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008			220414t20212021my a|||fram|| 001 0 eng d
020			_aTHE0009227(Local)
040			_aUMP _beng _cUMP _erda
090			_aKK .C45 2021 r Thesis
100	1		_aVi Vien, Chia , _eauthor.
245	1	0	_aThermal degradation kinetics and microencapsulation of terpenes derived from andrographis paniculata / _cChia Vi Vien
264		1	_aKuantan, Pahang : _bUMP, _c2021
264		4	_a© 2021
300			_axv, 164 pages : _billustrations (some color) ; _c30 cm. + _e1 CD ROM
336			_atext _2rdacontent
337			_aunmediated _2rdamedia
338			_avolume _2rdacarrier
347			_atext file _bPDF _2rda
500			_aCollege of Engineering
502			_aThesis (Doctor of Philosophy) -- Universiti Malaysia Pahang – 2021
504			_aIncludes bibliographical references
520	3		_aAndrographis paniculata (ver. name Hempedu Bumi), an annual plant with broad range of nutraceutical properties and its major terpenes are andrographolide (AND), 14-deoxy-11,12-didehydroandrographolide (DDA) and neoandrographolide (NEA). A. paniculata extract is effective in regulating blood pressure and sugar level although they poorly soluble in water with an extreme bitterness flavor. Thus, various types of extraction have been studied independently to maximise the yield of extraction. Traditionally, terpenes were extracted via maceration (ME) whereas ultrasonic (UAE) and microwave assisted extraction (MAE) are applied in modern times. However, comparison between conventional and non-conventional extraction techniques involving different level of auxiliary energy is yet to be study and, hence, this is the aim of this research. Elevation of temperature during processing such as extraction and spray drying can caused degradation of terpenes in A. paniculata extract. Thus, it is crucial to understand thermal kinetic of terpenes and elucidate its degradation mechanism in order to maintain its efficacy. Besides that, microencapsulation of A. paniculata extract with different wall material is another aim of this work to improve its solubility and storage stability. Three different level of auxiliary energy; ME (0.22 – 0.24 W/mL), UAE (1.04 – 1.07 W/mL) and MAE (5 – 50 W/mL) were employed to simultaneously extract AND, DDA and NEA. The optimum condition of ME (80 °C for 2 hours), UAE (50 % for 10 min) and MAE (125 W for 4 min) were proceeded with principle component analysis (PCA). Heat treatment of A. paniculata’s standard and extract were performed at 100, 120 and 150 °C for 90 min in order to evaluate reaction rate constant (k), half-life (t1/2), activation energy (Ea), activation enthalpy (ΔH), Gibbs free energy (ΔG) and activation entropy (ΔS). Microencapsulation via spray drying was performed with 3 different formulations including 10 wt.% of gum arabic (GA), whey protein isolate (WPI) and GA:WPI (9:1). The release rate of terpenes were evaluated by four different models; Baker and Lonsdale, Korsmeyer-Peppas, Hixon-Crowell and Higuchi. In addition, the storage stability of microcapsule was studied for 1 year at amber, room temperature and -80 °C. The highest yield of AND (20.10 mg/gDW) and NEA (9.54 mg/gDW) were harvested at relatively lower level of auxiliary energy (UAE; 1.34 W/mL) meanwhile DDA was obtained at higher level of auxiliary energy (MAE; 25 W/mL). Eight terpenes namely neoandrographolide, 19β-glucosyl-14-deoxyandrographoside, 19β-glucosylandrographoside, 3-O-β-D-glucopyranosyl-14,19-dideoxyandrographolide, bis-andrographolide C, bis-andrographolide A, isoandrographolide and 12S-hydroxyandrographolide were elucidated via PCA with 88 % of total variability. Standards of A. paniculata in this work obeyed zero-order kinetic. Both standard of AND (0.0007 min-1) and NEA (0.0020 min-1) has single k value whereas DDA resulted double k values (0.0044 and 0.0027 min-1). Standard AND (714.29 min) has the highest t1/2 followed by NEA (250 min) and DDA (113.64 and 185.19 min). The negative ΔS (-0.20 to -0.47 J/mol.K) and positive ΔG (106.80 – 130.96 kJ/mol) values in this works indicates terpenes are of thermally stable and non-spontaneous during heat treatment. Microencapsulation with 10 wt.% GA retained 100 % of terpenes and the microcapsules fits Korsmeyer-Peppas model as its release mechanism. Stability study shows -80 °C is the best storage condition for AND (96.0 %), DDA (99.98 %) and NEA (94.69 %) after 1 year of study. In conclusion, the extraction conditions, kinetic parameters, elucidated degradation pathways and microencapsulation formula of this work serves a useful reference for nutraceutical industry.
610	2	0	_aCollege of Engineering _xDissertations
650		0	_aUniversities and colleges _xDissertations
650		0	_aTheses
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