THE EFFECT OF DRYING AND STORAGE ON THE QUALITY OF COSMECEUTICAL SPECIES LEUCOSIDEA SERICEA AND GREYIA FLANAGANII by ENDY TAU Submitted in accordance with the requirements for the degree of MASTER OF SCIENCE In the subject AGRICULTURE at the UNIVERSITY OF SOUTH AFRICA SUPERVISOR: Dr Gerhard Prinsloo Co-SUPERVISOR: Dr Noluyolo Nogemane October 2018 DECLARATION Name: Tau Endy Student number: 51894068 Degree: MSC in Agriculture Title: The effect of drying and storage on the quality of cosmeceutical species Leucosidea sericea and Greyia flanaganii I declare that the above dissertation/thesis is my own work and that all the sources that I have used or quoted have been indicated and acknowledged by means of complete references. _______________________ 2/10/2018 SIGNATURE DATE Acknowledgements I give glory to God for the courage and wisdom to complete the study. I thank my family that supported me throughout the period of study. My gratitude also goes to my supervisor, Dr Gerhard Prinsloo and co-supervisor, Dr Noluyolo Nogemane for their support and encouragement during this study. I extend my gratitude to the laboratory manager, Garland (College of Agriculture and Environmental Studies) who patiently assisted me to do the laboratory work. Thank you collegues Kemello, Cynthia, for your assistance to carry out the metabolomic analysis at the University of Pretoria. iii Contents Contents ...................................................................................................................................................... iv Table of figures .......................................................................................................................................... vii List of tables................................................................................................................................................ ix Abstract ........................................................................................................................................................ x Chapter 1 ..................................................................................................................................................... 1 Introduction ................................................................................................................................................. 1 1.1 Potential of the new plant species .................................................................................................... 1 1.2 Processing factors .............................................................................................................................. 2 1.2.1 Drying .......................................................................................................................................... 2 1.2.2 Storage ........................................................................................................................................ 3 1.3 Phytochemicals .................................................................................................................................. 4 1.4 Aim of study....................................................................................................................................... 5 1.5 Objectives........................................................................................................................................... 5 1.6 Layout of the study ........................................................................................................................... 5 Chapter 2 ..................................................................................................................................................... 6 Literature study .......................................................................................................................................... 6 2.1: Drying techniques ............................................................................................................................ 6 2.1.1 Freeze drying (Lyophilisation) .................................................................................................. 8 2.1.2 Oven drying ................................................................................................................................ 9 2.1.3 Air drying ................................................................................................................................... 9 2.1.4 Sun drying ................................................................................................................................. 10 2.1.5 Microwave drying .................................................................................................................... 11 2.2 Storage ............................................................................................................................................. 11 2.2.1. Shade storage ........................................................................................................................... 12 2.2.2. Freeze storage .......................................................................................................................... 12 2.3 Bioassays .......................................................................................................................................... 13 2.3.1 Anti- bacterial activity ............................................................................................................. 13 2.3.2 Anti-tyrosinase activity ............................................................................................................ 14 2.4 Metabolomics ................................................................................................................................... 15 Chapter 3 ................................................................................................................................................... 17 The effect of drying and storage on the quality of Greyia flanaganii leaf samples ............................. 17 iv 3.1 Introduction ..................................................................................................................................... 17 3.2 Materials and method ..................................................................................................................... 18 3.2.1 Collection of materials ............................................................................................................. 18 3.2.2 Sample preparation.................................................................................................................. 18 3.2.3 Storage ...................................................................................................................................... 19 3.2.4. Extract preparation for NMR analysis ................................................................................. 19 3.2.5 Pre-processing of data ............................................................................................................. 19 3.2.6 Data analysis ............................................................................................................................. 20 3.3 Results and discussion .................................................................................................................... 20 The effect of drying and storage on the quality of Greyia flanaganii leaf samples ......................... 20 3.3.1 Impact of drying on quality of leaf material .......................................................................... 20 3.3.2 Impact of Storage on chemical composition of the leaf materials ....................................... 23 3.3.3 Impact of storage duration on chemical composition ........................................................... 25 3.3.4. Impact of different locations on the chemical composition of the leaf materials .............. 27 3.4. Conclusion ...................................................................................................................................... 28 Chapter 4 ................................................................................................................................................... 29 The effect of drying and storage on the quality of Leucosidea sericea leaf samples ........................... 29 4.1 Introduction ..................................................................................................................................... 29 4.2 Materials and methods ................................................................................................................... 30 4.2.1 Collection of materials ............................................................................................................. 30 4.2.2 Sample preparation.................................................................................................................. 30 4.2.3 Storage ...................................................................................................................................... 30 4.2.4. Extract preparation for NMR ................................................................................................ 30 4.2.5 Pre-processing of data ............................................................................................................. 30 4.2.6 Analysis of data ........................................................................................................................ 30 4.3 Results and discussion