17C-6 |
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W.-Y. WU1, H. E. Huff2, and F. Hsieh2. (1) Food Science, University of Missouri-Columbia, 1406 E. Rollins Street, 145 Ag. Eng. Bldg., Columbia, MO 65211, (2) Dept. of Biological Engineering, Univ. of Missouri, 254 Ag. Eng. Bldg., 1406 E. Rollins St., Columbia, MO 65211-5200 Flaxseed is rich in a-linolenic acid and has good quality protein. It is also a natural source of flavonoids, lignans and phenolic compounds and is one of the six plant materials targeted by the U.S. National Cancer Institute (NCI) for study as cancer-preventive foods. An extruded flaxseed-containing product that can be consumed as a breakfast cereal or snack may encourage the consumption of flaxseed and provide the health benefits for consumers. The objective of this research was to investigate the effects of flaxseed meal and extrusion processing variables on physical and chemical properties of flaxseed-corn puff. A factorial experiment with 4 levels of flaxseed meal (0, 5, 10 and 15%), 3 levels of feed moisture (16, 18 and 20% w.b.), 3 levels of screw speed (200, 300 and 400 rpm) and 2 replications was conducted with an APV Baker MPF 50/25 twin-screw extruder. The extrudates were analyzed for their properties in expansion, color, texture and lignan content by an electronic caliper, Hunter colorimeter, TA.XT2 Texture Analyzer, and high-performance liquid chromatography (HPLC) with a spectrophotometer at 204 nm, respectively. Increasing flaxseed meal level, increasing feed moisture or decreasing screw speed significantly reduced the expansion and resulted in browner and harder extrudate. The lignan compounds in the flaxseed meal and corn meal were 2.24 and 0 mg/g, respectively, before extrusion. About 34 to 45% lignan compounds were lost after extrusion. A higher flaxseed meal level and a higher screw speed favored the retention of lignan compounds, but higher feed moisture showed the opposite effect. These results showed that higher flaxseed meal levels and higher feed moistures would yield less expanded, browner and harder flaxseed-corn puff products. Furthermore, more than 55% of initial lignan compounds remained in the final products after extrusion.
Session 17C, Food Chemistry: Cereals, grains, legumes and their products
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