Biofuel co-products as livestock feed - Opportunities and challenges

318Biofuel co-products as livestock feed – Opportunities and challengesFIGURE 5Structures of the main phospholipids in vegetable lecithinsOOOR 2R 1OOO PO-CH 2-CH 2-N + H 3-OOOR 2OOR O1O PO-CH 2-CH 2-N + (CH 3) 3- O3 - sn - Phosphatidylcholine (PS) 3 - sn - Phosphatidylethanolamine (PE)OOR 2OOR 1O OP- O OHOHOORO2OR 1 O2 -O POOHOHOHHOHHPhosphatidic acid (PA)HHHONote: R1 and R2 indicate -C15 and -C17 hydrocarbonchains.Source: Joshi, Paratkar and Thorat, 2006.3 - sn - Phosphatidylinisositol (PI)R 1and R 2-C 15-C 17hydrocarbon chainsTABLE 11Phospholipid composition of liquid vegetable lecithins(g/100 g of lecithins fraction) by 31 P-NMRPhospholipid Soybean Sunflower seed RapeseedPC 15 16 17PE 11 8 9PI 10 14 10PA 4 3 4Other phospholipids 7 6 6Notes: 31 P-NMR indicates analysis of P isotpe-marked lecithins usingnuclear magnetic resonance techniques. For PC, PE, PI andPA see Figure 5. Source: Van Nieuwenhuyzen and Tomas, 2008.protein digestion in the hindgut both in vitro and invivo (Jenkins and Fotouhi, 1990; Wettstein, Machmullerand Kreuzer, 2000; Hristov, Neill and McAllister, 2003;Pivoda et al., 2010). Both methane production andammonia concentration in the rumen were significantlyreduced, implying that efficiency of feed conversion wasincreased.SqualeneSqualene – an isoprenoid compound with 6 isoprene units(triterpene) – is an intermediate metabolite in the synthesisof cholesterol and phytosterols (Figure 6). This unsaturated,thermally unstable and light-sensitive hydrocarbon appearsin high concentrations (50–90 percent by weight) in theliver oils of certain species of deepsea sharks (Bakes andNichols, 1995; Wetherbee and Nichols, 2000). It is alsopresent in lower concentrations in foods such as avocado,aubergine, poultry and tuna, as well as in some commonedible oils such as olive, palm, groundnut, and rapeseed(Catchpole and von Kamp, 1997; Catchpole, Von Kampand Grey, 1997; Chua et al., 2007).Concentration of squalene in olive oil can be from136 to 708 ppm (Kiritsakis, 1990).Squalene has been demonstrated to be effective indecreasing total cholesterol, low-density lipoprotein-cholesteroland triglyceride levels. It is also used extensively asa strong antioxidant in the food and cosmetic industries