Deland J. Myers

Properties of fibers produced from soy protein isolate by extrusion and wet-spinning

Fibers were produced from soy protein isolate by both wet-spinning and extrusion. In the wet-spinning process, aged, alkaline protein solution was forced through a spinnerette into an acid coagulating bath. In the extrusion process, a twinscrew extruder forced a protein isolate-water mixture through a die. The physical properties of the fibers were measured at various water activities. The fibers produced by both methods were brittle and lacked tensile strength (tenacity). The addition of glycerol reduced brittleness in extruded fibers. Zinc and calcium ions decreased the brittleness of wet-spun fibers. The tenacity of soy fibers was significantly improved by post-spinning treatments, including acetic anhydride, acetaldehyde, glyoxal, glutaraldehyde, a combination of glutaraldehyde and acetic anhydride, and stretching. The best extruded fibers were produced with a mixture of 45% soy protein, 15% glycerol, and 40% water, finished with a combination of glutaraldehyde and acetic anhydride and then stretched to 150% their original lengths. The best wet-spun fibers were produced with a 19.61% soy protein suspension at pH 12.1; coagulated in a 4% hydrochloric acid solution that contained 3.3% sodium chloride, 3.3% zinc chloride, and 3.3% calcium chloride; and followed by treatment with 25% glutaraldehyde and stretching to 170% their original lengths.

Comparison of protein-based adhesive resins for wood composites

The search for new value-added uses for oilseed and animal proteins led us to develop protein-based wood adhesives. Low-fat soy and peanut flours and blood meal were hydrolyzed in an alkaline state, and PF-cross-linked protein resins were formulated by reacting the protein hydrolyzates with phenol-formaldehyde (PF) in solid-tosolid ratios ranging from 70% to 50% hydrolyzates and 30% to 50% PF. Physical properties of medium density fiberboard (MDF) bonded with protein-based phenolic resins were compared to those of boards bonded with ureaformaldehyde (UF) and PF resins, and flakeboard bonded with soy protein-based phenolic resin was compared to PF-bonded board. As MDF binders, adhesive properties of protein-based phenolic resins depended upon protein content of proteinacious materials. MDF board bonded with blood-based phenolic resin was comparable to PF-bonded board and met the requirements for exterior MDF. Boards bonded with soy-protein-based phenolic resin met requirements for interior MDF, while peanut-based phenolic failed to meet some of the requirements. Flakeboard bonded with soy-protein-based phenolic resins was inferior to PF-bonded board but outperformed PF-bonded board in accelerated aging tests. Although they exhibit a slow curing rate, the cost effectiveness and superior dimensional stability of protein-based phenolic resins may make them attractive for some uses.

Production of Textile Fibers from Zein and a Soy Protein-Zein Blend

ABSTRACT Zein fibers were successfully prepared by a wet-spinning technique from a zein suspension formulated with 15% zein, 60% water, 22% 0.4N sodium hydroxide, and 3% urea by weight. Tenacities were measured with an Instron machine, and flexibility was determined by noting the smallest diameter rod around which a fiber could be looped without breaking. After spinning, the tenacity of the zein fibers was improved by modification with several agents: acetic anhydride for acetylation, glutaraldehyde, and dialcohols for cross-linking and physical stretching. The tenacity and flexibility of the fibers were measured at 11, 65, and 100% rh. Untreated fibers had tenacities of 3.41, 2.65, and 0.17 g/tex at 11, 65, and 100% rh, respectively. A combination of chemical treatments (20% glutaraldehyde and 95% acetic anhydride) and 115% stretching increased tenacities to 6.89. 6.56, and 1.17 g/tex at 11, 65, and 100% rh, respectively. Control zein fibers had flexibilities of 5 and 2.5 mm at 11 and 65% rh, respectivel...

Functional properties of protein extracted from flaked, defatted, whole corn by ethanol/alkali during sequential extraction processing

Functional properties (solubility, foaming capacity and stability, emulsifying capacity, emulsion stability, heat coagulability, heat gelation and film formation) of protein extracted by 45% ethanol/55% 0.1 M NaOH from flaked, defatted, undergermed corn during the Sequential Extraction Process (SEP) were evaluated and compared with those of a laboratory-prepared soy protein concentrate. SEP is a new approach to corn fractionation that recycles the ethanol produced from the fermentation of cornstarch to unstream steps of protein extraction and the simultaneous extraction of corn oil and dehydration of the ethanol. Freeze-dried corn protein extracts contained at least 80% crude protein (dry basis), which is indicative of protein concentrates. SEP protein concentrates had solubilities in water of greater than 80% at pH values of 7 or above and were significantly more soluble than the soy protein concentrate at pH above 3. SEP corn proteins also showed better heat stabilities and greater emulsifying capacities and emulsion stabilities. Dilute dispersions (0.1%) of corn protein produced substantial but less stable foams. Corn proteins produced films similar to zein and soy protein films but were unable to form heat-induced gels. These results indicate that SEP produces a protein concentrate with functional properties suitable for food and industrial uses.

Factors affecting yield and composition of zein extracted from commercial corn gluten meal

ABSTRACT Twelve corn gluten meal samples obtained from six wet-milling plants were processed into zein. Zein was extracted using 88% aqueous isopropyl alcohol at pH 12.5, followed by chilling. Protein recovery ranged from 21.3 to 32.0%, and protein purity ranged from 82.1 to 87.6%. Protein recovery increased as the protein purity increased (r = 0.76) (P < 0.01). One of the major factors influencing extraction yield was protein composition; especially α-zein content, which ranged from 53.4 to 64% of the total protein in the corn gluten meal samples. The intensity of red color of the corn gluten meal was negatively correlated with protein recovery and zein purity (r = -0.66 and -0.72, respectively) (P < 0.02).

Industrial Uses for Soybeans

Publisher Summary Industrial uses for soybeans comprise no more than 0.5% of the protein and 2.6% of the oil produced from soybeans grown in the United States. There are no current industrial uses for whole soybeans. There is one instance when soybeans were used for ship ballast, and powdered soybeans were patented as a floor covering. The economically viable industrial uses today are paper coatings and wood veneer adhesives, and alkyd resins, printing ink, and oleochemicals. Today, imminent growth of soybean usage in fuel, adhesives, plastics, and construction materials is predicted. Industrial uses for soybean protein include: wood adhesives, plastics, textile fibers, paper coatings, etc. Soybean oil is often regarded as being too viscous and reactive to atmospheric oxygen to be used as fuels, cosmetics, lubricants, and chemical additives, but not reactive enough for most paints and coatings applications. However, more stringent environmental standards, rising costs for competing petroleum-derived products, ability to tailor soybean oil for improved performance properties, and more cost effective chemical conversion processes are leading to increased attention on soybean oil as a feedstock for industrial products.

Economic-Engineering Assessment of Sequential Extraction Processing of Corn

A simulation model, termed SIMSEP for simulating the Sequential Extraction Process (SEP), was developed to assess the economic and engineering feasibilities of SEP, an innovative approach to processing corn into ethanol, edible oil, industrial and edible proteins, and feed ingredients. SEP is designed to produce a new mix of value-added co-products that could improve the profitability of processing corn and corn-derived ethanol. Simulations were carried out for various system variables to examine their effects on profitability. Results showed that SEP is economically and technically feasible. Estimates for return on investment for a proposed plant are attractive under many likely market situations, and several additional opportunities exist to further improve profitability. The SEP technology should not be commercialized until additional potential technical and market problems are resolved; but based on this analysis, continued research and development activities are warranted.

Characterization of protein extracted from flaked, defatted, whole corn by the sequential extraction process

An investigation was conducted to identify and characterize protein extracted by 45% ethanol:55% 0.1 M NaOH from flaked, defatted, undegermed corn (Zea mays L.) during Sequential Extraction Processing (SEP). This new approach to corn milling, SEP, recycles the ethanol produced from the fermentation of cornstarch to upstream steps of protein extraction and the simultaneous extraction of corn oil and dehydration of the ethanol. About 10% of the protein was extracted by ethanol during counter-current-percolation oil extraction. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and amino acid analysis identified this protein as zein. Nearly 65% of the total protein was recovered by the process in the protein extraction step from soft dent corn (Pioneer 3377), medium-hard dent corn (Pioneer 3732) and high-lysine corn. The freeze-dried solids of the ethanol/alkali extracts from these corn hybrids contained about 80% crude protein (db). The amino acids were present in quantities similar to those in whole corn and markedly higher than those in corn gluten meal. These results indicate that SEP produces high-quality protein suitable for food and industrial uses.

Effects of Maturity on Corn Starch Properties

ABSTRACT The effect of maturity on the quality of starch for two corn hybrids harvested at three different stages of development was measured by differential scanning calorimetry, rapid viscosity analysis, scanning electron microscopy, and image analysis. The onset of gelatinization and peak temperatures were 2–5°C higher for starch from immature grain than starch from mature grain. The gelatinization temperature range was 5°C larger as the grain matured. Peak and trough viscosities decreased with maturity, while pasting temperature increased. Between the two hybrids, the late maturing hybrid yielded a larger peak viscosity and trough. The early maturing hybrid exhibited a higher pasting temperature. Image analysis data showed that the starch granules from mature grain showed an increase in size compared with the starch granules from grain that were harvested at the late milk line stage for one, but not both hybrids.

Effects of maize hybrid and meal drying conditions on yield and quality of extracted zein

ABSTRACT Corn gluten meal (CGM) produced from two maize hybrids and subjected to five drying treatments were used to determine the effects of variables on zein extraction. Zein extraction yields, protein recoveries, and purities were higher in the CGM with the higher protein content. The yield and protein recovery of zein decreased as the drying temperature increased. Zein yield, protein recovery, and purity were significantly lower in the CGM subjected to freeze- and spray-drying than in those subjected to oven-drying. A relatively higher pH value in the CGM slurries was a characteristic of freeze- and spray-dried CGM. An explanation of these results based on the mechanisms of protein changes during drying is given.