scholarly journals Use of Rapid Capillary Zone Electrophoresis to Determine Amino Acids Indicators of Herring Ripening during Salting

Foods ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2518
Author(s):  
Katarzyna Felisiak ◽  
Mariusz Szymczak
Keyword(s):  
Amino Acids ◽  
Sensory Evaluation ◽  
Free Amino Acids ◽  
Free Amino ◽  
Hydrolysis Product ◽  
Principal Component ◽  
Statistical Regression ◽  
Protein Nitrogen ◽  
Salted Fish ◽  
Evaluation Parameters

Currently, herring fillets are salted with acetic acid to activate muscle proteases. This causes a change in the composition of free amino acids, compared to salting of whole fish with viscera proteases. Therefore, old indicators of the ripening dynamics of salted fish based on amino acids are not current. Determination of free amino acids can be performed by many methods, but most are labor intensive and expensive. Therefore, a capillary electrophoresis method without derivatization (CZE) was used to determine the actual ripening rates of salted herring fillets. A group of hydrophobic and basic amino acids were determined in trichloroacetic acid (TCA) extracts of meat and brine to develop 16 indicators. Statistical regression analysis of the indicators (R2adj, RMSE, cluster analysis) followed by principal component analysis (PCA) correlation analysis of the indicators vs sensory evaluation parameters of texture and TPA-hardness of salted fillet meat allowed the choice of the most precise indicators. The best indicator in meat was Phe/Tyr-height, which value increased during salting. A more precise indicator of ripening was His/Tyr-height in brine, which value decreased during salting. Sensory evaluation parameters of salted herring texture correlated strongly with TPA-hardness and traditional indicators such as non-protein nitrogen and protein hydrolysis product fraction content. However, the most precise indicators were those obtained from amino acids determined by the CZE method. Results obtained in this study may be suitable for fast monitoring of the salted herring ripening process in industry.

scholarly journals Quantification of non-protein nitrogen components of infant formulae and follow-up milks: comparison with cows' and human milk

2003 ◽  
Vol 90 (1) ◽  
pp. 127-133 ◽  
Author(s):  
I. M. P. L. V. O. Ferreira
Keyword(s):  
Amino Acids ◽  
Human Milk ◽  
Free Amino Acids ◽  
Free Amino ◽  
Orotic Acid ◽  
Statistical Treatment ◽  
Principal Component ◽  
Protein Nitrogen ◽  
Infant Formulae

The composition of fourteen infant formulae and six follow-up milks with regard to their free amino acids (including taurine), free nucleotides, orotic acid, and free and total L-carnitine content was studied. The levels found were compared with the limits established in European legislation and with the composition of human and cows' milk samples. HPLC methodologies, optimized and validated for the matrices under study, were used, except for free and total L-carnitine contents that were quantified using a flow-injection manifold, also optimized and validated for the matrices under study. Global statistical treatment of the results by cluster analysis indicated similarities between the contents of the N compounds under study of infant formulae, follow-up milks and cows' milk and differences with regard to human milk composition. The principal component analysis showed that 60·2% of the variation in data was due to the first principal component, and the second component represented 23·8% of the total information. Nucleotide profiles, orotic acid, and free and total L-carnitine contents explain the main differences observed between human milk and the other milks studied (cows' milk, infant formulae and follow-up milks). Cows' milk is distinguished from infant formulae and follow-up milks mainly owing to the different uric acid contents and free amino acids profiles.

scholarly journals Effect of Different Edaphic Crop Conditions on the Free Amino Acid Profile of PH-16 Dry Cacao Beans

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1637
Author(s):  
Quintino Reis de Araujo ◽  
Guilherme Amorim Homem de Abreu Loureiro ◽  
Cid Edson Mendonça Póvoas ◽  
Douglas Steinmacher ◽  
Stephane Sacramento de Almeida ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Free Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Principal Component ◽  
Amino Acid Profile ◽  
Gamma Aminobutyric Acid ◽  
Significant Difference

Free amino acids in cacao beans are important precursors to the aroma and flavor of chocolate. In this research, we used inferential and explanatory statistical techniques to verify the effect of different edaphic crop conditions on the free amino acid profile of PH-16 dry cacao beans. The decreasing order of free amino acids in PH-16 dry cacao beans is leucine, phenylalanine, glutamic acid, alanine, asparagine, tyrosine, gamma-aminobutyric acid, valine, isoleucine, glutamine, lysine, aspartic acid, serine, tryptophan, threonine, glycine. With the exception of lysine, no other free amino acid showed a significant difference between means of different edaphic conditions under the ANOVA F-test. The hydrophobic free amino acids provided the largest contribution to the explained variance with 58.01% of the first dimension of the principal component analysis. Glutamic acid stands out in the second dimension with 13.09%. Due to the stability of the biochemical profile of free amino acids in this clonal variety, it is recommended that cacao producers consider the genotype as the primary source of variation in the quality of cacao beans and ultimately the chocolate to be produced.

Free Amino Acid and Haemolymph Concentration Changes in Sphaeroma Rugicauda (Isopoda) During Adaptation to a Dilute Salinity

1969 ◽  
Vol 50 (2) ◽  
pp. 319-326
Author(s):  
R. R. HARRIS
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Sea Water ◽  
Protein Nitrogen ◽  
Body Sodium ◽  
Concentration Changes ◽  
Total Body

1. Non-protein and protein nitrogen fractions of the isopod Sphaeroma rugicauda were measured in animals adapted to 100 and 2% sea water. 2. The non-protein nitrogen component was reduced in animals acclimatized to the lower salinity. 3. Free amino acids accounted for 88 and 74% respectively of the non-protein nitrogen in the two salinities. 4. In 2% sea water taurine, proline, glycine, alanine and glutamic acid showed the greatest decreases in concentration compared to the levels measured in animals adapted to 100% sea water. 5. The decrease in total free amino acids of animals acclimatized to 100% sea water and transferred to 2% sea water was measured. 6. The total free amino acid concentration is reduced to the 2% sea water level within 12 hr. after transfer. 7. Free amino acid, haemolymph sodium and total body sodium levels after transfer to 2% sea water were compared. 8. The asymmetry between the fall in haemolymph sodium concentration and the decrease in total body sodium under these conditions is thought to be due to a water shift from the haemolymph into the tissues. 9. It is suggested that the osmotic pressure of the cells falls at a slower rate than that of the haemolymph.

scholarly journals Identification of Umami Taste in Sous-Vide Beef by Chemical Analyses, Equivalent Umami Concentration, and Electronic Tongue System

Foods ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 251 ◽  
Author(s):  
Young-Hwa Hwang ◽  
Ishamri Ismail ◽  
Seon-Tea Joo
Keyword(s):  
Amino Acids ◽  
Principal Component Analysis ◽  
Food Processing ◽  
Free Amino Acids ◽  
Free Amino ◽  
Electronic Tongue ◽  
Principal Component ◽  
Chemical Analyses ◽  
Umami Taste ◽  
Sous Vide

Behaviour of umami compounds that are associated with non-volatile compounds on slow cooking regimes remains less explored. This study aims to assess the ability of the electronic tongue system on the umami taste from sous-vide beef semitendinosus. The identification was based on the taste-enhancing synergism between umami compounds 5’-nucleotides (IMP, GMP, AMP, inosine, and hypoxanthine) and free amino acids (glutamic and aspartic acid) using the estimation of equivalent umami concentration (EUC) and electronic tongue system. Sous-vide cooked at 60 and 70 °C for 6 and 12 h and cooked using the conventional method at 70 °C for 30 min (as control) were compared. The temperature had a significant effect on 5’-nucleotides, but aspartic and glutamic acid were not influenced by any treatments applied. Sous-vide cooked at 60 °C tended to have higher inosine and hypoxanthine. Meanwhile, desirable 5’-nucleotides IMP, AMP, and GMP were more intensified at the temperature of 70 °C. The principal component analysis predicted a good correlation between EUC and the electronic tongue, with sous-vide at 70 °C for 12 h presenting the most umami. Therefore, the electronic tongue system is a useful tool in food processing, particularly in determining complex sensory properties such as umami, which cannot be evaluated objectively.

Nitrogenous components of human milk: non-protein nitrogen, true protein and free amino acids

2003 ◽  
Vol 81 (3) ◽  
pp. 357-362 ◽  
Author(s):  
Brunella Carratù ◽  
Concetta Boniglia ◽  
Francesco Scalise ◽  
Amalia Maria Ambruzzi ◽  
Elisabetta Sanzini
Keyword(s):  
Amino Acids ◽  
Human Milk ◽  
Free Amino Acids ◽  
Free Amino ◽  
Protein Nitrogen ◽  
True Protein

scholarly journals THE CHEMISTRY OF INSECT HEMOLYMPH

1956 ◽  
Vol 39 (6) ◽  
pp. 853-868 ◽  
Author(s):  
G. R. Wyatt ◽  
T. C. Loughheed ◽  
S. S. Wyatt
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Developmental Stages ◽  
Galleria Mellonella ◽  
Similar Distribution ◽  
Total Acid ◽  
Protein Nitrogen ◽  
Larval Hemolymph

1. Hemolymph was collected for analysis from the silkworm, Bombyx mori, in a series of developmental stages ranging from the second molt to the late pupa. The mean pH of larval hemolymph after collection was found to be 6.45, that of pupal hemolymph, 6.57; in vivo values may be slightly lower. Total dry solids ranged from 5.4 to 10.6 per cent. Total protein ranged from 1.2 to 5.3 per cent, increasing rapidly during the fifth instar. 2. Free amino acids were separated chromatographically and estimated. Of 19 amino acids identified, amounting collectively to 823 to 1497 mg. per 100 ml., glutamine, histidine, and lysine generally occurred in greatest amount. Tryptophan was not detected, and cystine (or cysteine) was found in only one sample. The total free amino acids account for 35 to 55 per cent of the non-protein nitrogen of the plasma. 3. Free sugars, estimated semiquantitatively on chromatograms, comprise glucose, fructose, and sucrose in total amount ranging from about 5 to 40 mg. per 100 ml. Total acid-soluble, ultrafiltrable carbohydrate, estimated as glucose by the anthrone reaction, ranged from 166 to 635 mg. per 100 ml., indicating the presence of low molecular weight sugar derivatives. 4. Inorganic phosphate amounted to 5 to 15 mg. per 100 ml., and acid-soluble organic phosphate to 100 to 200 mg. per 100 ml. The latter fraction includes several substances, of which one was tentatively identified as glucose-6-phosphate and the remainder are as yet unidentified. 5. Single samples of hemolymph were also taken from larvae of the wax moth, Galleria mellonella, and the spruce sawfly, Diprion hercyniae. These contained even higher concentrations of solutes than the silkworm samples, but with a generally similar distribution. The proportions of the free amino acids were different in each species.

Note. Effect of brining time on proteolytic changes in Idiazábal cheese during ripening / Nota. Cambios proteolíticos durante la maduración del queso Idiazábal por efecto del tiempo en salmuera

1996 ◽  
Vol 2 (5) ◽  
pp. 335-339 ◽  
Author(s):  
F.C. Ibáñez ◽  
A.I. Ordóñez ◽  
M.S. Vicente ◽  
M.I. Torres ◽  
Y. Barcina
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Total Nitrogen ◽  
Free Amino Acids ◽  
Free Amino ◽  
Dry Matter ◽  
Electrophoretic Analysis ◽  
Soluble Nitrogen ◽  
Clear Trend ◽  
Protein Nitrogen

Idiazábal cheeses were made employing brining times of 12 h (batch A) and 36 h (batch B). Proteolytic changes in both batches were examined over 270 d of ripening; proteolysis was low in both batches, but lower in batch B than in batch A. Electrophoretic analysis revealed incom plete breakdown of αs and β-caseins at the end of the ripening period, particularly in batch B. The proportion of soluble nitrogen as a percentage of total nitrogen was 17.55% in batch B and 19.48% in batch A, while the proportion of non-protein nitrogen was 11.78% in batch B and 15.16% in batch A. The proportion of non-protein nitrogen as a percentage of soluble nitrogen was 67.17% in batch B and 77.88% in batch A. The free amino acids, the smallest non-protein nitrogen frac tion, attained values of 1203 mg/100 g of dry matter in batch B and 1902 mg/100 g of dry matter in batch A. After 60 d of ripening, the main free amino acids were glutamic acid, valine, leucine, lysine, and phenylalanine in both batches, although levels were higher in the batch with the shorter brining time. There was no clear trend in the non-protein-forming amino acids with either ripening time or brining time.

scholarly journals Plasma Free Amino Acids and Risk of Cardiovascular Disease in Chinese Patients With Type 2 Diabetes

2021 ◽  
Vol 11 ◽  
Author(s):  
Tie Li ◽  
Hui-Huan Luo ◽  
Xiao-Fei Feng ◽  
Yu Bai ◽  
Zhong-Ze Fang ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Cardiovascular Disease ◽  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Principal Component ◽  
Chinese Patients ◽  
Cvd Risk ◽  
Plasma Free Amino Acids

ObjectivesThis study aimed to explore associations between plasma free amino acids (PFAA) and risk of cardiovascular disease (CVD) in Chinese with Type 2 diabetes (T2D).MethodsWe retrieved 741 inpatients with T2D consecutively from tertiary hospital. Twenty-three PFAA were measured. CVD was defined as having coronary heart disease (CHD) or stroke. Principal component analysis was used to extract factors of PFAA. Factors and their components were introduced into binary logistic regressions as continuous and tertiles to obtain OR (odds ratio) and 95% confidence interval (CI) for CVD (or its components) risk.ResultsOf 741 inpatients, 282 (38.1%) had CVD (CHD alone: 122, stroke alone: 109, both: 51). Five factors were extracted, accounting for 65% of the total variance. Factor 3 composed of glutamate and tryptophan was associated with increased CVD risk (ORs, 95%CI of top vs. bottom tertiles: 1.60, 1.02–2.50 for CVD; 2.19, 1.17–4.07 for stroke, 1.51, 0.83–2.73 for CHD); the ORs (top vs. bottom tertiles) of glutamate were 2.62 (95%CI, 1.18–5.84) for stroke and 1.44 (0.80–2.61) for CHD; the ORs (top vs. bottom tertiles) of tryptophan were 1.50 (0.81–2.75) for stroke and 1.07 (0.58–1.97) for CHD. Comparable results were observed according to important confounders (all P for interaction >0.05).ConclusionsElevated factor 3 composed of glutamate and tryptophan was associated with increased CVD, especially stroke in T2D in China.

scholarly journals The contents of free amino acids and elements in As-hyperaccumulator Pteris cretica and non-hyperaccumulator Pteris straminea during reversible senescence

2017 ◽  
Vol 63 (No. 10) ◽  
pp. 455-460 ◽  
Author(s):  
Pavlíková Daniela ◽  
Zemanová Veronika ◽  
Pavlík Milan
Keyword(s):  
Amino Acids ◽  
Principal Component Analysis ◽  
Free Amino Acids ◽  
Free Amino ◽  
Time Course ◽  
Principal Component ◽  
Pteris Cretica ◽  
Stress Metabolites ◽  
The Relationship ◽  
Hyperaccumulator Plant

The objectives of this study were to analyse the relationship between the contents of elements and free amino acids (AAs) in fronds of As-hyperaccumulator Pteris cretica cv. Albo-lineata (PC) and non-hyperaccumulator Pteris straminea (PS) during reversible senescence. The time-course effect on senescence was also investigated. The two ferns were grown in a pot experiment with soil containing 16 mg As<sub>total</sub>/kg soil for 160 days. The contents of elements and AAs in both ferns and in individual sampling periods differed. The highest accumulation of elements and AAs was measured in PS fronds after 83 days; however, the accumulation of As, Ca, Cu, Fe, Mg, P and asparagin in PC fronds was highest after 160 days. The results of principal component analysis showed more rapid senescence of PS compared to PC. This was caused by changes in the relationship between the contents of elements (cofactors of metalloenzymes, stress metabolites) and AAs (transport of NH<sub>2</sub> group and stress metabolites). The hyperaccumulator plant (PC) was more resistant than the bioindicator plant (PS) to the conversion from reversible to irreversible senescence.

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