This review covers recent developments in kokumi taste (thickness, richness, mouthfulness, and continuity) studies of γ-glutamyl peptides. Aspects covered include food sources of the peptides, their ...enzymatic synthesis, activation on the kokumi receptors, and functional properties. γ-Glutamyl peptides, including γ-glutamyl dipeptides, tripeptides, and sulfur-containing γ-glutamyl-S-alk(en)yl-l-cysteine, are widely found in edible legumes, alliaceae, and fermented foods like soy sauce and cheese. These peptides, including γ-Glu(n≦5)-Phe/Val/Met/Tyr/Leu/His/Tau, γ-glutamyl-S-allyl-cysteine and γ-glutamyl-S-methyl-cysteine, have been successfully synthesized via catalysis with γ-glutamyl transpeptidase and L-glutaminases. These kokumi-active γ-glutamyl peptides exhibit astringency only in aqueous solution, but kokumi-imparting properties result when the peptides are added to food. Several of these peptides exhibit certain basic tastes, including sourness, bitterness, or umaminess in aqueous solution, and some can enhance the intensity of the basic taste. Several γ-glutamyl peptides can aid the treatment of intestinal inflammation for the positive allosteric activation on the calcium-sensing receptor. Future areas of research include further investigation of sensory physiology, screening microbial enzymes with high affinity for different acceptors, functional properties like triggering the release of cholecystokinin via the activation of the calcium-sensing receptor, and metabolic mechanism of the exogenous γ-glutamyl peptides in tissues.
•Naturally occurring γ-glutamyl peptides in food.•The taste characteristics of γ-glutamyl peptides.•The physiological function of γ-glutamyl peptides.
A
bstract
We present a new calculation of the energy distribution of high-energy neutrinos from the decay of charm and bottom hadrons produced at the Large Hadron Collider (LHC). In the kinematical ...region of very forward rapidities, heavy-flavor production and decay is a source of tau neutrinos that leads to thousands of charged-current tau neutrino events in a 1 m long, 1 m radius lead neutrino detector at a distance of 480 m from the interaction region. In our computation, next-to-leading order QCD radiative corrections are accounted for in the production cross-sections. Non-perturbative intrinsic-
k
T
effects are approximated by a simple phenomenological model introducing a Gaussian
k
T
-smearing of the parton distribution functions, which might also mimic perturbative effects due to multiple initial-state soft-gluon emissions. The transition from partonic to hadronic states is described by phenomenological fragmentation functions. To study the effect of various input parameters, theoretical predictions for
D
s
±
production are compared with LHCb data on double-differential cross-sections in transverse momentum and rapidity. The uncertain- ties related to the choice of the input parameter values, ultimately affecting the predictions of the tau neutrino event distributions, are discussed. We consider a 3+1 neutrino mixing scenario to illustrate the potential for a neutrino experiment to constrain the 3+1 parameter space using tau neutrinos and antineutrinos. We find large theoretical uncertainties in the predictions of the neutrino fluxes in the far-forward region. Untangling the effects of tau neutrino oscillations into sterile neutrinos and distinguishing a 3+1 scenario from the standard scenario with three active neutrino flavours, will be challenging due to the large theoretical uncertainties from QCD.
A
bstract
We present a new evaluation of the far-forward neutrino plus antineutrino flux and number of events from charm hadron decays in a 400 GeV proton beam dump experiment like the Search for ...Hidden Particles (SHiP). Using next-to-leading order perturbative QCD and a model for intrinsic charm, we include intrinsic transverse momentum effects and other kinematic angular corrections. We compare this flux to a far-forward flux evaluated with next-to-leading order perturbative QCD, without intrinsic transverse momentum, that used the angular distribution of charm quarks rather than the neutrinos from their decays. The tau neutrino plus antineutrino number of events in the perturbative QCD evaluation is reduced by a factor of about three when intrinsic transverse momentum and the full decay kinematics are included. We show that intrinsic charm contributions can significantly enhance the number of events from neutrinos from charm hadron decays. Measurements of the number of events from tau neutrino plus antineutrino interactions and of the muon charge asymmetry as a function of energy can be used to constrain intrinsic charm models.
This study aimed at gaining insight into the mechanism of interactions between sorghum starch and mushroom polysaccharides (MPs) obtained from three cultivars Lentinula edodes (LEP), Auricularia ...auricula (AAP), and Tremella fuciformis polysaccharides (TFP) in relation to gelatinization, retrogradation and digestibility of starch, and microstructures before and after digestion. MPs decreased the degree of gelatinization, activation energy (retrogradation energy), and digestibility of sorghum starch, whilst they increased the particle size of digesta in a concentration dependent manner (0.15–0.6%, w/v). Confocal laser scanning microscopic (CLSM) images of starch suspensions, gels, and digesta illustrated that LEP was able to coat the sorghum starch granules through electrostatic interaction, which promoted starch retrogradation in gels after long-term storage. AAP and TFP were found to possess ability to suppress starch crystallization in sorghum starch gels, achieved through hydrophobic interaction with starch. TFP (glucuronoxylomannan) and most AAP particles were unable to coat sorghum starch granules, although a small number of AAP particles complexed with the starch through hydrogen bonding. The interaction between sorghum starch and MPs depended on the nature of MPs and their concentration. These findings would provide fundamentals for the utilization of MPs as glycaemic controller of starch and starch-rich foods.
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•Mushroom polysaccharides declined the degree of starch gelatinization and digestion.•Shiitake β-glucan interacted with sorghum starch via electrostatic interaction.•Ear mushroom glucuronoxylomannan hydrophobically interacted with sorghum starch.•Shiitake β-glucan promoted starch crystallization after long-term storage at 4 °C.•Glucuronoxylomannan suppressed sorghum starch crystallization during cold storage.
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•Hydrophobicity, emulsifying ability of AM was improved by complexing with polyphenol.•Emulsifying ability of polyphenols/AM complexes was regulated by polyphenol/AM ...ratio.•Emulsifying ability of complexes was also regulated by polyphenolic structure.•The Rt decreased with increasing of pyrogallol group number on molecular (TA < EGCG).•TA/AM complexes had best hydrophobicity, emulsifying property, emulsion stability.
O/W emulsions stabilized by polyphenol/amylose (AM) complexes with several polyphenol/AM mass ratios and different polyphenols (gallic acid (GA), epigallocatechin gallate (EGCG) and tannic acid (TA)) were prepared by a high-intensity ultrasound emulsification technique. The effect of the pyrogallol group number of polyphenols and the mass ratio of polyphenols/AM on polyphenol/AM complexes and emulsions was studied. The soluble and/or insoluble complexes gradually formed upon adding polyphenols into the AM system. However, insoluble complexes were not formed in the GA/AM systems because GA has only one pyrogallol group. In addition, the hydrophobicity of AM could also be improved by forming polyphenol/AM complexes. The emulsion size decreased with increasing pyrogallol group number on the polyphenol molecules at a fixed ratio, and the size could also be controlled by the polyphenol/AM ratio. Moreover, all emulsions presented various degrees of creaming, which was restrained by decreasing emulsion size or the formation of a thick complex network. The complex network was enhanced by increasing the ratio or pyrogallol group number on the polyphenol molecules, which was because the increasing number of complexes was adsorbed onto the interface. Altogether, compared to GA/AM and EGCG/AM, the TA/AM complex emulsifier had the best hydrophobicity and emulsifying properties, and the TA/AM emulsion had the best emulsion stability.
A
bstract
New experiments dealing with neutrinos in the far-forward region at the Large Hadron Collider (LHC) are under design or already in preparation. Two of them, FASER
ν
and SND@LHC, are ...expected to be active during Run 3 and have the potential to detect the interactions of
ν
and
ν
¯
that come from high-energy collisions in one of the LHC interaction points, extracted along the direction tangent to the beam line. Tau neutrinos and antineutrinos come predominantly from
D
s
±
production in
pp
collisions, followed by the leptonic decay of these mesons. Neutrino pseudorapidities in the range of
η >
6
.
9 and
η >
8
.
9 are relevant to these future experiments. At such pseudorapidities at high energies, QCD theoretical predictions for the flux of
ν
τ
plus
ν
¯
τ
rely on parton distribution functions (PDFs) in a combination of very small and large parton
−x
values. We evaluate PDF un certainties affecting the flux of
ν
τ
+
ν
¯
τ
produced by
D
s
±
decay in the far forward region at the LHC. Next-to-leading order (NLO) QCD uncertainties are included in the calculation of
D
s
±
production and NLO PDF sets are used for consistency. The theoretical uncertainty associated with the 40 PDF sets of the PROSA19 group amounts to
±
(20
−
30)% for the (
ν
τ
+
ν
¯
τ
) number of charged-current (CC) events. Scale uncertainties are much larger, resulting in a range of CC event predictions from ~70% lower to ~90% higher than the central prediction. A comparison of the predictions with those obtained using as input the central PDFs from the 3-flavour NLO PDF sets of the CT14, ABMP16 and NNPDF3.1 collaborations show that far-forward neutrino energy distributions vary by as much as a factor of ~2 – 4 relative to the PROSA19 predictions at TeV neutrino energies. The Forward Physics Facility in the high luminosity LHC era will provide data capable of constraining NLO QCD evaluations with these PDF sets.
A
bstract
The high-energy atmospheric neutrino flux is dominated by neutrinos from the decays of charmed hadrons produced in the forward direction by cosmic ray interactions with air nuclei. We ...evaluate the charm contributions to the prompt atmospheric neutrino flux as a function of the center-of-mass energy
s
of the hadronic collision and of the center-of-mass rapidity
y
of the produced charm hadron. Uncertainties associated with parton distribution functions are also evaluated as a function of
y
. We find that the
y
coverage of LHCb for forward heavy-flavour production, complemented by the angular coverage of present and future forward neutrino experiments at the LHC, bracket the most interesting
y
regions for the prompt atmospheric neutrino flux. At
s
= 14 TeV foreseen for the HL-LHC phase, nucleon collisions in air contribute to the prompt neutrino flux prominently below
E
ν
~ 10
7
GeV. Measurements of forward charm and/or forward neutrinos produced in hadron collisions up to
s
= 100 TeV, which might become possible at the FCC, are relevant for the prompt atmospheric neutrino flux up to
E
ν
= 10
8
GeV and beyond.
Xiaoqu starter serves as the saccharifying and fermenting agent in the production of Cantonese soybean-flavor (Chi-flavor) Baijiu , and the complex microbial communities determine the flavor and ...quality of the product. Round-Koji-mechanical starter (produced by using an automated starter-making disk machine) is advantageous as it decreases operator influence, labor costs, and fermentation time, but the product quality is lower compared to traditional starter. Thus, two types of starters (traditional and Round-Koji-mechanical starter) from a Cantonese Baijiu factory were compared in a metagenomic analysis to investigate the differences in microbial community composition and core microbes. The results showed that several core microbes related to carbohydrate metabolism, amino acid metabolism and lipid metabolism, were differentially enriched in the traditional starter. Mucor lusitanicus and Rhizopus delemar were significantly positively correlated with the three key metabolic pathways. Saccharomyces cerevisiae, Cyberlindnera fabianii, Kluyveromyces marxianus, Lactobacillus fermentum, Mucor ambiguous, Rhizopus microspores, Rhizopus azygosporus, Mucor circinelloides, and Ascoidea rubescens were significantly positively correlated with two of the three key metabolic pathways. The results of this study provide a basis for understanding the differential core microbes in traditional and Round-Koji-mechanical starters of Chi-flavor Baijiu , and they also provide guidance for improving Round-Koji-mechanical starter.
2-amino-1-methyl-6-phenylimidazole 4,5-b pyridine (PhIP) is one of the higher levels of HAAs produced in protein foods during heating. The effects of heating temperature, time, and concentration of ...precursors on PhIP and related substances in the chemical model system and roast pork patty were studied using HPLC-Q-Orbitrap-HRMS and GC–MS. Results showed that the heating temperature, time, and concentration of four precursors significantly affected PhIP and its related substances (P < 0.05) in the chemical model system. Among them, PhIP production was greatest when heating at 200 min with 220 °C, and the concentrations of phenylalanine, creatinine, glucose, and creatine added were 10, 20, 20, and 20 mmol/L, respectively. Moreover, as the fat proportion of roast pork patties increased, PhIP and its intermediate-phenylacetaldehyde concentrations increased substantially (P < 0.05). PCA results showed that the samples of PhIP and related substances gradually dispersed as the temperature and time increased, and there were obvious effects among them.
•Processing conditions significantly affected PhIP and its related substances.•Influence rule of precursors and intermediates on PhIP in chemical model was found.•Increase of fat proportion increased PhIP and intermediate-phenylacetaldehyde.•Raised glucose level can prevent the formation of PhIP in chemical model system.
Dried salted fish is a traditional dry-cured fish that is sprinkled with salt before the curing process. With a unique flavor as well as diverse varieties, dry-cured fish is popular among consumers ...worldwide. The presence of various microbial communities during the curing process leads to numerous metabolic reactions, especially lipid oxidation and protein degradation, which influence the formation of flavor substances. However, during industrial curing, the quality of dry-cured fish is difficult to control, leading to the formation of products with diverse flavors. This review describes the curing process of dried salted fish, the key microorganisms involved in the curing process of typical dried salted fish products at home and abroad, and the correlation between biological metabolism and flavor formation and the underlying mechanism. This review also investigates the prospects of dried salted fish products, proposing methods for the analysis of improved curing processes and the mechanisms of dried salted fish. Through a comprehensive understanding of this review, modern production challenges can be addressed to achieve greater control of microbial growth in the system and improved product safety. In addition to advancing our understanding of the processes by which volatile flavor compounds are formed in conventional dry-cured fish products, we expect that this work will also offer a theoretical framework for enhancing their flavor in food processing.
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