Characterisation of bresaola products made from beef, veal, wagyu, mutton and lamb Renyu Zhang A thesis submitted to Auckland University of Technology in partial fulfilment of the requirements for the degree of Master of Applied Science (MAppSc) School of Applied Sciences 2015 Characterisation of bresaola products made from beef, veal, wagyu, mutton and lamb Approved by: Supervisors: Dr. Michelle Yoo: _______________________ A/Pro. Nazimah Hamid: ____________________ Dr. Mustafa Farouk: _______________________ Table of contents Table of contents .................................................................................................... i List of Figures ...................................................................................................... iv List of Tables......................................................................................................... v Attestation of Authorship .................................................................................... vii Acknowledgements ............................................................................................ viii Abstract ................................................................................................................ ix Chapter 1 Introduction .......................................................................................... 1 Chapter 2 Literature review .................................................................................. 3 2.1 Meat and meat derived products ..................................................................... 3 2.1.1 Protein and amino acids in red meat ........................................................ 3 2.1.2 Fat and fatty acids in red meat ................................................................. 6 2.1.3 New Zealand meat.................................................................................... 8 2.1.4 Consumption of sheep meat ..................................................................... 9 2.1.5 Advantages of New Zealand red meat products .................................... 11 2.1.6 Processed meat products ........................................................................ 12 2.1.6.1 Colour of cured meat products ........................................................ 12 2.1.6.2 Texture of cured meat products....................................................... 15 2.1.6.3 Bresaola products ............................................................................ 16 2.2 Sensory characteristics of meat products ...................................................... 19 2.2.1 Flavour of cured meat products.............................................................. 19 2.2.2 Texture of cured meat products.............................................................. 20 2.2.2.1 Texture profile analysis ................................................................... 22 2.2.3 Projective mapping................................................................................. 23 2.3 Digestibility study ......................................................................................... 29 i 2.3.1 Human digestive system ........................................................................ 29 2.3.1.1 Stomach ........................................................................................... 29 2.3.1.2 Small intestine ................................................................................. 30 2.3.2 In vitro digestion models for food application ....................................... 31 2.3.3 In vitro protein digestibility studies ....................................................... 33 Chapter 3. Materials and Methods ...................................................................... 38 3.1 Sample acquisition .................................................................................... 38 3.2 Physicochemical characterisation of bresaola ........................................... 39 3.2.1 Proximate analysis ............................................................................. 39 3.2.2 Texture profile analysis (TPA)........................................................... 43 3.2.3 Instrumental colour analysis .............................................................. 44 3.2.4 Fatty acids profile ............................................................................... 45 3.2.5 Free amino acids analysis .................................................................. 46 3.3 Sensory evaluation of bresaola products ................................................... 46 3.3.1 Consumer Testing .............................................................................. 47 3.3.2 Projective mapping............................................................................. 47 3.4 In vitro digestion of bresaola products ...................................................... 49 3.4.1 Enzyme activity assay ........................................................................ 49 3.4.2 Static in vitro digestion protocol ........................................................ 50 3.4.3 Amino acids profile ............................................................................ 53 Chapter 4. Results and Discussion ...................................................................... 54 4.1 Physicochemical results ............................................................................ 54 4.1.1 Proximate analysis ............................................................................. 54 4.1.2 Texture profile analysis (TPA)........................................................... 58 4.1.3 Instrumental colour ............................................................................ 64 4.1.4 Fatty acids profile ............................................................................... 69 4.4.5 Free amino acids analysis .................................................................. 74 ii 4.2 Sensory evaluation .................................................................................... 78 4.2.1 Consumer testing ................................................................................ 78 4.2.2 Projective mapping............................................................................. 79 4.3 Digestibility of bresaola products ............................................................. 82 Chapter 5. Conclusion ......................................................................................... 89 References ........................................................................................................... 92 Appendices ........................................................................................................ 110 1. Instruction and questionnaire for consumer testing .................................. 110 2. Instruction and questionnaires for projective mapping ............................. 113 3. Letter of Approval from AUT Ethics committee (AUTEC) ..................... 114 4. Enzyme activity protocol for α-Amylase (EC 3.2.1.1) ............................. 115 5. Enzyme activity protocol for Pepsin (EC 3.4.23.1) .................................. 119 6. Enzyme activity protocol for Trypsin (EC 3.4.21.4) ................................ 122 7. Enzyme activity protocol for Chymotrypsin ............................................. 125 8. Reagents and procedures of EZ: Faast amino acids kit (GC-FID) ............ 129 9. The RV coefficient between projective maps and multifactor analysis .... 134 iii List of Figures Figure 1 Haem in the myoglobin molecule (Honikel, 2008) .......................................... 13 Figure 2 Interchange of various myoglobin derivatives in meat and meat products ...... 14 Figure 3 Preparation protocol for veal, mutton and lamb bresaola samples ................... 38 Figure 4 Photos of Stable Micro Systems TA.XT plus Texture analyser ....................... 43 Figure 5 Photo of Hunter lab (45/0, Colourflex) Chroma meter .................................... 45 Figure 6 Flow diagram of a simulated static in vitro digestion method. SSF, SGF, SIG refer to Simulated Salivary Fluid, Simulated Gastric Fluid and Simulated Intestinal Fluid, respectively. .................................................................................................................... 51 Figure 7 Intramuscular fat, protein and moisture content of five bresaola samples. Mean values are plotted with error bars representing standard error (S.E.).............................. 55 Figure 8 Pictures of sliced bresaola (1.5 mm thickness). a to e represent beef, veal, wagyu, mutton and lamb bresaola, respectively. ......................................................................... 64 Figure 9 Fatty acids composition (%) of bresaola products made from five animal species ......................................................................................................................................... 71 Figure 10 Composition of free essential amino acids (FEAAs) extracted from bresaola products (mg/100g dry matter). Mean values are plotted with error bars representing S.E. ......................................................................................................................................... 75 Figure 11 Principal Component Analysis of bresaola samples over the combined three sensory trials. .................................................................................................................. 80 Figure 12 Total FAAs of bresaola products from 5 time points of in vitro digestion.