Production of Soy Isolates by Ultrafiltration: Factors Affecting Yield and Composition

Water extracts of defatted soy flour were prepared by multiple extraction and centrifugation. Ultrafiltration of extracts in hollowfiber units showed significant deviation from ideal behavior for removal of nonprotein components, probably due to solute-solute and solute-membrane interactions. These interactions affected the retentate composition as well as the yield of protein. Membrane adsorption losses increased with feed concentration and were higher for the XM than for the PM series of membranes. A retentate washing step, such as the continuous diafiltration mode of operation, was necessary to produce a true protein isolate. Overall yield of protein was 86% of that in the defatted soy flour.     

Ultrafiltration of Acid Whey in a Spiral-Wound Unit: Effect of Operating Parameters on Membrane Fouling

Membrane fouling by acid (cottage cheese) whey could be minimized by appropriate pH adjustment and removal of insoluble particulates. Acidifying pasteurized whey to pH 2 or 3 followed by conventional centrifugal clarification (e.g. 5000g for 20–30 sec) significantly improved flux over that of unadjusted whey. Neutralizing whey to pH 7 was also just as effective provided resulting insoluble particles could be removed efficiently. Operating at 50°C was slightly more beneficial than 40° or 30°C. High flow rates were beneficial only if transmembrane pressure was below some critical value (about 50 psig or 350 kPa in this case). At pressures higher than this, high flow rates significantly increased fouling rates. After prolonged operating time, neither flow rate nor pressure appeared to have a significant effect, due perhaps to a change in the mode of fouling from surface deposition to pore adsorption.     

Extrusion of defatted soy flour-hydrocolloid mixtures

Defatted soy flour containing low levels of added hydrocolloid (either sodium alginate or methylcellulose) was thermoextruded in a laboratory single-screw extruder, and the effect of operating parameters on selected textural properties (maximum peak force, determined in an Ottawa Measuring (OTMS) cell, and chewiness) and physical properties (bulk density and water absorption capacity) were studied. Adding sodium alginate generally increased OTMS peak force, chewiness and water absorption capacity and increased bulk density. Extruding at a feed moisture content of 22% w/w resulted in the best properties, regardless of the levels of other independent variables. Maximum force and chewiness were positively correlated while bulk density and water absorption capacity were negatively correlated to each other.     

用大豆强化的谷物离乳期食品的制备和性质

脱水的,以谷物为基料用全大豆强化的离乳期食品可由一简便的加工过程(即:热烫、碾磨、烧煮、和鼓式干燥,而制得。添加少量碳酸氢钠至碾磨水中可改进成品的风味。大豆-谷物混合物在进行鼓式干燥前先经胶凝化处理可改进干燥特性和感官性能。大豆的加入可克服谷物中赖氨酸的缺乏和增加大豆-谷物混合物中蛋白质的含量。加工条件对蛋白质质量的影响相对地较小。大豆含量为25~30%的大豆-谷物混合物具有最佳营养品质。感官鉴定指出,掺入20 %以上的大豆才使它的评定分数明显降低。     

An AWG based colorless WDM-PON with RZ-DPSK modulated downstream and re-modulation of DL signal for OOK upstream

We proposed an arrayed waveguide granting (AWG) based 10 Gbps full duplex wavelength division multiplexing passive optical network (WDM-PON) utilizing a retum-to-zero differential phase shift keying (R...     

Sunflower Protein Concentrates and Isolates' Low in Polyphenols and Phytate

Protein concentrates and isolates from sunflower (Helianthus annuus L.), essentially free of polyphenols and/or low in phytate, were prepared from dehulled seeds by a sequential extraction procedure using organic solvents, such as hexane for defatting and acidic butanol for removing polyphenols. Phytate was removed by aqueous extraction and separation at acidic and/or alkaline conditions, depending on the relative solubility of the protein and phytate. Reduced-phytate concentrates and isolates developed off-colors unless the polyphenol concentration was less than 0.05%. The protein solubility profile of the reduced-phytate products was much better than that of the defatted meal, especially below the isoelectric point.     

Concentration of Vinegar by Electrodialysis

Vinegar (9–12% w/v acetic acid) was concentrated by electrodialysis (ED) to produce triple-strength vinegar (30–33% acetate). At a current density of 174 Amps/m², acetate flux was 520 g/m²/hr (GMH) for 9.1% acetate and increased to 920 GMH at 31% acetate. Increasing feed concentration decreased water flux from 2.6 to 1.3 L/m²/hr and energy consumption from 1.2 to 0.7 kWh/kg acetate transported. Increasing current increased acetate flux, energy consumption and water flux. A multi-stage ED system could produce triple-strength vinegar at much lower costs per unit of single-strength vinegar.