Factors Affecting the Rapid Equilibrium Method for Analysis of Total Oil in Soybean Cultivars

Abstract

A one minute rapid equilibrium extraction for total oil in soybeans was developed and factors influencing the extraction were examined. Comparisons of the rapid equilibrium extraction with a Goldfisch extraction were made, using 100 mesh flour on ten cultivars over a three year period. The equilibrium extraction consists of slurrying 100 mesh flour in hexane until an equilibrium between oil content inside and outside of the soybean particle is achieved. One minute was required for equilibration of 98% of the oil in the soybean flour, and one hour was required for complete equilibration when compared with a five hour Goldfisch extraction. Accuracy and precision of the method were excellent when proper technique was followed. A comparison of the rapid equilibrium and the Goldfisch extractions showed similar changes in oil content due to changes in soybean flour moisture and in preheating the soybeans. The amounts of phospholipid extracted from fine flour were considerably less than usually extracted from flakes under commercial conditions. The correlation between the rapid equilibrium and Goldfisch extractions for ten cultivars was excellent (r=0.9956) when analyzing 100 mesh flour. Environmental conditions caused significant interactions between cultivars and years of production.

Rapid Oil Extraction from Potato Chips

“…Clark and Snyder [1] developed a rapid 1 min equilibrium extraction method of a 1-2 g sample to determine total oil content in soy flour with hexane at ambient temperature that produced results similar to those obtained by Goldfisch extraction. This allowed the rapid screening of a large number of soybean cultivars.…”

Effects of synthetic and natural extraction chemicals on yield, composition and protein quality of soy protein isolates extracted from full-fat and defatted flours

“…The resolubilized protein was then freeze dried, sealed in polythene bags and stored at 4°C until further analysis. Clark and Snyder (1989) rapid equilibrium extraction method, in the manner described by Clark and Proctor (1994) was used to defat the flour. Distilled or deionized water was used in sample preparation and all laboratory procedures.…”

Effect of Xanthan and Arabic Gums on Foaming Properties of Pumpkin (Cucurbita pepo) Seed Protein Isolate

“…The pumpkin seed flour was defatted using the rapid equilibrium method (Clark & Snyder, 1989) with some modifications.The flour was suspended in n-hexane (bp 30-60 ºC) in a glass bottle using flour to solvent ratio of 1:4 (w/v). The flour-hexane slurry was shaken for 10 minutes-this procedure was repeated twice to remove residual lipids.…”