This body of research focuses on three major areas related to soy protein ingredients. The first area is the use of genetically modified high-sucrose/low-stachyose soybeans (HS/LS) in a new simplified procedure to prepare soy protein concentrate; secondly, fractionating soy protein into ingredients enriched in either glycinin or [Beta]-conglycinin; and lastly, processing effects on soy protein isolate functionality. Soy protein fractionation was significantly improved by increasing protein yields and reducing processing costs. In the three-step or Wu fractionation procedure, significant advances were made by identifying the optimum SO2 concentration to be 5 mM, the optimum NaCl concentration to be 250 mM, and the optimum dilution factor to be 1-fold. Furthermore, this procedure was modified by using mM amounts of CaCl2 at pH 6.4 improving both yield and purity of the [Beta]-conglycinin-rich fraction. A new two-step fractionation procedure was developed based on the differential calcium reactivity of glycinin and [Beta]-conglycinin. The use of 5 mM SO2 in combination with 5 mM CaCl2 in this fractionation procedure yielded improved purities in the glycinin-rich (85.2%) and [Beta]-conglycinin-rich (80.9%) fractions. This procedure yielded fractions with improved solids, protein, and isofiavone yields. In addition, the ingredients produced by this method had unique and improved functional properties. Phytic acid was proposed as playing an important role in fractionating soybean storage proteins because of its ability to complex with calcium ions and soy protein. HS/LS soybeans were used to produce a new soy protein concentrate that was low in fiber, high in isoflavones and soluble sugars, and had unique functional properties, which were, in most cases, similar to or better than those found in traditional soy protein isolates. HS/LS soybeans were identified as good starting material for fractionating soy protein. In the Wu fractionation procedure, HS/LS soybeans yielded high amounts of the individual storage proteins with 100% electrophoretical purity. The functionality of soy protein isolate was affected by extraction temperatures and method of preservation. Spray-dried soy protein isolates (SPI) were more soluble, hydrophobic, and formed more stable emulsions than did freeze-dried SPIs. The drying method, however, did not affect denaturation enthalpy of SPI.

Protein hydrolysates, otherwise commonly known as peptones or peptides, are used in a wide variety of products in fermentation and biotechnology industries. The term “peptone” was first introduced in 1880 by Nagelli for growing bacterial cultures. However, later it was discovered that peptones derived from the partial digestion of proteins would furnish organic nitrogen in readily available form. Ever since, p- tones, which are commonly known as protein hydrolysates, have been used not only for growth of microbial cultures, but also as nitrogen source in commercial fermen- tions using animal cells and recombinant microorganisms for the production of value added products such as therapeutic proteins, hormones, vaccines, etc. Today, the characterization, screening and manufacturing of protein hyd- lysates has become more sophisticated, with the introduction of reliable analytical instrumentation, high throughput screening techniques coupled with statistical design approaches, novel enzymes and efficient downstream processing equipment. This has enabled the introduction of custom-built products for specialized appli- tions in diverse fields of fermentation and biotechnology, such as the following. 1. Protein hydrolysates are used as much more than a simple nitrogen source. For example, the productivities of several therapeutic drugs made by animal cells and recombinant microorganisms have been markedly increased by use of p- tein hydrolysates. This is extremely important when capacities are limited. 2. Protein hydrolysates are employed in the manufacturing of vaccines by ferm- tation processes and also used as vaccine stabilizers.

Protein hydrolysates, otherwise commonly known as peptones or peptides, are used in a wide variety of products in fermentation and biotechnology industries. The term “peptone” was first introduced in 1880 by Nagelli for growing bacterial cultures. However, later it was discovered that peptones derived from the partial digestion of proteins would furnish organic nitrogen in readily available form. Ever since, p- tones, which are commonly known as protein hydrolysates, have been used not only for growth of microbial cultures, but also as nitrogen source in commercial fermen- tions using animal cells and recombinant microorganisms for the production of value added products such as therapeutic proteins, hormones, vaccines, etc. Today, the characterization, screening and manufacturing of protein hyd- lysates has become more sophisticated, with the introduction of reliable analytical instrumentation, high throughput screening techniques coupled with statistical design approaches, novel enzymes and efficient downstream processing equipment. This has enabled the introduction of custom-built products for specialized appli- tions in diverse fields of fermentation and biotechnology, such as the following. 1. Protein hydrolysates are used as much more than a simple nitrogen source. For example, the productivities of several therapeutic drugs made by animal cells and recombinant microorganisms have been markedly increased by use of p- tein hydrolysates. This is extremely important when capacities are limited. 2. Protein hydrolysates are employed in the manufacturing of vaccines by ferm- tation processes and also used as vaccine stabilizers.