Effect of sonication pretreatment on physico-chemical, surface and thermal properties of date palm pollen protein concentrate

Publication date: Available online 14 February 2019Source: LWTAuthor(s): Haifa Sebii, Sirine Karra, Brahim Bchir, Abir Mokni Ghribi, Sabine Danthine, Christophe Blecker, Hamadi Attia, Souhail BesbesAbstractSonication assisted isoelectric precipitation protein extraction was investigated, to determine the effect of sonication pretreatment (20 KHz, 2 s pulse on and 1 s pulse off for 30 min) on the physico-chemical, surface and thermal properties of date palm pollen concentrate. Concentrates obtained only by isoelectric precipitation and with the addition of sonication pretreatment were compared on the basis of their structure and their functional properties. Significant differences (P < 0.05) were observed in surface properties, where sonicated sample exhibited a better capacity of reducing the surface tension at pH 7 even at low protein concentration (0.5 g/100 mL) reaching 40.7 mN/m. It was also deduced that thermal properties are strongly influenced by the sonication treatment since the temperature and enthalpy of protein's denaturation decreased significantly (P < 0.05). These differences were attributed to the induced modifications in protein's structure caused by sonication. Deductions align with what has been observed in the scanning electron microscopy that showed sonication leads to the modification of protein's structure.
Source: LWT Food Science and Technology - Category: Food Science Source Type: research