Development of a novel alcoholic spirit from the New Zealand native plant Cordyline australis Weiqing Huang Supervisor: Associate Professor Owen Young A research project in partial fulfillment for the degree Master of Applied Science AUT University October 2011 i PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.cn Cordyline australis（ti kouka）in New Zealand ii PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.cn Contents Page number Cover ................................................................................................................................................ i Picture of Cordyline australis.......................................................................................................... ii Table of contents ........................................................................................................................... iii List of figures ................................................................................................................................ vii List of tables ................................................................................................................................... ix List of appendices ............................................................................................................................ x Attestation of authorship ................................................................................................................ xi Acknowledgements ....................................................................................................................... xii Abstract ........................................................................................................................................ xiii CHAPTER 1 ............................................................................................................................... 1 Introduction ................................................................................................................................... 1 1.1 Distilled alcohol drinks .............................................................................................................. 1 1.2 Geographical distinctiveness in alcoholic drinks ...................................................................... 4 1.3 New Zealand alcoholic drinks ................................................................................................... 5 1.4 Botany of Cordyline australis ................................................................................................... 7 1.5 Māori uses of Cordyline australis ............................................................................................. 9 1.6 Cordyline australis as a source of carbohydrate ..................................................................... 12 1.7 Sugar extraction of Cordyline australis compared with agave ............................................... 13 1.8 Cordyline australis use for producing illicit alcoholic drinks ................................................. 14 1.9 The purpose of this research .................................................................................................... 15 CHAPTER 2 ............................................................................................................................. 16 Pilot Development of Ti kouka Spirit ........................................................................................ 16 2.1 Introduction ............................................................................................................................. 16 2.2 Materials and methods ............................................................................................................. 16 2.2.1 Yeast ..................................................................................................................................... 16 2.2.2 Preparation of Cordyline australis stems ............................................................................. 16 2.2.3 Fermentation treatments ....................................................................................................... 17 2.2.4 Simultaneous distillation and extraction of volatiles from Cordyline australis stem ...................................................................................................................................... 18 iii PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.cn 2.3 Results and discussion ............................................................................................................. 19 2.4 Brief summary ......................................................................................................................... 21 CHAPTER 3 ............................................................................................................................. 21 Kinetics Study on the Exponential Phase of the Ti kouka Fermentation Process ................. 22 3.1 Introduction ............................................................................................................................. 22 3.1.1 Mode of batch fermentation ................................................................................................. 22 3.1.2 Components of fermentation ................................................................................................ 22 3.1.3 Production of alcohol ........................................................................................................... 22 3.1.4 Production of other flavour compounds ............................................................................... 24 3.2 Materials and methods ............................................................................................................. 25 3.2.1 Chemicals ............................................................................................................................. 25 3.2.2 Preparation and characterization protocols of fermentation ............................................... 26 3.2.3 Physicochemical analyses..................................................................................................... 27 3.2.4 Microbiological analyses ...................................................................................................... 29 3.2.5 Data analysis ......................................................................................................................... 29 3.3 Results and discussion ............................................................................................................. 30 3.3.1 Kinetics of colour during fermentation ................................................................................ 30 3.3.2 Kinetics of yeast growth and biomass production ................................................................ 34 3.3.3 Kinetics of pH and CO2 production ...................................................................................... 36 3.3.4 Kinetics of sugar content expressed as Brix ......................................................................... 37 3.3.5 Kinetics of ethanol concentration and sugar concentration .................................................. 38 3.4 Mathematical model ................................................................................................................ 42 3.5 Brief summary ......................................................................................................................... 43 CHAPTER 4 ............................................................................................................................. 45 Study of the Maillard Reaction in a Top Stem/Fructose Model System ................................ 45 4.1 Introduction ............................................................................................................................. 45 4.1.1 Modelling of the Maillard reaction ....................................................................................... 45 4.1.2 Classes of aroma compounds formed in the Maillard reaction ............................................ 47 4.1.3 Detection of compound formation in the Maillard reaction ............................................... 48 iv PDF 文件使用 "pdfFactory Pro" 试用版本创建 www.fineprint.cn 4.1.4 Experimental design ............................................................................................................. 48 4.2 Materials and methods ............................................................................................................. 48 4.2.1 Preparation and characterization protocols of reflux ............................................................ 48 4.2.2 Physicochemical analyses..................................................................................................... 49 4.2.3 Statistical analysis ................................................................................................................ 50 4.3 Results and discussion ............................................................................................................. 50 4.3.1 Colour development from incubations of ti kouka stem with frutcose ................................ 50 4.3.2 Description of colour and odour from incubations of ti kouka stem with fructose .............. 54 4.3.3 Volatile compounds generated in Top stem/fructose model system .................................... 56 4.4 Brief summary ........................................................................................................................