Simmondsin concentrate from defatted jojoba meal

A water-extract of defatted jojoba meal was filtered and concentrated from 2.6 to 23% solids on a pilot scale in a reverse osmosis concentration apparatus and then freeze-dried. The characteristics of the membrane and new concentrator were determined with both glucose and the water-extract from jojoba meal. Permeate flux was not significantly affected by the change in total flow within the controllable limits at 1, 2, 10, or 20% glucose concentration. With the total flow past the membrane maintained at 57 l/m, the permeate flux was measured at various concentrations and at different pressures across the membrane. A permeate flux fate of 2.21 x 10(-5) m/s could be maintained for glucose concentrations up to 20%. For the extract, pressure across the membrane was adjusted to maintain a permeate flux of 1.24 x 10(-5) m/s (3.8 l/min for a 5.1 m(2) surface area membrane) not exceeding the system limit of 6.9 MPa. Using this method, 193 1 of 2.6% solids jojoba extract could be concentrated to 25.3 1 of 19.7% solids in 45 min. Permeate flux decreased with time because maximum pressure could not maintain a flux rate of 1.24 x 10(-5) m/s at the higher solids concentrations. The average permeate flux over the entire experiment was 0.99 x 10(-5) m/s. Based on the pilot scale tests, 568 kg of meal were extracted and processed on industrial equipment. The process included a vacuum drum dryer coated with diatomaceous earth with spray-drying of the concentrate. A powdery solid containing 42% simmondsin and related analogues was obtained. The results of the industrial trials and recommendations for process improvements are discussed. (C) 1997 Elsevier Science B.V.