Effects of polysaccharides on colonic targeting and colonic fermentation of ovalbumin-ferulic acid based emulsion.

Rutin is a polyphenol with beneficial pharmacological properties. However, its bioavailability is often compromised due to low solubility and poor stability. Encapsulation technologies, such as emulsion systems, have been proven to be promising delivery vehicles for enhancing the bioavailability of bioactive compounds. Thus, this study was proposed and designed to investigate the colonic targeting and colonic fermentation characteristics of rutin-loaded ovalbumin-ferulic acid-polysaccharide (OVA-FA-PS) complex emulsions. The results indicate that OVA-FA-PS emulsion effectively inhibits the degradation of rutin active substances and facilitates its transport of rutin to the colon. The analysis revealed that the OVA-FA-κ-carrageenan emulsion loaded with rutin exhibited superior elasticity and colon targeting properties compared to the OVA-FA-hyaluronic acid or OVA-FA-sodium alginate emulsions loaded with rutin in the composite emulsion. Additionally, it was observed that the rutin loaded within the OVA-FA-κ-carrageenan emulsion underwent degradation and was converted to 4-hydroxybenzoic acid during colonic fermentation.

Detection of wheat saccharification power and protein content using stacked models integrated with hyperspectral imaging.

BACKGROUND: Wheat is one of the key ingredients used to make Chinese liquor, and its saccharification power and protein content directly affect the quality of the liquor. In pursuit of a non-destructive assessment of wheat components and the optimization of raw material proportions in liquor, this study introduces a precise predictive model that integrates hyperspectral imaging (HSI) with stacked ensemble learning (SEL). RESULTS: This study extracted hyperspectral information from 14 different varieties of wheat and employed various algorithms for preprocessing. It was observed that multiplicative scatter correction (MSC) emerged as the most effective spectral preprocessing method. The feature wavelengths were extracted from the preprocessed spectral data using three different feature extraction methods. Then, single models (support vector machine (SVM), backpropagation neural network (BPNN), random forest (RF), and gradient boosting tree (XGBoost)) and a SEL model were developed to compare the prediction accuracies of the SEL model and the single models based on the full-band spectral data and the characteristic wavelengths. The findings indicate that the MSC-competitive adaptive reweighted sampling-SEL model demonstrated the highest prediction accuracy, with Rp 2 (test set-determined coefficient) values of 0.9308 and 0.9939 for predicting the saccharification power and protein content and root mean square error of the test set values of 0.0081 U and 0.0116 g kg-1, respectively. CONCLUSION: The predictive model established in this study, integrating HSI and SEL models, accurately detected wheat saccharification power and protein content. This validation underscores the practical potential of the SEL model and holds significant importance for non-destructive component analysis of raw materials used in liquor. © 2024 Society of Chemical Industry.

Serum procalcitonin levels are associated with rhabdomyolysis following exertional heatstroke: an over 10-year intensive care survey.

BACKGROUND: Heatstroke has become a common emergency event in hospitals. Procalcitonin (PCT) is used as a biomarker of infection in the emergency department (ED), but its role in rhabdomyolysis (RM) following exertional heatstroke (EHS) remains unclear. METHODS: A retrospective cohort study enrolled patients with EHS from the intensive care unit (ICU). We collected RM biomarkers, inflammation markers, critical disease scores at admission, 24 h, 48 h, and discharge, and 90-day mortality. Correlation analysis, linear regression and curve fitting were used to identify the relationship between PCT and RM. RESULTS: A total of 162 patients were recruited and divided into RM (n=56) and non-RM (n=106) groups. PCT was positively correlated with myoglobin (Mb), acute hepatic injury, disseminated intravascular coagulation (DIC), Sequential Organ Failure Assessment (SOFA) score, and Acute Physiology and Chronic Health Evaluation II (APACHE II) score, with correlation coefficients of 0.214, 0.237, 0.285, 0.454, and 0.368, respectively (all P<0.05). Interestingly, the results of curve fitting revealed a nonlinear relationship between PCT and RM, and a two-piecewise linear regression model showed that PCT was related to RM with an odds ratio of 1.3 and a cut-off of <4.6 ng/mL. Survival analysis revealed that RM was associated with higher mortality compared to non-RM cases (P=0.0093). CONCLUSION: High serum PCT concentrations are associated with RM after EHS in critically ill patients. Elevated PCT concentrations should be interpreted cautiously in patients with EHS in the ED.

Multicomponent hyperspectral grade evaluation of ilmenite using spectral-spatial joint features.

Obtaining a comprehensive understanding of ore grade information is of significant importance for evaluating the value of ore. However, the real-time detection of multicomponent grade needs more effective online methods. This study proposes a novel approach utilizing hyperspectral imaging (HSI) to evaluate the grade information of nine major ilmenite components by integrating spectral and spatial data. Four multivariate input-output models were developed to mitigate variable interference to predict each component's grade. The results demonstrated that the backpropagation neural network (BPNN) model built from iPLS-VCPA-IRIV feature selection spectral data worked best (RP2 = 0.9935, RMSEP = 0.1364, RPD = 12.8986, and RPIQ = 21.4871, with a computational time of approximately 0.8 s). Furthermore, applying the best optimal combination algorithm for multicomponent grade inversion yielded highly accurate results, in which 97% of the component inversion residuals were less than 1. This investigation affirms that HSI enables rapid and accurate prediction and inversion of the multicomponent grade of ilmenite, thereby presenting a promising alternative to online analysis in the mineral field.

Rapid nondestructive detecting of sorghum varieties based on hyperspectral imaging and convolutional neural network.

BACKGROUND: The purity of sorghum varieties is an important indicator of the quality of raw materials used in the distillation of liquors. Different varieties of sorghum may be mixed during the acquisition process, which will affect the flavor and quality of liquor. To facilitate the rapid identification of sorghum varieties, this study proposes a sorghum variety identification model using hyperspectral imaging (HSI) technology combined with convolutional neural network (AlexNet). RESULTS: First, the watershed algorithm, which was modified with the extended-maxim transform, was used to segment the hyperspectral images of a single sorghum grain. The isolated forest algorithm was used to eliminate abnormal spectral data from the complete spectral data. Secondly, the AlexNet model of sorghum variety identification was established based on the two-dimensional gray image data of sorghum grain in group 1. The effects of different preprocessing methods and different convolution kernel sizes on the performance of the AlexNet model were discussed. The eigenvalues of the last layer of the AlexNet model were visualized using the t-distributed random neighborhood embedding method, which is used to evaluate the separability of features extracted by the AlexNet model. The performance differences between the optimal AlexNet model and traditional machine learning models for sorghum variety identification were compared. Finally, the varieties of sorghum grains in groups 2 and 3 were identified based on the optimal AlexNet model, and the average accuracy values of the test set reached 95.62% and 95.91% respectively. CONCLUSION: The results in this study demonstrated that HSI combined with the AlexNet model could provide a feasible technical approach for the detection of sorghum varieties. © 2022 Society of Chemical Industry.

A label-free PEC aptasensor platform based on g-C3N4/BiVO4 heterojunction for tetracycline detection in food analysis.

A simple low-cost label-free photoelectrochemical (PEC) biosensing platform based on red blood cell shaped BiVO4 modified g-C3N4 was designed for tetracycline detection under room temperature. The prepared g-C3N4/BiVO4 heterojunction not only demonstrated a high surface area, excellent physicochemical stability and favorable PEC activity, but also can be employed as nanostructure support for aptamers to construct a visible-light-driven PEC aptasensor due to rich π-π accumulation sites. More importantly, the proposed PEC aptasensor showed a favorable linear toward tetracycline in the range from 5 × 10-9 to 2 × 10-7 M with a detection limit of 1.6 nM, which well covered the Food Standards Testing requirements. Practical food sample analysis further revealed the accuracy and feasibility of the g-C3N4/BiVO4 heterostructure based PEC platform. It is expected that such a label-free and cost-effective PEC strategy should act as a promising candidate for tetracycline determination in food quality control and supervision.

Nondestructive visualization and quantification of total acid and reducing sugar contents in fermented grains by combining spectral and color data through hyperspectral imaging.

Total acid content (TAC) and reducing sugar content (RSC) are important evaluation indicators for the quality of fermented grains. In this study, the TAC and RSC of fermented grains were quantified using hyperspectral imaging (HSI). Two combined algorithms were used to extract the characteristic wavelengths of TAC and RSC. Nine color features of fermented grains were extracted based on H, S and V color channels. Multivariate analytical models were developed to predict TAC and RSC using full wavelengths, characteristic wavelengths, color features and fused data, respectively. The CF model established based on characteristic wavelengths extracted by CARS-SPA showed the best results in predicting TAC. Meanwhile, the PSO-SVR model built using fused data was the best model for predicting RSC. The visualization of the TAC and RSC was achieved using the optimal models. These results show that HSI can achieve non-destructive detection and visualization of TAC and RSC in fermented grains.

Arsenic emission and distribution characteristics in the ultra-low emission coal-fired power plant.

The characteristics of arsenic emission and distribution of a typical Chinese coal-fired power plant renovated with ultra-low emission technique have been studied. The results showed that arsenic concentration in coal was 5.72 mg/kg, and the arsenic emissions in fly ash, bottom ash, gypsum, flue gas, and wastewater were 489.12 g/h, 5.15 g/h, 1.14 g/h, 0.46 g/h, and 0.03 g/h, respectively, corresponding to the proportion of arsenic in fly ash, bottom ash, gypsum, flue gas, and wastewater of 98.63%, 1.04%, 0.23%, 0.09%, and 0.01%, respectively. About 87.61% of the gaseous arsenic was absorbed by catalysts used for selective catalytic reduction (SCR). Low-low temperature electrostatic precipitator (LLT-ESP) plays a key role in decreasing particulate arsenic. Wet flue gas desulfurization (WFGD) has positive effects on absorbing both gaseous and particulate arsenic. The removal efficiencies across the air pollution control devices follow the order of LLT-ESP > WFGD > SCR. The LLT-ESP can achieve a significant arsenic removal efficiency of 99.94%, resulting in quite low arsenic emission to the atmosphere. According to the calculated arsenic emission factor, the total emission amount of arsenic to the atmosphere from all Chinese coal-fired stations with ultra-low emission control technique in 2020 is estimated to be about 9.67-11.59 tons/year.

Review of the formation and influencing factors of food-derived glycated lipids.

Glycated lipids are formed by a Maillard reaction between the aldehyde group of a reducing sugar with the free amino group of an amino-lipid. The formation and accumulation of glycated lipids are closely related to the prognosis of diabetes, vascular disease, and cancer. However, it is not clear whether food-derived glycated lipids pose a direct threat to the human body. In this review, potentially harmful effect, distribution, formation environment and mechanism, and determination and inhibitory methods of glycated lipids are presented. Future research directions for the study of food-derived glycated lipids include: (1) understanding their digestion, absorption, and metabolism in the human body; (2) expanding the available database for associated risk assessment; (3) relating their formation mechanism to food production processes; (4) revealing the formation mechanism of food-derived glycated lipids; (5) developing rapid, reliable, and inexpensive determination methods for the compounds in different foods; and (6) seeking effective inhibitors. This review will contribute to the final control of food-derived glycated lipids.

Effects of Methyl Cellulose and Soybean Protein Isolate Coating on Amount of Oil and Chemical Hazards in Chinese Fried Dough Cake.

ABSTRACT: Fat-related diseases and chemical hazards produced during the frying process pose a major threat to human health. Coatings have been used as a practical method to reduce the amount of oil and chemical hazards associated with fried foods. Methyl cellulose (MC) and soy protein isolate were used as coating materials to pretreat Chinese fried dough cake (CFDC) before frying. The 1.5% MC concentration was the best choice for coating to simultaneously lower oil and chemical hazards in CFDC. The CFDC prepared using 1.5% MC had 11.3% oil, 73.70 µg/kg acrylamide, 0.15 mg KOH/100 kg acid, 8.54 mmol/kg peroxide, p-anisidine value of 6.36, 0.36 µg/g malondialdehyde, 0.13 µg/g 4-hydroxy-2-(E)-hexenal (HHE), 0.51 µg/g 4-hydroxy-2-(E)-nonenal (HNE), and 4,272 µg/kg glycidyl ester. In contrast, the uncoated CFDC had 19.2% oil, 117.55 µg/kg acrylamide, 0.25 mg KOH/100 kg acid, 14.40 mmol/kg peroxide, p-anisidine value of 9.76, 0.63 µg/g malondialdehyde, 0.23 µg/g HHE, 0.86 µg/g HNE, and 5,758 µg/kg glycidyl ester. MC and soy protein isolate enhanced the oil barrier of the coating film, which effectively reduced the heat transfer coefficients, oil transfer, oil oxidation, and chemical hazards in the CFDC. Our work on this edible coating contributes to methods for control of oil and chemical hazards in fried foods.

The inhibitory effects of sesamol and sesamolin on the glycidyl esters formation during deodorization of vegetables oils.

BACKGROUND: Glycidyl esters (GEs) have attracted worldwide attention for their potential harm to human health. The GEs in edible oils mainly form during the deodorization of the oil refining processes. We used sesamol and sesamolin to inhibit the formation of GEs in model corn oil (MCO), model palm oil (MPO) and model rice bran oil (MRO) during a deodorization process. RESULTS: The results showed that, in the three model oils, the total GE content was in the following order from highest to lowest: MRO (1437.98 µg kg-1 ) > MPO (388.64 µg kg-1 ) > MCO (314.81 µg kg-1 ). The inhibitory effect of the three antioxidants on the formation of GEs in the MCO was in the following order from strongest to weakest: tert-butylhydroquinone (TBHQ) > sesamol > sesamolin. CONCLUSION: When the mass percentage of sesamol was 0.05%, its inhibition percentage on GEs was close to the inhibition percentage of 0.02% added TBHQ. The present study provides a foundation for understanding how to inhibit the formation of GEs in oils by adding sesamol during the deodorization process.

Gentamicin decorated phosphatidylcholine-chitosan nanoparticles against biofilms and intracellular bacteria.

Biofilms and intracellular bacteria often cause a series of overwhelming public health issues due to their strong drug resistance. Hence, chitosan nanoparticles (CS NPs), phosphatidylcholine and gentamicin were used to synthesize a novel nanodrug delivery system (GPC NPs). Dynamic light scattering (DLS) demonstrated that the surface zeta-potential of GPC NPs was -19.5 mV. The morphology of GPC NPs was observed by scanning electron microscopy (SEM). The gentamicin adsorption and release behaviors of GPC NPs were also investigated. The GPC NPs could effectively damage and remove the biofilm formed by pathogens through permeation of the antibiotic into the biofilm. In addition, the nanoparticles were readily engulfed by macrophages which facilitated the killing of intracellular bacteria and had neglectable cytotoxicity. Our study indicated that GPC NPs could be used as a promising nanoantibacterial agent against biofilms and intracellular bacteria.

Inhibition Mechanism of Catechin, Resveratrol, Butylated Hydroxylanisole, and Tert-Butylhydroquinone on Carboxymethyl 1,2-Dipalmitoyl-sn-Glycero-3-Phosphatidylethanolamine Formation.

It is important to inhibit the food-derived, potentially hazardous chemical glycated lipids by natural products. A model system was established and the products are identified to study the inhibitory mechanism of four types of catechin, resveratrol (RES), and the synthetic antioxidants butylated hydroxylanisole (BHA) and tert-butylhydroquinone (TBHQ) on the formation of carboxymethyl 1,2-dipalmitoyl-sn-glycero-3-phosphatidylethanolamine (CM-DPPE) by determining hydroxyl radical (OH·), Amadori-1,2-dipalmitoyl-sn-glycero-3-phosphatidylethanolamine (Amadori-DPPE) and glyoxal (GO). The results show that the inhibitory rates of catechin and RES on the content of CM-DPPE in the model system are higher than those of BHA and TBHQ. There are at least two inhibitory mechanisms of antioxidants on CM-DPPE. (1) Antioxidants scavenge OH·, which blocks the process of Amadori-DPPE oxidation to form CM-DPPE. (2) Antioxidants trap GO, which blocks the reaction between GO and DPPE to form CM-DPPE. This research will reveal the inhibitory mechanisms of natural antioxidants on glycated lipids from the aspect of scavenging OH· and trapping GO. PRACTICAL APPLICATION: Food manufacturers should pay attention on the production of glycated lipids in food processing. This study will provide the theoretical basis for the use of natural products to inhibit the formation of food-derived glycated lipids. Natural products, such as catechin and resveratrol, can substitute chemical synthesis antioxidants, such as butylated hydroxylanisole and tert-butylhydroquinone, in food processing, which inhibit the formation of glycated lipids.

Lipids Promote Glycated Phospholipid Formation by Inducing Hydroxyl Radicals in a Maillard Reaction Model System.

Food-derived glycated phospholipids is potentially hazardous to human health. However, there are few studies on the effects of lipids on the formation of glycated phospholipids. In this work, two model systems were established: (1) a model system including 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (PE), glucose, and Fenton reagent and (2) a model system including PE, glucose, and five kind of vegetable oils. The contents of carboxymethyl-PE, carboxyethyl-PE, Amadori-PE, hydroxyl radical (OH•), glyoxal, and methylglyoxal were determined with high-performance liquid chromatography mass spectrometry. The results of the first model system showed that OH• oxidized glucose to produce glyoxal and methylglyoxal, which then reacted with PE to form carboxymethyl-PE and carboxyethyl-PE. OH• also oxidized Amadori-PE to form carboxymethyl-PE. The results of the second model system showed that vegetable oils with higher number of moles of carbon-carbon unsaturated double bond in vegetable oil per kilogram could produce more OH•, which promote the formation of carboxymethyl-PE and carboxyethyl-PE by oxidizing glucose and oil. We elucidated the effects of oils on the formation of glycated phospholipids in terms of OH• and intermediates. This work will contribute to better understanding the formation mechanism of glycated phospholipids with oil.

MoS2/ZnO-Heterostructures-Based Label-Free, Visible-Light-Excited Photoelectrochemical Sensor for Sensitive and Selective Determination of Synthetic Antioxidant Propyl Gallate.

Propyl gallate (PG) as one of the important synthetic antioxidants is widely used in the prevention of oxidative deterioration of oils during processing and storage. Determination of PG has received extensive concern because of its possible toxic effects on human health. Herein, we report a photoelectrochemical (PEC) sensor based on ZnO nanorods and MoS2 flakes with a vertically constructed p-n heterojunction. In this system, the n-type ZnO and p-type MoS2 heterostructures exhibited much better optoelectronic behaviors than their individual materials. Under an open circuit potential (zero potential) and visible light excitation (470 nm), the PEC sensor exhibited extraordinary response for PG determination, as well as excellent anti-inference properties and good reproducibility. The PEC sensor showed a wide linear range from 1.25 × 10-7 to 1.47 × 10-3 mol L-1 with a detection limit as low as 1.2 × 10-8 mol L-1. MoS2/ZnO heterostructure with proper band level between MoS2 and ZnO could make the photogenerated electrons and holes separated more easily, which eventually results in great improvement of sensitivity. On the other hand, formation of a five membered chelating ring structure of Zn(II) with adjacent oxygen atoms of PG played significant roles for selective detection of PG. Moreover, the PEC sensor was successfully used for PG analysis in different samples of edible oils. It demonstrated the ability and reliability of the MoS2/ZnO-based PEC sensor for PG detection in real samples, which is beneficial for food quality monitoring and reducing the risk of overuse of PG in foods.

Catechin inhibits glycated phosphatidylethanolamine formation by trapping dicarbonyl compounds and forming quinone.

It is important to inhibit food-derived potentially hazardous glycated lipids with natural products. A model reaction inhibition system was established, and products were identified with high-performance liquid chromatography-mass spectrometry (HPLC-MS/MS) to study the inhibitory effects of four types of catechins on the formation of glycated 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE) products. The results show that the percentage inhibition of epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC) and epigallocatechin gallate (EGCG) on the formation of carboxymethyl 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (CM-DPPE) are 38.84%, 33.31%, 20.71% and 22.66%, respectively. The percentage inhibition of EC, ECG, EGC and EGCG on the formation of carboxyethyl 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (CE-DPPE) is 42.04%, 41.99%, 31.70% and 36.24%, respectively. In addition, catechin can capture glyoxal (GO) and methylglyoxal (MGO) to produce multiple products. O-Benzoquinone, the oxidation products of catechin, also captures DPPE to produce quinone-DPPE adducts. Therefore, there are two inhibitory mechanisms of tea-derived catechin for glycated DPPE: (1) catechin inhibits the formation of CM-DPPE and CE-DPPE by trapping reactive GO and MGO; and (2) catechin is oxidized to o-benzoquinone. O-Benzoquinone reacts with DPPE through nucleophilic substitution, which competes with the reaction between glucose and DPPE. This study will provide a theoretical basis for the use of natural products to inhibit the formation of food-derived glycated lipids.

A preliminary study on the formation pathways of glycated phosphatidylethanolamine of food rich in phospholipid during the heat-processing.

The formation of food-derived glycated phosphatidylethanolamine (PE) in thermal process was investigated by designing a 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE)-glucose model system heated from 40 to 100 °C for 8 h. The main products of glycated PE were determined by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Results showed that the glycation of DPPE formed three major glycated compounds: amadori-glycated-1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (Amadori-DPPE), carboxymethyl-1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (CM-DPPE), and carboxyethyl-1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (CE-DPPE). Amadori-DPPE was identified to generate CM-DPPE through oxidative cleavage of glycated polar head group under high temperature and extended incubation time. Additionally, during thermal processing, retro-aldol reactions of glucose led to the formation of two reactive dicarbonyl intermediates: glyoxal (GO) and methylglyoxal (MGO), both of them reacted with amino group of DPPE to form CM-DPPE and CE-DPPE, respectively. Thus, the formation pathways of CM-PE might involve the irreversible rearrangements of Amadori-PE following oxidative cleavage, as well as the glycation of amino group of PE with GO. CE-PE could only be formed by reaction of PE with MGO. Moreover, the content of CM-DPPE was higher than that of CE-DPPE in the same incubation conditions, which indicated that CM-PE might be a more useful predictive marker for food-derived glycated amino-phospholipid, rather than Amadori-PE, particularly in thermal processed foodstuffs.

Adsorption Removal of Glycidyl Esters from Palm Oil and Oil Model Solution by Using Acid-Washed Oil Palm Wood-Based Activated Carbon: Kinetic and Mechanism Study.

Acid-washed oil palm wood-based activated carbon (OPAC) has been investigated for its potential application as a promising adsorbent in the removal of glycidyl esters (GEs) from both palm oil and oil model (hexadecane) solution. It was observed that the removal rate of GEs in palm oil was up to >95%, which was significantly higher than other adsorbents used in this study. In batch adsorption system, the adsorption efficiency and performance of acid-washed OPAC were evaluated as a function of several experimental parameters such as contact time, initial glycidyl palmitate (PGE) concentration, adsorbent dose, and temperature. The Langmuir, Freundlich, and Dubinin-Radushkevich models were used to describe the adsorption equilibrium isotherm, and the equilibrium data were fitted best by the Langmuir model. The maximum adsorption capacity of acid-washed OPAC was found to be 36.23 mg/g by using the Langmuir model. The thermodynamic analysis indicated that the adsorption of PGE on acid-washed OPAC was an endothermic and physical process in nature. The experimental data were fitted by using pseudo-first-order, pseudo-second-order, and intraparticle diffusion models. It was found that the kinetic of PGE adsorption onto acid-washed OPAC followed well the pseudo-second-order model for various initial PGE concentrations and the adsorption process was controlled by both film diffusion and intraparticle diffusion. The desorption test indicated the removal of GEs from palm oil was attributed to not only the adsorption of GEs on acid-washed OPAC, but also the degradation of GEs adsorbed at activated sites with acidic character. Furthermore, no significant difference between before and after PGE adsorption in oil quality was observed.

Hydroxyl radical induced by lipid in Maillard reaction model system promotes diet-derived N(ε)-carboxymethyllysine formation.

N(ε)-carboxymethyllysine (CML) is commonly found in food, and is considered as a potential hazard to human health. However, the effect of lipids on CML formation in Maillard reaction is still not clarified. In this study, the content of diet-derived CML and its key intermediates, epsilon-fructoselysine (FL) and glyoxal (GO), is determined with high performance liquid chromatography mass spectrum (HPLC-MS) in model system containing lipid compounds. According to the results, hydroxyl radical (OH) induced by Fenton reagent can promote the three pathways of CML formation. Moreover, in the Maillard reaction system, linoleic acid (Lin), oleic acid (Ole) and glycerol trioleate (Tri) can induce more OH·, which promotes CML formation. Their level of promoting CML formation is in the order of Ole>Lin>Tri. On the contrary, glycerol (Gly) can scavenge OH·, which inhibit the CML formation. Finally, it is proved that FL content and GO content decreases with heating time in model system, while CML content increases with heating time. Thus, it is concluded that in the Maillard reaction system lipids can induce more OH·, which promotes the conversion from FL and GO to CML. Our research may contribute to the development of inhibitory methods for diet-derived CML by scavenging OH·.

Review of the characteristics of food-derived and endogenous ne-carboxymethyllysine.

Ne-Carboxymethyllysine (CML), a representative of advanced glycation end products (AGEs), is commonly found in food and is considered a potential hazard to human health. Food scientists have begun to investigate the formation of CML in food processes. As the understanding of CML is mainly based on that of endogenous CML from the fields of biology and medicine, this review summarizes the different characteristics of food-derived CML and endogenous CML with respect to food safety, detection methods, formation environment, formation mechanism, and methods for inhibiting the formation of CML. Additionally, future research directions for the study of food-derived CML are proposed, including understanding its digestion, absorption, and metabolism in human health, developing rapid, reliable, and inexpensive detection methods, revealing its relationship with food components and production processes, and controlling the formation of CML through the addition of inhibitors and/or modification of food processing conditions, so as to contribute to the methods for controlling food-derived AGEs.