Robert T. Tyler

Review of the health benefits of peas ( Pisum sativum L.)

Pulses, including peas, have long been important components of the human diet due to their content of starch, protein and other nutrients. More recently, the health benefits other than nutrition associated with pulse consumption have attracted much interest. The focus of the present review paper is the demonstrated and potential health benefits associated with the consumption of peas, Pisum sativum L., specifically green and yellow cotyledon dry peas, also known as smooth peas or field peas. These health benefits derive mainly from the concentration and properties of starch, protein, fibre, vitamins, minerals and phytochemicals in peas. Fibre from the seed coat and the cell walls of the cotyledon contributes to gastrointestinal function and health, and reduces the digestibility of starch in peas. The intermediate amylose content of pea starch also contributes to its lower glycaemic index and reduced starch digestibility. Pea protein, when hydrolysed, may yield peptides with bioactivities, including angiotensin I-converting enzyme inhibitor activity and antioxidant activity. The vitamin and mineral contents of peas may play important roles in the prevention of deficiency-related diseases, specifically those related to deficiencies of Se or folate. Peas contain a variety of phytochemicals once thought of only as antinutritive factors. These include polyphenolics, in coloured seed coat types in particular, which may have antioxidant and anticarcinogenic activity, saponins which may exhibit hypocholesterolaemic and anticarcinogenic activity, and galactose oligosaccharides which may exert beneficial prebiotic effects in the large intestine.

THERMODYNAMICS OF MOISTURE SORPTION IN ALFALFA PELLETS

ABSTRACT Experimental data on sorption isotherms of alfalfa pellets were used to determine the thermodynamic functions (differential heat of sorption, spreading pressure, net integral enthalpy and entropy) of the pellets. The thermodynamic functions were then utilized in modeling the specific heats of pellets as a function of moisture content. The estimated values of the thermodynamic functions at different moisture contents confirmed the results of an earlier study on the influence of moisture sorption on the physical integrity of the pellets. The changes in the thermodynamic properties and physical integrity were prominent when the moisture of the pellets were between 0.10 and 0.12 (mass fraction basis). Using the differential heat of sorption, it was determined that alfalfa pellets have higher affinity for moisture uptake when compared to wheat and lentils. The specific heat of the solids of alfalfa pellets had a parabolic relationship with moisture whereas the specific heat of water fraction increased...

Wet-milling, composition and functional properties of starch and protein isolated from buckwheat groats

Abstract Buckwheat groats, containing 75% starch and 14% protein, were wet-milled into starch, protein, fiber, tailings and steep-water fractions, with 79 and 64% extraction efficiencies for starch and protein, respectively. About 5–10% of the total starch was found in protein and tailings fractions, while 29% of the total protein was found in the fiber fraction. About 72% of total lipid was recovered in the fiber fraction, indicating the separation of embryo tissue into this fraction. The refined starch product contained 98% starch, 0.6% protein and 21.3% amylose. Buckwheat starch exhibited a typical A-type x-ray diffraction pattern. The amylogram of native buckwheat starch showed higher peak and set-back viscosities than regular corn and rice starches; the pasting temperature was similar to those of corn and rice starches. Acetylation of the native starch lowered pasting and gelatinization temperatures and significantly improved cold storage stability of the gel. Amino acid composition and functional properties of buckwheat protein concentrates showed similarities to soybean protein. Compared to a freeze-dried protein sample, the spray-dried buckwheat protein concentrate was more white in color and showed higher nitrogen solubility index at neutral pH, and higher water holding, emulsifying and foaming capacities.

Diets supplemented with chickpea or its main oligosaccharide component raffinose modify faecal microbial composition in healthy adults

The effects of diets supplemented with either chickpea or its main oligosaccharide raffinose on the composition of the faecal microbial community were examined in 12 healthy adults (18-65 years) in a randomised crossover intervention study. Subjects consumed their usual diet supplemented with soups and desserts that were unfortified, or fortified with either 200 g/d of canned chickpeas or 5 g/d of raffinose for 3 week periods. Changes in faecal bacterial populations of subjects were examined using 16S rRNA-based terminal restriction fragment length polymorphisms (T-RFLP) and clone libraries generated from the diet pools. Classification of the clone libraries and T-RFLP analysis revealed that Faecalibacterium prausnitzii, reported to be an efficient butyrate producer and a highly metabolically active bacterium in the human intestinal microbiota, was more abundant in the raffinose diet and the chickpea diet compared to the control diet. However, no significant difference was observed in the faecal total short chain fatty acid concentration or in the levels of the components (butyrate, acetate and propionate) with the chickpea diet or the raffinose diet compared to the control diet. Bifidobacterium species were detected by T-RFLP in all three diet groups and quantitative real-time PCR (qPCR) analysis showed a marginal increase in 16S rRNA gene copies of Bifidobacterium with the raffinose diet compared to control (P>0.05). The number of individuals showing TRFs for the Clostridium histolyticum - Clostridum lituseburense groups, which include pathogenic bacteria species and putrefactive bacteria, were lower in the chickpea diet compared to the other two treatments. Diet appeared to affect colonisation by a high ammonia-producing bacterial isolate which was detected in 83%, 92% and 42% of individuals in the control, raffinose and chickpea groups, respectively. Our results indicate that chickpea and raffinose have the potential to modulate the intestinal microbial composition to promote intestinal health in humans.

Distribution of β-Glucan in the Grain of Hull-less Barley

ABSTRACT Nine hull-less barley (HB) containing waxy (0–7% amylose), normal (≈25% amylose), or high amylose (≈42% amylose) starch with normal or fractured granule make-up and 4–9% (1→3)(1→4)-β-d-glucans (β-glucan) were pearled to remove 70% of the original grain weight in 10% intervals. The pearled fractions were analyzed for β-glucan distribution within HB grain. Protein content of the pearled fractions indicated that the three outermost fractions contained pericarp and testa, aleurone, and subaleurone tissues, respectively. For all HB, β-glucan and acid-extract viscosity were very low in the outermost 20% of the kernel. For low β-glucan HB, β-glucan content was the greatest in the subaleurone region and declined slightly toward inner layers. For high β-glucan HB, however, more than 80% of grain β-glucan was distributed more evenly throughout the endosperm. Acid extract viscosity was significantly (P < 0.01) correlated with total (r = 0.75) and soluble (r = 0.87) β-glucan content throughout the kernel of ...

Characteristics of Starch from Eight Quinoa Lines

ABSTRACT Starches ranging in amylose content from 3 to 20% from eight quinoa (Chenopodium quinoa Willd.) lines were characterized with respect to thermal, retrogradation, and pasting properties; swelling and solubility behavior; freeze-thaw stability; water-binding capacity; shear stability; and granule size and morphology. The starches differed in gelatinization onset temperatures, peak temperatures, and retrogradation tendencies; these characteristics were positively correlated with amylose content. No variation in gelatinization enthalpy was observed. With the exception of pasting temperature, large variations in pasting characteristics were found among starches and were correlated with amylose content. Swelling, solubility, freeze-thaw stability, and water-binding capacity also differed among starches and were correlated with amylose content. Granule morphology and size were similar for all starches. The wide variation in amylose content and physicochemical characteristics of quinoa starches suggests ...

Improvement of the representation of bifidobacteria in fecal microbiota metagenomic libraries by application of the cpn60 universal primer cocktail.

ABSTRACT Actinobacteria, particularly bifidobacteria, are widely observed to be underrepresented in metagenomic studies of microbial communities. We have compared human fecal microbiota clone libraries based on 16S rRNA and cpn60 PCR products. Taxonomic profiles were similar except that the cpn60 libraries contained large numbers of bifidobacterial sequences.

Phenolic Compounds Contribute to Dark Bran Pigmentation in Hard White Wheat

Unacceptably dark bran color has prevented the white-kernelled variety Argent from meeting grain color marketing standards for hard white wheats (Triticum aestivum L.). The objective of this research was to identify phenolic compounds that negatively affect bran color in white wheat using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) and vanillin-HCl and NaOH staining methods. In mature bran, FT-ICR-MS detected derivatives of the flavonol quercetin in varieties Argent and RL4137 (red-kernelled wheat) but not in W98616, a white wheat variety with acceptable grain color. Derivatives of the isoflavone formononetin were more abundant in W98616 relative to RL4137 and Argent. Vanillin-HCl staining indicated that RL4137 sequestered high levels of proanthocyanidin (PA) throughout its entire seed coat, whereas white wheats sequestered PAs as discrete speckles. Argent possessed abundant speckles over its entire seed coat, whereas speckles were almost undetectable in W98616. In mature kernels, flavonoids throughout the seed coat of RL4137 reacted with NaOH, but only the speckles appeared to react in white wheats. W98616 consistently had lighter grain than Argent before and after NaOH treatment. Free and bound phenolic differences in bran samples confirmed that the darker seed coat color of Argent, relative to W98616, was likely due to higher total phenolic acid content. Although isoflavones accumulated in Argent and RL4137, it appears that the majority of the flux through the flavonoid pathway ultimately accumulates quercetin derivatives and PAs. In W98616, PAs accumulate, but it appears that flavonoid biosynthesis ultimately accumulates isoflavones. Argent, compared to W98616, generally accumulated higher levels of total phenolics (flavonols, stilbenes, and PAs) within its darker pigmented bran.

MODELLING THE INFRARED RADIATIVE HEATING OF AGRICULTURAL CROPS

ABSTRACT Simultaneous heat and mass transfer equations were developed to simulate the infrared radiative heating of agricultural crops. The equations assume that moisture diffuses to the outer boundaries of the material in liquid form and evaporation occurs at the surface of the kernel. Energy for moisture evaporation is supplied by the infrared radiant energy. The equations were validated with experimental data on surface temperature and average moisture content of barley kernels. Average deviations of predicted surface kernel temperature and average kernel moisture from experimental data were 3.9°C and 0.6%(w.b.), respectively. These comparisons were performed using kernels having initial moisture contents of 12.2%, 17.C% and 23.17%. Sensitivity analysis of process parameters showed that infrared burner temperature, distance of infrared burner from the grain bed, grain initial moisture content and grain heating time significantly affected kernel temperature. Burner temperature and burner height had no s...

A modified laboratory canning protocol for quality evaluation of dry bean (Phaseolus vulgaris L)

The effects of calcium (Ca2+ ) level in the soak water, blanch water and brine, blanching temperature, and total seed solids on dry bean canning quality were investigated to optimise a laboratory canning protocol. A linear increase in the Ca2+ level of soak water, blanch water and brine resulted in a linear decrease in hydration coefficient and percent washed drained weight but a linear increase in texture. Low Ca2+ level (10 mg kg-1 ) reduced the hydration time for dry bean seed from 14 to 1 h. Blanching temperatures of 50, 70 and 88 °C had non-significant effects on canning quality traits. Blanching for 30 min at 70 °C for black bean or at 88 °C for navy bean and pinto bean resulted in percent washed drained weight ≥ 60, as required by the Canada Agricultural Products Standards Act. Seed solids levels of 95-97 g per 300 × 407 (14 fl oz) can were sufficient to attain a percent washed drained weight of 60. It was confirmed that the thermal processing conditions (115.6 °C retort temperature, 45 min) used in this study were sufficient to achieve commercial sterility. The optimised lab protocol for evaluation of the canning quality of dry bean breeding lines is as follows. Seed containing 95 g of solids for pinto bean, 96 g for navy bean and 97 g for black bean is soaked in water for 30 min at 20 °C and blanched for 30 min at 70 °C for black bean and 88 °C for navy bean and pinto bean in water containing 10 mg kg-1 of Ca2+ . The seed is then transferred to a 300 × 407 can, filled with brine containing 10 mg kg-1 of Ca2+ , 1.3% (w/v) of NaCl and 1.6% (w/v) of sugar. The can is then sealed, processed in steam at 115.6 °C for 45 min and cooled at 20 °C for 20 min. Cans are stored for at least 2 weeks prior to quality evaluation of the canned product. Canning of dry bean seed according to this protocol results in precise estimation of canning quality traits, particularly percent washed drained weight.