Extrusion Conditions Modify Hypocholesterolemic Properties of Wheat Bran Fed to Hamsters

Abstract

Cereal Chem. 83(2):152-156 Wheat bran was extruded in a twin-screw extruder at five specific mechanical energy (SME) levels (0.120, 0.177, 0.234, 0.291, and 0.358 kWh/kg, dwb) and the cholesterol-lowering effects were compared with those of unprocessed wheat bran when fed to four-week-old male golden Syrian hamsters (n = 10/treatment) for three weeks. Diets contained 10% total dietary fiber, 10.3% fat, 3% nitrogen, and 0.4% cholesterol. Plasma total cholesterol and very-low-density lipoprotein cholesterol were significantly lower with 0.120 kWh/kg extruded wheat bran diet compared with the unextruded wheat bran control. Total triglycerides were significantly lower with 0.120 and 0.177 kWh/kg wheat bran diets compared with those fed 0.291 and 0.358 kWh/kg extruded wheat bran diets. Cholesterol digestibility, total liver cholesterol, and total liver lipids were significantly lower with all the extruded wheat bran diets compared Many popular foods of cereal origin (ready-to-eat cereals, snacks, and pasta) are produced by extrusion processing. The extrudates have physical and chemical characteristics different from those of the original food (Harper 1979; Linko 1981). These differences depend on the extrusion parameters (energy input, residence time, type of extruder used) and the physical and chemical properties (moisture, fat, and fiber content) of the raw material. Extrusion alters the starch, protein, fat, and fiber components of cereals, forming complexes that may affect cholesterol-lowering properties. Extrusion processing could result in fragmentation of proteins, starches, and nonstarch polysacchandes, creating reactive molecules that may form new linkages that could result in enhancing health potential (Camire 1998). Wheat bran in general does not lower cholesterol. In many studies, wheat bran has been used as a control treatment to evaluate cholesterol-lowering effects of other cereals (

In Vitro Bile Acid Binding Capacity of Milled Wheat Bran and Milled Extruded Wheat Bran at Five Specific Mechanical Energy Levels

“…Higher bile acid binding by MEB-177 observed here is encouraging, and the bile acid binding complexes formed and the mechanisms will be explored in future studies. Previously, the highest bile binding was observed with SME-177 extruded unmilled wheat bran (Kahlon et al 2006b), which was consistent with significant triglyceride lowering in hamsters with diets containing unmilled SME-177 extruded wheat bran (Kahlon et al 2006a). Data suggest that milling WB significantly improved its bile acid binding compared with unmilled wheat bran (21 vs. 18%); however, the expected increase of up to 5% in bile acid binding by extrusion as reported previously (Kahlon et al 2006b) was not observed in this study.…”

“…Specific changes in the physical and chemical composition as a result of reducing the particle sizes as they relate to bile acid binding potential will be explored in subsequent studies. Positive correlations have been reported in the cholesterol-and lipidlowering response in hamsters fed extruded wheat bran diets (Kahlon et al 2006a) and bile acid binding of wheat bran used in these diets (Kahlon et al 2006b). Hamster feeding studies are planned to validate the significant improvement in bile acid binding observed here by milling the wheat bran compared with the unmilled wheat bran.…”

“…With a similar pump variable amounts of water 19.6, 15.0, 11.0, 7.45, and 6.0 kg/hr was injected to obtain final SME input of 120 (MEB-120), 177(MEB-177), 234 (MEB-234), 291 (MEB-291), and 358 (MEB-358) Whr/kg on a dwb, respectively. The extrusion conditions such as SME levels, addition of peanut oil, water injection rates, feed rate, and temperature profile were the same optimized conditions as reported previously (Kahlon et al 1998(Kahlon et al , 2006a. A computer collected extruder parameter data at 1-sec intervals for a total of 5 min, using LabView data acquisition system (v. 5.0, National Instruments, Austin, TX).…”

“…Extruded wheat bran and other foods lower blood cholesterol in humans (Meshcheriakova et al 1995). Extruded wheat bran at low specific mechanical energy (SME) of 120-221 Whr/kg, significantly lowers lipids in hamsters compared with unextruded wheat bran (Kahlon et al 1998(Kahlon et al , 2006a. Extruding wheat bran at 120 and 177 Whr/kg bound significantly higher bile acid than unextruded wheat bran (WB) and that extruded at higher (234, 291, and 358 Whr/kg) SME levels (Kahlon et al 2006b).…”

Growth Performance, Organ Weights and Some Blood Parameters of Replacement Laying Pullets Fed with Increasing Levels of Wheat Bran

“…On the other hand, Kahlon et al (1998), Kahlon et al (2006), and Ali et al (2008) reported a reduction in blood cholesterol levels when WB was added to the diets. According to Savón et al (2007), dietary fiber reduces cholesterol absorption by binding with bile salts in the gastrointestinal tract, reducing intestinal transit time and increasing sterol excretion in the feces.…”