Simultaneous extraction of phenolic compounds of citrus peel extracts: Effect of ultrasound

Abstract

Ultrasound-assisted extraction (UAE) has been widely applied in the extraction of a variety of biologically active compounds including phenolic compounds. However, there is an insufficiency of information on simultaneous extraction of these compounds in this area. In the present study, seven phenolic compounds of two families including cinnamic acids (caffeic, p-coumaric, ferulic, sinapic acid), and benzoic acids (protocatechuic, p-hydroxybenzoic, vanillic acid) from citrus (Citrus unshiuMarc) peels were evaluated by UAE. The effects of ultrasonic variables including extraction time, temperature, and ultrasonic power on the yields of seven phenolic acids was investigated. Results showed that the yields of phenolic compounds increased with both ultrasonic time and temperature increased, whereas the opposite occurred with increasing time at higher temperature to some certain. In the case of 40 degrees C, the decrease in the yields of some phenolic compounds was observed with increased time, whereas those of other compounds did not significantly declined. Ultrasonic power has a positive effect on the yields of phenolic acids under study. Among all ultrasound variables, temperature is the most sensitive on stability of phenolic compounds. Moreover, when phenolic compounds from citrus peel extracts were subjected to ultrasound process, the benzoic acids were more stable than the cinnamic acids. Meanwhile, the optimal ultrasound condition was different one compound from another. These were partly attributed to both the differently chemical structures of phenolic acids and the combination effects of ultrasonic variables.

Comparison of microwave and ultrasound-assisted extraction techniques for leaching of phenolic compounds from nettle

“…In general, concentrations of phenolic compounds were slightly lower in microwave extraction as compared to conventional extraction (Table 2). Ma et al (2009) also showed that microwave radiation can easily degrade unstable phenolics due to their structural properties. Phenolic compounds with higher number of hydroxyl group in their aromatic rings are unstable and can easily be degraded under microwave radiation.…”

“…1c). Increasing power level of ultrasound supplies a faster and stronger mixing effect that reduces external resistance and enhances the mass transfer, so increasing power enhances the extraction and increases the efficiency (Chemat et al 2004;Ma et al 2009;Shalmashi 2009). By means of ultrasound, mixing occurs in the solid-liquid interface.…”

“…In addition, thermal decomposition of heat sensitive compounds is avoided in ultrasound since it is a non-thermal process (Ma et al 2008). Ultrasound extraction of phenolic compounds and antioxidants from citrus (Ma et al 2009), coconut shell powder (Rodrigues and Pinto 2007), acacia flowers and buds (Tung et al 2011), grape seeds (Ghafoor et al 2009), pomegranate seed (Abbasi et al 2008), strawberry (Herrera and Castro 2004); and olive leaves (Japon-Lujan et al 2006) were studied by various researchers.…”

Accumulation of phenolics in natural and micropropagated plantlets of Thymus pseudopulegioides Klokov & Des.-Shost. with their antioxidant potentials

“…RA enrichment In the present work, an economically feasible, low timeconsuming, safe, and efficient method has been proposed for the isolation, extraction, and purification of biosynthetic production of RA by T. pseudopulegioides. The wild species and micropropagated plantlets were assessed for RA production employing a traditional water extraction process involving acidification and then extraction with ethyl acetate (Ma et al, 2009). HPLC results revealed that among the all samples the highest RA was found in KINsupplied medium, among which KIN-2 produced the highest RA.…”

Optimization of ultrasound assisted extraction of anthocyanins from red cabbage using Taguchi design method

“…The extraction of bioactive compounds under ultrasound irradiation at frequency of 20-100 kHz is one of the newest extraction techniques that may offer high reproducibility in shorter times, simplified manipulation, reduced solvent consumption and temperature and lower energy input (Chemat et al 2008). Optimisation of ultrasound assisted extraction has been described recently to extract hesperidin from Penggan (Citrus reticulata) peel (Ma et al 2008a), phenolic acids and flavanone glycosides from Satsuma Mandarin (Citrus unshiu Marc) peel (Ma et al 2009;Ma et al 2008b) and total phenolic content from Penggan peel (Ma et al 2008a). …”