Determination of the solid fat content of commercial fats by pulsed nuclear magnetic resonance

Abstract

Fats ABSTRACTA method and instrumentation for measuring the solid fat content is reported that is both accurate and precise. It involves using transient nuclear magnetic resonance (NMR) measurements for determining the percentage of solids in commercial shortenings and hydrogenated oils at selected temperatures. The incorporation of a tempering step at 26.7 C for all samples before measurement has improved the precision of the solids content actually measured (+-0.2% solids) which approximates that of dilatometry. Duplicate measurements are not required to obtain this precision. The instrument is equipped with six 10-mm sample holders in combination with a precise variable temperature accessory system which eliminates the temperature difference between the sample and sample holder. This improved and exact temperature conditioning of samples provides better sample stability and easier handling for routine conditions of analysis. A single temperature result can be made in less than 1 hr and typical 5 temperature results obtained in 2.5 hr. Our work also indicates that temp e r i n g does influence results, the net effect being to decrease the amount of solids at temperatures less than the tempering temperature. In comparing the pulsed NMR measured solids with these measured by dilatometry, differences between methods of measurement are minimized when samples have had the s a m e tempering and temperature history. This method provides flexibility, speed, and increased sample throughput of up to 60 samples/day. The selfcontained equipment requires only 9 sq ft of space and is ready for measurements within 45 rain after start-up.

Trans FA and solid fat contents of margarines marketed in Turkey

“…They are largely a function of the solid glyceride contents of the fats at those temperatures (13). Solid fat content (SFC) is therefore analyzed to indicate the crystallization tendency and finished product quality (14).…”

Fat Crystal Networks: Structure and Rheological Properties

“…Methods of wide-line and pulsed NMR have been described by Haighton et af. (1971), Madison and Hill (1978) and van Boekel(l981). Mills and van der Voort (1981) compared direct and indirect wide-line NMR.…”

Structure and mechanical properties of fat crystal networks

“…(1 97 l), Madison and Hill (1978), Waddington (1980), van Boekel Most of the early investigations into the influence of solid fat content on the macroscopic rheological properties of plastic fats have been done on the effect of solid fût content on the penetration hardness (Bailey, 1950; de Man, 1962. It was found that the yield value (the definition and implications of this parameter will be discussed in Chapter 3, however, it can be viewed loosely as a measure of rnacroscopic hardness) was inversely proportional to the second power of the solid fat content.…”