"Microcalorimetric monitoring of grape withering",
, vol. 630, pp. 31–36, Apr, 2016.
<p>tThis work aimed at monitoring the metabolic activity of grapes during withering by microcalorimetry.Samples of Corvina grapes, a cultivar used in the production of Amarone wine, were dehydrated for about120 days at an industrial scale plants (fruttaia). Single berries, sampled in the course of the witheringprocess, were closed in ampoules and maintained at constant temperature. As biochemical events (i.e.berry respiration, microbial growth, etc.) are always accompanied by the production of heat (q), the heat-flow (dq/dt) emitted by berries enclosed in the ampoules was used to monitor their metabolic activityduring withering, i.e. respiration. For each sampling time, the heat rate production of the berries at 298 Kwas monitored till a steady state signal was achieved (within 60 h). Such heat flow value was used asmarker during the entire withering process (120 days). Its trend allowed to characterize the changesin the metabolic activity of the grape berries along the withering process. To understand the origin ofsuch changes, the emission of volatile organic compounds (VOCs) were also measured by proton transfermass spectrometry (PTR-MS). The use of microcalorimetry associated with the analysis of specific VOCsfragments offered a valuable information to describe the withering process.</p>