects of CS, CSEO và CSBWEO coating films on the firmness of bananas during storage. Change in color at the head of the banana of Control sample, CS, CSEO, CSBW and CSBWEO coatings at different concentrations. Change in color at the banana body position of control sample, CS, CSEO, CSBW and CSBWEO coatings at different concentrations.
Change in color at the tip of the banana tail of Control sample, CS, CSEO, CSBW and CSBWEO coatings at different concentrations. The samples were observed for color changes over a 7-day period to evaluate any visual modifications or degradation .69 xx LIST OF TABLES Table 2. Active packaging categories and functions. Various types of wall material for the encapsulation process.
Phytochemical composition of thyme and functional properties of the main components in thyme essential oil. All types of film formulation. 1 Visual appearanceof films. The IR spectra of the film samples.
Day 1st color parameters of coating films for preservation bananas. Day 6th color parameters of coating films for preservation bananas. 66 xxi LIST OF ACRONYMS MC: Moisture contents SC: Swelling capacity FTIR: Fourier Transform Infrared Spectroscopy ITS: Internal transcribed spacer WVP: Water vapor permeability WVTR: Water vapor transmission rate ∆E: Overall color difference RH: Relative humidity EO: Essential oil CS: Chitosan CSEO: Chitosan essential oil CSBW: Chitosan beeswax CSEOBW: Chitosan essential oil beewax L*: degree of brightness a*: degree of redness b*: degree of yellowness TS: Tensile strength EB: Elongation at break PDA: Potato dextrose agar xxii ABSTRACTS In this study, we investigated the properties of activated films made from chitosan and supplemented with essential oils and beeswax. We examined the effects of these components on various film properties, including thickness, moisture content, solubility, water absorption, color, mechanical properties, and optical transmittance.
Particular emphasis was placed on evaluating the antifungal activity of the active films against the in vitro mycelial growth of Lasiodiplodia theobromae. Furthermore, we explored the application of these films on fruits, specifically bananas. The results demonstrated that the film containing thyme essential oil exhibited significant activity against Lasiodiplodia theobromae after 48 hours of exposure. The application of active films on food products has the potential to extend their shelf life by inhibiting the growth of microorganisms.
Overall, our findings indicate that a chitosan-based active film incorporating beeswax and thyme essential oil is effective in food preservation. Keywords: chitosan, beeswax, thyme essential oil, antifungal activity, L. xxiii CHAPTER 1: INTRODUCTION 1.1 Aim This research investigated the development of an active coating film based on chitosan, incorporating beeswax and thyme (Thymus vulgaris) essential oils. The study aimed to evaluate the physicochemical, mechanical, and antioxidant properties of the film, its essential oil release ability, and its antifungal activity.
The research identified the optimal concentration of thyme essential oil and the ideal ratio between chitosan and beeswax for incorporation into the film-forming solution to maximize its functionalities. Ultimately, the researchers investigated the possible use of this remarkably efficient chitosan-derived coating to safeguard bananas (Musa sapientum).2 Problem statement The idea of food packaging originated from careful observations of nature, which highlighted the inherent protection provided by the sturdy shells of nuts and the outer layer of fruits. These natural barriers shield against physical damage, chemical exposure, and microbial contamination. Additionally, they play a role in preserving moisture, controlling the passage of oxygen and carbon dioxide, and maintaining the visual appeal and aroma of food.
However, it is important to acknowledge that not all food items possess natural protective coatings, especially fruits, which are highly prone to spoilage and have a limited shelf life. Fruits have a vulnerable natural coating that is susceptible to heat, humidity, and the presence of ethylene gas. Hence, the responsibility falls on scientists, including food technologists, to create synthetic food packaging solutions that can prolong the shelf life of food products, protect their nutritional value, and meet the expectations of discerning consumers. Among the different categories of food packaging, active packaging has emerged as an innovative and noteworthy concept that has attracted considerable interest.
According to Prasad (Prasad and Kochhar 2014), active packaging refers to packaging that interacts with the product and the environment to ensure safety and sensory properties while preserving the overall quality of the products. As highlighted by Brockgreitens (Brockgreitens and Abbas 2016), the protective role of packaging has evolved over time, resulting in the emergence of cutting-edge packaging technologies like active packaging. Necessity In the modern era, the issue of plastic pollution has become a matter of great concern for both human well-being and the environment. The production of plastic has reached staggering levels, but only a small fraction of it can be effectively recycled.
In 2015, out of 381 million tons of plastics utilized, a mere 19.5 % were recycled, while the rest were either discarded or incinerated (Ritchie and Roser 2018). Improper management of plastic waste poses a significant threat to the environment, particularly in marine ecosystems. Additionally, while plastics are generally considered safe, the chemicals used in their manufacturing processes can potentially endanger human health. An illustrative example is the use of antimony trioxide as a catalyst in the production of polyethylene terephthalate (PET), which can migrate into food products through prolonged contact and exposure to heat.
This chemical is classified as a carcinogen (Proshad, Kormoker et al. Despite the negative impacts associated with plastics, no viable alternative has been discovered thus far to completely replace them, primarily because of their numerous advantages in various industries such as machinery, textiles, electronics, packaging, and construction. Notably, the packaging sector significantly contributes to plastic consumption, with plastics being the second most commonly used packaging material (Kim, Chang et al. Particularly in food packaging, plastics offer exceptional characteristics such as affordability, lightweightness, strength, durability, corrosion resistance, and high thermal and electrical insulation properties (Thompson, Moore et al.
Materials like polyethylene (PE), polyvinyl chloride (PVC), polyvinyl alcohol (PVA), polylactic acid (PLA), nylon, and others are frequently employed in food packaging applications. In this project, in addition to chitosan, beeswax will be mixed into the film-forming solution to further improve the form and mechanical properties of the film.