Changes in Protein Non-Covalent Bonds and Aggregate Size during Dough Formation

This research investigated changes in the amounts and sizes of monomeric proteins and protein aggregates during dough mixing, with a focus on the contribution of non-covalent bonds in the aggregation of gluten proteins. High protein flour (HF) and low protein flour (LF) were used in this study. As dough mixing progressed from flour to overmixed dough, the total amount of protein aggregates increased while the amount of monomeric protein decreased. Omega-gliadin was the major monomeric protein that decreased in quantity. Interestingly, the amount of larger-sized protein aggregates decreased and that of smaller-sized protein aggregates increased. The amount of gluten protein macro-polymer aggregated through strong non-covalent bonds decreased whereas aggregates formed with weaker non-covalent bonds increased. LF dough behaved similar to HF dough. Large-sized gluten protein aggregates disaggregated due to the weakening of non-covalent bonds and became smaller. Omega-gliadin was incorporated into gluten protein aggregates during dough mixing.

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Changes in Hydrophobic Interactions among Gluten Proteins during Dough Formation

Processes ◽

10.3390/pr9071244 ◽

2021 ◽

Vol 9 (7) ◽

pp. 1244

Author(s):

Sonoo Iwaki ◽

Katsuyuki Hayakawa ◽

Bin-Xiao Fu ◽

Chikako Otobe

Keyword(s):

High Performance ◽

Hydrophobic Interactions ◽

Fluorescence Analysis ◽

Size Exclusion ◽

Front Face ◽

Low Molecular Weight ◽

Gluten Proteins ◽

Dough Mixing ◽

Difference Gel Electrophoresis ◽

Monomeric Proteins

In this study, changes in hydrophobic interactions among gluten proteins were analyzed during dough mixing. Size-exclusion high-performance chromatography and two-dimensional fluorescence difference gel electrophoresis were performed on proteins extracted with 1-propanol by weakening the hydrophobic interaction. The amount of proteins extracted with 30% 1-propanol increased from the start of mixing to peak consistency, suggesting that the hydrophobic interactions among the strongly aggregated proteins weakened and resulted in disaggregation. The amount of proteins extracted with 10% 1-propanol decreased during hydration, indicating that these proteins aggregated through relatively weak hydrophobic interactions. The proteins that extractability decreased were mainly low molecular weight glutenin, α-gliadin, and γ-gliadin. The amount of monomeric proteins extracted with 30% 1-propanol decreased after peak consistency. The decreased protein was mainly ω-gliadin, indicating that ω-gliadin aggregated with other proteins through hydrophobic interactions. A front-face fluorescence analysis was performed on the dough with the addition of 8-anilino-1-naphthalenesulfonic acid or thioflavin T. The fluorescence intensity increased as a result of exposure to the hydrophobic groups of the gluten proteins and the formation of protein aggregates during dough mixing. These results indicate the importance of hydrophobic interactions in dough formation.

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THE EFFECT OF FERMENTATION ON SOME PROPERTIES OF GLUTEN

Canadian Journal of Research ◽

10.1139/cjr36c-019 ◽

1936 ◽

Vol 14c (6) ◽

pp. 222-228

Author(s):

G. H. Guest ◽

R. K. Larmour

Keyword(s):

Protein Content ◽

Wheat Flour ◽

Water Holding Capacity ◽

High Protein ◽

Gluten Protein ◽

High Protein Content ◽

Protein Flour ◽

Water Holding

Except in the cases of a flour of unusually high protein content (19%) and a Pacific Club wheat flour of 7.6% protein, the loss of gluten protein after four hours' fermentation was about 17% and the change in water-holding capacity was negligible. There was practically no differentiation between flours from heavily frosted wheat and average sound flours. The 19% protein flour, however, showed a loss of gluten protein of only 5 % and a slight increase in water-holding capacity; the Club flour showed a loss of 43.4% in gluten protein and a decrease of 27% in water-holding capacity. It is concluded that these two properties of gluten cannot be used to differentiate most flours.

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Study of structural changes of gluten proteins during bread dough mixing by Raman spectroscopy

Food Chemistry ◽

10.1016/j.foodchem.2021.129916 ◽

2021 ◽

Vol 358 ◽

pp. 129916

Author(s):

Eloïse Lancelot ◽

Joran Fontaine ◽

Joëlle Grua-Priol ◽

Ali Assaf ◽

Gérald Thouand ◽

...

Keyword(s):

Raman Spectroscopy ◽

Structural Changes ◽

Bread Dough ◽

Gluten Proteins ◽

Dough Mixing

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Adaptive changes in the capacity of systems used for the synthesis of citrulline in rat liver mitochondria in response to high- and low-protein diets

Biochemical Journal ◽

10.1042/bj1420359 ◽

1974 ◽

Vol 142 (2) ◽

pp. 359-364 ◽

Cited By ~ 30

Author(s):

J. D. McGivan ◽

Norah M. Bradford ◽

J. B. Chappell

Keyword(s):

Nitrogen Source ◽

High Protein Diet ◽

Liver Mitochondria ◽

High Protein ◽

Protein Diet ◽

Rat Liver Mitochondria ◽

Standard Diet ◽

Adaptive Changes ◽

Low Protein ◽

Citrulline Synthesis

1. Citrulline synthesis was measured in mitochondria from rats fed on a standard diet, a high-protein diet, or on glucose. 2. With NH4Cl as the nitrogen source the rate of citrulline synthesis was higher in mitochondria from rats fed on a high-protein diet than in those from rats fed on a standard diet. When rats were fed solely on glucose the rate of synthesis of citrulline from NH4Cl was very low. 3. With glutamate as the nitrogen source the relative rates of citrulline synthesis were much lower than when NH4Cl was present, but similar adaptive changes occurred. 4. The activity of the mitochondrial glutamate-transporting system increased two to three times on feeding rats on a high-protein diet, but the Km for glutamate was unchanged. 5. Adaptive changes in certain intramitochondrial enzymes were also measured. 6. The results were interpreted to indicate that when an excess of substrate was present, citrulline synthesis from NH4Cl was rate-limited by the intramitochondrial concentration of N-acetyl-glutamate, but citrulline synthesis from glutamate was rate-limited primarily by the activity of the glutamate-transporting system.

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Effect of chronic food restriction on pulsatile luteinizing hormone secretion and hypothalamic neuropeptide Y gene expression in castrate male sheep

Journal of Endocrinology ◽

10.1677/joe.0.1520329 ◽

1997 ◽

Vol 152 (2) ◽

pp. 329-337 ◽

Cited By ~ 45

Author(s):

C L Adam ◽

P A Findlay ◽

C E Kyle ◽

P Young ◽

J G Mercer

Keyword(s):

Gene Expression ◽

Neuropeptide Y ◽

Pulse Amplitude ◽

Pulse Frequency ◽

High Energy ◽

Low Energy ◽

High Protein ◽

Castrate Male ◽

Low Protein ◽

Male Sheep

Abstract Castrate male sheep (wethers, average liveweight 38 ± 0·6 kg) were given one of the following diets for 10 weeks followed by euthanasia (n=8/group): high-energy high-protein providing 1·5 times the energy required to maintain liveweight (maintenance) (group 1·5M), low-energy low-protein at 0·5 maintenance (0·5M), or low-energy high-protein at 0·5 maintenance (0·5M+P). 1·5M wethers gained 22% liveweight whereas 0·5M and 0·5M+P wethers lost 18 and 13% liveweight respectively. Relative to the 1·5M group, the 0·5M and 0·5M+P groups had similar plasma concentrations of glucose and cortisol throughout, but elevated non-esterified fatty acids (P<0·001) and reduced IGF-I and insulin (P<0·05, 0·01 or 0·001) from 1 week onwards. Each week blood samples were taken every 12 min for 4 h and plasma assayed for LH. Mean concentration over 4 h, LH pulse frequency and LH pulse amplitude showed no progressive change in 1·5M sheep. However, in both 0·5M and 0·5M+P groups mean LH increased (P<0·001 and P<0·01 respectively), pulse frequency decreased (P<0·01 and P<0·01) and pulse amplitude increased (P<0·001 and P<0·01) over the 10-week period. Anterior pituitary LH content was greater in 0·5M (P<0·01) and 0·5M+P (P<0·05) than in 1·5M sheep. Coronal sections (20 μm) of hypothalamic brain tissue were subjected to in situ hybridisation to determine gene expression for neuropeptide Y (NPY). NPY mRNA was concentrated in the arcuate nucleus and median eminence, with total amounts greater in both 0·5M (310%, P<0·001) and 0·5M+P (333%, P<0·01) groups than in 1·5M sheep (100%). These data reveal that chronic low dietary energy intake by long-term castrates, with high or low protein intake, reduces LH pulse frequency but increases the circulating levels of LH by virtue of an increase in pulse amplitude, and concomitantly increases hypothalamic NPY gene expression. Journal of Endocrinology (1997) 152, 329–337

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Influence of high-protein diets on brain phospholipid, ganglioside and monogalactosyl glycolipid content previously altered by long-term low-protein and ethanol administration.

Journal of Studies on Alcohol ◽

10.15288/jsa.1988.49.369 ◽

1988 ◽

Vol 49 (4) ◽

pp. 369-374 ◽

Cited By ~ 1

Author(s):

S R Vrbaski ◽

G T Petrović ◽

V I Ristić ◽

M S Ristić

Keyword(s):

High Protein ◽

Ethanol Administration ◽

Low Protein ◽

Brain Phospholipid ◽

High Protein Diets ◽

Protein Diets

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Kualitas Organoleptik Telur Itik yang Diberi Pakan Maggot Hidup (Hermetia illucens)

AL ULUM JURNAL SAINS DAN TEKNOLOGI ◽

10.31602/ajst.v5i1.2418 ◽

2019 ◽

Vol 5 (1) ◽

pp. 1

Author(s):

Aam Gunawan

Keyword(s):

High Protein ◽

Protein Source ◽

Hermetia Illucens ◽

Organoleptic Quality ◽

Low Protein ◽

Randomized Design ◽

Living State ◽

Completely Randomized Design ◽

Range Test

Maggot black soldier fly (Hermetia illucens) is a protein source of feed which is highly favored by poultry, especially ducks and chickens. However, it is feared that the provision of live maggot in ducks will affect the organoleptic quality of the egg, especially its taste and aroma. Therefore this study aims to determine the organoleptic quality of duck eggs fed Hermetia illucens maggot feeds in a living state. The study used 120 alabio ducks which were placed in a postal cage. The design used was a completely randomized design, each treatment using six replications. Each replication is taken egg sample to be tested panelists. The panelists used were 67 panelists who were somewhat trained. The data obtained were analyzed of variance and Duncan's multiple range test. The treatments that were tried consisted of P1: low protein rations without live maggot, P2: low protein rations with live maggot administration 40 g/bird/day, P3: high protein rations without live maggot administration, and P4: high protein rations with live maggot administration 40g/bird/day. The results showed that the treatment affected the texture, flavor, and aroma of boiled eggs. Ducks fed with high protein ration coupled with the provision of live maggot 40 g/bird/day produce softer textures, tastes quite good, and aroma more fishy. Keywords: Maggot, duck eggs, organoleptics

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Protein intake and outcome of critically ill patients: analysis of a large international database using piece-wise exponential additive mixed models

Critical Care ◽

10.1186/s13054-021-03870-5 ◽

2022 ◽

Vol 26 (1) ◽

Author(s):

Wolfgang H. Hartl ◽

Philipp Kopper ◽

Andreas Bender ◽

Fabian Scheipl ◽

Andrew G. Day ◽

...

Keyword(s):

Hospital Discharge ◽

Critically Ill ◽

Acute Phase ◽

Critically Ill Patients ◽

Protein Intake ◽

High Protein ◽

Protein Diet ◽

High Protein Intake ◽

Low Protein ◽

Standard Protein

Abstract Background Proteins are an essential part of medical nutrition therapy in critically ill patients. Guidelines almost universally recommend a high protein intake without robust evidence supporting its use. Methods Using a large international database, we modelled associations between the hazard rate of in-hospital death and live hospital discharge (competing risks) and three categories of protein intake (low: < 0.8 g/kg per day, standard: 0.8–1.2 g/kg per day, high: > 1.2 g/kg per day) during the first 11 days after ICU admission (acute phase). Time-varying cause-specific hazard ratios (HR) were calculated from piece-wise exponential additive mixed models. We used the estimated model to compare five different hypothetical protein diets (an exclusively low protein diet, a standard protein diet administered early (day 1 to 4) or late (day 5 to 11) after ICU admission, and an early or late high protein diet). Results Of 21,100 critically ill patients in the database, 16,489 fulfilled inclusion criteria for the analysis. By day 60, 11,360 (68.9%) patients had been discharged from hospital, 4,192 patients (25.4%) had died in hospital, and 937 patients (5.7%) were still hospitalized. Median daily low protein intake was 0.49 g/kg [IQR 0.27–0.66], standard intake 0.99 g/kg [IQR 0.89– 1.09], and high intake 1.41 g/kg [IQR 1.29–1.60]. In comparison with an exclusively low protein diet, a late standard protein diet was associated with a lower hazard of in-hospital death: minimum 0.75 (95% CI 0.64, 0.87), and a higher hazard of live hospital discharge: maximum HR 1.98 (95% CI 1.72, 2.28). Results on hospital discharge, however, were qualitatively changed by a sensitivity analysis. There was no evidence that an early standard or a high protein intake during the acute phase was associated with a further improvement of outcome. Conclusions Provision of a standard protein intake during the late acute phase may improve outcome compared to an exclusively low protein diet. In unselected critically ill patients, clinical outcome may not be improved by a high protein intake during the acute phase. Study registration ID number ISRCTN17829198

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