scholarly journals Short Communication: Differences in Levels of Free Amino Acids and Total Protein in Human Foremilk and Hindmilk

Nutrients ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1828 ◽  
Author(s):  
Joris van Sadelhoff ◽  
Dimitra Mastorakou ◽  
Hugo Weenen ◽  
Bernd Stahl ◽  
Johan Garssen ◽  
...  

Free amino acids (FAAs) in human milk are indicated to have specific functional roles in infant development. Studies have shown differences between human milk that is expressed at the beginning of a feed (i.e., foremilk) and the remainder of the milk expressed (i.e., hindmilk). For example, it is well established that human hindmilk is richer in fat and energy than foremilk. Hence, exclusively feeding hindmilk is used to enhance weight gain of preterm, low birthweight infants. Whether FAAs occur differently between foremilk and hindmilk has never been reported, but given their bioactive capacities, this is relevant to consider especially in situations where hindmilk is fed exclusively. Therefore, this study analyzed and compared the FAA and total protein content in human foremilk and hindmilk samples donated by 30 healthy lactating women. The total protein content was found to be significantly higher in hindmilk (p < 0.001), whereas foremilk contained a significantly higher total content of FAAs (p = 0.015). With regards to individual FAAs, foremilk contained significantly higher levels of phenylalanine (p = 0.009), threonine (p = 0.003), valine (p = 0.018), alanine (p = 0.004), glutamine (p < 0.001), and serine (p = 0.012) than hindmilk. Although statistical significance was reached, effect size analysis of the milk fraction on FAA levels in milk revealed that the observed differences were only small. To what extent these differences are of physiological importance for infant development remains to be examined in future research.

Foods ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2431
Author(s):  
Nicola Landi ◽  
Sara Ragucci ◽  
Antimo Di Maro

Cow, sheep and goat raw milk raised in Ailano and Valle Agricola territories (‘Alto Casertano’, Italy) were characterized (raw proteins, free and total amino acids content) to assess milk quality. Raw milk with the highest total protein content is sheep milk followed by goat and cow milk from both localities. Total amino acid content in cow, goat and sheep raw milk is 4.58, 4.81 and 6.62 g per 100 g, respectively, in which the most abundant amino acid is glutamic acid (~20.36 g per 100 g of proteins). Vice versa, the free amino acids content characteristic profiles are different for each species. In particular, the most abundant free amino acid in cow, sheep and goat raw milk is glutamic acid (9.07 mg per 100 g), tyrosine (4.72 mg per 100 g) and glycine (4.54 mg per 100 g), respectively. In addition, goat raw milk is a source of taurine (14.92 mg per 100 g), retrieved in low amount in cow (1.38 mg per 100 g) and sheep (2.10 mg per 100 g) raw milk. Overall, raw milk from ‘Alto Casertano’ show a high total protein content and are a good source of essential amino acids.


1998 ◽  
Vol 25 (1) ◽  
pp. 31-34 ◽  
Author(s):  
M. Ali-Ahmad ◽  
S. M. Basha

Abstract Water stress was induced in peanut (Arachis hypogaea L. cv. Marc 1) plants by withholding water for 5 to 20 d. Leaves from the water-stressed plants were analyzed to determine the effect of water stress on amino acids, sugars, protein content, and polypeptide composition of peanut plants. The results showed that the total protein content of the leaves significantly increased when peanut plants were subjected to water stress for 5 to 20 d as compared to irrigated controls. Analysis of the leaf protein by SDS polyacrylamide gel electrophoresis showed higher levels of polypeptides in stressed leaves compared to the control leaves. Peanut leaves from water-stressed plants also showed higher amounts of free amino acids and soluble sugars as compared to the irrigated plants. Thus, water stress enhanced accumulation of proteins, free amino acids, and soluble sugars in the peanut plants.


PEDIATRICS ◽  
1977 ◽  
Vol 59 (3) ◽  
pp. 407-422 ◽  
Author(s):  
David K. Rassin ◽  
Gerald E. Gaull ◽  
Kirsti Heinonen ◽  
Niels C. R. Räihäa

The optimal quantity and quality of protein for low-birth-weight infants is undefined. In this study, 106 well, appropriate-for-gestational-age, low-birth-weight infants weighing 2,100 gm or less were divided into three gestational age groups and assigned randomly within each age group to one of five feeding regimens: pooled human milk; formula 1 (protein content, 1.5 gm/100 ml, 60 parts bovine whey proteins to 40 parts bovine caseins); formula 2 (3.0 gm/100 ml, 60:40); formula 3 (1.5 gm/100 ml, 18:82); and formula 4 (3.0 gm/100 ml, 18:82). The concentrations of the free amino acids in the plasma and urine of these infants were determined. The plasma concentrations of free amino acids were generally far greater in the infants fed the 3.0-gm/100 ml protein diets than they were in the infants fed pooled human milk. The plasma concentrations of free amino acids of the infants fed the 1.5-gm/100 ml protein diets were intermediate. In general, the concentrations of the free amino acids in the plasma of the infants fed the 3.0-gm/100 ml caseinpredominant formula (F4) were furthest from those fed pooled human milk. Glutamate showed the highest plasma amino acid concentrations in infants fed both the high- and low-protein casein-predominant formulas. This was true despite the fact that the intake of glutamate on the high-protein, whey-predominant formula was twice that on the low-protein, casein-predominant formula. The differences between groups in the essential amino acids in plasma were generally greater than those of the nonessential amino acids. The concentrations of amino acids in the urine tended to parallel those of the plasma.


1979 ◽  
Vol 56 (5) ◽  
pp. 427-432 ◽  
Author(s):  
P. Möller ◽  
J. Bergström ◽  
S. Eriksson ◽  
P. Fürst ◽  
K. Hellström

1. The concentrations of electrolytes and free amino acids in plasma and the quadriceps femoris muscle were studied in ten apparently healthy elderly men, 52–77 years of age. The results were compared with those previously recorded for men 20–36 years old. 2. The two groups of subjects did not differ with regard to serum electrolytes and intracellular water content but the extracellular water in the older subjects exceeded that of the younger group by about 50%. The muscle specimens of the elderly men were also characterized by a 40% elevation of their total contents of Na+ and Cl−, whereas the content of K+ and Mg2+ was almost identical in both groups. 3. The means recorded for the plasma concentrations of most amino acids tended to be higher in the elderly men. The differences reached statistical significance for tyrosine, histidine, valine, lysine and total essential amino acids. In keeping with the findings in plasma, the amino acid concentrations in the muscle of the older group tended to exceed those of the younger ones. The difference reached statistical significance with regard to total amino acids, essential and non-essential amino acids, aspartate, alanine, citrulline, histidine, arginine, leucine and lysine. The various mechanisms that may contribute to these findings are discussed.


2005 ◽  
Vol 40 (4) ◽  
pp. 496-500 ◽  
Author(s):  
Chih-Kuang Chuang ◽  
Shuan-Pei Lin ◽  
Hung-Chang Lee ◽  
Tuen-Jen Wang ◽  
Yu-Shu Shih ◽  
...  

2003 ◽  
Vol 81 (3) ◽  
pp. 357-362 ◽  
Author(s):  
Brunella Carratù ◽  
Concetta Boniglia ◽  
Francesco Scalise ◽  
Amalia Maria Ambruzzi ◽  
Elisabetta Sanzini

1984 ◽  
Vol 39 (3) ◽  
pp. 441-448 ◽  
Author(s):  
Y. Zhang ◽  
I. G. Partridge ◽  
H. D. Keal ◽  
K. G. Mitchell

ABSTRACTNitrogen balance was measured in a series of experiments to determine the optimum balance between lysine, threonine and methionine plus cystine by successive additions of the free amino acids to a basal diet of barley, soya bean meal and tallow. The basal diet had a calculated digestible energy (DE) value of 14·5 MJ/kg and a crude protein content of 146 g/kg. The ranges of total lysine; threonine and methionine plus cystine tested were (g/kg) 6·6 to 11·8, 4·9 to 6·9 and 4·3 to 71, respectively. Latin-square designs were used involving a total of 33 pigs. Nitrogen utilization was optimized in pigs of 3 to 9 weeks of age when each kg of diet contained 10·5 g lysine, 6·4 g threonine and 5·0 g methionine plus cystine, corresponding to a ratio of 100: 61: 48. Thereafter, five diets were formulated in which the same ratio was maintained, but at different protein levels (129 to 192 g/kg). Again the diets were based on barley, soya bean meal and tallow supplemented with free amino acids. These diets were compared, in both nitrogen balance and performance experiments, with a conventional early-weaning diet with a protein content of 240 g/kg. All six diets had the same calculated DE value (14·5 MJ/kg). The N balance experiment was of Latin-square design and involved 18 pigs, and the performance experiment used 36 pigs fed individually from 3 to 9 weeks of age. A diet containing 0·99 g lysine per MJ DE (14·4 g lysine and 192 g balanced protein per kg) was considered to be adequate on the basis of the growth rate and food conversion efficiency results obtained.


2016 ◽  
Vol 63 (3) ◽  
pp. 374-378 ◽  
Author(s):  
Anni Larnkjær ◽  
Signe Bruun ◽  
Dorthe Pedersen ◽  
Gitte Zachariassen ◽  
Vibeke Barkholt ◽  
...  

2000 ◽  
Vol 43 (2) ◽  
pp. 179-192
Author(s):  
H. Nonn ◽  
H. Jeroch

Abstract. Title of the Paper: Investigation on N-reduced feeding and use of free amino acids in fattening pigs The aim of the present study was to investigate the N-reduced feeding by fattening pigs feed by cereals rieh feedmixture supplemented with the free amino-acids L-lysine, DL-methionine, L-threonine, L-tryptophane, Lleucine, L-isoleucine, L-histidine and L-valine. It was to test extreme low crude protein content by requirement sufficient supply on amino-aeid. The reaction of the animals in growth, carcass quality and the reduction of Nexeretion was to investigate. The pigs were divided in two groups (control and experimental group) with 24 animals per group (12 females and 12 castrates). The experiment was divided into three periods (25–60, 60–85 and 85–110 kg body weight). The protein content of the feedmixture was by the control group 18.3, 15.6 and 13.6% and by the experimental group 14.0, 11.8 and 10.7%, respectively. The lysine-energy ratio of the feedmixture was by all three feeding periods by 0.72 or 0.74, 0.61 or 0.62 and 0.55 or 0.57 g lysine per MJ ME in control feedmixture or experimental feedmixture, respectively. By a high Performance are the average daily life weight gain (control group 869 and experimental group 863 g) and the lean meat rate (control group 55.2 and experimental group 55:0%) not influenced by the high of crude protein supply. The calculated N-excretion were by the control group 4.16 kg (as 100%) and by experimental group 2.60 kg (62.5%) per 100 kg body weight gain.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12343
Author(s):  
Vijay Joshi ◽  
Padma Nimmakayala ◽  
Qiushuo Song ◽  
Venkata Abburi ◽  
Purushothaman Natarajan ◽  
...  

Background Watermelon seeds are a powerhouse of value-added traits such as proteins, free amino acids, vitamins, and essential minerals, offering a paleo-friendly dietary option. Despite the availability of substantial genetic variation, there is no sufficient information on the natural variation in seed-bound amino acids or proteins across the watermelon germplasm. This study aimed to analyze the natural variation in watermelon seed amino acids and total protein and explore underpinning genetic loci by genome-wide association study (GWAS). Methods The study evaluated the distribution of seed-bound free amino acids and total protein in 211 watermelon accessions of Citrullus spp, including 154 of Citrullus lanatus, 54 of Citrullus mucosospermus (egusi) and three of Citrullus amarus. We used the GWAS approach to associate seed phenotypes with 11,456 single nucleotide polymorphisms (SNPs) generated by genotyping-by-sequencing (GBS). Results Our results demonstrate a significant natural variation in different free amino acids and total protein content across accessions and geographic regions. The accessions with high protein content and proportion of essential amino acids warrant its use for value-added benefits in the food and feed industries via biofortification. The GWAS analysis identified 188 SNPs coinciding with 167 candidate genes associated with watermelon seed-bound amino acids and total protein. Clustering of SNPs associated with individual amino acids found by principal component analysis was independent of the speciation or cultivar groups and was not selected during the domestication of sweet watermelon. The identified candidate genes were involved in metabolic pathways associated with amino acid metabolism, such as Argininosuccinate synthase, explaining 7% of the variation in arginine content, which validate their functional relevance and potential for marker-assisted analysis selection. This study provides a platform for exploring potential gene loci involved in seed-bound amino acids metabolism, useful in genetic analysis and development of watermelon varieties with superior seed nutritional values.


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