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Journal of Thermal Analysis and Calorimetry
Authors: J. Amorim, S. Eliziário, D. Gouveia, A. Simőes, J. Santos, M. Conceiçăo, A. Souza, and M. Trindade

Abstract  

The thermogravimetry (TG) is a technique used in the quality control of foods. In this work the moisture and ash contents in the rice and by-products (bran and husk), the thermal stability and the gelatinization process by conventional, thermogravimetric and calorimetric methods were studied. The moisture and ash contents obtained by TG and conventional methods did not present significant differences. The rice presented higher starch content, while the bran presented higher protein content. The thermogravimetric data presented the following thermal stability order: rice>bran>husk. The calorimetric curves indicated the gelatinization of the starch. The kinetic parameters were compatible.

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Journal of Thermal Analysis and Calorimetry
Authors: S. Silva, M. Conceiçăo, A. Souza, S. Prasad, M. Silva, V. Fernandes, A. Araújo, and F. Sinfrônio

Abstract  

The powder and the bran of algaroba pods, submitted to drying temperatures of 55, 65, 75, 85, 95 and 105C, were studied by conventional and thermogravimetric methods. The dynamic thermogravimetric curves of the samples indicated the following thermal stability order: 105>55>65>95>85>75C. The powder and the bran of algaroba pods, dried at 55C, presented protein content higher and isothermal thermogravimetric profiles comparable. The calorimetric curves of samples, dried at 55C, indicated the gelatinization of starch.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: A. Belokobylsky, E. Ginturi, N. Kuchava, E. Kirkesali, L. Mosulishvili, M. Frontasyeva, S. Pavlov, and N. Aksenova

Abstract  

The dynamics of accumulation of Se(IV) and Cr(III) in Spirulina platensis (S. platensis) cells was studied using epithermal neutron activation analysis. The effect of Se(IV) and Cr(III) apart and together on growth and morphology of S. platensis cells is discussed. It was established that accumulation of Cr is more intensive than that of Se. As follows from the results obtained, the simultaneous loading of Se and Cr affects the biomass growth dynamics of S. platensis without changing its morphology and protein content. This finding serves the ground for developing the pharmaceuticals based on Se and Cr enriched biomass.

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Chemical (N' methyl-N'-nitro-N-nitrosoguanidine) mutagenesis and penicillin selection were utilised to isolate a phenotypically altered mutant of cyanobacterium Synechocystis sp. This mutant (ntm60A) exhibited enhanced protein content and nitrogen fixing potential but lower amount of chlorophyll and nitrate reductase activity. A remarkable and significant increase was observed in the total phycobiliprotein content of the mutant, especially in relation to the amount of phycoerythrin. This strain can be exploited as a rich source of natural coloring agent such as phycobilins in the bioindustry.

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Spores of four Frankia strains, the nitrogen-fixing actinomycete, were exposed to short wavelength UV-C radiation of 254 nm at 1 lux cm2 (0.24 mw cm2 of energy) for 10 min. The used strains were HFP020203, UGL020604, UGL020602q and ORS021001. Exposure to UV was followed by reactivation with visible white light at 327.4 lux cm2 for the same period of time. Spore germination percentage, spore protein content, and cell growth were damaged by this treatment. The lower and higher percentages of reduction in spore germination were 32 and 63% and, for the same strains, the recovery by white light was 7.2 and 37%. The lower percentages of UV damage and subsequent low recovery were recorded for strain ORS021001 that is considered more resistant to UV than the other strains. The higher percentages were recorded for strain HFP020203 that is more sensitive to UV but having more efficient repairing mechanisms. All the tested strains showed repairing activity induced by white light as indicated from the increase in their spore germination, protein content and almost restoring the normal shape of Frankia hyphae, after being damaged, as revealed by scanning electron microscope. This is the first evidence that photo-repairing systems are present in Frankia strains although there are variations in their response to both UV-C and photoreactivation by white light.

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Cereal Research Communications
Authors: Daniela Horvat, Zdenko Loncaric, Vladimir Vukadinovic, Georg Drezner, Blazenka Bertic, and Kresimir Dvojković

The effect of the N, P and K fertilisation on yield and quality parameters of cultivar Žitarka during two growing seasons (2002/03 and 2003/04) was studied. Fertilization increased yield, although only treatment with 200 kg N ha −1 yielded significantly higher than treatments with 80 kg N ha −1 . Protein content increased significantly (P<0.001) with the application of 80 kg N ha −1 , 120 kg N ha −1 and 160 kg N ha −1 . The highest N applications with 200 kg N ha −1 and 240 kg N ha −1 increased protein content on the same level as with 160 kg N ha −1 . Wet gluten and sedimentation value were also significantly (P<0.001) affected by N fertilizer treatments. Although increment of N fertilization increased values of these quality parameters, 120 kg N ha −1 , 160 kg N ha −1 and 200 kg N ha −1 treatments showed similar effect, while treatment with 240 kg N ha −1 resulted with significantly higher values. Gluten index increased only with applying 80 kg N ha −1 while the highest N levels (200 kg N ha −1 and 240 kg N ha −1 ) showed dramatically gluten weakening. Considering grain hardness only treatment with 80 kg N ha −1 had significant (P<0.001) influence. Simultaneously, P and K did not affect grain yield and quality, neither comparing PK to controle, or N 2 P 1 K 1 to N 2 P 2 K 2 .

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An experiment was set up at five locations in Hungary in 2005, in a randomised block design with four replications. At each location 24 hybrids were tested from each of four maturity groups (FAO 200, FAO 300, FAO 400, FAO 500). Evaluations were made of the yield average (t/ha) and the yield components of the sample ears: ear length, number of kernel rows, thousand-kernel mass and kernel/cob ratio. This was followed by chemical analysis to determine the protein, oil and starch contents of the kernels. The chemical quality parameters were recorded for almost 100 hybrids, and the correlations of the protein, oil and starch contents with yield and yield components were analysed. It was found that in all the maturity groups the yield was closely correlated with the thousand-kernel mass (0.72). In each maturity group the highest yield averages were associated with the greatest average starch contents, except for the FAO 500 group in the Szarvas location, where the development of secondary ears contributed to the achievement of the highest yield average. A very close correlation was found between the starch content and the thousand kernel mass (0.91). The variety caused greater differences in protein content than the location. This was also true for the oil content in the FAO 200 and FAO 400 groups, but only in the FAO 400 group in the case of starch content. More starch was incorporated at wetter locations, where the protein content of the samples was lower.

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Increasing the protein and antioxidant content of food products is a constant challenge amongst researchers. Dried pasta products are popular amongst all groups of society. The most important factor in pasta processing is the quality of the flour. Millet (Panicum miliaceum) flour has high nutritional value, enriching it with cricket (Gryllus bimaculatus) flour is good choice to increase the quality of protein composition and antioxidant properties of products. Flour mixtures of millet and insect flours (5% and 10%) were analysed after mixing and pasta processing. Addition of wheat gluten improved both texture and nutrition value of pasta products. Total polyphenol content, antioxidant capacity, total protein content, free and total amino acid composition were studied. Quality analysis of dried pasta products were carried out according to Hungarian standards. Data was analysed with Kruskal-Wallis test, Dunn's pair-wise post hoc test was used with Bonferroni correction. The correlation was determined by Spearman's rank. Addition of cricket flour modified the pH, acid value, moisture content, and colour of the samples, these changes lasted during storage. Enrichment could increase the total phenol content significantly even at the low level of 10%. Heat treatment during pasta processing had negative effect on the antioxidant capacity except at higher cricket flour contents. Cricket flour's high protein content proportionately increased millet flour's, thus pasta products'. Dried pasta products passed all quality norms. Enrichment of millet flour with cricket flour is favourable from both nutritional and quality aspects.

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The protein content, solubility and functional properties of a total protein concentrate prepared from the seeds of Ailanthus excelsa Roxb. were determined. The effects of pH and/or NaCl concentration on some of these functional properties were also investigated. The protein content of the seed protein concentrate was found to be 65.88%. The minimal protein solubility was observed at pH 4 and the maximum was at pH 12. Water- and oil-holding capacities of the seed protein concentrate were 2.77 g g −1 and 5.79 g g −1 , respectively. The emulsifying activity and emulsion stability, as well as foaming capacity and foam stability, were greatly affected by pH levels and salt concentrations. Lower values were observed at slightly acidic pH (pH 4.0) and high salt concentration. Total protein concentrate was highly viscous which depends on concentration and pH levels. The lowest gelation concentration of seed protein concentrate was found to be 14% and 8% when the proteins were dissolved in distilled water and 0.5 M or 1 M NaCl solution, respectively.

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Comparative study of composition and technological quality of amaranth

I. Gross chemical composition, amino acid and mineral content

Acta Alimentaria
Authors: S. Tömösközi, I. Baracskai, R. Schönlechner, E. Berghofer, and R. Läsztity

Eight groups of amaranth grain samples, belonging to the species Amaranthus cruentus and A. hypochondriacus , grown in Austria and Hungary were studied. Gross chemical composition, amino acid content and mineral composition of the whole grain were determined. The effect of heat treatment on amino acid content was also investigated. The range of concentration of main constituents of samples studied corresponded to the average data reported by other researchers. However, the relatively big difference between lowest (14.23%) and highest (17.40%) protein content suggests that genetic potential for increasing the protein content may be realized in breeding. Amino acid composition profile is generally closer to Leguminosae than to cereal grains except for sulphur containing amino acids being present in higher amount in amaranth than in legumes. The concentrations of minerals in seeds varied in a relatively wide range, and the micro-components, like Fe, Cu, Zn, were present in higher amount in amaranth seeds compared to the average values found in wheat. It was confirmed that heat treatment of amaranth grain (e.g. popping) might reduce the available lysine content. Contradictory data published in the literature may be explained by differences in initial sugar and moisture content of grain, which influence the rate of potential Maillard-reaction.

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