title: Wheat germ: not only a by-product.
abstract: The wheat germ (embryonic axis and scutellum) represents about 2.5-3.8% of total seed weight and is an important by-product of the flour milling industry. The germ contains about 10-15% lipids, 26-35% proteins, 17% sugars, 1.5-4.5% fibre and 4% minerals, as well as significant quantities of bioactive compounds such as tocopherols [300-740 mg/kg dry matter (DM)], phytosterols (24-50 mg/kg), policosanols (10 mg/kg), carotenoids (4-38 mg/kg), thiamin (15-23 mg/kg) and riboflavin (6-10 mg/kg). Oil recovery is achieved by mechanical pressing or solvent extraction, which retrieve about 50% or 90% lipids, respectively; innovative approaches, such as supercritical carbon dioxide extraction, are also proposed. The oil is rich in triglycerides (57% of total lipids), mainly linoleic (18:2), palmitic (16:0) and oleic (18:1) acids, but relevant amounts of sterols, mono- and diglycerides, phospho- and glycolipids are present. The lypophilic antioxidants tocopherols and carotenoids are also abundant. The main by-product of oil extraction is defatted germ meal, which has high protein content (30-32%), is rich in albumin (34.5% of total protein) and globulin (15.6%), and thus presents a well-balanced amino acid profile. Its principal mineral constituents are potassium, magnesium, calcium, zinc and manganese, in decreasing order. Total flavonoid content is about 0.35 g rutin equivalent/100 g DM. The wheat germ is therefore a unique source of concentrated nutrients, highly valued as food supplement. While the oil is widely appreciated for its pharmaceutical and nutritional value, the defatted germ meal is a promising source of high-quality vegetable proteins. Better nutrient separation from the kernel and improved fractioning techniques could also provide high-purity molecules with positive health benefits.
authors.affiliation: CRA-SCV, S. Angelo Lodigiano, Via R. Forlani 3, 26866 S. Angelo Lodigiano (LO), Italy. andrea.brandolini@entecra.it
authors.forename: Andrea
authors.initials: A
authors.lastname: Brandolini
authors.forename: Alyssa
authors.initials: A
authors.lastname: Hidalgo
mesh_terms: D000821:Animal Feed / Q000032:analysis / Q000191:economics; D000818:Animals; D019587:Dietary Supplements / Q000032:analysis / Q000191:economics; D005527:Food, Fortified / Q000032:analysis* / Q000191:economics; D005525:Food-Processing Industry / Q000191:economics; D006801:Humans; D007220:Industrial Waste / Q000032:analysis / Q000191:economics; D009753:Nutritive Value; D010938:Plant Oils / Q000008:administration & dosage / Q000032:analysis; D012639:Seeds / Q000737:chemistry*; D014908:Triticum / Q000737:chemistry*
chemical_list: D007220:Industrial Waste; D010938:Plant Oils; C050055:wheat germ oil