P.S. Kindstedt, G.F Tansman and J.M. Hughes

University of Vermont, Burlington, USA

Rigaku Miniflex

Powder X-ray Diffractometer

The Research Team

John Hughes, Gil Tansman and

Paul Kindstedt

The Instrument

Laboratory synthesized D/L-calcium lactate pentahydrate

Cheddar Parmigiano-Reggiano

Gouda Washed Rind (Smear ripened)

Cheese crystals of interest

Calcium lactate pentahydrate crystals in Cheddar exist in two enantiomeric forms:

D(-)/L(+) CLP

L(+) CLP

D(-) lactate L(+) lactate

Reagent grade L-calcium lactate pentahydrate

D/L-CLP

L-CLP

Differentiating the D/L and L enantiomeric forms of calcium lactate pentahydrate

CLP crystal defects in Cheddar

surface crystals

embedded

crystals

Parmigiano-Reggiano Cheese

Source: http://en.wikipedia.org/wiki/Parmigiano-

Reggiano#mediaviewer/File:Parmigiano_reggiano_piece.jpg

Tyrosine crystals in Parmigiano-Reggiano cheese

tyrosine

Smooth vs. rough surface Parmigiano-Reggiano

Source: http://en.wikipedia.org/wiki/Parmigiano-

Reggiano#mediaviewer/File:Parmigiano_reggiano_piece.jpg

Size distribution of “pearls” harvested from a Parmigiano-Reggiano cheese sample

Size distribution of “pearls” harvested from 5 Parmigiano-Reggiano cheese samples

Diameter of pearls

Composition of “pearls” from Parmigiano-Reggiano

Cheese Matrix Pearls

% fat 32% 28%

% moisture 29.63% 20.91%

leucine 1.00%

X-ray diffraction pattern of “pearls” in Parmigiano-Reggiano

Parmigiano-Reggiano “pearls

Rindless Parmesan surface crystals (cheese sample courtesy of Mark Johnson,

University of Wisconsin, CDR)

Crystal formation in Gouda cheese

tyrosine

tyrosine

Leucine?

Crystal formation in Gouda cheese

Crystal formation in Gouda cheese

Leucine?

Gouda pearls Parmigiano-Reggiano pearls

X-ray diffraction patterns of “pearls” in Parmigiano-Reggiano

and Gouda cheeses

Washed rind/smear ripened

cheese

MineralCa P K Mg Nag/Kgofsample

78.662 33.258 4.337 2.102 9.666

StDev 0.238 0.11 0.102 0.0458 0.226

Washed rind/smear ripened cheese

Washed rind/smear ripened cheese