Chemistry Reference
In-Depth Information
7.7.
Methods for Monitoring Maillard Reactions in Milk
Products
Many methods are available for evaluating the extent of Maillard reactions in
foods (Table 7.1). The objective of such measurements is to determine the
nutritional value of the product or the impact of such reactions on the
organoleptic quality and functional properties of products (Fayle and
Gerrard, 2002; Silvan et al., 2006). Although still of limited value for mon-
itoring the quality of dairy products, the measurement of brown colour, A
280
,
fluorescence and reducing power are crude approaches to monitoring Mail-
Table 7.1.
Methods for monitoring the Maillard reaction in foods
Based on chemically reactive lysine
Dye-binding methods (e.g. Acid Orange 12 or Remazol Brilliant Blue R)
Fluorodinitrobenzene (FDNB)
Guanidation
Trinitrobenzene sulphonic acid (TNBS)
Reduction by borohydride
Amino acid analysis, HPLC
Lysine oxidase electrode
Based on biologically available lysine
Rat bioassay (e.g. protein efficiency ratio, net protein utilization)
Microbiological bioassays based
Based on measurement of Amadori products
Direct measurement of Amadori products using HPLC or amino acid analysis following
enzymatic hydrolysis
Separation of glycated proteins using capillary electrophoresis or LC-electrospray MS
Measurement of furosine and pyridosine following acid hydrolysis using HPLC, GC or
amino acid analysis
Immunoassay of the protein Amadori adduct
Measurement of HMF (colorimetric or HPLC) following its formation from Amadori
products by mild acid treatment
Based on the measurement of low molecular weight advanced products of the reaction
Measurement of N-
"
-carboxymethyl lysine
Determination of hydroxymethylfurfural and/or 2-furaldehyde (HPLC or colorimetric)
Headspace CO
2
measurement
Measurement of volatile products of the reaction
Determination of
"
-pyrrole lysine
Miscellaneous methods
Measurement of brown colour (transmission or reflectance spectrophotometry)
A
280
measurement
Fluorescence measurement
Measurement of reducing power
