Ahmed Idouraine

Extraction and fractionation of insoluble fiber from five fiber sources

Abstract Commercially processed wheat bran (WB), rice bran (RB), oat fiber (OF), tomato fiber (TF), and apple fiber (AF) were analyzed for proximate composition, soluble fiber (SF), insoluble fiber (IF) and total dietary fiber (TDF). IF was further fractionated into four fractions: cellulose, hemicellulose A and B, and lignin. Protein, IF, and TDF values were significantly different among the samples. Protein content ranged from 4.6% in OF to 24.9% in TF. SF values ranged from 1.5% in OF to 13.9% in AF. IF values varied from 46.7% in RB to 73.6% in OF. TDF ranged from 51.4% in RB to 75.1% in OF. Hemicellulose A to B ratio was high in all the samples except rice bran. WB had the highest total hemicellulose (44.0% of TDF) content followed by AF (38.4%), OF (38.3%), TF (36.5%), and RB (31.6%). Cellulose was 32.2, 26.6, 24.4, 20.8, and 19.7% of TDF in WB, OF, RB, AF, and TF, respectively. Lignin levels ranged from 5.2% in WB to 21.4% in OF.

In vitro mineral binding capacity of three fiber sources for Ca, Mg, Cu and Zn by two different methods

Acid-washing centrifugation (AWC) and cold-hot-water-enzyme incubation (WEI) methods were used to study the binding capacity (BC) of wheat bran, rice bran, and oat fiber for calcium, magnesium, copper, and zinc. Treated fibers were analyzed for protein, phytic acid (PA), total dietary fiber (TDF), and minerals. Protein content was significantly (P < 0.05) lower in WEI fibers than AWC fibers. WEI fibers had low protein concentration and no PA but higher TDF values (P < 0.05). Levels of Mg were the highest among the minerals studied. AWC treatment was significantly (P < 0.05) more efficient in stripping minerals than the WEI treatment. AWC fibers bound more minerals. Results indicate that the BC values of the fibers for minerals by the two methods were not comparable.

Composition of tepary bean (Phaseolus acutifolius) of the Southwestern U.S. and Northern Mexico

Fourteen samples of white (WT), brown (BT), speckled (ST), and black (BKT) tepary beans (Phaseolus acutifolius) grown in the semiarid and arid areas of the southwestern U.S. and northern Mexico, were evaluated for their weight and sizes and analyzed for proximate composition, dietary fiber, trypsin inhibitor activity (TIA), and phytic acid (PA). Seed weight (0.105 g to 0.145 g) and size (7.1 × 5.0 mm to 9.3 × 6.4 mm) were not significantly different among WT, BT, ST and BKT. Protein (N × 6.25) and fat contents ranged from 17.3% to 23.1% and from 0.73% to 1.18%, respectively. No significant difference (P < 0.05) in protein and fat levels were observed among tepary types. Soluble, insoluble, and total dietary fiber were not significantly different. Total dietary fiber ranged from 17.97% to 20.96%. TIA (14.82 TIU to 24.58 TIU/mg sample) was not significantly different among raw tepary types. Autoclaving for 10 min and 20 min reduced significantly TIA. PA content (1.83 mg to 5.34 mg PA/g sample) was not signi...

Antinutritional factors in protein fractions of tepary bean (Phaseolus acutifolius)

Abstract Proteins from tepary bean were extracted according to their solubility in sodium phosphate buffer (SPB), sodium chloride (NaCl), ethanol, 2-mercaptoethanol (2-ME), and sodium dodecyl sulfate (SDS) and evaluated for trypsin inhibitor activity (TIA), hemagglutinating activity (HA), and phytic acid (PA). TIA varied from 1·9 TIU/mg sample for 2-ME to 161·01 TIU/mg sample for ethanol fraction. HA was high in SPB (29 300 HU/g sample) and tepary flour (TF) (20 000 HU/g), but lower in NaCl (5000 HU/g), 2-ME (1800 HU/g), and ethanol (100 HU/g) fractions. No HA was detected in SDS fraction. PA was high in TF (4·61 mg/g sample) and SPB (6·83 mg/g) and lower in SDS (0·06 mg/g) and 2-ME (0·41 mg/g).

Fractionation and partial characterization of tepary bean (Phaseolus acutifolius) proteins

Tepary bean (Phaseolus acutifolius) proteins were fractionated sequentially according to solubility in sodium phosphate buffer (SPB), sodium chloride (salt), ethanol, 2-mercaptoethanol (2-ME), and sodium dodecyl sulfate (SDS) solutions, and characterized. The SPB protein fraction was significantly (P < 0.05) the highest (83.2% of the recovered protein) followed by salt protein fraction (13.7%), 2-ME (1.5%), ethanol (0.8%), and SDS (0.8%) protein fractions. The amino acid compositions of SPB, salt, ethanol, and 2-ME protein fractions were not significantly different. Methionine and cysteine concentrations were low in all fractions. The ethanol protein fraction had a significantly (P < 0.05) higher cysteine content (1.5%) than 2-ME (0.95%), salt (0.2%) or SPB (trace) protein fractions. SDS-PAGE of SPB and salt protein fractions contained 37 and 27 polypeptides, respectively, with major bands at 29, 45, and 49 kDa. Ethanol and SDS protein fractions had only a limited number of small polypeptides.

Composition of sonoran desert foods used by Tohono O'Odham and Pima Indians

Fifty‐eight raw food samples were analyzed for proximate, acid detergent fiber (ADF) and dietary (soluble & insoluble) fiber and mineral composition. Food samples were from both home gardens and samples collected from desert plants. The two major sources were bean and corn samples. Bean samples averaged 22.72% (19.66% to 25.6%) protein and 7.16% ADF. Corn samples ranged from 9.2% to 12.2% protein and cactus pads ranged from 0.5% to 0.9% protein and from 0.4% to 2.4% ADF. Cactus fruit ranged from 0.8% to 3.4% protein and 3.6% to 10.7% ADF. The wild greens ranged from 5.1% to 7.6% protein and from 4.4% to 10.7% ADF. Total dietary fiber (TDF) ranged from 1.37% to 69.86% and soluble fiber from 0.05% to 7.64%.

Chemical and nutritional composition of tree legume seeds and pods from Southwestern United States and Sonora Mexico

Ten different types of legume tree seeds and pods collected from legume trees growing in the desert area of Tucson, Arizona were analyzed for proximate composition, acid detergent (ADF), dietary fiber, phytic acid (PA), trypsin inhibitor activity (TIA), minerals, and amino acids composition. Protein content of seeds ranged from 19.09% for desert willow to 25.66% for feather tree. The lipid content of seeds ranged from 1.7% for mesquite to 34.25% for ironwood. The soluble fiber content of seeds ranged from 4.23% for ironwood to 23.16% for green palo verde, while the insoluble fiber ranged from 19.71% for Acacia angustissima to 45.67% for sweet acacia. PA levels varied from 1.4mg/g for feather tree seeds to 7.4mg/g for blue palo verde seeds. TIA was extremely high in feather tree and Acacia angustissima seeds (27,323 and 26,338 TIU/g, respectively). Mineral content varied among seeds, calcium and phosphorus being consistently the highest. Amino acid content was similar to that of other legumes with cysteine...