Influence of Heat Treatment on the Volatile Compounds of Milk

Abstract

In this work dynamic headspace capillary gas chromatography coupled with multivariate statistical techniques was applied to distinguish milks subjected to different heat treatments (pasteurization, direct ultrahigh-temperature method, and “in-bottle” sterilization). Results were obtained by taking into account a reduced, though significant, number of volatile compounds (acetone, 2-butanone, 2-pentanone, 2-heptanone, 3-methylbutanal, pentanal, hexanal, heptanal, dimethyl disulfide, toluene, and limonene). Moreover, the concentration of these volatile compounds, especially aldehydes and ketones, provided discriminant information about storage time and storage temperature in both whole and partially skimmed UHT milk. The analytical method was quite simple, rapid, and reliable and permitted the analysis of a large number of milks to be carried out by using a small volume of sample. This work represents an attempt to apply a method, generally used only for research purposes, to the quality assessment of heat-treated milk. Keywords: Milk volatile compounds; heat treatment; storage; thermal cold trapping (TCT)

Impact of Microfiltration on Particle Size Distribution, Volatile Compounds and Protein Quality of Pasteurized Milk during Shelf Life

“…They have a very limited influence on foodstuffs because they have a high perception threshold [12,15,26]. Storage led to a decrease in heptane, dodecane, tridecane, o-xylene and styrene, but increased or retained the levels of decane, 6-ethyl-2-methyl-octane, tetradecane, pentadecane, toluene and ethylbenzene in both milks.…”

“…These differences between MPM and PM might reflect MF's ability to remove microbes and selectively fractionate the components in the milk, resulting in different reactions and compositions during processing and storage. Reports on the changing behavior of volatiles during storage did not show the same clear trend, or are contradictory, which may be influenced by milk source, compositions, processing and storage conditions [12,15,26,29].…”

Creation and quality characterization of processed cheeses derived mainly from Halloumi cheese

“…Ketones have different origins: acetone is mainly derived from animal feed, and 2-pentanone and 2-heptanone have both a natural and a technological origin [6,11]. During heat treatment the pathways of their formation occur via the oxidation of saturated fatty acids, followed by decarboxylation of β-ketoacids [7,11]. Acetoin can be derived from diacetyl metabolism or from pyruvate metabolism during the conversion of lactose into lactic acid [24] and is characterized by buttery notes.…”

Multi-channel open tubular traps for headspace sampling, gas chromatographic fraction collection and olfactory assessment of milk volatiles

“…Limit of quantification (LOQ) calculated as the concentration that gives a signal-to-noise (S/N) ratio of 10. 1 Olfactory evaluation of packaged long life UHT milk (2% milk fat): spiked and unspiked. For each sample nine secondary MCTs were each desorbed in the portable sniffing device at specific temperatures with a flow of nitrogen gas of 20 ml/min.…”

“…The ultra high temperature (UHT) treatment of milk imparts an undesirable cooked (cabbage, sulphurous, stale, heated, sterile milk) flavour to packaged long life milk [1][2][3][4]. Analytical methods that have been used to study the aroma of dairy products are gas chromatography mass spectrometry (GC-MS) and gas chromatography olfactometry (GCO) [5][6][7][8].…”