Optimización de las condiciones para la extracción enzimática de aceite de girasol

Vol. 43 Faso. 5 (1992)

281

Optimizing conditions for enzymatic extraction of sunflower oil.
By F.H. Badr and M.Z. Sitohy. Food Science Department and Biochemistry Department. Faculty of Agriculture, Zagazig University

RESUMEN Condiciones de optimización para la extracción enzimática de aceite de girasol. Aceite de semilla de girasol fue extraído mediante un proceso enzimático usandodiferentes enzimas hidrolíticos: celulasa, hemicelulasa, proteinasa animal, proteinasa acida, pectinasa y pectinex, comparando con la extracción acuosa libre de enzima. Todos los enzimas hidrolíticos incrementan la extracción de aceites de semilla de girasol. Las condiciones óptimas para la extracción de aceite a partir de semillas de girasol fueron: 2% de concentración de enzima, 30% deconcentración de sustrato y un período de 3 horas. La ecuación de Boganov y Buchkov mostró que el tiempo debe ser prolongado para alcanzar altos rendimientos. El máximo rendimiento durante tres horas de extracción con proceso enzimático osciló entre el 44,5%-57,1% del aceite extraído con soxhlet. La potencia de los enzimas investigados en la extracción de aceite siguió el orden: proteinasa acida > celulasa >hemicelulasa > proteinasa animal > pectinex > pectinasa cuando fue previamente comparado con las condiciones óptimas. PALABRAS-CLAVE: Aceite de girasol - Enzima hidrolítico - Extracción - Optimización. SUMMARY Optimizing conditions for enzymatic extraction of sunflower oil. Sunflower seed oil was extracted with an enzymatic processes using different hydrolytic enzymes: cellulase, hemicellulase,animal proteinase, acid proteinase, pectinase and pectinex, as compared to enzyme - free aqueous extraction. All the hydrolytic enzymes enhanced oil extraction from sunflower seeds. The most optimal conditions for oil extraction from sunflower seeds were: 2% enzyme concentration, 30% substrate concentration and 3 hrs period. Using Boganov and Buchkov equation showed that time must be prolonged to gethigher yields. The maximum yield during 3 hrs extraction with enzymatic process ranged between 44,5%-57,1% of the soxhlet extractable oil. The potency of the investigated enzymes in extracting oil was in the following order: acid proteinase > cellulase > hemicellulase > animal proteinase > pectinex > pectinase when compared at the previous optimal conditions. KEY-WORDS: Extraction flower oil.Hydrolytic enzyme - Optimizing - Sun-

Interactions while phospholipids bind more tightly through polar linkages. Covalent bonds were also found between the oxidation products of unsaturated lipids constituent and proteins (Cheftel et al., 1984). Hence, separation of oil with apolar organic solvents, e.g. hexane, might be only effective in case of neutral glycerides linked to protein through apolarlinkages, but lipid constituents bound through polar linkages require polar solvent. Solvent mixtures consisting of polar and apolar solvents such as ethyl: chloroform (1:1) were developed for more efficient oil extraction (Steinkraus, 1973). Using organic solvents in oil extraction may pose some hygienic hazarads to those working with them or the food if contaminated with traces of them. Theyalso may affect quality of the separated protein. So, the use of enzymatic extraction of vegetable oil may be safe and more efficient as the enzymes may be capable of dissociating most of the linkages between the lipid and other constituents as indicated by Mac-Glone et al., (1986) who developed an enzymatic process for the extraction of coconut oil. Therefore, this work was designed to identify theoptimal conditions for an enzymatic extraction of sunflower oil using different enzymes such as proteases, cellulases and pectinases.

2. MATERIALS AND METHODS Sunflower seeds obtained from Zagazig local market were dehulled and thoroughly chopped. The ground dehulled seeds were used as the substrate for oil extraction. Animal and acid proteinase were obtained from Institute of Microbiology,...