Michael Agnew

Mr. Michael Agnew


Research Focus & Metrics

Academic Career Length

46Years (1981-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 April 2020 in Journal of Dairy Science
Verified
Journal Article
Closed access
LBLauren Brink
Lauren Brink
AHAnthony W. Herren
Anthony W. Herren
Shasta McMillenShasta McMillen
Shasta McMillen
KFKarl Fraser
Karl Fraser
MAMichael Agnew
Michael Agnew
BLBo Lars Lonnerdal
Bo Lars Lonnerdal
Milk fat globule membrane (MFGM) is a glycosylated, protein-embedded, phospholipid fraction that surrounds triglycerides in milk. Commercial bovine sources have recently come to the market as a novel food ingredient and have been added to various products, including infant formula. Considering that MFGM is a heterogeneous mixture of fat, protein, and carbohydrate, it can be expected that variations among MFGM products exist. For this reason, our aim was to characterize the composition of commercial MFGM samples through a combination of proteomic and lipidomic analyses. Six bovine milk fractions, represented as MFGM fractions or phospholipid fractions, were obtained from various commercial sources. Additionally, the MFGM samples were compared with 2 infant formulas, a standard formula as well as a premium formula containing MFGM. For proteomic analysis, bottom-up data-dependent liquid chromatography-tandem mass spectrometry (LC-MS/MS) was performed on each MFGM fraction, and nearly a thousand proteins were identified across all samples, with 364 of them having different abundance across the samples tested. One hundred twelve proteins differed by a fold-change of 10 or greater, 14 by a fold-change of 50, and 2 by a fold-change of 100 in at least 1 pair, suggesting large differences in the proteins present in these fractions. Even though the classical MFGM proteins were enriched in the MFGM fractions, the relative protein composition varied considerably, and all contain an abundance of milk (casein and whey) proteins. Lipidomic analysis identified a total of 393 lipid species across both positive and negative ionization modes, with the major classes detected being triglycerides, sphingomyelins, and several phospholipids. Across all samples, triglycerides comprised at least 50% of total lipids, with phosphatidylcholine and sphingomyelin being the second and third most abundant lipid classes, respectively. These findings demonstrate the heterogeneous nature of various bovine commercial MFGM fractions. This variation must be considered when evaluating and describing potential functional benefits of these products shown in clinical trials.

1 February 2015 in Meat Science
Verified
Journal Article
Closed access
RPReddy R. Pullanagari
Reddy R. Pullanagari
IYIan J. Yule
Ian J. Yule
MAMichael Agnew
Michael Agnew

1 October 2017 in Meat Science
Verified
Journal Article
Closed access
CCC.R. Craigie
C.R. Craigie
PJP.L. Johnson
P.L. Johnson
PSP.R. Shorten
P.R. Shorten
ACA. Charteris
A. Charteris
GMG. Maclennan
G. Maclennan
MRM.M. Reis
M.M. Reis

1 January 1991 in Journal of Chromatography A
Verified
Journal Article
Closed access
MAMichael Agnew
Michael Agnew
DLDennis R. Lauren
Dennis R. Lauren

1 January 2008 in International Journal of Food Sciences and Nutrition
Verified
Journal Article
Closed access
CPColin Prosser
Colin Prosser
RMRobert D. McLaren
Robert D. McLaren
DFDeborah Frost
Deborah Frost
MAMichael Agnew
Michael Agnew
DLDianne J. Lowry
Dianne J. Lowry
The non-protein nitrogen fraction of goat whole milk powder and of infant and follow-on formulae made from goat milk was characterized and compared with cow milk powder and formulae. Goat milk infant formula contained 10% non-protein nitrogen, expressed as a proportion of total nitrogen, compared with 7.1% for cow milk formula. Goat follow-on formula contained 9.3% and cow 7.4% non-protein nitrogen. Urea, at 30%, was quantitatively the most abundant component of the non-protein nitrogen fraction of goat milk and formulae, followed by free amino acids at 7%. Taurine, glycine and glutamic acid were the most abundant free amino acids in goat milk powders. Goat milk infant formula contained 4 mg/100 ml total nucleotide monophosphates, all derived from the goat milk itself. Goat milk has a very different profile of the non-protein nitrogen fraction to cow milk, with several constituents such as nucleotides at concentrations approaching those in human breast milk.

1 October 2006 in New Zealand Journal of Agricultural Research
Verified
Journal Article
Open access
OYOwen Young
Owen Young
GLG. A. Lane
G. A. Lane
CPC. Podmore
C. Podmore
KFKarl Fraser
Karl Fraser
MAMichael Agnew
Michael Agnew
NCN. R. Cox
N. R. Cox
A comprehensive set of quality parameters has been recorded for meat and fat from groups of castrate and ram lambs raised on pasture and slaughtered in groups of six at 91‐day intervals from 122 to 668 days of age. These include mechanical evaluation of meat tenderness, sensory evaluations of meat flavour and fat odour, and measurements of fat colour, fatty acid composition, vitamins C and E, free glucose and iron in the meat, and of the concentrations of the flavour compounds indoles, phenols, and branched chain fatty acids in the fat. There was significant variation in many parameters between slaughter days, including markedly lower meat tenderness in one slaughter group, probably in response to unfavourable pasture conditions. Older ram lambs tended to be less tender than castrates of the same age. However, no longer‐term age‐related trends were observed in tenderness or flavour quality. Concentrations of free glucose in rigor muscle and vitamin C showed a declining trend with age. Concentrations of the branched chain fatty acids 4‐methyloctanoic and 4‐methylnonanoic acids in fat increased with age. Sex category effects were observed for the branched chain fatty acids and for indole and skatole. Higher concentrations were observed in ram lambs. The data indicate there is only a limited decline in lamb meat quality characteristics up to nearly 2 years of age, but that pasture feeding conditions may affect quality significantly.