Analysis of the relationship between heterocyclic amines and the oxidation and thermal decomposition of protein using the dry heated soy protein isolate system

Effects of basic amino acids on heterocyclic amines and quality characteristics of fried beef patties at low NaCl level

The impact of basic amino acids (Lysine, Arginine, Histidine) on the formation of total heterocyclic amines (HAs) was investigated in fried beef patties at 1% NaCl level. Different levels of basic amino acids (0.1%, 0.5%, 1%) significantly inhibited the formation of the total and individual HAs at 1% NaCl, and the inhibitory effect was more effective than 3% NaCl (6.19 ng/g, 26.93% inhibition) (P < 0.05). Lys at 1% reduced total HAs the most (2.46 ng/g, 70.88% inhibition), followed by 1% His (2.79 ng/g, 67.03% inhibition) and 1% Arg (3.43 ng/g, 59.51% inhibition). Compared to the 3% NaCl, the quality characteristics (moisture content, frying loss, texture profile, and color) of the fried beef patties were significantly improved when basic amino acids were added at 1% NaCl (P < 0.05). The lipid oxidation of fried beef patties was significantly inhibited by 1% Arg and 1% Lys at 1% NaCl level (P < 0.05). The results indicated that basic amino acids could inhibit the formation of total HAs while maintaining the quality of meat products at low NaCl condition.

Effect of baking on the structure and bioavailability of protein-binding zinc from oyster (Crassoetrea hongkongensis)

To compare the bioavailability of protein-binding zinc, we investigated the impact of baking on the structure of zinc-binding proteins. The results showed that zinc-binding proteins enriched in zinc with relative molecular weights distributed at 6 kDa and 3 kDa. Protein-binding zinc is predisposed to separate from proteins' interiors and converge on proteins' surface after being baked, and its structure tends to be crystalline. Especially -COO, -C-O, and -C-N played vital roles in the sites of zinc-binding proteins. However, baking did not affect protein-binding zinc's bioavailability which was superior to that of ZnSO4 and C12H22O14Zn. They were digested in the intestine, zinc-binding complexes that were easily transported and uptaken by Caco-2 cells, with transport and uptake rates as high as 62.15% and 15.85%. Consequently, baking can alter the conformation of zinc-binding proteins without any impact on protein-binding zinc's bioavailability which is superior to that of ZnSO4 and C12H22O14Zn.

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

β-Carboline heterocyclic amines (β-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 β-CHAs in smoked meat and meat processed at high temperatures. In this research, the concentration of β-CHAs in smoked meats prepared using a variety of wood materials was measured using LCMS/MS. Additionally, key volatile organic compound markers associated with β-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 β-CHAs levels in smoked meat. The findings indicated that smoke exposure indeed increases the β-CHAs content of meat. However, only the strainer capable of filtering PM2.5-sized particles reduced the amount of β-CHAs present compared to the control group. In contrast, strainers with larger pore sizes facilitated excessive accumulation of β-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 β-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 β-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.

Comparing application methods of reishi mushroom (Ganoderma lucidum) extract in deep-fried meatballs: impact on heterocyclic aromatic amine formation

BACKGROUND

The present research was conducted to investigate the impact of reishi mushroom extract (RME) on the formation of heterocyclic aromatic amines (HAAs) in meatballs. Sample preparations involved applying RME using either the spreading or addition method, with varying concentrations (0%, 0.25%, 0.5%, and 1% of RME), followed by deep-frying at temperatures of 150 and 190 °C for 3 min.

RESULTS

The types and levels of HAAs varied based on the frying temperature, method of extract application, and the extract concentration. Notably, total HAA contents increased with rising the frying temperature (P < 0.01) and varied from undetectable levels to 4.91 ng g-1 across all analyzed meatballs. The addition method was more effective than the spreading method (P < 0.01), and among the concentrations tested 0.25% RME exhibited the highest efficacy in reducing total HAAs (P < 0.05). Furthermore, the addition method inhibited lipid oxidation more efficiently compared to the surface spreading method (P < 0.05).

CONCLUSION

This study demonstrated that RME had mitigating effects on HAAs depending on the concentration and frying conditions in deep-fried meatball samples. © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effect of Chinese quince proanthocyanidins on the inhibition of heterocyclic amines and quality of fried chicken meatballs and tofu

Heterocyclic amines (HCAs) have potential carcinogenic and mutagenic activity and are generated in cooked protein-rich foods. Adding proanthocyanidins (PAs) to these foods before frying is an effective way to reduce HCAs. In this study, polymeric PAs (PPA) and ultrasound-assisted acid-catalyzed/catechin nucleophilic depolymerized PAs (UAPA, a type of oligomeric PA) were prepared from Chinese quince fruits (CQF). Different levels of PPA and UAPA (0.05%, 0.1%, and 0.15%) were added to chicken meatballs and tofu; then these foods were fried, and the content of HCAs in them after frying was investigated. The results showed that PPA and, particularly, UAPA significantly inhibited the formation of HCAs in fried meatballs and tofu, and this inhibition was dose-dependent. The inhibition of HCAs by both PPA and UAPA was stronger in the chicken meatballs than in fried tofu. The level of total HCAs was significantly reduced by 57.84% (from 11.93 to 5.03 ng/g) after treatment of meatballs with 0.15% UAPA, with inhibition rates of 78.94%, 50.37%, and 17.81% for norharman, harman, and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), respectively. Of note, there was a negative correlation between water, lipid, protein, creatine, and glucose content and HCA content in the crust, interior, and whole (crust-plus-interior) measurements of all fried samples. Interestingly, PPA and UAPA were found more effective in inhibiting HCAs in the exterior crust than in the interior of the fried chicken meatballs. These results provide evidence that further studies on the reduction of the formation of harmful HCAs in fried foods by adding CQF PAs could be valuable to the fried food industry. PRACTICAL APPLICATION: Chinese quince proanthocyanidins treatments significantly inhibited the generation of heterocyclic amines (HCAs) in chicken meatballs and tofu when deep-fried. These results suggest that Chinese quince proanthocyanidins can be used as natural food additive for reducing HCAs in fried foods, laying the foundation for using Chinese quince fruit proanthocyanidins for HCA inhibition in the food industry.

Effect of enzymolysis combined with Maillard reaction treatment on functional and structural properties of gluten protein

In this work, the modified gluten was prepared by enzymolysis combined with Maillard reaction (MEG), and its functional and structural properties were investigated. The result showed that the maximum foamability of MEG was 19.58 m2/g, the foam stability was increased by 1.8 times compared with gluten, and the solubility and degree of graft were increased to 44.4 % and 28.1 % at 100 °C, whereas the content of sulfhydryl group decreased to 0.81 μmol/g. The scavenging ability on ABTS+radical and DPPH radical of MEG was positively correlated with reaction temperature, and the maximum values were 86.57 % and 71.71 % at 140 °C, respectively. Furthermore, the fluorescence quenching effect of tryptophan and tyrosine residues was enhanced, while the fluorescence intensity decreased with the temperature increase. Scanning electron microscopy revealed that the surface of enzymatically hydrolyzed-gluten became smooth and the cross section became straightened, while MEG turned smaller and irregular approaching a circular structure. FT-IR spectroscopy showed that enzymatic hydrolysis promoted the occurrence of more carbonyl ammonia reactions and the formation of precursors of advanced glycosylation end products. These results provide a feasible method for improving the structure and functional properties of gluten protein.

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.

Effect of heat treatment on the physical stability, interfacial composition and protein-lipid co-oxidation of whey protein isolate-stabilised O/W emulsions

This work aimed to investigate the effects of heat treatments at different temperatures (60, 70 and 90 °C, expressed as HT-60, HT-70 and HT-90) on interfacial composition and protein-lipid co-oxidation in whey protein isolate (WPI)-stabilised O/W emulsions during storage. Compared with control group, all heated emulsions exhibited weaker physical stability over 10 days of storage, which verified by the increased droplet size, as well as decreased adsorbed protein levels and absolute ζ-potential values. Moreover, proteins recovered from the HT-90 emulsion showed the highest fluorescence intensity and red-shift of the maximum emission wavelength, indicating partial unfolding of the protein structure. Meanwhile, severe changes in protein structure were also observed in the HT-70 and HT-90 emulsions, which clearly verified by the degradation of bovine serum albumin, α-lactalbumin and β-lactoglobulin. Furthermore, HT-70 and HT-90 emulsions showed lower levels of lipid hydroperoxides and thiobarbituric acid reactive substances. In contrast, the recovered proteins were subject to severe oxidative stress as indicated by carbonyl and N'-formyl-L-kynurenine. Hierarchical cluster and correlation analysis implied that the process of protein-lipid co-oxidation is inevitable, but it can be retarded by heat treatment. Our results clearly revealed the relevance among heat treatment, interfacial adsorption property, and the protein-lipid co-oxidation of O/W emulsions.

Development of meat analogs: Focus on the current status and challenges of regulatory legislation

Population growth and the rising enthusiasm for meat consumption in developing countries have increased the global demand for animal protein. The limited increase in traditional meat production, which results in high resource consumption, greenhouse gas emissions, and zoonotic diseases, has affected the sustainable supply of meat protein. The technological development and commercialization of meat analogs derived from plant and microbial proteins provide a strategy for solving the abovementioned problems. However, before these innovative foods are marketed, they should comply with regulations and standards to ensure food safety and consumer rights. This review briefly summarizes the global development status and challenges of plant- and fungi-based meat analog products. It focuses on the current status, characteristics, and disputes in the regulations and standards worldwide for plant- and fungi-based meat analogs and proposes suggestions for perfecting the regulatory system from the perspective of ensuring safety and supporting innovation. Although plant- and fungi-based meat analogs have had a history of safe usage as foods for a certain period around the world, the nomenclature and product standards are uncertain, which affects product innovation and global sales. Regulatory authorities should promptly formulate and revise regulations or standards to clarify the naming of meat analogs and product standards, especially the use of animal-derived ingredients and limits of nutrients (e.g., protein, fat, vitamins, and minerals) to continuously introduce start-up products to the market.

Effect of Oxidative Modification by Peroxyl Radical on the Characterization and Identification of Oxidative Aggregates and In Vitro Digestion Products of Walnut (Juglans regia L.) Protein Isolates

Walnut protein is a key plant protein resource due to its high nutritional value, but walnuts are prone to oxidation during storage and processing. This article explored the oxidative modification and digestion mechanism of walnut protein isolates by peroxyl radical and obtained new findings. SDS-PAGE and spectral analysis were used to identify structural changes in the protein after oxidative modification, and LC-MS/MS was used to identify the digestion products. The findings demonstrated that as the AAPH concentration increased, protein carbonyl content increased from 2.36 to 5.12 nmol/mg, while free sulfhydryl content, free amino content, and surface hydrophobicity decreased from 4.30 nmol/mg, 1.47 μmol/mg, and 167.92 to 1.72 nmol/mg, 1.13 μmol/mg, and 40.93 nmol/mg, respectively. Furthermore, the result of Tricine-SDS-PAGE in vitro digestion revealed that protein oxidation could cause gastric digestion resistance and a tendency for intestinal digestion promotion. Carbonyl content increased dramatically during the early stages of gastric digestion and again after 90 min of intestine digestion, and LC-MS/MS identified the last digestive products of the stomach and intestine as essential seed storage proteins. Oxidation causes walnut proteins to form aggregates, which are then re-oxidized during digestion, and proper oxidative modification may benefit intestinal digestion.

The Effects of Volatile Organic Compounds (VOCs) on the Formation of Heterocyclic Amines (HAs) in Meat Patties, under Different Smoking Temperatures and Durations

In this study, UPLC-MS/MS was used to study the effects of smoking duration and temperature on the formation of heterocyclic amines (HAs) in smoke-processed meat patties. Four kinds of free HAs—including F-7,8-DiMeIQx; F-MeAαC; F-Harman and F-Norharman—and six kinds of protein-bound HAs—including B-AαC; B-7,8-DiMeIQx; B-Glu-p-1; B-MeAαC; B-Harman and B-Norharman—were detected and quantified. Among the free HAs, we observed a 23-fold content increase (p < 0.05), from 0−4 h (at 0 h and 4 h they were 4.24 ng·g−1 and 98.33 ng·g−1, respectively), and the content of the free HAs decreased to 78.80 ng·g−1, at 5 h. At the same time, the free HAs content increased from 53.52 ng·g−1, at 50 °C, to 127.16 ng·g−1, at 60 °C, and then decreased continuously. The content of the free HAs was the highest at 60 °C. For the protein-bound HAs, their content was found to generally decrease with the increase in smoking duration and temperature. However, at 5 h, the content of protein-bound HAs slightly increased to 984.2 ng·g−1. Meanwhile, at 90 °C, it increased to 1643.53 ng·g−1. Additionally, a total of 16 volatile organic compounds (VOCs) were found in all of the meat samples, of which 10 VOCs (one acid, three aldehydes and seven phenols) were significantly related to the formation of free HAs. These findings showed that all the different types of HAs were produced under low-temperature processing, which provided scientific insights into the potential generation of HAs during meat smoking processes and could be used as a reference to minimize the risks of cancer related to the consumption of smoked meat products.

Effect of Different Roasting Conditions and Coreopsis Extract on Heterocyclic Amine Formation in Roast Lamb Products

ABSTRACT

Heterocyclic amines (HCAs), which are known carcinogens in thermally processed foods, were investigated in roast lamb patties under various time and temperature conditions. HCAs in lamb products roasted at some temperatures increased with roasting time. An exponential model with a time factor fit well for the production of HCAs. The mean pH and cooking loss at various temperatures were also determined. The mean pH decreased as the temperature increased. Coreopsis extract was added to lamb patties roasted at 230°C for 15 min per side. The amount of coreopsis extract added had a significant effect on HCA development. A weak positive relationship was observed between the antioxidant activity of the lamb patty with the coreopsis extract and the inhibitory effect of coreopsis extract on various HCAs, with a correlation coefficient of 0.14 to 0.44 (P > 0.05). Coreopsis extract containing flavonoids can be a beneficial additive for production of barbecue meat.

HIGHLIGHTS

Gas- and Particle-Phase Amide Emissions from Cooking: Mechanisms and Air Quality Impacts

The high-temperature cooking of protein-rich foods represents an important but poorly constrained source of nitrogen-containing gases and particles to indoor and outdoor atmospheres. For example, panfrying meat may form and emit these nitrogen-containing compounds through complex chemistry occurring between heated proteins and cooking oils. Here, we simulate this cooking process by heating amino acids together with triglycerides. We explore their interactions across different temperatures, triglyceride types, and amino acid precursors to form amide-containing products. Ammonia, arising from the thermal degradation of amino acids, may react with a triglyceride's ester linkages, forming amides and promoting de-esterification reactions that break the triglyceride into volatilizable products. Additionally, triglycerides may thermally oxidize and fragment as they are heated, and the resulting oxygenated breakdown products may react with ammonia to form amides. We observed evidence for amide formation through both of these pathways, including gas-phase emissions of C_2-11H_5-23NO species, whose emission factors ranged from 33 to 813 μg total gas-phase amides per gram of amino acid precursor. Comparable quantities of particle-phase oleamide (C₁₈H₃₅NO) were emitted, ranging from 45 to 218 μg/g. The observed amide products had variable predicted toxicities, highlighting the importance of understanding their emissions from cooking and their ultimate inhalation exposure risks.