Characterization of the proteins and flour of Distichlis palmeri (Vasey) grain and Distichlis spp. fiber.
AuthorYensen, Susana Bojórquez.
Committee ChairWeber, Charles W.
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractProteins from a halophyte cereal Distichlis palmeri, whole-grain flour were fractionated on the basis of their solubility. Five fractions were obtained and each analyzed for fifteen amino acids. The amino acid pattern of the whole-grain was similar to that of a cereal. The percent of amino acids for the ethanol extraction ranged from a high of 35% glutamine to a low of 0.18% lysine. The fractions were rich in asparagine and glutamines. The lysine content of this grain is higher than that of wheat and the highest percentage (6.3%) was found in the water soluble fraction. Protein recovery of the different fractions ranged from 78% to 87%. SDS polyacrylamide gel electrophoresis showed that the water soluble fraction had a wide range of molecular weight proteins; the NaCl fraction had circa 10 proteins in high concentrations; the prolamine fraction had a band at about 22,000 daltons with two weak bands at 45,000 and 66,000 daltons; the 2-mercaptoethanol fraction had few weak bands, and the SDS fraction had circa 6 bands present in high concentrations. The foaming capacity and stability of the albumin fraction of Distichlis palmeri was excellent. The whole-grain flour of Distichlis palmeri had a better water and oil holding capacity as g/g protein. The emulsion capacity of the whole-grain flour was also better than in its protein fractions. When evaluated with a Hedonic scale for taste preference there was no significant difference in flavor acceptance between the "exclusive" eaters and "frequent" eaters of whole-wheat products. Overall, the "exclusive" eaters of whole wheat rated Distichlis palmeri muffins significantly higher than either the "occasional" eaters or the "frequent" eaters. The 50/50 mix received the highest rating. The grain of Distichlis palmeri has 5.15% soluble fiber and 12.7% of insoluble fiber. No trypsin inhibitor activity was detected in the flour. The two forages (Distichlis spp.) analyzed had 6.10% and 15.20% of protein respectively. Acid detergent fiber was 33% and 20%. Low lignin was found in both grasses (6.8% and 5.10%). Mineral content for both forages was: Ca (0.3% and 0.5%); Mg (0.09% and 0.2%); P (0.12% and 0.21%); Zn (6.2 ppm and 20 ppm), and Cu (5.5 ppm and 6.7 ppm).
Degree ProgramNutritional Sciences