Some Nutritional and Functional Properties of Defatted Wheat Germ Protein

Abstract

Defatted wheat germ protein (DWGP) was isolated by alkaline extraction at pH 9.5 and subsequent isoelectric precipitation at pH 4.0, and its nutritional and functional properties were studied. The results showed that the amino acid content of defatted wheat germ was as high as 26.793 g/100 g, and the contents of eight essential amino acids were all relatively high. The isoelectric point of DWGP was 4.0. When pH >6.0, the DWGP had high solubility with a nitrogen solubility index of 70%. The emulsifying activity and emulsifying stability of DWGP were similar to those of bovine serum albumin and a little higher than those of casein. DWGP had good foaming capacity, but its foaming stability (FS) was not very good. However, the FS of DWGP can be improved through physical, chemical, or enzymatic methods. Moreover, DWGP had excellent water retention (WR); especially at pH 8.0 and a temperature of 70 degrees C, the WR of DWGP was the highest at 229.4%. DWGP offers is a potential source of functional protein isolate for possible food applications.

Physicochemical and functional properties of a protein-rich fraction produced by dry fractionation of chia seeds (Salvia hispanicaL.)

“…This may indicate a strong influence from PRF microparticles (Wu, 2001), which could be promoting greater proteinprotein interaction (Damodaran, 1997). Similar results have been reported for wheat germ proteins (EA near 70% at pH 7, ES ¼ 60%; Ge et al, 2000). The ES observed here is apparently linked to protein solubility at the evaluated pH levels (Figure 1), which coincides with the suggested association between soluble proteins and emulsion stability (Njintang, Mbofung, & Waldron, 2001).…”

“…Examples of this pattern include flours from watermelon seeds (Ige, Ogunsua, & Oke, 1984), sunflower seeds (Venktesh & Prakash, 1993), wheat germ proteins (Ge, Sun, Ni, & Cai, 2000), rice bran protein isolate (Wang, Hettiarachchy, Burks, & Siebenmorgen, 1999) and quinoa protein concentrate (Aluko & Monu, 2003). High solubility values have been reported at extreme acid and alkaline pH in C. ensiformis flour (Chel-Guerrero, Pe´rez-Flores, Betancur-Ancona, & Da´vila-Ortiz, 2002).…”

Optimization and evaluation of wheat germ oil extracted by supercritical CO₂

“…As can be observed in Table 10, the amino acid composition did not change significantly among the different extraction methods. The most striking was the abundance of lysine, which is the first limiting amino acid in the grain (Ge et al, 2000). However, cysteine was lower in wheat germ.…”

“…The defatted wheat germ, after extraction of valuable wheat germ oil, is a highly valued nutritive protein material. It contains about 30% protein and is rich in amino acids, especially the essential amino acids, such as lysine, methionine, and threonine, in which many cereals are deficient (Ge et al, 2000;Zhu et al, 2006). Therefore, wheat germ oil and defatted wheat germ are potential nutritious food supplements (Arshad et al, 2007;Ge et al, 2001;Matteuzzi et al, 2004).…”

Development of a novel milk‐based fermented product fortified with wheat germ

“…Also, it is characterised by a palatable taste due to its high oil and sugar contents. Although plant proteins are generally considered of low biological value, protein isolate from defatted wheat germ meal has been recognised as a highly nutritious product (Ge et al 2000) that has a very well-balanced amino acid make-up (Shurpalekar and Haridas Rao 1977) and is a rich source of lysine.…”