Functional properties of protein ingredients prepared from high‐sucrose/low‐stachyose soybeans

Abstract

High-sucrose/low-stachyose (HS/LS) soybeans were used to prepare ethanol-washed soy protein concentrate (EWSPC), soy protein isolate (SPI), and a new low-fiber soy protein concentrate (LFSPC) in which the protein was extracted with alkali to remove fiber and the protein extract was neutralized and freeze-dried. LFSPC prepared from HS/LS soybeans contained significantly higher ratios of β-conglycinin to glycinin (1:1.32) than did EWSPC (1:1.75) or SPI (1:1.69), which may have affected functional properties. The LFSPC were also high in soluble sugars (14.7%) and low in fiber (0.3%) compared with traditional EWSPC (2.9 and 3.4%, respectively) and SPI (1.8 and 0.3%, respectively). For both normal and HS/LS soybean varieties, the LFSPC, especially when extracted at pH 7.5 as opposed to pH 8.5, had higher denaturation enthalpies than did EWSPC and SPI, indicating less denaturation had occurred. Water solubilities, surface hydrophobicities, and emulsification properties were highest for the LFSPC and lowest for EWSPC. The LFSPC also had good foaming properties and low viscosities. These desirable functional properties of the LFSPC make them unique among alternative soy protein ingredients and highly suitable for industrial applications as food additives and ingredients.

Effects of Drying Method on Physicochemical and Functional Properties of Soy Protein Isolates

“…Although the onset ( T o ) and peak ( T p ) denaturation temperatures and the enthalpy of denaturation (Δ H ) measured by DSC are usually affected by the heating rates and protein concentrations, the peak denaturation temperatures ( T p ) of 7S and 11S in the present study are in agreement with those obtained by Scilingo and Añón (1996), and the enthalpies of denaturation of 7S and 11S are close to those obtained by Hua et al. (2005) and Deak and Johnson (2006b).…”

“…The spray-dried SPI showed the highest denaturation enthalpy for both 7S and 11S, while the vacuum-dried SPI the lowest, which could be attributed to lower protein denaturation for the spray-dried SPI and higher protein denaturation for the vacuum-dried SPI during drying. Although the onset (T o ) and peak (T p ) denaturation temperatures and the enthalpy of denaturation (DH) measured by DSC are usually affected by the heating rates and protein concentrations, the peak denaturation temperatures (T p ) of 7S and 11S in the present study are in agreement with those obtained by Scilingo and Añón (1996), and the enthalpies of denaturation of 7S and 11S are close to those obtained by Hua et al (2005) and Deak and Johnson (2006b). Data are expressed as mean Ϯ SD and are the means of three replicates.…”

“…Contrarily, hydrophilic ones are located on their surfaces. Surface hydrophobicity is related to two main factors: one being the slight denaturation of protein by heating, freezing and other processes, which results in increasing surface hydrophobicity by unfolding the structure and exposing hydrophobic regions, and the other being the aggregation of protein by means of protein‐protein interactions resulting in reducing exposed hydrophobic regions and consequently decreasing surface hydrophobicity (Petrucelli and Añón 1996; Deak and Johnson 2006b).…”

Simplified soy molasses-based medium for reduced-cost production of sophorolipids by Candida bombicola

“…In this regard, soy molasses is an attractive feedstock because it is a low-value coproduct of soybean processing but is high in potentially fermentable sugar content useful for sustaining microbial growth. As health-conscious consumers continue to drive up the demands for soy protein-based foods and drinks, the soy protein industry has experienced a sustained 10% annual growth for the past several years with a market value of nearly $4 billion (Kinney 2003;Deak and Johnson 2006). As a result, large quantities of the low-value soy molasses are generated annually, demanding the development of valueadded new uses for this coproduct stream (Cherry 2004).…”

Exploitation of Agro-Industrial Wastes to Produce Low-Cost Microbial Surfactants

“…Soy molasses, a by-product of soybean oil processing, is rich in fermentable carbohydrate (30 % w/v) mainly glucose, arabinose, sucrose, raffi nose, and stachyose. Due to increase in demand of soy protein-based foods and drinks, soy molasses is available as by-product and can be used as a medium supplement for supporting microbial growth (Deak and Johnson 2006 ). The cost of soy molasses is approximately 20 % lower than glucose, thus reducing the overall cost of biosurfactant production (Lynd et al 1999 ).…”