Development of standard operating procedures for differential scanning calorimeters

Abstract

This paper describes an assessment of the behavior of a differential scanning calorimeter and the development of satisfactory calibration, operation, and data reduction procedures, which depend on performance characteristics of the individual instrument. Factors that contribute to thermal lag are identified; suggestions for evaluating and compensating for it are given.

Characteristics of Differential Scanning Calorimetry Determination of Thermophysical Properties of Meats

“…In all experiments, the samples were stabilized at -40°C for 5 min and then heated to 40°C at a rate of 2°C/min, a low value that minimizes temperature lags, which may occur if the thermal contact, sample-capsule-base is poor (20). As usual in DSC measurements, two empty capsules were used to determine a baseline before the tests.…”

“…This area was used to calculate enthalpy (H) and heat capacity (Cp) vs temperature (T). In all cases, temperature and enthalpies were corrected, as suggested in Callanan and Sullivan's research (20), by running two standards whose enthalpy of fusion and melting points are known, one above and the other below the extreme values of the temperature range covered in this research. Greater detail concerning operating conditions and data handling is presented in a previous paper (11).…”

“…3 presents the experimental variation of H between -40 and 10°C for beef, lamb and pork, as measured in this research, and also the available data from the literature on fresh meats. We selected this temperature range because it not only covers the entire temperature range, but also reduces measuring errors (for instance, imperfect contact between the sample and the capsule and/or the capsule and the base in the DSC head or a high scanning rate causing a shift in the H vs T register (20)). These errors would be greater if the higher limit of the temperature range was very close to the end of thawing, for example at 0°C.…”

Heat transfer properties of chicken-drum muscle

“…It is direct, quick and well suited for determining the e †ect of temperature on heat capacity of samples. Callanan and Sullivan (1986) have thoroughly discussed the DSC measurement technique. Sweat (1986) compiled some published linear correlation of speciÐc heat capacity as a function of moisture content for high moisture foods.…”

Thermal behavior and polymorphism in medium–high temperature range of the sulfur containing amino acids l-cysteine and l-cystine

“…A fresh sample was used for each run. Heat capacities were determined by the ''scanning method'' following the experimental methodology previously described [40][41][42] with synthetic sapphire (a-aluminum oxide) as reference material [39][40][41]. DSC is a commonly accepted method for the quantitative determination of heat capacities and it has been proven as a suitable technique to obtain reliable and accurate values [43,44].…”