Optimization of ultrasonic-assisted extraction of phenolic compounds from fenugreek ( Trigonella foenum-graecum L.) seed

摘要

ABSTRACT Fenugreek ( Trigonella foenum-graecum L.) seed was used for the recovery of phenolic compounds by employing different process modifications of ultrasonic-assisted extraction (UAE). It was observed that a 3-day germination (35???°C) process negatively affected the phenolic contents of seed. Preliminary studies found that maximum quantities of phenolic compounds obtained from germinated and un-germinated seed were 5.882 and 7.534????mg GAE/g when extraction was carried out at 35???°C for 30????min using ethanol (30%) as solvent. Un-germinated seed was used for further studies. In order to improve total phenolic compound recovery, Box?￠????Behnken experimental design, regression analysis and response surface methodology were applied following the initial studies. The optimum UAE conditions were established as 38???°C temperature, 32????min time and 33% ethanol for the maximum total phenolics (8.41????mg GAE/g DW). Fenugreek seed extract also showed a good radical scavenging activity (62.74???????±????1.66%).