Identification and quantification of seed carotenoids in selected wheat species

Selected primitive and modern wheat species were evaluated on the basis of their carotenoid composition and effects of the genotype and environment on lutein using spectrometry and liquid chromatography. Carotenoids in the wheat extracts were identified and confirmed on the basis of their UV/vis and mass spectra compared with those of authentic standards. The protonated molecule (M + 1)+ at m/z 569 was the predominant ion for zeaxanthin compared to the fragment ion at m/z 551 for lutein. A similar carotenoid profile was obtained for the wheat species investigated, but significant differences were observed in the concentration of carotenoids. Einkorn (Triticum monococcum) exhibited the highest level of all-trans-lutein, averaging 7.41 microg/g with small amounts of all-trans-zeaxanthin, cis-lutein isomers, and beta-carotene. Durum, Kamut, and Khorasan (Triticum turgidum) had intermediate levels of lutein (5.41-5.77 microg/g), while common bread or pastry wheat (Triticum aestivum) had the lowest content (2.01-2.11 microg/g). Lutein in einkorn appeared to be influenced significantly by environmental growing conditions.     

Enzymatic extraction of beta-glucan from oat bran cereals and oat crackers and optimization of viscosity measurement

The viscosity of the soluble fibre, β-glucan, has been shown to influence its ability to lower serum cholesterol and postprandial blood glucose levels. The impact of various amylases, proteases and lipase on the solubility and resulting viscosity of β-glucan extracted from oat bran cereals with a range of β-glucan concentrations and molecular weights was investigated. Addition of enzymes increased the final viscosity of high molecular weight β-glucan in cereals by facilitating the release of β-glucan from the food matrix. For cereals with partially depolymerized β-glucan, the addition of digestive enzymes decreased the final viscosity by eliminating the contribution of starch and protein to viscosity. Final viscosity varied depending on enzyme combinations including pancreatin, salivary and microbial α-amylases, microbial protease, porcine protease, trypsin and α-chymotrypsin. Addition of lipase did not significantly affect viscosity or solubility of β-glucan extracted from oat crackers. Addition of lichenase showed that β-glucan was the major contributor of viscosity to the system, with negligible interference from other components. The viscosity of the optimized protocol was compared to physiological results previously obtained. The viscosity of β-glucan extracted with pancreatin plus microbial α-amylase (pH 6.9) was predictive of LDL-cholesterol reduction (R² = 0.847) and glycemic response (R² = 0.883).     

Selected nutritional,physical and sensory characteristics of pan and flat breads prepared from composite flours containing fababean

Composite flour blends containing wheat (W), fababean (F), cottonseed and sesame flours were formulated to provide the FAO/WHO/UNU protein requirements for the 2–5 year old child, and evaluated in pan and flat bread applications. Water absorption of composite flour doughs was up to 35% greater than the control but gluten strength and slurry viscosities were markedly reduced. Loaf volume and specific volume of pan breads prepared from composite flours were 25–60% less than that of the control bread but flat breads tolerated the protein supplements extremely well. The W/F flat bread, containing 27% of fababean flour, received acceptable taste, texture and colour scores and was only slightly inferior to the control in puffing and layer separation. Additions of cottonseed or sesame flours to the W/F blend failed to improve sensory properties of the flat breads.     

Composition and stability of anthocyanins in blue-grained wheat

Wheat grain is recognized as a good source of potentially health-enhancing components such as dietary fiber, phenolics, tocopherols, and carotenoids. Anthocyanins, another group of bioactive compounds, are found in blue and purple wheat grains. In the present study, a blue aleurone spring wheat line "Purendo 38" with relatively high content of total anthocyanins was used to investigate the composition and stability of anthocyanins over three crop years. Commercial cultivars of purple (Konini) and red (Katepwa) wheats were included in the study. Separation of anthocyanins by high-performance liquid chromatography (HPLC) showed that each wheat had a distinct anthocyanin profile. Four major anthocyanins were separated from blue wheat extracts as compared to five anthocyanins in purple wheat. Cyanidin 3-glucoside was the predominant anthocyanin in purple wheat, whereas it was the second major anthocyanin in blue wheat. The predominant anthocyanin in blue wheat, making up approximately 41% of the total anthocyanin content, remains to be structurally unidentified. Blue wheat anthocyanins were thermally most stable at pH 1. Their degradation was slightly lower at pH 3 as compared to pH 5. Increasing the temperature from 65 to 95 degrees C increased degradation of blue wheat anthocyanins. Addition of SO(2) during heating of blue wheat had a stabilizing effect on anthocyanin pigments. The optimal SO(2) concentrations were 500-1000 ppm for whole meals and 1000-3000 ppm for isolated anthocyanins. Further studies are underway to identify and verify individual anthocyanins in blue wheat and their potential end uses.     

Formulation and characteristics of new recipes of Egyptian patti beans (Falafel)

New recipes of Falafel were formulated and evaluated regarding acceptability, proximate chemical composition and nutritive value. Soybean meal and/or cotyledons were used to substitute for faba bean at different levels (i.e. zero %, 20%, 40%, 60%, 80% and 100%. Data indicated that blends of faba bean (20%) and soybean meal and/or cotyledons (80%) were the most acceptable recipes compared to the control (100% faba bean) as well as the other substitution levels. Blending soybean with faba bean led to appreciable improvement in some essential amino acids. The in vitro digestibility for soybean blends were comparable to the control.     

Kernel, Milling and Baking Properties of Spring-Type Spelt and Einkorn Wheats

One accession of einkorn (Triticum monococcum) and five spring spelt accessions (T. aestivumsubsp.spelta) were selected and grown at five locations in 1992 and 1993 for evaluation of kernel, milling and baking properties. The high protein einkorn accession (TM23) was similar to common hard red spring (HRS) wheat in kernel size but the soft grain gave low flour yields. Einkorn flour had low sedimentation values, weak Mixograph curves and low loaf volumes with no bromate response. The two large-seeded spelt accessions, SK0021 and PGR8801, were comparable to common HRS wheat in kernel hardness, flour yield and protein content, but were very inferior in falling number, sedimentation value, Mixograph characteristics, loaf volume, crumb texture and colour. The spelt accessions, SK0505, SK0263 and RL5407, also exhibited large kernels but were soft in texture and gave high flour yields, intermediate sedimentation values, weak Mixograph characteristics, but satisfactory loaf volumes and bromate responses relative to HRS wheat. With addition of only 15 ppm bromate, the latter spelt accessions gave breads with loaf volumes similar to those of HRS wheat breads. In sensory tests, these spelt breads were intermediate in preference as compared to HRS wheat breads.     

Kinetic properties of the inhibition of juvenile hormone esterase by two trifluoromethylketones and O-ethyl,S-phenyl phosphoramidothioate

Some inhibition kinetic properties and in vivo inhibition of the plasma juvenile hormone esterase from the cabbage looper (Trichoplusia ni Hübner) by one phosphoramidothioate and two trifluoromethylketones were examined. O-ethyl,S-phenyl phosphoramidothioate was shown to react irreversibly with the enzyme in a time-dependent manner, and the inhibition reaction can be factored into a reversible step with a dissociation constant, K_d, of 4.55 × 10^?5M followed by a phosphorylation step with a rate constant, k₂, of 1.98 min^?1. The phosphorylated enzyme did not show spontaneous recovery after 48 hr of dialysis. On the other hand, the two trifluoromethylketones were shown to act as reversible inhibitors, as their inhibited enzyme was regenerated completely after dialysis. However, 1,1,1,-trifluoro-3-thiooctylpropan-2-one, in contrast to 1,1,1-trifluorotetradecan-2-one, showed progressive time-dependent inhibition, and its reaction with the enzyme followed characteristic bimolecular second-order kinetics with a rate constant, k_i, of 3.37 × 10⁷M^?1 min^?1. The in vivo inhibition data of topically treated larvae at equimolar amounts of the tested compounds indicated rapid penetration, and the stability of the inhibition was higher for the phosphoramidothioate than for the trifluoromethylketones. The relationship of the mechanism of inhibition and the in vivo inhibition of these compounds to the understanding of the interactions between juvenile hormone and juvenile hormone esterase is discussed.     

Pyrethroid-hydrolyzing esterases in southern armyworm larvae: Tissue distribution,kinetic properties,and selective inhibition

Esterase activity hydrolyzing both [1RS,trans]- and [1RS,cis]-permethrin was detected in crude homogenates of the following southern armyworm (Spodoptera eridania Cramer) larval tissues: cuticle, gut, fat body, head capsule, Malpighian tubules, and silk gland. Neither substrate was detectably hydrolyzed by hemolymph. The highest esterase activities per insect equivalent of tissue were found in cuticle, gut, and fat body for the trans isomer and in cuticle and gut for the cis isomer. Each preparation hydrolyzed the trans isomer more rapidly, but the degree of specificity varied greatly between tissues. Differences in apparent K_m and V_max values between the three most active tissues were threefold or less for trans isomer hydrolysis, but differences between tissues of up to 100-fold were found for K_m and V_max values for cis isomer hydrolysis. Hydrolysis of the trans isomer in cuticle, gut, and fat body homogenates was only partially inhibited by α-naphthyl N-propylcarbamate (NPC). Concentrations of NPC giving maximal inhibition of trans isomer hydrolysis had little effect on the hydrolysis of the cis isomer. These results demonstrate that pyrethroid-hydrolyzing activity is broadly distributed in insect tissues and results from the combined activity of several esterases with different properties. It is likely that the trans and cis isomers of permethrin are hydrolyzed by separate enzymes in this insect.     

Anthocyanin composition in black, blue, pink, purple, and red cereal grains

Anthocyanin pigments from a wide variety of edible and ornamental black, blue, pink, purple, red, and white wheat, barley, corn, rice, and wild rice were identified and quantified to evaluate their potential as natural colorants or functional food ingredients. The total anthocyanin contents varied significantly and exhibited a range of 7-3276 microg/g. Some grains, such as red rice and black rice, contained a limited number of pigments, whereas others, such as blue, pink, purple, and red corns, had complex anthocyanin profiles. Of the 42 anthocyanin compounds observed, 9 were characterized by comparison of the spectroscopic and chromatographic properties with those of authentic standards. The remaining compounds were tentatively identified on the basis of spectroscopic properties and electrospray ionization mass spectra. The most abundant anthocyanins were cyanidin 3-glucoside in black and red rices and in blue, purple, and red corns, pelargonidin 3-glucoside in pink corn, and delphinidin 3-glucoside in blue wheat.