γ‐Oryzanol is considered to be an important fraction in rice bran oil. Due to the low concentration levels (1–3%) of γ‐oryzanol in crude rice bran oil (CRBO), isolation and purification would be necessary before practical usage. This study developed an efficient and easy‐to‐scale‐up chromatographic separation method for the production of γ‐oryzanol. First, the CRBO was prepared using a Soxhlet extractor operated under an optimal extraction condition (using 130 mL of hexane for 2 hr per 15 g rice bran). The extraction yield was 16–18% (w/w) and the purity of γ‐oryzanol was 2.4–3.0% (w/w). Then, γ‐oryzanol in the CRBO was purified by preparative elution chromatography under the normal phase mode. Column operation was optimized by using a silica gel column packed with small particles (12 µm) and operated by a three‐step gradient elution mode, where the mobile phase composition of hexane/ethyl acetate was from 90:10 or 85:15 to 50:50 v/v to pure ethyl acetate. The injection amount was increased as la...

Preparative separation of γ-oryzanol from rice bran oil by silica gel column chromatography

Se determino el efecto sobre el consumo y digestibilidad aparente de niveles crecientes de cama de pollo (Cp) con harina gruesa de subproductos de maiz (Hm) o pulitura de arroz (Pa) y bagacillo de cana amonificado (40%, Ba), en raciones para corderos en crecimiento en confinamiento total. Se realizo un experimento en un arreglo factorial 2x4 en diseno de cuadrado latino con 8 corderos canulados en el rumen, incorporando Hm o Pa (48, 39, 30 y 21%, en ambos casos) y Cp (11,4; 20,4; 29,4 y 38,4%). Las raciones con Cp y Hm fueron mas consumidas que las de Cp y Pa (10 a 12,1% del peso metabolico en materia seca (MS), para Hm vs. 7,6 a 9,3% para Pa) y para la materia organica (MO) 8,1 a 8,5% del peso metabolico para Hm y 5,8 a 6,4% para Pa; respecto a la digestibilidad aparente (DA) se obtuvo un 34,2 a 43% de la MS y 67,8 a 67,1% de la MO para raciones con Hm vs. 30,5 a 37,2% de la MS y 65,5 a 66,1% de la MO para raciones con Pa. Se aprecio que el pH y el nitrogeno amoniacal, no alcanzaron los valores indicativos de acidosis ni de intoxicacion con amoniaco, lo cual se correspondio con valores normales de su fisiologia sanguinea para raciones con Cp y Hm. Los resultados indican que Hm y Ba en raciones con Cp permitieron un consumo y digestibilidad de los nutrientes dentro de rangos normales para corderos, sin riesgos para la salud del animal, lo cual no ocurrio con las raciones que contenian Pa y Cp.

http://www.uco.es/organiza/servicios/publica/az/php/img/web/09_10_23_03EfectoBorges.pdf

Efecto de cama de pollos, subproductos de cereales y caña sobre la fisiología ruminal de ovinos effects of poultry litter, cereal byproducts and sugar cane bagasse on lamb ruminal physiology

The thesis was initiated through an exhaustive review of research conducted
worldwide towards degumming, dewaxing, decolourizing and deacidifying
edible oils using membrane technology. To begin with, the influence of
phospholipid (PL) composition and solvent (hexane) medium on critical
micelle concentration levels in crude oil and crude oil-hexane systems was
investigated, which explained the dependency of ultrafiltration membranes on
the initial PL concentration in their degumming performance and how the
nonporous membranes achieved near complete degumming in vegetable oils
under various conditions. Attempts made to enhance oil flux showed that the
nonporous membrane did not reject triglycerides (TG) over a wide range of
hexane dilution due to a positive flow coupling with hexane while improving
the oil flux by an order of magnitude. Besides, the results revealed that the oil
flux followed an inverse relationship with average molecular weights of TG
despite their narrow range of existence in various vegetable oils, interestingly
even under hexane-diluted conditions. Assessing the potential of nonporous
membranes revealed its prospect as a single-step pretreatment process for
simultaneous degumming, dewaxing and decolourizing crude rice bran oil
besides eliminating the problem causing phosphoglycolipids. Enzymatic
degumming employing phospholipase-A1 was found to be effective in oil
system, however only to a moderate extent in hexane-oil system. Further,
potential applications of membrane technology in nonaqueous systems were
examined, specifically for enriching beneficial oryzanol in rice bran oil (RBO)
and deoiling lecithin. Nonporous membrane exhibited moderate rejection of
oryzanol (ferulate esters) in RBO owing to their hydrophilic nature, suggesting
8
a physical method for enriching oryzanol in RBO and thereby the possibility of
producing a standard RBO with a guaranteed oryzanol content. The
phenomenally high selectivity of nonporous membrane for PL was responsible
for its high efficacy in deoiling lecithin in a favourable solvent (hexane) scoring
over the industrially-practiced acetone-extraction method. Nonporous
membranes possess the potential for being employed in various steps of
vegetable oil processing, however the flux needs further improvement for
industrial adoption. Thus present study has clearly brought out the
effectiveness of nonporous membranes on their suitability in nonaqueous
applications, principally in vegetable oil processing.

Arlene Karan

Papers

Separation of oryzanol from crude rice bran oil