Changes in lipid content and composition during germination of groundnuts

The cotyledons of two varieties of germinating groundnut seeds (Runner and Bunch) were analysed periodically for their lipid content and fatty acid composition over a period of 132 h. The lipid content decreased drastically during germination. More drastic changes in lipid constituents were observed for light-grown seedlings than for dark-grown ones. In general, the non-polar lipids (NPL) were metabolised faster than the polar ones (P > 0.05) especially in those seeds grown in the dark. The rate of decrease in NPL content almost paralleled that of increase in glycolipid (GL) content. Triacyl glycerol content decreased noticeably during germination while other NPL tended to increase. Among the GL, sterylglucoside increased rapidly during early germination under darkness, only to decrease steadily thereafter. A converse effect was observed for acyl sterylglucoside which, in the dark, decreased rapidly at early germination only to increase equally rapidly later on. Among the phospholipids (PL), only phosphatidic acid showed a marked increase during germination, under both growth conditions, while others tended to decrease in varying degrees. The changing patterns of GL and PL during germination seem to follow the pattern of the formation of photosynthetic tissues and the metabolic conversion of PL. The major fatty acids of the three lipid groups, which more or less decreased or increased in varying degrees with germination in light-grown seeds were oleic, linoleic, palmitic, stearic, arachidic and lignoceric acids in decreasing order of prominence at early germination.     

Changes in carbohydrates during germination of lentils

Summary The effect of germination on soluble carbohydrates, total and digestible starch, and components of dietary fiber (neutral detergent fiber, cellulose and hemicellulose) in two varieties of lentils (Lens culinaris medicus var. vulgaris and variabilis) were investigated. In germinated lentils the amount of total soluble sugars decreased (from 4.3% to 2.0% and from 5.3% to 2.2%, respectively); glucose, not present in raw seeds, was relatively high (0.6% and 0.7%), fructose increased slightly, and sucrose decreased slightly. The oligosaccharides of the raffinose family disappeared from germinated seeds. Total starch decreased considerably in germinated lentils (from 60.3% to 41.4% and from 57.4% to 36.4%), but the digestibility of the starch was greatly improved. In germinated lentils, the content of neutral detergent fiber and hemicellulose were lower but that of cellulose and lignin were higher than in raw lentils. Thus, the nutritive value of both varieties of lentils may increase with germination processes.

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Veränderungen im Kohlenhydratgehalt in keimenden Linsen

Zusammenfassung In der vorliegenden Arbeit wurde der Einfluß der Keimung auf die Gehalte an löslichen Kohlenhydraten, Gesamt- und verdaulicher Stärke und Komponenten der Rohfaser (neutral detergent fiber, Cellulose und Hemicellulose), in zwei Linsensorten (Lens culinaris medicus var. vulgaris und variabilis) untersucht. Der Gesamtzuckergehalt nimmt durch die Keimung bei beiden Sorten ab (von 4,3% bis 2,0% und von 5,3% bis 2,2%). Glucose, die sich in rohen Samen nicht findet, lag bei 0,6% und 0,7% in den gekeimten Linsen. Fructose und Sucrose änderten sich nur wenig. Die Raffinose-Oligosaccharide sind bei den gekeimten Linsen nicht vorhanden. Die Gesamt-Stärke nimmt deutlich während der Keimung ab (von 60,27% bis 41,39% und von 57,41% bis 36,39%), aber die Verdaulichkeit der Stärke wurde signifikant verbessert. Die Gehalte an neutral detergent fiber und Hemicellulose bei gekeimten Linsen waren niedriger als bei rohen Linsen, aber die Cellulose- und Ligningehalte waren nach der Keimung größer. Der Proteinnährwert bei beiden Linsensorten kann durch die Keimung verbessert werden.

     

Biochemical changes in phosphorus compounds and in the activity of phytase and α-amylase in the rice (Oryza sativa) grain during germination

Changes in the phytic acid, inorganic phosphorus and ATP contents, and in the activity of phytase and α-amylase in rice (Oryza sativa L) grains were determined during 18 days of germination in a dark room. The effect of phytic acid on α-amylase activity was studied in vitro. Rice grains immersed in sterilised deionised water at 14^°C germinated on the fifth day. Phytase activity, detected in the ripening rice grains, increased linearly until the eighth day and reached a maximum on the tenth day. There was a marked decrease in phytate and an increase in inorganic phosphorus accompanying germination. There was a good inverse correlation between the levels of both phytase activity and inorganic phosphorus, and phytate breakdown. α-Amylase activity was detected on the fourth day and increased markedly from the 12th to the 16th day of germination. ATP level increased from the second to the fourth day and slightly decreased from the fourth to the eighth day; it increased rapidly again from the eighth to the 18th day of germination. α-Amylase activity was influenced by both pH and phytic acid concentration in the assay system. At 75 mM phytic acid, α-amylase activity was lowered by 23%, 93% and 52% at pH 4–0, 5–0 and 6–0 respectively. When the enzyme, phytate and Ca²⁺ were incubated together at pH 5–0, the inhibition of α-amylase by phytic acid was markedly decreased by addition of Ca²⁺. The chemical affinity of Ca²⁺ for phytic acid was higher in the reaction at pH 5–0 than in those at pH 4–0 and pH 6–0, and over 98% of Ca²⁺ in the reaction system was precipitated as Ca-phytate.     

Reduction of raffinose oligosaccharides in chickpea (Cicer arietinum) flour by crude extracellular fungal α-galactosidase

The efficiency of crude extracelluar α-galactosidases from Cladosporium cladosporides, Aspergillus oryzae and A niger in reducing the raffinose and stachyose content in chickpea flours was studied and compared with other traditional treatments. The optimum pH for α-galactosidase activity was found to be 4·5 for A oryzae and 5·0 for Cl cladosporides and A niger, while the optimum temperature of enzyme activity was 40°C for Cl cladosporides and 50°C for A oryzae and A niger. The specific activities of α-galactosidase from Cl cladosporides, A oryzae and A niger were 3·35, 3·94 and 5·94 units μg⁻¹ protein, respectively. The enzyme activity was stable between pH 4·0 and 7·0 for A oryzae and A niger and between pH 5·0 and 7·0 for Cl cladosporides. The enzymes were thermostable when incubated at temperature ranges of 40–60°C for Cl cladosporides and 40–50°C for A oryzae and A niger. The optimum conditions for removing the raffinose and stachyose were obtained by incubating chickpea flours with 30 ml of crude fungal α-galactosidase extract (290, 210 and 130 units ml⁻¹ for Cl cladosporides, A oryzae and A niger, respectively) for 3 h at the optimum conditions of each strain. Crude fungal α-galactosidases reduced the raffinose oligosaccharides content in chickpea flours by 100%, while germination reduced the raffinose content by 69% and stachyose content by 75%. Other traditional techniques reduced the raffinose content by 13–49% and stachyose content by 10–32%. © 1998 Society of Chemical Industry     

Variations in ascorbic acid content of gramineae during germination and the effect of β- and γ- radiation

The ascorbic acid content of three types of Gramineae, viz., Triticum vulgare, Hordeum vulgare and Zea mays (Nab El-Gamal and Beladi), is given and also the average variations in the seeds during germination are shown. The effects on the seedlings of β-irradiation emitted from small doses of radioactive H₃³²PO₄ as well as by irradiation with 131 I, are investigated.     

Accumulating mechanism of γ‐aminobutyric acid in soybean (Glycine max L.) during germination

γ‐aminobutyric acid (GABA) has been found accumulating significantly in soybean seeds during germination. However, the mechanism of the accumulating process is not clear. Therefore, gene expression, enzyme activity and metabolites associated with GABA shunt in ZH 13 soybean during germination were analysed in this paper. GABA content in 5‐day germinated soybean was 0.26 ± 0.016 mg g^?1 DW, which was equivalent to six times concentration of original soybean. The GAD activity has a positive effect on the accumulation of GABA, as well as the GABA‐T activity was found to play a significant role in the degradation of GABA. The expression levels of GmGAD and GmGABA‐T may affect the GABA content by regulating the respective enzyme activities. In conclusion, upregulation of GAD and downregulation of GABA‐T may cause the accumulation of GABA.     

Physico-Chemical Characteristics of Khesari Dhal (Lathyrus sativus): Changes in α-Galactosides,Monosaccharides and Disaccharides during Food Processing

Lathyrus sativus , also known as Khesari dhal in India, is a good source of protein and also desirable from the agricultural point of view as it is drought-resistant and can be grown with low agriculture inputs of fertiliser, irrigation and pesticide. In common with other legume seeds, Lathyrus contains the flatulence causing α-galactosides. This is a study of the physico-chemical properties of four selected Lathyrus sativus lines (Red flower, a high β-ODAP line; EC-242692, a medium β-ODAP line; L-1276, a low β-ODAP line; and Pusa-24, a very low β-ODAP line) to determine the most effective way of removing the flatulence factors by using simple processes such as soaking, dehusking and germination. Physico-chemical properties like swelling and hydration capacity of Lathyrus seeds were higher than other legumes, which suggests higher consumer preference in terms of cooking time and fuel consumption over other beans. Germination was the most effective procedure for removing α-galatosides (85–92%). Dehusking of pre-soaked seeds also achieved a high α-galactoside reduction (61–80%). Soaking in alkaline medium and thereafter boiling for 9 min brought about a lower reduction (33–74%), but these losses were still higher than those obtained by soaking in drinking water or soaking in boiled water for 2 h (11–49% and 7–44%, respectively).     

Properties of α-amylase produced by different barley lines and their hybrids during germination

The amount of activity, the thermal stability and the calcium retaining ability of α-amylases produced by different barley varieties and their reciprocal hybrids have been investigated. α-Amylase was produced by seeds germinated normally and by de-embryonated seeds incubated with gibberellic acid. The activity of the enzyme has been compared between lines on various bases and the validity of these comparisons is discussed. The inactivation constants of the partly purified enzymes dialysed against EDTA in the presence of trypsin have been calculated and compared. Similarly the rate of thermal inactivation of the enzymes has been investigated. In general, little evidence was found to suggest that heterosis existed in terms of any of the characteristics studied.     

Effect of soaking,cooking and crude α-galactosidase treatment on the oligosaccharide content of cowpea flours

Abstract : The effects of soaking, cooking and crude α-galactosidase treatment on the level of stachyose and raffinose present in cowpea flours were investigated. Soaking for 16 h resulted in an average reduction of 26·2% for stachyose and 28·0% for raffinose, while cooking for 50 min resulted in a reduction of 28·6% for stachyose and 44·0% for raffinose. On the other hand, treatment of cowpea flours for 2 h at 50°C with crude fungal preparations having an α-galactosidase activity equivalent to 64 units μg^?1 protein, brought about a mean decrease of 82·3% for stachyose and 93·3% for raffinose. These results show that the enzyme treatment was more effective in removing the raffinose-family oligosaccharides and hence could be a useful technique for control of the flatulence-inducing activity of cowpea flours.     

Hydrolysis of galactooligosaccharides by commercial preparations of α-galactosidase and β-fruetofuranosidase: Potential for use as dietary additives

In vitro and in vivo studies were conducted with six commercial enzyme preparations (SP249, Energex, Rohament CW, Novozyme 230 and crude α -galactosidase) to determine their effectiveness in hydrolysing galactooligosaccharides from soya bean and canola meal in the gastrointestinal tract of poultry. The use of the enzyme invertase to enhance galactoside hydrolysis was also studied. A wide range of α -galactosidase activity was observed in vitro, with crude α-galactosidase from Mortirella vinacea and Novozyme 230 preparation showing the highest activity values of 4.3 and 1.5 nkat mg^?1, respectively. All preparations with the exception of crude α-galactosidase showed invertase activity which is known to convert raffinose and stachyose to the corresponding di-and trisaccharide, melibiose and manninotriose. Although the activity of invertase was highest on sucrose, the Novozyme 230 preparation showed activity values of 4.2 and 2.3 nkat mg^?1 toward raffinose and stachyose substrates, respectively. De novo synthesis of raffinose was observed when soya bean meal, canola meal or pure sucrose and galactose were incubated with certain enzyme preparations (ie Energex). In general, preparations possessing hydrolytic activity towards galactooligosaccharides showed very little synthesis of raffinose while preparations capable of generating raffinose were very weak in the hydrolysis of galactooligosaccharides. The best result in terms of galactooligosaccharide in vitro hydrolysis of canola and soya bean meal was obtained with a combination of α-galactosidase and invertase. In the in vivo study with caecectomised hens, hydrolysis of galactooligosaccharides averaged 88% when crude α-galactosidase (2 g kg^?1) and invertase (1 g kg^?1) were added to laying, hen diet containing 200 g soya bean meal per kilogram. A problem identified in the current study was that minerals such as calcium phosphate and calcium carbonate common in poultry diets inhibit the hydrolysis activity of α-galactosidase, indicating that high levels of activity would be required to yield a response in practical poultry feeding.     

Statistical Modeling of β-galactosidase Inhibition During Lactose Hydrolysis

A statistical model approach called response surface methodology was used to describe the product and substrate inhibition effect on β-galactosidase enzyme during lactose hydrolysis. The effect of independent variables, namely the initial concentrations of lactose (73 - 146 mM), galactose (44 - 122 mM) and glucose (83 - 167 mM) on the reaction rate of β-galactosidase was evaluated. The enzymatic reaction rate was influenced by both combined and individual effects of all the substrate and products. Although, glucose acted as an activator at low lactose and low galactose concentrations, glucose caused the inhibition of β-galactosidase at higher concentrations of lactose and galactose. The effect of galactose concentration on β-galactosidase enzyme was in the direction of inhibition. At low lactose concentrations and high glucose concentrations, galactose concentration became more effective on the reaction rate.     

Changes in chemical composition of lupin seeds (Lupinus angustifolius) after selective α‐galactoside extraction

A selective procedure for the extraction of α‐galactosides has been employed in two sweet lupin seeds (Lupinus angustifolius var. Troll and var. Emir) in order to reduce flatulence‐causing factors. Different nutritional parameters (proteins, fat, ash, dietary fibre, starch, sucrose, vitamins B₁, B₂, E and C) and antinutritional factors (α‐galactosides, trypsin inhibitor activity and inositol phosphates) were studied in raw and processed seeds. The α‐galactoside content in both varieties was reduced by 87–100%. The extracted lupins seeds presented a high retention in protein and fat (109–136% and 95–104%, respectively). Sucrose and soluble dietary fibre, however, decreased significantly as a result of processing and retentions ranged between 5 and 29%. The vitamin B₁, B₂, and E contents decreased during selective extraction, the retentions being in the ranges 25–47%, 38–40%, and 48–54%, respectively, for var. Troll and Emir. However extracted lupin seeds still contained important amounts of vitamins and insoluble dietary fibre, compounds with nutritional importance. Raw and processed lupins did not contain starch. TIA and vitamin C were not detected, and total inositol phosphates were modified slightly after extraction. In conclusion, the lupin seeds obtained by the extraction of α‐galactosides can be an adequate proteic ingredient to be incorporated in functional foods. Copyright © 2005 Society of Chemical Industry     

Changes of porcine pancreas α‐amylase in activity and secondary conformations under inhibition of tea polyphenols

To investigate two‐sided functions of tea polyphenols (TP) in antinutrition and energy balance modulation, TP were extracted from Chinese green tea and used to complex porcine pancreas α‐amylase (PPA). Changes of PPA in activity and secondary conformations were analysed. Porcine pancreas α‐amylase was found sensitive to TP treatment. Tea polyphenols exhibited IC₅₀ at 0.41 mg mL^?1 against PPA and maximum inhibitory rate (98.17%) at 3.0 mg mL^?1. Tea polyphenols inhibition was concluded as noncompetitive pattern based on its unchanged Km value (0.98 mg mL^?1) for soluble starch substrate. Tea polyphenols inhibition arose from pH 1.5 to 10.14, covering gastric and intestinal environments inside body. Circular dichroism spectra analysis revealed regular changes of PPA in secondary conformations (increased proportions of α‐helix and β‐sheet) prior to its inactivation at low TP concentrations. Tea polyphenols‐inhibited PPA had distinct double‐negative peaks at 204 nm and 208 nm. Porcine pancreas α‐amylase was inactivated by TP in ways of complexation and modification of secondary conformations.     

Genetic mapping of the α-galactosidase MEL gene family on right and left telomeres of Saccharomyces cerevisiae

The α-galactosidase MEL2–MEL10 genes have been genetically mapped to right and left telomere regions of the following chromosomes of Saccharomyces cerevisiae: MEL2 at VII L, MEL3 at XVI L, MEL4 at XI L, MEL5 at IV L, MEL6 at XIII R, MEL7 at VI R, MEL8 at XV R, MEL9 at X R and MEL10 at XII R. A set of tester strains with URA3 inserted into individual telomeres and no MEL genes was used for mapping.     

Investigation of selected toxicological parameters of γ-pentachlorocyclohexene (γ-PCCH)

The toxic effects of the γ-hexachlorocyclohexane metabolite γ-pentachlorocyclohexene (γ-PCCH) were studied by acute and subacute (6 weeks) experiments. The investigations included cerebral convulsibility with chemoshock (Tetrazolium), reactivity with hot plate method, the learning ability with learning tests, and peripheral nervous activity (EMG). Nociceptive reaction time was not influenced, the learning process (6 weeks) was inhibited by γ-PCCH. The conduction velocity of the peripheral nerve was decreased. At the end of the 6th week liver enlargement was found.