Ultrasonic-assisted and watercyclodextrin based extraction of hydrophilic and hydrophobic components of peruvian purple corn

DOS SANTOS, CRISTINA; CUETO, MARIO; FARRONI, ABEL; MARIA FLORENCIA MAZZOBRE; BUERA, MARÍA DEL PILAR

Punta del Este

Congreso; 2do Congreso Iberoamericano de Ingeniería en Alimentos (CIIAL 2016).; 2016

Currently there is a growing consumer´s demand in foods formulated with bioactive compounds to replace synthetic additives or to provide nutraceutical value. Vegetables are promising sources of these compounds but its extraction is generally associated to time-consuming techniques or to the use of organic solvents. These facts demand the optimization of suitable techniques for more efficient and effective clean extraction of available active matters from the plant materials.Purple corn of variety Zea mays (L.?Kculli?) has been used as food from thousands of years in Peru, and lately has gained interest because of its properties as antioxidant, hypotension and hypoglycemic agent. It has a large amount of polyphenols so the extract can be used as nutraceutical food additive. The aim of this work was to optimize the optimization of the ultrasound assisted extraction conditions for obtaining anthocyanins and phenolic compounds from purple corn and to study the solvent potential of aqueous β-cyclodextrin (BCD) solutions for components extraction. Flour was obtained by a dry milling process followed by passage through a sieve of 200μm mesh. The extractions were carried out using different solvent systems, 70% v/v ethanol-water, BCD-water solutions (3 to 15mM) and water. Response surface methodology was employed to optimize the extraction of the bioactive compounds with BCD solutions. The constructed models were adequate to predict the responses: total phenolics, anthocyanins contents and antioxidant capacity. The studied factors, temperature, extraction time, and BCD molar concentration had influence on the responses. The anthocyanin content was evaluated by the differential pH method, polyphenols content by Folin Ciocalteu and the antioxidant capacity by antiradical scavenging technique (DDPH). Conditions that maximized the extraction of anthocyanins, polyphenols and antiradical scavenging activity were ultrasonication of BCD (15mM)-aqueous suspensions (4% w/v) of purple corn flour with a 125 m amplitude, an 130 W/cm2 power, for 15 minutes at 55°C. The ultrasound assisted extraction and the presence of BCD improved the anthocyanins and polyphenols content of the purple corn extracts, avoiding the use of organic solvents and long extraction times. The use of ultrasound combined with BCD aqueous extraction allowed to get an extract with potential for antioxidant enriched functional foods.