The Kjeldahl Digestion

Bradstreet, R. B.

doi:10.1016/b978-1-4832-3298-0.50005-9

Cited by 67 publications

(11 citation statements)

References 83 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Protein as determined by the Kjeldahl method results in determination of TN, requiring adjustment for NPN and the subsequent conversion of this derived value to protein equivalents ( 29 ) . In this review, protein is defined as bioavailable N multiplied by the general conversion factor 6·25 ( 30 ) .…”

Section: Methodsmentioning

confidence: 99%

Preterm human milk composition: a systematic literature review

et al. 2016

View full text Add to dashboard Cite

There are wide variations in the macronutrient values adopted by neonatal intensive care units and industry to fortify milk in efforts to achieve recommended intakes for preterm infants. Contributing to this is the variation in macronutrient composition of preterm milk between and within mothers and the variable quality of milk analyses used to determine the macronutrient content of milk. We conducted a systematic review of the literature using articles published in English between 1959 and 2013 that reported the concentrations of one or more macronutrients or energy content in human preterm milk, sampled over a representative 24-h period. Searched medical databases included Ovid Medline, Scopus, CINAHL and the Cochrane Library. Results are presented as mean values and ranges for each macronutrient during weeks 1-8 of lactation, and preferred mean values (g/100 ml) for colostrum (week 1) and mature milk (weeks 2-8; protein: 1·27, fat: 3·46, lactose: 6·15 and carbohydrate: 7·34), using data from studies employing the highest-quality analyses. Industry-directed fortification practices using these mean values fail to meet protein targets for infants weighing <1000 g when the fortified milk is fed <170-190 ml/kg per d, and the protein:energy ratio of the fortified milk is inadequate. This study aimed to provide additional information to industry in order to guide their future formulation of breast milk fortifiers. Quality macronutrient analyses of adequately sampled preterm breast milk would improve our understanding of the level of fortification needed to meet recommended protein and energy intakes and growth targets, as well as support standardised reporting of nutritional outcomes.

show abstract

Section: Methodsmentioning

confidence: 99%

Preterm human milk composition: a systematic literature review

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Sample dry weights (DW) were recorded after conventional oven-drying at 80°C for 72 h. Dried samples were subsequently milled. Total leaf P and K concentrations were determined using the micro Kjeldahl method, in which a 0.1 g subsample of dried leaf material was digested for 1 h, after the addition of 1 mL of H 2 O 2 and 2 mL of a H 2 SO 4 /Se catalyst [88] . Inductively-coupled plasma emission spectrometry (JY Ultima 2, Jobin Yvon Ltd., Stanmore, Middlesex, UK) was used to determine elemental tissue concentrations.…”

Section: Methodsmentioning

confidence: 99%

Gene Expression Changes in Phosphorus Deficient Potato (Solanum tuberosum L.) Leaves and the Potential for Diagnostic Gene Expression Markers

et al. 2011

View full text Add to dashboard Cite

BackgroundThere are compelling economic and environmental reasons to reduce our reliance on inorganic phosphate (Pi) fertilisers. Better management of Pi fertiliser applications is one option to improve the efficiency of Pi fertiliser use, whilst maintaining crop yields. Application rates of Pi fertilisers are traditionally determined from analyses of soil or plant tissues. Alternatively, diagnostic genes with altered expression under Pi limiting conditions that suggest a physiological requirement for Pi fertilisation, could be used to manage Pifertiliser applications, and might be more precise than indirect measurements of soil or tissue samples.ResultsWe grew potato (Solanum tuberosum L.) plants hydroponically, under glasshouse conditions, to control their nutrient status accurately. Samples of total leaf RNA taken periodically after Pi was removed from the nutrient solution were labelled and hybridised to potato oligonucleotide arrays. A total of 1,659 genes were significantly differentially expressed following Pi withdrawal. These included genes that encode proteins involved in lipid, protein, and carbohydrate metabolism, characteristic of Pi deficient leaves and included potential novel roles for genes encoding patatin like proteins in potatoes. The array data were analysed using a support vector machine algorithm to identify groups of genes that could predict the Pi status of the crop. These groups of diagnostic genes were tested using field grown potatoes that had either been fertilised or unfertilised. A group of 200 genes could correctly predict the Pi status of field grown potatoes.ConclusionsThis paper provides a proof-of-concept demonstration for using microarrays and class prediction tools to predict the Pi status of a field grown potato crop. There is potential to develop this technology for other biotic and abiotic stresses in field grown crops. Ultimately, a better understanding of crop stresses may improve our management of the crop, improving the sustainability of agriculture.

show abstract

“…Protein levels were determined according to the Kjeldahl method − . Samples were manually digested on a heating block using sulfuric acid and a selenium catalyst and then transferred to the analyzer unit, where the digests were distilled and titrated.…”

Section: Methodsmentioning

confidence: 99%

Compositions of Seed, Forage, and Processed Fractions from Insect-Protected Soybean MON 87701 Are Equivalent to Those of Conventional Soybean

Berman

Harrigan²,

Riordan³

et al. 2009

J. Agric. Food Chem.

View full text Add to dashboard Cite

Monsanto Co. has developed biotechnology-derived, insect-protected soybean MON 87701 that produces the Cry1Ac insecticidal crystal (delta-endotoxin) protein derived from Bacillus thuringiensis (Bt) subsp. kurstaki. Cry1Ac provides protection from feeding damage caused by certain targeted lepidopteran pests. The purpose of this work was to assess whether the compositions of seed, forage, and processed fractions (meal, oil, protein isolate, and lecithin) of MON 87701 are comparable to those of conventional soybean. Compositional analyses were conducted on seed and forage tissues harvested from MON 87701 and conventional soybean grown in multiple replicated sites in the United States during the 2007 growing season and in Argentina during the 2007-2008 growing season. Seed, forage, and processed fractions from conventional soybean varieties currently in the marketplace were included in the analyses to establish a range of natural variability for each compositional component; the range of variability was defined by a 99% tolerance interval. Additional seed was collected from soybean grown in a separate U.S. production during the 2007 season. This seed and processed fractions (meal, oil, protein isolate, and crude lecithin) derived from it were also subjected to compositional analyses. Forage samples were analyzed for levels of proximates (ash, fat, moisture, and protein), carbohydrates by calculation, and fiber. Seed samples were analyzed for proximates, carbohydrates by calculation, fiber, amino acids, fatty acids, antinutrients, and vitamin E. Toasted, defatted (TD) meal was analyzed for proximates, fiber, amino acids, and antinutrients. Refined, bleached, and deodorized (RBD) oil was analyzed for fatty acids and vitamin E. Protein isolate was analyzed for amino acids and moisture. Crude lecithin was analyzed for phosphatides. Overall, results demonstrated that the seed, forage, and processed fractions of MON 87701 are compositionally equivalent to those of conventional soybean.

show abstract

The Kjeldahl Digestion

Cited by 67 publications

References 83 publications

Preterm human milk composition: a systematic literature review

Preterm human milk composition: a systematic literature review

Gene Expression Changes in Phosphorus Deficient Potato (Solanum tuberosum L.) Leaves and the Potential for Diagnostic Gene Expression Markers

Compositions of Seed, Forage, and Processed Fractions from Insect-Protected Soybean MON 87701 Are Equivalent to Those of Conventional Soybean

Contact Info

Product

Resources

About