Molecular size and molecular size distribution affecting traditional balsamic vinegar aging.
A first attempt at a semiquantitative study of molecular weight (MW) and molecular weight distribution (MWD) in cooked grape must and traditional balsamic vinegar (TBV) with increasing well-defined age was performed by high-performance liquid size exclusion chromatography (SEC) using dual detection, that is, differential refractive index (DRI) and absorbance (UV-vis) based detectors. With this aim, MW and MWD, including number- and weight-average MW and polydispersity, were determined with respect to a secondary standard and then analyzed. All investigated vinegar samples were recognized as compositionally and structurally heterogeneous blends of copolymers (melanoidins) spreading over a wide range of molecular sizes: the relative MW ranged from 2 to >2000 kDa. The extent of the polymerization reactions was in agreement with the TBV browning kinetics. MWD parameters varied asymptotically toward either upper or lower limits during aging, reflecting a nonequilibrium status of the balance between polymerization and depolymerization reactions in TBV. MWD parameters were proposed as potential aging markers of TBV.
Falcone
Pasquale Massimiliano
PM
Department of Agricultural and Food Science, University of Modena and Reggio Emilia, Kennedy 17, 42100 Reggio Emilia, Italy. pm.falcone@unimore.it
Giudici
Paolo
P
D019342:Acetic Acid / Q000737:chemistry*; D002850:Chromatography, Gel; D005511:Food Handling / Q000379:methods*; D005638:Fruit / Q000737:chemistry; D006358:Hot Temperature; D015416:Maillard Reaction; D008970:Molecular Weight; D011108:Polymers / Q000032:analysis / Q000737:chemistry; D013997:Time Factors; D027843:Vitis / Q000737:chemistry
D011108:Polymers; C011908:melanoidin polymers; D019342:Acetic Acid