Synthesis, characterisation and application of biopolymer films incorporated with natural additives for food preservation
This research investigated the potential of biopolymer-additive films for foodpreservation. Three biopolymers, namely chitosan (CS), gelatin (GL) and methylcellulose (MC) wereused in this research. Ascorbic acid (AA), tannic acid (TA), banana leaf essential oil (BA), cloveessential oil (CL), turmeri...
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| Format: | thesis |
| Language: | eng |
| Published: |
2018
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| Subjects: | |
| Online Access: | https://ir.upsi.edu.my/detailsg.php?det=5079 |
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| Summary: | This research investigated the potential of biopolymer-additive films for foodpreservation. Three biopolymers, namely chitosan (CS), gelatin (GL) and methylcellulose (MC) wereused in this research. Ascorbic acid (AA), tannic acid (TA), banana leaf essential oil (BA), cloveessential oil (CL), turmeric extract (TU) and chamomile extract (CH) were used as natural additive.This research is divided into five main studies, namely synthesis, characterisation, antimicrobialactivity, food preservation and biodegradation. The main scientific instruments used in this studywere Fourier transform infrared (FTIR) spectrometer, scanning electron microscope (SEM), universaltesting machine, water vapour permeability (WVP) analyser, oxygen permeability (OP) analyser,ultraviolet-visible (UV-Vis) spectrophotometer and thermogravimetric analyser (TGA). The bacteriaused for antimicrobial activity were Staphylococcus aureus (Gram-positive) and Escherichia coli(Gram-negative). The preservation of food samples was conducted for 7 and 14 days at two differentsurrounding temperatures, namely 23-25C and 27-30 C. Cherry tomatoes (Solanum lycopersicum var.cerasiforme) and grapes (Vitis vinifera) were used as food samples in preservation studies.Research findings found that several natural additives havesuccessfully decreased the WVP value of GL-TA (1.73-1.28 g m-1 day-1 atm-1), CS- TU (1.44 -1.20 gm-1 day-1 atm-1) and MC-TA (1.27-1.18 g m-1 day-1 atm-1). With exception of incorporation of TAwith GL, the addition of natural additives reducedthe tensile strength (TS) of biopolymer films. Meanwhile, a contrast effect was obtained forelongation at break (EAB). Based on antimicrobial activity studies, the inhibition zone for CSagainst E. coli was increased from 10 to 25 mm following addition of TU, while the inhibition forCS against S. aureus was increased from 15 to 20 mm with BA treatment. All biopolymer filmsincorporated with natural additives were able to reduce the percentage of weight loss and browningindex of fruit samples. In conclusion, the addition of natural additives changed thephysicochemical characteristics of CS, GL, and MC films which favour to prolong the shelf-life offoods. In implication, the application of biopolymer-natural additive films as alternatives topetroleum-based films for food preservation could create a green andsustainable environment. |
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