Effect of soaking process on nutritional quality and protein solubility of some legume seeds

Abstract

Legume seeds (soy bean, lupin and bean seeds) were soaked in 0.5% sodium bicarbonate in attempt to evaluate their nutritional quality and protein solubility index. Soaking process led to an increase in the hydration coefficient, seed weight, total protein, ash, fat, fiber, while non protein nitrogen, total carbohydrates, starch, stachyose, raffinose, reducing sugars, and minerals (except Na) were decreased. All antinutritional factors such as phytic acid, tannin, trypsin inhibitor and hemagglutinin activity were decreased during soaking in 0.5% sodium bicarbonate; it was the same for the protein solubility in different solutions, while the in-vitro protein digestibility and available lysine were increased.

Functionality of oilseed protein products: A review

“…Hydrothermal cooking before water extraction improves foaming and emulsifying properties (Wang & Johnson, 2001) and thermal treatments of the grain (extrusion, microwave) cause changes of chemical composition and nutritive quality (Zilic, Bozovic, Savic, MladenovicDrinic, & Bekric, 2002) affecting the techno-functional properties (Lampart-Szczapa et al, 2006). Soaking seeds in water or in sodium salts (bicarbonate, chloride) solutions or treatment with carbohydrases reduces the amount of oligosaccharides (El-Adawy, Rahma, El-Bedawey, & Sobihah, 2000; Wanasundara & Shahidi, 1997), and improves the functional properties of proteins (El-Adawy et al, 2000;Inyang & Ekanem, 1996). Soaking seeds in sodium bisulfite solutions and in acidic media remove phenolics compounds (Bau, Mohtadi-Nia, Mejean, & Debry, 1983;Kilara, Humbert, & Sosulski, 1972).…”

“…Chemical modifications are commonly used in studies performed to characterize the relationships between structure, stability and functional properties of isolates (Dua, Mahajan, & Mahajan, 1996;El-Adawy et al, 2000;Gruener & Ismond, 1997). Most studies performed with food proteins are based on the derivatization of the groups e-amino of lysine residues.…”

Physico-chemical and functional properties of native and hydrolysed protein isolates from Indian black gram (Phaseolus mungo L.) cultivars

“…The highest yield was obtained from Mash 1-1 and the lowest yield from PU-19 (Table 1). Previous studies have reported that yield of protein isolates from mung bean flour was 13.0e19.0% (El-Adawy, Rahma, El-Bedawy, & Sobihah, 2000;Rahma, Dudek, Mothes, Gornitz, & Schwenke, 2000). Thus, present findings were comparable with reported values.…”

Bioactive proteins and peptides in pulse crops: Pea, chickpea and lentil

“…After soaking 17 different pea varieties for 18 h and then boiling them for 20 min, trypsin inhibitor content was reduced in all of the varieties by 42-92% (TIU/mg DM), with an average reduction of 78% (TIU/mg DM) (Morrison et al, 2007). Other studies demonstrate variability in protease inhibitor activity after utilizing different time and temperature combinations, depending on the species, cultivar and treatment method (Alonso et al, 1998;El-Adawy, Rahma, El-Bedawy, & Sobihah, 1999;Marquez & Alonso, 1999).…”