Improved encapsulation efficiency and storage stability of lutein by soy protein isolate nanocarriers with thermal and trypsin treatments.

BACKGROUND: Encapsulation of bioactive compounds within protein-based nanoparticles has garnered considerable attention in the food and pharmaceutical industries because of its potential to enhance stability and delivery. Soy protein isolate (SPI) has emerged as a promising candidate, prompting the present study aiming to modify its properties through controlled thermal and trypsin treatments for improved encapsulation efficiency (EE) of lutein and its storage stability. RESULTS: The EE of lutein nanoparticles encapsulated using SPI trypsin hydrolysates (SPIT) with three varying degrees of hydrolysis (4.11%, 6.91% and 10.61% for SPIT1, SPIT2 and SPIT3, respectively) increased by 12.00%, 15.78% and 18.59%, respectively, compared to SPI. Additionally, the photostability of SPIT2 showed a remarkable increase of 38.21% compared to SPI. The superior encapsulation efficiency and photostability of SPIT2 was attributed to increased exposure of hydrophobic groups, excellent antioxidant activity and uniform particle stability, despite exhibiting lower binding affinity to lutein compared to SPI. Furthermore, in SPIT2, the protein structure unfolded, with minimal impact on overall secondary structure upon lutein addition. CONCLUSION: The precise application of controlled thermal and trypsin treatments to SPI has been shown to effectively produce protein nanoparticles with substantially improved encapsulation efficiency for lutein and enhanced storage stability of the encapsulated lutein. These findings underscore the potential of controlled thermal and trypsin treatments to modify protein properties effectively and offer significant opportunities for expanding the applications of protein-based formulations across diverse fields. © 2024 Society of Chemical Industry.

Identification and selection of volatile compounds derived from lipid oxidation as indicators for quality deterioration of frozen white meat and red meat using HS-SPME-GC-MS combined with OPLS-DA.

This work aimed to investigate the effects of frozen storage on volatile compounds of white meats (chicken and duck) and red meats (pork, beef, and mutton). The samples were stored at -18 °C for 0, 2, 4, 10, 18 weeks, and volatile compounds were analyzed by headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry. Results indicated that the total amounts of volatile compounds increased with frozen storage duration of meats. The correlations were observed between frozen storage duration and levels of 2-ethyl-1-hexanol, tetradecane, nonanal, decanal, octanal, tridecanal, benzaldehyde, pentadecane, propanoic acid,2-methyl-,3-hydroxy-2,2,4-trimethylpentyl ester, heptadecane, and hexanal (r = 0.7456-0.9873). Levels of octanal and propanoic acid,2-methyl-,3-hydroxy-2,2,4-trimethylpentyl ester in white meat and benzaldehyde in red meat versus frozen storage duration fitted very well with zero-order reactions. Therefore, it was concluded that changes in volatile compounds derived from lipid oxidation may be used as indicators of quality deterioration during frozen storage of meat.

Investigation on synergistic inhibition of protein-bound heterocyclic amines in sarcoplasmic and myofibrillar model systems by amino acid combinations.

The inhibition of amino acids on the formation of protein-bound HAs was assessed in both model systems and roast beef patties, and the synergism between these amino acids was also investigated. The amino acids can promote the formation of protein-bound HAs at low addition amount, and the total content of protein-bound HAs increased from 444.05 ± 4.98 ng/g of the control group to 517.36 ± 16.51 ng/g when 0.05 % cysteine was added. Amino acid combinations exhibited stable inhibitory effects, with the maximum inhibitory rate of 64 % in the treatment with histidine-proline combination (1:4). The synergistic inhibition may be caused by simultaneously scavenging intermediates and competing for the binding sites of muscle proteins, and the reaction with protein-bound HAs to form adduct can serve as supporting factors to co-mitigate the promotion in protein-bound HAs from increased protein solubility. These findings proposed the potential mitigation strategies against protein-bound HAs formation.

Simultaneous mitigation of heterocyclic aromatic amines and advanced glycation end products in roasted beef patties by plasma-activated water: Effects and mechanisms.

Heterocyclic aromatic amines (HAAs) and advanced glycation end products (AGEs) are hazardous substances produced when food is heated. In this study, the ability of plasma-activated water (PAW) to simultaneously mitigate production of HAAs and AGEs in roasted beef patties was investigated. Assays of free radicals, lipid peroxidation, and active carbonyls were used to analyze the mechanisms. PAW treatment decreased the contents of free HAAs, free AGEs, bound HAAs, and bound AGEs to 12.65 ng/g, 0.10 µg/g, 297.74 ng/g, and 4.32 µg/g, with the inhibition rates of 23.88%, 23.08%, 11.02%, and 8.47%, respectively. PAW treatment decreased HAAs and AGEs and mitigated their increase during storage. The decrease of HAAs and AGEs in PAW-treated samples was correlated with the enhancement of antioxidant capacity. The increase of free radical scavenging ability by PAW treatment led to the decrease of lipid peroxidation and the decrease of active carbonyls, HAAs, and AGEs in meat products.

Rational Design of Loop Dynamics for a Barrel-Shaped Enzyme by Introducing Disulfide Bonds.

Loop dynamics redesign is an important strategy to manipulate protein function. Cellobiose 2-epimerase (CE) and other members of its superfamily are widely used for diverse industrial applications. The structural feature of the loops connecting barrel helices contributes greatly to the differences in their functional characteristics. Inspired by the in-silico mutation with molecular dynamics (MD) simulation analysis, we propose a strategy for identifying disulfide bond mutation candidates based on the prediction of protein flexibility and residue-residue interaction. The most beneficial mutant with the newly introduced disulfide bond would simultaneously improve both its thermostability and its reaction propensity to the targeting isomerization product. The ratio of the isomerization/epimerization catalytic rate was improved from 4:103 to 9:22. MD simulation and binding free energy calculations were applied to provide insights into molecular recognition upon mutations. The comparative analysis of enzyme/substrate binding modes indicates that the altered catalytic reaction pathway is due to less efficient binding of the native product. The key residue responsible for the observed phenotype was identified by energy decomposition and was further confirmed by the mutation experiment. The rational design of the key loop region might be a promising strategy to alter the catalytic behavior of all (α/α)6-barrel-like proteins.

Effects and mechanisms of using "clean" smoke particles in the smoking process on the formation of ß-carboline heterocyclic amines (ß-CHAs) in smoked meat patties.

ß-Carboline heterocyclic amines (ß-CHAs), known for their synergistic neurotoxic and carcinogenic effects, are predominantly produced by humans through cigarette smoke and food and are found particularly in meats cooked at high temperatures. Few studies have explored the differences in the mechanisms of accumulation of ß-CHAs in smoked meat and meat processed at high temperatures. In this research, the concentration of ß-CHAs in smoked meats prepared using a variety of wood materials was measured using LCMS/MS. Additionally, key volatile organic compound markers associated with ß-CHAs accumulation in smoke were identified through GCMS and multivariate statistical analysis and subsequently confirmed in a chemical simulation system. Three types of strainers, each with a distinct aperture size, were used to assess the efficacy of particle filtration in reducing ß-CHAs levels in smoked meat. The findings indicated that smoke exposure indeed increases the ß-CHAs content of meat. However, only the strainer capable of filtering PM2.5-sized particles reduced the amount of ß-CHAs present compared to the control group. In contrast, strainers with larger pore sizes facilitated excessive accumulation of ß-CHAs. The presence of aldehydes such as 1 H-pyrrole-2-carboxaldehyde, 5-methylfurfural, benzaldehyde, furfural, and nonanal exhibited a positive correlation with the accumulation of ß-CHAs. Conversely, phenolic compounds, including 2-methoxy-4-vinylphenol, 2-methoxy-5-methylphenol, p-cresol, phenol, 2-methoxy-4-(1-propenyl)-, (Z)-, phenol, 3-ethyl-, and phenol, 4-ethyl-2-methoxy-, showed a negative correlation. Thus, filters made from chelated carbonyl trap materials both chemically and physically disrupt the buildup of ß-CHAs in smoked meats. The use of this approach will not only improve the quality of these products but will also contribute to decreasing the amount of inhalation pollutants released into the environment.

BCM-7: Opioid-like Peptide with Potential Role in Disease Mechanisms.

Bovine milk is an essential supplement due to its rich energy- and nutrient-rich qualities. Caseins constitute the vast majority of the proteins in milk. Among these, ß-casein comprises around 37% of all caseins, and it is an important type of casein with several different variants. The A1 and A2 variants of ß-casein are the most researched genotypes due to the changes in their composition. It is accepted that the A2 variant is ancestral, while a point mutation in the 67th amino acid created the A1 variant. The digestion derived of both A1 and A2 milk is BCM-7. Digestion of A2 milk in the human intestine also forms BCM-9 peptide molecule. The opioid-like characteristics of BCM-7 are highlighted for their potential triggering effect on several diseases. Most research has been focused on gastrointestinal-related diseases; however other metabolic and nervous system-based diseases are also potentially triggered. By manipulating the mechanisms of these diseases, BCM-7 can induce certain situations, such as conformational changes, reduction in protein activity, and the creation of undesired activity in the biological system. Furthermore, the genotype of casein can also play a role in bone health, such as altering fracture rates, and calcium contents can change the characteristics of dietary products. The context between opioid molecules and BCM-7 points to a potential triggering mechanism for the central nervous system and other metabolic diseases discussed.

In Vitro Comparative Analysis of the Effect and Structure-Based Influencing Factors of Flavonols on Lipid Accumulation.

Flavonols represented by quercetin have been widely reported to have biological activities of regulating lipid metabolism. However, the differences in flavonols with different structures in lipid-lowering activity and the influencing factors remain unclear. In this study, the stability, transmembrane uptake ratio, and lipid metabolism regulation activities of 12 flavonol compounds in the 3T3-L1 cell model were systematically compared. The results showed that kaempferide had the highest cellular uptake ratio and the most potent inhibitory effect on adipogenesis at a dosing concentration of 20 µM, followed by isorhamnetin and kaempferol. They inhibited TG accumulation by more than 65% and downregulated the expression of PPARγ and SREBP1c by more than 60%. The other four aglycones, including quercetin, did not exhibit significant activity due to the structural instability in the cell culture medium. Meanwhile, five quercetin glucosides were quite stable but showed a low uptake ratio that no obvious activity was observed. Correlation analysis also showed that for 11 compounds except galangin, the activity was positively correlated with the cellular uptake ratio (p < 0.05, r = 0.6349). These findings may provide a valuable idea and insight for exploring the structure-based activity of flavonoids at the cellular level.

Synergistic inhibition against heterocyclic amines in beef patties: Caused by carbonyl-trapping and toxicity-reducing of amino acid combinations.

The inhibitory effects of amino acids and their combinations on the formation of heterocyclic amines were investigated in this study. The great potential in the inhibition of HAs was observed in amino acid combinations compared with that of single agents. At a mass ratio of 1:1, a His-Pro combination achieved a maximum inhibitory rate of 80 %, and the total HAs content decreased to 4.70 ± 0.18 ng/g relative to the control (24.49 ± 2.18 ng/g). However, the inhibitory rate of triple combinations showed no obvious increase compared with the binary combinations. Benzaldehyde, phenylacetaldehyde, methylglyoxal, and glyoxal were positively correlated with HAs formation, and His-Pro combination (1:4) led to a significant reduction of benzaldehyde and phenylacetaldehyde at scavenging rates of 79 % and 92 %. Thus, the synergistic inhibition was achieved by simultaneously scavenging these aldehyde intermediates, and other inhibitory target, such as competition with precursors and elimination of final products can serve as supporting factors. These results provide a new perspective for approaches to enhance the suppression of HAs and control the formation of flavor compounds.

Improving the Storage Stability of Soy Protein Isolate through Annealing.

This study investigated the effect of annealing treatment on the stability of soy protein isolate (SPI) during storage. Different SPI samples with varying denaturation levels were subjected to varying annealing temperatures and durations before being stored at 37 °C for 12 weeks to assess their stability. Our findings revealed that annealing at 65 °C for 30 min significantly mitigated protein deterioration, improving the stability of highly denatured proteins during storage. Surface hydrophobicity and endogenous fluorescence analyses indicated that this annealing condition induced protein structure unfolding, an initial increase in SPI hydrophobicity, and a blue shift in the maximum absorption wavelength (λmax). The slowest increase in hydrophobicity occurred during storage, along with a red shift in the maximum absorption wavelength by the 12th week. These results suggest that annealing treatment holds promise for mitigating the issue of reduced SPI stability during storage.

Mitophagy suppression by miquelianin-rich lotus leaf extract induces 'beiging' of white fat via AMPK/DRP1-PINK1/PARKIN signaling axis.

BACKGROUND: Lotus (Nelumbo nucifera) leaf has been described to have anti-obesity activity, but the role of white fat 'browning' or 'beiging' in its beneficial metabolic actions remains unclear. Here, 3T3-L1 cells and high-fat-diet (HFD)-fed mice were used to evaluate the effects of miquelianin-rich lotus leaf extract (LLE) on white-to-beige fat conversion and its regulatory mechanisms. RESULTS: Treatment with LLE increased mitochondrial abundance, mitochondrial membrane potential and NAD+ /NADH ratio in 3T3-L1 cells, suggesting its potential in promoting mitochondrial activity. qPCR and/or western blotting analysis confirmed that LLE induced the expression of beige fat-enriched gene signatures (e.g. Sirt1, Cidea, Dio2, Prdm16, Ucp1, Cd40, Cd137, Cited1) and mitochondrial biogenesis-related markers (e.g. Nrf1, Cox2, Cox7a, Tfam) in 3T3-L1 cells and inguinal white adipose tissue of HFD-fed mice. Furthermore, we found that LLE treatment inhibited mitochondrial fission protein DRP1 and blocked mitophagy markers such as PINK1, PARKIN, BECLIN1 and LC-3B. Chemical inhibition experiments revealed that AMPK/DRP1 signaling was required for LLE-induced beige fat formation via suppressing PINK1/PARKIN/mitophagy. CONCLUSION: Our data reveal a novel mechanism underlying the anti-obesity effect of LLE, namely the induction of white fat beiging via AMPK/DRP1/mitophagy signaling. © 2023 Society of Chemical Industry.

Effect of Angelica dahurica, Angelica dahurica polysaccharides, and imperatorin on free and bound heterocyclic amine generation in roasted beef patties and release profiles of bound heterocyclic amines during in vitro digestion.

This study explored the suppressive activity of Angelica dahurica (AD), AD polysaccharides, and imperatorin on free and bound heterocyclic amine (HA) formation in roast beef patties and release profiles of bound HAs during in vitro digestion. The suppressive effects and potential mechanisms associated with free radical quenching were explored using UPLC-MS/MS, multivariate statistical analysis, and electron paramagnetic resonance (EPR). AD (0.5%, 1.0%, and 1.5%) and imperatorin (0.005%, 0.010%, and 0.015%) showed a dose-dependent inhibition for both free and bound HAs, with AD polysaccharides showing a slight inhibitory capacity. The maximum inhibition of free and bound HAs was 36.31% (1.5% AD) and 35.68% (0.015% imperatorin). The EPR results demonstrated that alkyl radicals and 1O2 were the pivotal free radicals for HAs. Furthermore, AD and imperatorin dose-dependently decreased the level of these radicals. Intriguingly, after in vitro digestion, only AD polysaccharides significantly inhibited the release of bound HAs, with imperatorin even facilitating the release process. In this study, the capacity of the AD polysaccharide to suppress the release of bound HAs and the ability of AD and imperatorin to inhibit free and bound HAs in beef patties were identified for the first time.

Inhibitory Effects of Some Hydrocolloids on the Formation of Advanced Glycation End Products and Heterocyclic Amines in Chemical Models and Grilled Beef Patties.

Effectively inhibiting the formation of heterocyclic amines (HAs) and advanced glycation end products (AGEs) is crucial to human health. In the present study, chemical model systems were used to evaluate the inhibitory effects of seven hydrocolloids on HA and AGE formation. The results showed that hydrocolloids effectively inhibited the formation of two major AGEs. However, their inhibitory action against HA formation showed unexpected results, wherein alginic acid, carrageenan and konjac glucomannan promoted the formation of 2-Amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP), harmane, norharmane and 2-amino-3,8-dimethyl-imidazo [4,5-f]-quinoline (MeIQx). Only chitosan and pectin showed significant inhibitory effects on HAs, reducing HA levels by 34.5-56.3% and 30.1-56.6%, respectively. In grilled beef patties, the addition of 1.5% chitosan and pectin significantly decreased AGE and HA content by 53.8-67.0% and 46.9-68.1%, respectively. Moreover, it had a limited impact on quality and sensory properties. Further mechanism studies conducted in model systems revealed that chitosan and pectin decreased the formation of key intermediates of AGEs and HAs. These findings suggest that chitosan and pectin are powerful inhibitors against AGE and HA formation with minimal impact on food quality. Therefore, their application in meat preparation and processing could effectively decrease human dietary exposure to HAs and AGEs.

Processing Stage-Induced Formation of Advanced Glycation End Products in Cooked Sausages with the Addition of Spices.

This study aims to evaluate the relationship between the four processing stages of cooked sausage preparation (raw, drying, baking, and steaming) and the formation of advanced glycation end products (AGEs), 1,2-dicarbonyl compounds, and lipid and protein oxidation in sausages with spices. Baking and steaming significantly promoted lipid and protein oxidation. The Nε-carboxymethyllysine (CML) content increased from 4.32-4.81 µg/g in raw samples to 10.68-16.20 µg/g in the steamed sausages. Nε-carboxyethyllysine (CEL) concentrations increased by approximately 1.7-3.7 times after steaming. The methylglyoxal concentration increased dramatically after baking and then rapidly decreased in the steaming stage. Chili promoted the formation of CML and CEL. The CEL concentration increased in samples containing garlic, but yellow mustard and garlic slightly reduced CML concentrations in the cooked sausages. The spices decreased the lipid and protein stability of the cooked sausages, increasing malondialdehyde and protein carbonyls. Lipid oxidation and 3-deoxyglucosone positively correlated with CML and CEL levels. Black pepper had no impact on CML when the sausages were baked but remarkably increased the content of both CML and CEL in the steaming stage. Thus, the impact of spices on sausages depends on both the specific spices used and the category of AGEs formed.

The Generation and Control of Harmful Products in Food Processing.

Food processing is an integral part of the modern food industry aimed at improving the quality, taste, and preservation of food products [...].

Effects of volatile organic compounds of smoke from different woods on the heterocyclic amine formation and quality changes in pork patty.

This study investigated the effects of smoke derived from cypress (CY), mulberry (MU), metasequoia (ME), pine (PI), and camphor (CA) on the heterocyclic aromatic amines (HAs), flavor, and sensory attributes of smoked pork patty. The results showed that the smoke derived from the five kinds of wood and the flavor of the corresponding smoked meat were classified into three types. Moreover, the smoke of CY and PI, and the smoke of MU and ME can be classified into one category respectively, which significantly improved the flavor of the smoked meat. Both free and protein-bound HAs were detected in smoked meat, while the smoking process significantly increased the HAs content, especially free Norharman (3.26 ng/g in control meat, and 82.24 ng/g in meat smoked with CY). Correlation analysis showed that various volatile organic compounds (VOCs) and HAs were closely associated. Future research should pay attention to the VOCs in smoked meat including vanillin, Close attention should be paid to tridecane and crotonic acid, as well as tetradecane and α-Dehydro-ar-himachalene in smoke, which were consistently correlated with various HAs and may participate in HAs formation. These results may reveal how the smoking process influences the formation of HAs and which factors should be targeted to inhibit HAs in smoked meat products.

Investigation on the simultaneous inhibition of advanced glycation end products, 4-methylimidazole and hydroxymethylfurfural in thermal reaction meat flavorings by liquiritigenin, liquiritin and glycyrrhizic acid and possible pathways.

The inhibitory effects of liquiritigenin, liquiritin and glycyrrhizic acid against the hazards during the preparation of thermal reaction beef flavoring were investigated using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Liquiritigenin(1.5 mM) inhibited Nε-carboxymethyl-L-lysine and Nε-carboxyethyl-L-lysine by up to 38.69 % and 61.27 %, respectively; 1.5 mM liquiritin inhibited 4-methylimidazole by up to 48.28 %; and 1.5 mM liquiritigenin and 1.0 mM liquiritin inhibited hydroxymethylfurfural by up to 61.20 % and 59.31 %, respectively. The results of the model system showed that the inhibitory effect of the 3 inhibitors could be extended to other thermal reaction flavoring systems. The 3 inhibitors can effectively block key intermediates in beef flavoring, and liquiritigenin can inhibit up to 22.97 % of glyoxal and 22.89 % of methylglyoxal. In addition, liquiritigenin and liquiritin can directly eliminate up to 25.87 % and 21.01 % of methylglyoxal by addition and other means. Free radicals in the simultaneous formation model system were measured using electron spin resonance (ESR), and the results showed that liquiritigenin, liquiritin and glycyrrhizic acid could scavenge free radicals in the system in a dose-dependent manner, with scavenging rates of up to 44.88-57.09 %. Therefore, the inhibitory effects of the 3 inhibitors can be attributed to the intermediate blocking and free radical scavenging pathways.

Isotope dilution-HPLC-MS/MS to investigate the production patterns and possible pathways of free and protein-bound AGEs and 4-MI in cookies.

A qualitative and quantitative method for detecting free and protein-bound advanced glycation end products (AGEs) and 4-methylimidazole (4-MI) was established using isotope dilution-HPLC-MS/MS, and successfully applied in cookies and model systems. The effects of different temperatures (160-220 °C) on the formation of free and protein-bound AGEs and 4-MI in cookies were discussed, and the possible model systems (Maillard reaction pathway 1 using wheat gluten protein + glucose + sucrose; direct addition pathway 1 using wheat gluten protein + CML/CEL/4-MI) of protein-bound AGEs and 4-MI were verified. The results showed that the contents of protein-bound CML, CEL, and 4-MI were higher than free content with a tendency of increasing first and subsequently decreasing with temperature, reaching a maximum at 200 °C in cookies. In the model systems, the levels of protein-bound CML, CEL, and 4-MI are higher than those of free CML, CEL, and 4-MI. The protein-bound CML, CEL, and 4-MI accounted for 90.73, 87.64, and 97.56% of the total amount in the model system 1, while accounting for 68.19, 59.00, and 50.96% in the model system 2, respectively. In comparison, protein-bound CML, CEL, and 4-MI could be easily generated directly by Maillard reaction.

Miquelianin in Folium Nelumbinis extract promotes white-to-beige fat conversion via blocking AMPK/DRP1/mitophagy and modulating gut microbiota in HFD-fed mice.

The main purpose of the present study was to investigate the effect of miquelianin (quercetin 3-O-glucuronide, Q3G), one of the main flavonoids in the Folium Nelumbinis extract (FNE), on beige adipocyte formation and its underlying mechanisms. In 3T3-L1 adipocytes Q3G (12.8%)-rich FNE treatment upregulated beige-related markers such as SIRT1, COX2, PGC-1α, TFAM, and UCP1. Furthermore, Q3G enhanced mitochondrial biosynthesis and inhibited mitophagy by downregulating the expression of PINK1, PARKIN, BECLIN1 and LC-3B in 3T3-L1 cells. Moreover, in high-fat-diet (HFD)-fed mice, Q3G markedly inhibited body weight gain, reduced blood glucose/lipid levels, reduced white adipose tissues (WAT) and mitigated hepatic steatosis. Meanwhile, the induced beiging accompanied by suppressed mitophagy was also demonstrated in inguinal WAT (iWAT). Chemical intervention of AMPK activity with Compound C (Com C) and Acadesine (AICAR) revealed that AMPK/DRP1 signaling was involved in Q3G-mediated mitophagy and the beiging process. Importantly, 16S rRNA sequencing analysis showed that Q3G beneficially reshaped gut microbiota structure, specifically inhibiting unclassified_Lachnospiraceae, Faecalibaculum, Roseburia and Colidextribacter while increasing Bacteroides, Akkermansia and Mucispirillum, which may potentially facilitate WAT beiging. Collectively, our findings provide a novel biological function for Folium Nelumbinis and Q3G in the fight against obesity through activating the energy-dissipating capacity of beige fat.