Studies on the amino acid and mineral content of buckwheat protein fractions

Protein fractions were extracted by successive extraction and analysis method in four buckwheat varieties including Japanese spring buckwheat, Japanese summer buckwheat, Yuqiao No. 1 and Yuqiao 6-21. The amino acid and the mineral content of each protein fraction were also analyzed in this paper. The basis for the data on the experiment was the relationship between protein fractions and amino acids, and the mineral contents of protein fractions. The distribution and proportion of amino acids and the minerals in each protein fraction in the buckwheat kernel as well as the nutritional value of buckwheat kernel were discussed. The results showed that there is a high amount of soluble protein and very low amount of prolamin in the buckwheat kernel. Leucine is the first limited amino acid in buckwheat, and buckwheat protein is only a seminutritional protein. The buckwheat kernel is rich in K, Zn in the albumin, Ca, Mg and Mn in the globulin, Na in the prolamin and glutelin.     

Quantity and carbohydrate content of glycomacropeptide fractions isolated from raw and heat-treated milk

To determine the effect of heat treatment of milk on the release and carbohydrate content of glycomacropeptide (GMP), raw milk was subjected to five heat treatments of varying severity, cooled, incubated with chymosin and separated into whey and curd fractions. GMP was isolated from each whey fraction using an ion-exchange method and carbohydrates were released from each GMP sample using an optimised acid hydrolysis procedure. The carbohydrates released were derivatised with 1-phenyl-3-methyl-5-pyrazolone, separated and quantified by capillary electrophoresis. The severity of heat treatment significantly influenced the amount of GMP released and the residual glycosylation of GMP. Removal of small ionic species using dialysis was able to fractionate GMP into water-soluble and insoluble forms, which contained high and low quantities of carbohydrates, respectively. These results indicate that the amount of GMP released and its level of glycosylation can be influenced by the severity of milk heat treatment, and possibly the technique employed to isolate the GMP.     

Characterization of the mineral composition of isolated krill proteins

Antarctic krill is considered to be a very promising source of food proteins and other biologically essential components, including microelements. In the present article the microelement composition of krill proteins obtained by alkaline extraction is studied. The studies showed that the ash content of the isolated krill proteins is rather constant and does not depend on the different lots of krill. It could be demonstrated that isolated krill proteins are a source of biologically essential microelements. The fluorine and heavy metal contents are within allowable limits and do not restrict the use in food production.     

Proximate composition and selected mineral content of commercially important fish species from the black sea

Proximate composition, selected mineral (Zn, Fe, Cd, As, Hg, Pb, Ni, Cu) content and fatty acid profiles were determined in some widely consumed fish species obtained from the Black Sea. All fish species analysed individually were fairly high in protein (14·1–25·1%) and lipid (7·4–18·4%). Moisture and ash content varied within a narrow range. The mineral content was highly variable. The most abundant microelements in fish were Zn and Fe followed by Cu, and the remaining elements were present in amounts below toxic levels. Eight fatty acids (16: 0, 16:1, n-7, 18: 0, 18:1 n-9, 18: 2 n-6, 20:1 n-9, 20: 5 n-3, 22: 6 n-3) represented more than 60% of the fatty acid content. Saturated fatty acids ranged from 25·8 to 45·1%. Anchovy and whiting contained almost 35% of polyunsaturated fatty acids. The percentage of docosahexaenoic acid (DHA) exceeded that of eicosapentaenoic acid (EPA) in almost all the fish species examined, and the actual content of these acids has shown that sprat, whiting, garfish, red mullet, shad and sea bream provide the recommended daily intake of 1 g of EPA+DHA with reasonable amounts of fillet. These results indicate that biological differences existing in fish species can influence the values to be set for the standards and composition. © 1998 Society of Chemical Industry.     

Effect of micronisation on dietary fibre content and hydration properties of lotus node powder fractions

Fibre‐rich fractions were obtained from nodes of lotus root and micronised by nine different ball‐milling treatments. The optimum milling conditions were screened out by comparing its effects on physicochemical and hydration properties of micro‐sized particles of lotus node powder fraction (LNPF). The micronisation by ball‐milling treatments was carried out at different speeds (200–400 r min^?1) and time (4–12 h). Ball‐milling treatments could effectively (P < 0.05) pulverise the LNPF particles to different micro‐sizes. As particle size decreased, a redistribution of fibre components from insoluble to soluble fractions was observed. Furthermore, micronisation treatments, especially 12 h at 300 r min^?1, could significantly (P < 0.05) increase the hydration characteristics, as well as impart lightness in colour to different extents. Our findings suggested that micronisation can improve physicochemical and hydration characteristics of the fibre components, which provide an opportunity to improve the utilisation and application of lotus node dietary fibre.     

Certain physicochemical and functional properties of fibre fractions from pulses

The physicochemical and functional properties of the fibre fractions from peas (Pisum sativum), lentils (Lens culinaris), chickpeas (Cicer arietinum L.) and navy beans (Phaseolus vulgaris) were evaluated, and the relationships amongst those properties were determined. Fibre fractions from several varieties of each species were prepared using a laboratory wet milling procedure. The fibre fractions contained 663.2 to 808.5 g/kg DM of total dietary fibre, 45.4 to 171.1 g/kg DM of crude protein, 102.7 to 195.6 g/kg DM of starch and 1.9 to 10.5 g/kg DM of crude fat. Fibre fractions from pea and kabuli chickpea displayed significant higher fat absorption (FA) than those from lentil, navy bean and desi chickpea. Lentil and navy bean fibre fractions exhibited larger mean particle size than did pea and chickpea fibre fractions. Pulse fibre fractions exhibited significantly higher water hydration, swelling and water retention capacities in comparison to commercial pea fibre products. A significant reverse relationship (r = − 0.956, p < 0.001) between mean particle size and specific surface area (SpSA) of pulse fibre fractions was observed. FA of fibre fractions was positively correlated with SpSA (r = 0.820, p < 0.001).     

Phytate and mineral content in different milling fractions of some Pakistani spring wheats

Six Pakistani wheat cultivars, namely C-273, Inqulab-91, Pasban-90, Parwaz-94, Shahkar-95 and Rohtas-90, were included in the present study. The kernel weight of the wheat cultivars varied from 31.43 to 36.76 g (per thousand kernels), Parwaz-94 having the highest and Rohtas-90 having the lowest. The test weight of cultivars ranged from 70.23 (Shakar-95) to 76.13 kg hL^–1 (Pasban-90). The bran contained the highest amount of phytic acid (6.12%) in C-273 followed by whole-wheat flour (2.23%) in Inqulab-91, and straight-grade flour (0.24%) in Parwaz-94. The phytate content was reduced during the baking of bread and chapati. The bread scores and other quality characteristics varied significantly among cultivars. The total bread scores ranged from 35.20 to 42.00, out of a possible fifty, with Parwaz-94 being the highest. The concentration of minerals varied widely in different milling fractions of various wheat cultivars. The concentration of Cu, Fe, Mn and Zn ranged from 5.00 to 52.50, 26 to 147.50, 0.00 to 97.00, 9.0 to 80.80 ppm, respectively, in different milling fractions of the wheat cultivars. The total chapati scores ranged from 22.40 to 24.20 of a possible score of 30. The minimum chapati scores were found in Rohtas-90 and Parwaz-94, while Inqulab-91 produced the maximum score.     

Effects of different additives on the cell wall and mineral fractions of artichoke (Cynara scolymusL) and orange (Citrus aurantiumL) by-product silage

The quality of the cell wall fraction content of two silage by-products was assessed together with their different mineral composition. Various treatments to test possible improvements in the ensilage of canning industry artichoke and orange by-products were compared with the addition of different additives. Three treatments were assessed: sodium chloride (25 g kg⁻¹), dehydrated beet pulp (62·5 g kg⁻¹), formic acid at 4% in doses of 62·5 ml kg⁻¹. A fourth batch acted as a control group. Samples were analysed for their nutritive characteristics. After a 100-day ensilage period the results showed that the use of the additives in the given doses did not significantly improve the quality of the silage, although the composition of the sodium chloride batch appeared to be better. © 1998 SCI.     

Dietary fibre from berry-processing waste and its impact on bread structure: a review

The structure and function of by-products of berry-processing industries are reviewed, with particular attention to dietary fibre (DF) and its effects in food products. The complex chemical composition and physicochemical characteristics of DF have been investigated and strategies for extraction of specific fractions that provide tailored technological and physiological functionality have been reviewed. The aim of this review is to describe in detail the structural composition and isolation methods of dietary fibre derived from berry by-products, and to explore their potential functionality in foods. The goal is to introduce DF from berry waste streams into the food chain, for which bread is a major vehicle. However, the appeal of bread lies in its aerated structure, for which DF is generally detrimental. The technological influence of DF on the formation and stabilization of the aerated structure of bread is therefore reviewed, in order to understand how to incorporate DF into bread while maintaining palatability. The aerated structure of bread is stabilized by two mechanisms: the gluten matrix and the liquid film surrounding bubbles. Incorporating DF successfully into bread requires understanding its interactions with both of these mechanisms. DF fractions from berries offer superior nutritional value compared to cereal fibre, potentially with less damage to bread structure, due to the higher proportion of soluble fibre. By-products from berry-processing industries could be used as a source of technologically and nutritionally distinctive DF to fabricate foods with enhanced nutritional value. © 2019 Society of Chemical Industry     

半纤维素含量对二次纤维孔隙结构及其成纸性能影响的研究

通过低温氮吸附法研究半纤维素含量对二次纤维孔隙结构及纤维成纸性能的影响.结果表明:随着聚戊糖含量的降低,纤维成纸性能下降;聚戊糖含量和保水值呈线性关系.当聚戊糖含量从23.46%降低到13.39%时,平均孔径下降了11.64%;当聚戊糖含量从13.39%再次降低到11.74%时,二次纤维平均孔径反而上升了8.98%;而纤维BET比表面积变化很小.保留一定含量的半纤维素能够有效地抑制麦草纤维经历抄造过程之后发生的孔隙的不可逆关闭,但是在聚戊糖含量降低到一定程度时,纤维孔隙结构反而能够得到改善.     

Effects of saline stress on mineral composition,phenolic acids and flavonoids in leaves of artichoke and cardoon genotypes grown in floating system

BACKGROUND: Cynara cardunculus is a species native to the Mediterranean basin. It includes globe artichoke and cultivated cardoon as well as their progenitor wild cardoon. The species is a source of biophenols, and its leaf extracts have been widely used in herbal medicine as hepatoprotectors and choleretics since ancient times. The aim of this study was to determine the effect of increasing the level of salinity in the nutrient solution (1 or 30 mmol L^?1 NaCl) on biomass production, mineral composition, radical‐scavenging activity, caffeoylquinic acids and flavonoids in three artichoke (‘Romolo’, ‘Violetto di Provenza’ and ‘Violetto di Romagna’) and three cultivated cardoon (‘Bianco Avorio’, ‘Bianco Gigante Inerme’ and ‘Gigante di Romagna’) cultivars grown in a floating system. RESULTS: Increased salinity in the nutrient solution decreased the leaf dry biomass and leaf number of artichoke and cultivated cardoon cultivars. Salinity reduced macro‐ and microelement accumulation in leaves (e.g. N, K, Ca, Mg, Fe, Mn and B) but improved their antioxidant activity, total polyphenols, chlorogenic acid, cynarin and luteolin. The cultivated cardoons, especially ‘Bianco Avorio’ and ‘Gigante di Romagna’, showed higher biomass and leaf number than those observed in artichoke genotypes. ‘Violetto di Provenza’ exhibited the highest content of chlorogenic acid, closely followed by ‘Violetto di Romagna’, whereas for cynarin content the highest values were recorded in ‘Violetto di Provenza’, ‘Bianco Avorio’ and ‘Gigante di Romagna’. The highest content of luteolin was recorded in ‘Gigante di Romagna’ and ‘Bianco Avorio’, while the highest content of apigenin was observed in ‘Gigante di Romagna’. CONCLUSION: The results showed that the floating system could be considered an effective tool to improve quality aspects through proper management of the salt concentration in the nutrient solution. They also suggest that specific cultivars should be selected to obtain the desired profile of bioactive compounds. © 2012 Society of Chemical Industry     

Proximate,mineral, amino acid,fatty acid,vitamin E,phytate phosphate and fibre composition of Mimusops zeyheri (Red Milkwood) seed

Mimusops zeyheri, an indigenous tree widely distributed in sub‐Saharan Africa, provides edible fruit. Research on the tree has focused on fruit pulp composition and uses. This study evaluated the nutritional potential of M. zeyheri seed by determining the proximate, fibre and phytate‐phosphate content, the amino acid and fatty acid profiles and vitamin E content of the seed. Dry matter, organic matter, crude protein, ether extract and ash constituted 91.1%, 88.3%, 9.3%, 25.6% and 2.8% of the seed mass respectively. Glutamic acid (1.29 g per 100 g) was the most abundant amino acid. Lysine and phenylalanine were low. Calcium (587.4 mg per 100 g) was the most concentrated macro‐mineral assayed. Gross energy value was 24.34 MJ kg^?1. Lipid yield was 21.3%. Oleic acid was the most abundant fatty acid. Vitamin E concentration was about 2 μg g^?1. Phytate‐phosphate content was 0.03%. Neutral detergent fibre and acid detergent fibre constituted 33.2% and 15.3% respectively. M. zeyheri seed could be exploited as a dietary energy supplement and an oil source rich in oleic acid.     

Selenium content of goat milk and its distribution in protein fractions

Summary This study reports on selenium distribution in goat milk. Skim milk was found to contain the major part (94%) of total milk selenium. The selenium distribution over casein and whey protein fractions depends on the separation method used, but irrespective of these methods, skim milk selenium is mainly associated with the casein fraction (> 69%). Approximately 9%, 7% and 24% of selenium is removed by dialysis (molecular cutoff 10–12 kDa) from skim milk, casein and whey respectively, indicating a major association of selenium with milk proteins. This observation is confirmed by selenium analysis of individual caseins and whey proteins isolated through ion-exchange chromatography and gel filtration. Selenium concentrations of the different isolated milk proteins show considerable variation (caseins: 294–550 ng Se/g; whey proteins: 217–457 ng Se/g).

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Der Selengehalt von Ziegenmilch und seine Verteilung in den Proteinfraktionen

Zusammenfassung Diese Studie bespricht die Selen-Verteilung in Ziegenmilch. Magermilch enthält 94% des gesamten Selens der Milch. Die Selen-Verteilung ist abhängig von der Technik des Abtrennens des Caseins von den Molkenproteinen, aber ungeachtet dessen befindet sich das Selen der Magermilch hauptsächlich in der Casein-Fraktion (>69%). Ungefähr 9% bzw. 7% bzw. 24% des Selens wurden aus Magermilch bzw. Casein bzw. Molke durch Dialyse (molekulare Ausschaltung 10–12 kDa) entfernt, was auf eine Assoziation des Selens mit den Milchproteinen hinweist. Dies wurde bestätigt durch die Selenanalyse des durch Ionenaustauschchromatographie bzw. Gelfiltration isolierten Caseins und der Molkeproteine. Der Selengehalt der verschiedenen isolierten Milchproteine zeigt bemerkenswerte Differenzen (Caseine: 294–550 ng Se/g; Molkeproteinen: 217–457 ng Se/g).

     

Selenium content of sheep's milk and its distribution in protein fractions

The selenium (Se) distribution in sheep's milk is reported. Skim milk was found to contain the major part (98%) of total milk Se. The Se distribution over casein and whey protein fractions depends on the separation method used, but irrespective of these methods, skim milk Se is mainly associated with the casein fraction (>68%). Approximately 11%, 4% and 17% Se is removed by dialysis (molecular mass cut-off 10–12 kDa) from skim milk, casein and whey respectively, indicating a major association of Se with milk proteins. This observation is confirmed through Se analysis of individual caseins and whey proteins isolated through ion-exchange chromatography and gel filtration. Se concentrations of the different isolated milk proteins show considerable variations (caseins, 304–750 ng Se/g; whey proteins, 241–806 ng Se/g).

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Der Selengehalt von Schafsmilch und seine Verteilung in den Proteinfraktionen

Zusammenfassung Diese Studie bespricht die Selen-Verteilung in Schafsmilch. Magermilch enthält 98% des gesamten Se der Milch. Die Se-Verteilung ist abhängig von der Trennungstechnik bei der Abscheidung des Caseins und der Molkenproteine. Das Selen befindet sich in der Magermilch, hauptsächlich in der Casein-Fraktion (>68%). Ungefähr 11% bzw. 4% bzw. 17% des Se wurden aus Magermilch bzw. Casein bzw. Molke durch Dialyse (molekulare Ausschaltung 10–12 kDa) entfernt, was auf eine Assoziation von Se mit den Milchproteinen hinweist. Dies wird bestätigt durch eine spezielle Se-analyse des Caseins und den Molkeproteinen mit Hilfe der Ionen-austauschchromatographie bzw. Gelfiltration. Der Segehalt der isolierten Milchproteine zeigt bemerkenswerte Unterschiede: Casein: 304–750 ng Se/g; Molkenproteine: 241–806 ng Se/g.

     

Proximate composition,mineral and amino acid content of mature Canavalia gladiata seeds

The chemical composition and the nutritional quality of protein and carbohydrates of mature seeds of Canavalia gladiata (L.) were investigated. The whole and cotyledon flour of mature seeds contained; crude protein 26.8 and 29.2%; fat 2.8 and 3.1%; fibre 33.2 and 10.2%; ash 3.9 and 4.3%; carbohydrate 33.3 and 53.2% on dry matter basis respectively. The carbohydrate fractions have starch contents of 30.7 and 39.6% and 27.7 and 34.6 mg g⁻¹ low molecular weight carbohydrates on dry matter basis. The energy content of whole seed and cotyledon flour was 11,082 and 14,923 kJ kg⁻¹. Sucrose represents the highest fraction of low molecular weight carbohydrates with fructose being the lowest. The mineral analysis showed K, Mg, Ca, P and S to be present in high quantities. The essential amino acid profile compared well with FAO/WHO recommended pattern except for sulphur containing amino acids, cysteine and methionine. Therefore the chemical composition of the raw mature seeds of Canavalia gladiata (kernel) indicates the bean to be a good supplement to cereal-based diets.