Starch but not protein digestibility is altered in pigs fed transgenic peas containing α‐amylase inhibitor

Eighteen individually housed boars were randomly allocated to one of three dietary treatments, an experimental wheat diet containing 989.4 g kg^?1 of a basal wheat diet, or this experimental wheat diet with 500 g kg^?1 of the basal wheat diet replaced with 500 g kg^?1 of either transgenic or non‐transgenic peas. The transgenic peas expressed the bean (Phaseolus vulgaris L.) α‐amylase inhibitor 1 gene. Diets contained n‐hexatriacontane (0.2 g kg^?1) as an indigestible marker to allow the determination of nutrient digestibility at the terminal ileum. Pigs were offered 1.6 kg day^?1 for 15 days, after which they were anaesthetised, the ileal and faecal digesta collected and the pigs subsequently euthanased. The ileal dry matter and starch digestibilities of the experimental wheat, non‐transgenic and transgenic pea diets were 78.3, 74.2 and 45.8% and 95.9, 95.2 and 42.4%, respectively. The apparent nutrient digestibilities of the non‐transgenic and transgenic peas were determined by difference. The ileal dry matter digestibility was significantly reduced in the transgenic peas compared with the non‐transgenic peas (12.7 and 69.9%, respectively; P = 0.006), which was largely due to a reduced starch digestibility. The apparent crude protein digestibilities of the transgenic peas were similar to the non‐transgenic, being 79.7 and 78.5%, respectively. The amino acid digestibilities of the transgenic and non‐transgenic peas were also similar. Copyright © 2006 Society of Chemical Industry     

Distribution of fatty acids in triacylglycerols and phospholipids from peas (Pisum sativum L.)

BACKGROUND: The fatty acid distribution of triacylglycerols (TAG) and major phospholipids (PL) obtained from four varieties of peas (Pisum sativum) was investigated. The total lipids extracted from the peas were separated by thin layer chromatography into seven fractions. RESULTS: The major lipid components were PL (52.2–61.3%) and TAG (31.2–40.3%), while hydrocarbons, steryl esters, free fatty acids and diacylglycerols (sn‐1,3 and sn‐1,2) were also present in minor proportions (5.6–9.2%). The main PL components isolated from the four varieties were phosphatidylcholine (42.3–49.2%), phosphatidylinositol (23.3–25.2%) and phosphatidylethanolamine (17.7–20.5%). Significant differences (P < 0.05) in fatty acid distribution were found for different pea varieties. Phosphatidylinositol was unique in that it had the highest saturated fatty acid content among the three PL. However, the principal characteristics of the fatty acid distribution in the TAG and three PL were evident among the four varieties: unsaturated fatty acids were predominantly located in the sn‐2 position while saturated fatty acids primarily occupied the sn‐1 or sn‐3 position in the oils of the peas. CONCLUSION: These results should be useful to both producers and consumers for the manufacture of pea foods in Japan. Copyright © 2007 Society of Chemical Industry     

The apparent ileal digestibility,determined with young broilers,of amino acids in near‐isogenic lines of peas (Pisum sativum L) differing in trypsin inhibitor activity

Two pairs of near‐isogenic lines of peas were developed to have high and low concentrations of seed trypsin inhibitor. HA5 and LA5 contained 8.73 ± 0.19 and 1.45 ± 0.19 trypsin inhibitor units per mg dry weight respectively, whereas HB5 and LB5 contained 7.40 ± 0.65 and 1.78 ± 0.15 trypsin inhibitor units per mg dry weight respectively. The four pea samples were included in semi‐synthetic diets and evaluated in a poultry metabolism experiment, using birds aged 3 weeks, to determine the coefficient of apparent ileal amino acid digestibility (CAID). There was a significant difference in CAID for the amino acids reported that correlated with pea genotype. Thus, for example, CAID for cystine was 0.738 ± 0.0196 and 0.812 ± 0.0128 for HA5 and LA5 respectively and 0.721 ± 0.0139 and 0.804 ± 0.0178 for HB5 and LB5 respectively. Corresponding data for methionine, the other main nutritionally deficient amino acid in peas, were 0.887 ± 0.0103, 0.930 ± 0.0089, 0.885 ± 0.0083 and 0.929 ± 0.0125 respectively. Other amino acids followed similar patterns. These data provide information on the nutritional consequences of variation in trypsin inhibitor content of pea seeds in near‐isogenic backgrounds. Plant breeding for low trypsin inhibitor activity in seeds accordingly offers potential for improving nutritional value. © 2003 Society of Chemical Industry     

The effect of pea (Pisum sativum L.)‐originated asparaginase on acrylamide formation in certain bread types

The aim of this study was to investigate the effect of pea (Pisum sativum L.)‐originated asparaginase on acrylamide formation in white wheat, wheat bran and whole‐grain wheat breads. Two‐day germinated pea flour was used at 0%, 1%, 3% and 5% levels for each bread type. Acrylamide analysis was performed with liquid chromatography–mass spectrometry. Besides, colour and sensory properties of the breads were evaluated to search out the effects of pea flour substitution on the consumer acceptance. Reduction of acrylamide in white wheat bread was not found significant and addition of pea flour decreased the acceptance. However, it was found that acrylamide level can be reduced by 57% and 68% with addition of 5% pea flour in wheat bran and whole‐grain breads, respectively, without any negative impact on colour and sensory properties.     

In vitro inhibitory effects of cranberry bean (Phaseolus vulgaris L.) extracts on aldose reductase, α‐glucosidase and α‐amylase

The in vitro inhibitory activities of different seed extracts prepared from cranberry bean mutant SA‐05 and its wild‐type variety Hwachia against aldose reductase, α‐glucosidase and α‐amylase were examined. The results indicated that the polyphenolics‐rich extracts obtained using 800 g kg^?1 methanol and 500 g kg^?1 ethanol demonstrated inhibitory activities against aldose reductase (IC₅₀ of 0.36–0.46 mg mL^?1) and α‐glucosidase (IC₅₀ of 1.32–1.94 mg mL^?1). The 500 g kg^?1 ethanol extracts also showed α‐amylase inhibitory activities (IC₅₀ of 70.11–80.22 μg mL^?1). Subsequent extracts, prepared further with NaCl and H₂O from precipitates of 800 g kg^?1 methanol or 500 g kg^?1 ethanol extracts, exhibited potent α‐amylase inhibitory activities (IC₅₀ of 17.68–38.68 μg mL^?1). A combination of 500 g kg^?1 ethanol extraction plus a subsequent H₂O extraction produced highest polyphenolics and α‐amylase inhibitors. The SA‐05 α‐amylase inhibitor extracts showed greater inhibitory activities than that of Hwachia. Thus, cranberry bean mutant SA‐05 is an advantageous choice for producing anti‐hyperglycaemic compounds.     

Nutritional evaluation of transgenic high‐methionine lupins (Lupinus angustifolius L) with broiler chickens

The nutritive value of transgenic lupin seeds (Lupinus angustifolius L) with higher contents of methionine was evaluated with broiler chickens. The crude protein, methionine and cysteine contents in the conventional and transgenic lupins were 322 and 324, 2.0 and 4.5, and 3.6 and 3.7 g kg^?1 dry matter respectively. In the feeding trial, conventional and transgenic lupins with hulls were incorporated into a maize–soyabean meal diet at 250 g kg^?1 level and the diets were fed to female broiler chicks from 6 to 20 days of age. All diets were balanced to contain similar levels of apparent metabolisable energy (AME), lysine and sulphur‐containing amino acids. The levels of free methionine added to the maize–soyabean meal control, conventional lupin and transgenic lupin diets were 2.2, 2.8 and 2.2 g kg^?1 respectively. Weight gain and feed intake were not influenced by dietary treatments, but feed/gain tended to be higher (P = 0.09) in birds fed lupin diets compared with those fed the control diet. Feed/gain of birds fed the conventional lupin diet was higher (1.82 vs 1.74) than for those fed the transgenic lupin diet. These results showed that the supplemental methionine required in poultry diets containing 250 g kg^?1 lupin can be lowered by 0.6 g kg^?1 diet by the use of high‐methionine lupins. The AME values of conventional and transgenic lupins were determined to be 9.42 and 10.18 MJ kg^?1 dry matter respectively. The higher AME value in transgenic lupins may be related to the lower content of soluble non‐starch polysaccharides (45.6 vs 60.7 g kg^?1 air‐dry basis). Data on ileal amino acid digestibility indicate that the amino acids in transgenic lupins are as digestible as those in conventional lupins. © 2002 Society of Chemical Industry     

Effect of high moisture extrusion cooking on protein–protein interactions of pea (Pisum sativum L.) protein isolates

This study focuses on protein alterations in fibrous meat substitutes produced by high moisture extrusion cooking of pea protein isolates. Three commercially available pea protein isolates and their respective extrudates were evaluated regarding their amino acid composition, molecular weight distribution and protein–protein interactions. Extrusion had no effect on the degree of hydrolysis and amino acid composition indicating that the thermal and mechanical energy during extrusion did not cause the formation of peptide bonds or the degradation of amino acids due to Maillard reactions. Decrease of protein solubilised from extrudates in a buffered solution containing urea indicated that the structural integrity of extrudates could be attributed mainly to covalent disulphide bonding and, to a smaller extent, to non‐covalent interactions. Additionally, the disappearance of legumin bands in extrudates as determined by electrophoresis could be explained by its participation in a macromolecular network that was aggregated and cross‐linked via disulphide bonds. This study contributes to a better understanding of the way the proteins interact during extrusion of pea protein isolates.     

Effect of treatment with α‐galactosidase,tannase or a cell‐wall‐degrading enzyme complex on the nutritive utilisation of protein and carbohydrates from pea (Pisum sativum L.) flour

The effect of treatment with α‐galactosidase, tannase or a cell‐wall‐degrading enzyme complex under optimal conditions of pH, temperature and length of incubation time on the chemical composition and nutritive utilisation of protein and carbohydrates from pea (Pisum sativum L.) flour was studied. Soaking of pea flours in combination with enzyme treatment led to reductions of 77–90% in the levels of α‐galactosides, and of 60–80% in the levels of trypsin inhibitor activity, increasing the content of total available sugars, which was highest in the pea flour treated with the cell‐wall‐degrading enzyme complex. All the treatments assayed caused a significant improvement in daily food intake, whereas the nutritive utilisation of protein was not increased in any of the pea products tested when compared to the raw pea flour. However, all the soaking and enzymatic treatments led to a significant improvement in daily weight gain associated with a higher dietary intake of food and total available sugars. Copyright © 2007 Society of Chemical Industry     

Reversible Regulation of Gelatinization of Potato Starch with Poly(ε‐lysine) and Amino Acids

Poly(ε‐lysine) (PL), lysine (Lys), monosodium glutamate (GluNa), glycine (Gly), alanine (Ala), and leucine (Leu) were used to regulate the characteristic gelatinization behavior of potato starch. As determined by differential scanning calorimetry, PL, Lys, and GluNa with positive or negative net charge elevated the gelatinization temperature with increasing amount added as compared with the small effect of Gly, Ala, and Leu with zero net charge. The peak viscosity evaluated by a Rapid Viscoanalyser was markedly decreased by adding PL, Lys, and GluNa, whereas Gly and Ala had no effect on the peak viscosity. The swelling was also decreased by added PL, Lys, and GluNa, whereas it was unchanged by added Gly, Ala, and Leu. Potato starch immersed in PL or amino acid solution released most of the retained PL and amino acids by the subsequent washing with water. The increased gelatinization temperature of the PL‐treat­ed potato starch returned to the original value by washing with water. It is thus considered that the regulatory effects of PL and amino acids on the gelatinization behavior of potato starch were substantially reversible.     

The Effects of Hop‐α‐Acids and Proline‐Specific Endoprotease (PSEP) Treatments on the Foam Quality of Beer

Influences on foam stability and cling were compared by brewing trials investigating beer hopping rate, hopping type and modification of beer protein composition by the inclusion of a proline specific protease (PSEP). The comparison of the NIBEM, Rudin and lacing foam assessment methods with the level of hopping demonstrated the superiority of hydrogenated hop α‐acids with respect to foam stability and particularly lacing. In addition, the NIBEM and Rudin foam analysis tests appear to respond relatively similarly with respect to hopping rate and hop type, with the NIBEM being somewhat more responsive in terms of foam stability measurments. The PSEP trials suggested that protein composition may only have a subtle effect on foam stability. Although more specific to haze active proteins, PSEP treatment in the small and pilot scale trials generally, but not always, resulted in a minor reduction in foam stability. This effect was not observed in 20 hL pilot and industrial scale beer productions. It was verified that both NIBEM and Rudin were positively influenced by increased levels of foam positive proteins. Although both foam tests were responsive to hopping rate and type, it is suggested that the Rudin foam test is somewhat biased towards foam positive proteins, particularly albuminous foam positive proteins (LTP1 and protein Z4), while in comparison the NIBEM foam test appears somewhat biased towards hordein foam positive proteins.     

Enhanced production of α‐amylase from Bacillus subtilis subsp. spizizenii in solid state fermentation by response surface methodology and its evaluation in the hydrolysis of raw potato starch

This is an attempt to lower the cost of starch hydrolysis by the discovery of new generation α‐amylase. A natural isolate of Bacillus subtilis subsp. spizizenii was capable of producing appreciable amounts of raw potato starch digesting α‐amylase in solid state fermentation of wheat bran. The enzyme productivity has been substantially enhanced by supplementing various nutrients and statistically studying their interactions by response surface methodology. A central composite design for amylase production system elucidated a wheat bran‐based medium supplemented with soybean meal, threonine, and B‐complex vitamins predicting a yield of 521 391 U/g dry solids. The enzyme preparation could effectively digest 5–15% suspension of insoluble potato starch in 6 h revealing the dextrose equivalent of 32–44. The supplementation of a glucoamylase preparation, thereafter, brought about complete saccharification. The yield achieved in the statistically optimized amylase system may be one of the best to date and its capability in directly liquefying raw potato starch granules makes this study novel.     

The effects of steaming and roasting treatments on β‐glucan,lipid and starch in the kernels of naked oat (Avena nuda)

BACKGROUND: Normal pressure steaming (NPS), autoclaved steaming (AS), and hot‐air roasting (HAR) are widely used to deactivate oat enzyme in the oat‐processing industry. Infrared roasting (IR) is a new oat deactivation method, and is welcomed and employed by increasing numbers of oat‐processing plants in China. It is widely known that oat starch plays an important role in the processing function of oat food, and that oat β‐glucan and lipid contribute greatly to the health benefits of oat food. However, the effects of steaming and roasting treatments on the starch, β‐glucan and lipid in oat kernels are poorly known. RESULTS: In this research, the level and distribution of β‐glucan and lipid in oat kernels with and without deactivation treatments were tested. We also measured the viscosity properties of oat flour from kernels after NPS, AS, HAR and IR treatments, and examined the effects of these treatments on oat starch granularity using scanning electron microscopy. The results showed that the deactivation treatments did not have significant effects on oat β‐glucan and lipid levels in oat kernels (P < 0.01). The distribution of β‐glucan and lipid in enzyme‐deactivated kernels was very similar to that in normal kernels. NPS, AS, HAR and IR treatments changed the shape of starch granules, crumbled large starch granules, reduced the connection between the protein network and starch granules, and improved starch gelatinization properties. CONCLUSIONS: NPS, AS, HAR and IR treatments can change the structure of oat starch granules and improve the viscosity property of oat starch without causing β‐glucan and lipid loss to oat food. Copyright © 2010 Society of Chemical Industry