Milk Fat Globule Membrane and Its effects on Flavour Release

Transcription

1 Milk Fat Globule Membrane and Its effects on Flavour Release General Introduction 4th-July-2011 By Haotian Zheng

2 Project Introduction Riddet Institute & University of Otago Supervision Key-supervisor: Dr. David W. Everett (Otago & Riddet) Co-supervisors: Dr. Matt Golding (Massey & Riddet) Prof. Keith C. Gordon (Otago/Chemistry) Self-introduction

3 Content Research Introduction Research Question Research Aim Research Scheme & Approaches On-going work

4 Component Nutritional aspects References Polar lipids Research Introduction Sphingolipids and metabolites Sphingosine 1-phosphate Milk Fat Globule Membrane (MFGM) What is MFGM (Patton & Keenan, 1975) Why MFGM is interesting (Dewettinck et al 2008) What MFGM looks like Reduction of the number of aberrant crypt foci and adenocarcinomas Shift in tumor type (malignant benign) Dillehay et al. (1994) Schmelz et al. (1996) and Schmelz, Sullards, Dillehay, & Merrill (2000), Symolon et al. (2004), Spitsberg (2005) Anticholesterolemic Noh & Koo (2003) and Noh & Koo (2004), Nyberg et al. (2000), Eckhardt et al. (2002) Protection of the liver from fat- and cholesterol-induced steatosis Duivenvoorden et al., 2006 Suppression of gastrointestinal pathogens Sprong et al. (2002), Vesper et al. (1999), Pfeuffer and Schrezenmeir (2001) Neonatal gut maturation Oshida et al. (2003) Myelination of the developing central nervous system Oshida et al. (2003) Endogenous modulators of vascular function Michel et al. (2007) Associated with age-related diseases and the development Parodi (2001), Spitsberg (2005) of Alzheimer Mitogenic Zhang et al. (1990), Zhang et al. (1991) Phosphatidylserine (PS) Restore normal memory on a variety of tasks McDaniel et al. (2003) Phosphatidylcholine (PC) Positive effects on alzheimer patients Improve exercise capacity of exercising humans Support liver recovery from toxic chemical attack or viral damage Crook et al. (1992), Heiss et al. (1994), Pepeu et al. (1996), Gindin et al. (1998), Hashioka et al. (2004) Kingsley (2006) Kidd (2002) Protects the human GI mucosa against toxic attack Anand et al. (1999) Reduction of necrotising enterocolitis Carlson et al. (1998) Lysophosphatidylcholine (lysopc) Bacteriostatic and bactericidal capacity Van Rensburg et al. (1992) Kivinen, Salminen et al. (1992), Kivinen, Tarpila et al. Strong gastroprotective role in the duodenal mucosa (1992) ; Kivinen et al. (1995) Dewettinck, K., Rombaut, R., Thienpont, N., Le, T., Messens, K., & Vancamp, J. (2008). Nutritional and technological aspects of milk fat globule membrane material. International Dairy Journal, 18(5),

5 MFGM under Confocal Laser Scanning Microscopy (CLSM) Gallier, S., Gragson, D., Jimenez-Flores, R., and Everett, D.W. Using Confocal Laser Scanning Microscopy to Probe the Milk Fat Globule Membrane and Associated Proteins. Journal of Agricultural and Food Chemistry 58(7):

6 Raman Spectra of Milk Fat Globule - MFG (16 um) Raman Intensity Cholesterol & Acyl chains PL headgroup FA PC,PI,PS Cholesterol Carotenoids PC,PI,PS Triacylglycerol Raman shift (cm -1 )

7 Deduced MFGM model (schematic) Lopez C et al, Fat globule selected from whole milk according to their size: Different compositions and structure of the biomembrane, revealing sphingomyelin-rich domains. Food Chemistry 125 (2011)

8 Research Question 1. Changes to the MFGM after processing of fat globules Previous research on protein & phospholipid changes in the MFGM (Anderson et al, 1972; Dickow et al 2011; Ye et al, 2005; Lee et al 2002; Bermúdez-Aguirre 2008) (Morin et al 2007; Gallier et al ) Microscopic studies have been carried out, but reports on changes in MFGM lipids are still scarce (Gallier et al ) More details about phospholipid changes on the milk fat globule surface under different processing conditions are needed.

9 Research Question 2. Mechanism of incompatibility of MFGM lipids Giant Unilamellar Vesicles (Wolf et al 2001; Veatch et al 2003; Thompson et al 2006) Controlling the organization of MFGM lipids on a model bio-membrane Is the incompatibility of MFGM lipids meaningful for physicochemical properties of MFGs (interfacial tension)?

10 Research Qeustion 3. Impact of MFGM on Flavor Release Effect of MFGM and its associated materials on flavor release (Emulsions are stabilized by different emulsifiers) Effect of lipid level, lipid type and proteins on flavor release (Roberts, Pollien, & Watzke, 2002; Relkin, Fabre, & Guichard, 2004; etc. ) Different lipids in the MFGM (Gallier et al ) Effect of different types of emulsifiers (Waninge et al 2005) (MFGM phospholipids; whey protein; casein micelles; caseinate) Is the incompatibility of MFGM lipids meaningful for flavor release? Phospholipid incompatibility in the MFGM (Gallier et al )

11 Research Aim Extending knowledge on composition and microstructure of MFGM & How the composition and structure of MFGM (materials) influence(s) flavor release.

12 Research Scheme & Approaches Raw milk Cooling; Heating; Homogenization; Processes Thermo-sonicationLSCM observation (different breeds) PL: Isolation MFGs isolation Methods HPLC-ELSD NL (Triglycerides, Cholesterol): LC+GC Protein: SDS-PAGE Raman Spectroscopy Chemical Analysis (Equivalent Correlation of Samples: fat content/specific area) AMF emulsified by (different emulsifiers) Isolated MFGs; Re-dispersion (SMUF buffer) Equivalent Correlation of Samples: fat content/specific area GUV formation Volatile Compounds Static headspace analysis (GC) Raman Confocal Microscopy

13 On-going Work MFG isolation method Investigation on process-induced changes in the MFGM Chemically Structurally GUV formation Investigation of flavor partitioning and milk fat globules via Raman Confocal Microscopy

14 Raman Spectra of mixture of milk fat globule and flavor Raman Intensity um Trans-2-hexenal + milk fat globule Raman shift (cm -1 )

15 End Thank you for your time!