Effects of NaCl content and drying temperature on lipid oxidation, protein oxidation, and physical properties of dry-cured chicken

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 Starter Culture and Temperature on the Flavor and Sensory Characteristics of Dry-Cured Ham

This study focused on understanding the effects of yeast and mold on the sensory properties of dry-cured ham aged at 20°C and 25°C. Debaryomyces hansenii isolated from Doenjang and fermented sausages, and Penicillium nalgiovense isolated from fermented sausages were utilized. The CIE a* tended to increase in all treatments as the aging period increased. At 6 weeks of aging, DFD25 showed a significantly higher CIE a* value than other treatments. The shear force tended to increase in all treatments as the aging period increased. At 6 weeks of aging, among the treatments aged at 25°C, DFD25 showed a low tendency to shear force. The PC1 of the electronic nose was 42.872%. At 25°C, the hexane content was higher and levels of ethanol, propan-2-one, 2,4,5-trimethylthiazole, and limonene were lower than that at 20°C. DFD25 showed significantly higher hexane content and significantly lower limonene content than other treatments. The PC1 of the electronic tongue was 84.529%. All treatments, except for the C starter, exhibited higher salt and lower sour levels at 25°C compared to 20°C when the same starter was used. The DFD25 showed the lowest sour taste and a higher tendency of umami than the other treatments. Sensory evaluation revealed that DFD25 had significantly higher scores for texture than C25, whereas no significant differences were observed in other aspects. Therefore, the used starters are considered suitable for aging at 25°C; among them, the DFD starter demonstrates superior qualities and enhanced commercial potential compared to the control.

Characterization of the Effects of Low-Sodium Salt Substitution on Sensory Quality, Protein Oxidation, and Hydrolysis of Air-Dried Chicken Meat and Its Molecular Mechanisms Based on Tandem Mass Tagging-Labeled Quantitative Proteomics

The effects of low-sodium salt mixture substitution on the sensory quality, protein oxidation, and hydrolysis of air-dried chicken and its molecular mechanisms were investigated based on tandem mass tagging (TMT) quantitative proteomics. The composite salt formulated with 1.6% KCl, 0.8% MgCl2, and 5.6% NaCl was found to improve the freshness and texture quality scores. Low-sodium salt mixture substitution significantly decreased the carbonyl content (1.52 nmol/mg), surface hydrophobicity (102.58 μg), and dimeric tyrosine content (2.69 A.U.), and significantly increased the sulfhydryl content (74.46 nmol/mg) and tryptophan fluorescence intensity, suggesting that protein oxidation was inhibited. Furthermore, low-sodium salt mixture substitution significantly increased the protein hydrolysis index (0.067), and cathepsin B and L activities (102.13 U/g and 349.25 U/g), suggesting that protein hydrolysis was facilitated. The correlation results showed that changes in the degree of protein hydrolysis and protein oxidation were closely related to sensory quality. TMT quantitative proteomics indicated that the degradation of myosin and titin as well as changes in the activities of the enzymes, CNDP2, DPP7, ABHD12B, FADH2A, and AASS, were responsible for the changes in the taste quality. In addition, CNDP2, ALDH1A1, and NMNAT1 are key enzymes that reduce protein oxidation. Overall, KCl and MgCl2 composite salt substitution is an effective method for producing low-sodium air-dried chicken.

Uncovering quality changes of salted bighead carp fillets during frozen storage: The potential role of time-dependent protein denaturation and oxidation

This study aimed to find the specific relationship between quality traits and myofibrillar proteins (MPs) alteration of salted fish during frozen storage. Protein denaturation and oxidation occurred in frozen fillets, with the denaturation occurring before oxidation. In the pre-phase of storage (0-12 weeks), protein structural changes (secondary structure and surface hydrophobicity) were closely related to the water-holding capacity (WHC) and textural properties of fillets. The MPs oxidation (sulfhydryl loss, carbonyl and Schiff base formation) were dominated and associated with changes in pH, color, WHC, and textural properties during the later stage of frozen storage (12-24 weeks). Besides, the brining at 0.5 M improved the WHC of fillets with less undesirable changes in MPs and quality traits compared to other concentrations. The 12 weeks was an advisable storage time for salted frozen fish and our results might provide an available suggestion for fish preservation in aquatic industry.

Utilizing of the Common Dehydrating Techniques to obtain maximum benefit from the Protein and mineral Composition of rosemary leaves for Spice and Herbal Tea Production

In the study, we examined in detail the effect of dehydrating using natural drying in the shade, convection drying, and microwave drying, which are the most widely used techniques, especially for tea and spices, both in practice and in theory, on the protein, and mineral composition of rosemary leaves. Also, we determined the color parameters, which are the reason for the selection because it creates the allure for spices. In microwave drying at 600 W, we obtained results close to fresh rosemary in all color parameters, especially brightness and greenness. Although natural drying, which does not have any energy and investment costs, is the second-best method in terms of color, 50 °C, which is the most common drying technique in the market, caused significant color losses affecting the commercial value of the product. We reached the closest protein and P, Ca, Mg, Fe, Zn, Mn, and contents to fresh products in dried ones at 600 W. In contrast, in K only, the highest measurement was at 200 W. Strikingly, we observed dramatic losses reducing the benefit obtained from the product regarding protein and almost all nutrients in both convective and natural drying techniques, the most common methods in practice.

Improving the poor texture and technological properties of chicken wooden breast by enzymatic hydrolysis and low-frequency ultrasound

Abstract

Wooden breast (WB) is a recurrent myopathy in fast‐growing birds, which alters the appearance, functionality, and the texture of the breast muscle. The objectives of this study were (i) to evaluate the effect of a combined use of papain enzyme and ultrasound on the texture of WB chicken using response surface methodology and (ii) to assess the effect of marinating on the quality of WB chicken meat. Full factorial experimental design method was used to obtain the ideal conditions to soften the WB meat. The independent variables were the concentration of papain (0.1%–0.3%) and the time in ultrasonic bath (10–30 min); shear force (SF) was the dependent variable. The optimum results were obtained at a concentration of 0.2% papain and 20 min on ultrasound. Papain enzyme had a great influence on the texture of WB meat, reducing its hardness. However, the effect of the ultrasound time on the SF response was not observed. The marinated WB meat showed similar SF values and texture profile than those from normal (N) meat, with reduction in the parameters of protein and lipid oxidation. The use of papain without ultrasound bath proved to be an efficient means for improving the tenderness of WB breasts.

Practical Application

This study shows the efficiency of the application of two technological procedures (enzymatic treatment and ultrasound) to improve the texture profile and technological properties of chicken breasts affected by the wooden breast myopathy. The economic loss caused by the world‐wide occurrence of wooden breast is enormous, and the application of papain has been found to counteract the impaired properties of this abnormal chicken breasts. Since papain is already widely used in the food industry to tenderize meat, its application in improving the quality of WB meat is straightforward.

Effect of Cedrus deodara extract on the physiochemical and sensory properties of salted meat and its action mechanism

The effect of pine needle extract from Cedrus deodara (PNE) on the quality of salted meat was reported, and its action mechanism was further investigated. With the treatment of PNE, the physicochemical properties of salted meat were improved. The peroxide value decreased from 16.18 to 6.78 mmol O₂ /kg, while the thiobarbituric acid value decreased from 0.79 to 0.40 mg MDA/kg. Moreover, the salted meat with PNE also had the better texture, color, and volatile compositions. The 0.2% PNE group showed the highest ΔE value (63.16 ± 0.56), hardness (813.5 ± 48.7 g), and volatility (45.86 ± 0.39), while the control group showed the lowest ΔE value (43.92 ± 2.13), hardness (515.8 ± 17.3 g) and volatility (29.97 ± 0.56). In addition, with the analysis of fluorescence and circular dichroism spectroscopy, the spatial structures of myofibrillar protein (MP) in salted meat were obviously changed by PNE. Meanwhile, methylconiferin, 1-O-feruloyl-β-D-glucose, nortrachelogenin, secoxyloganin, 1-O-(4-coumaroyl)-β-D-glucose and pelargonidin-3-O-glucoside were identified from PNE. Furthermore, according to the analysis of molecular docking, hydrogen bond, hydrophobic force, and electrostatic force were obtained as the main molecular forces between MP and the phenolic compounds of PNE, while arginine, glutamic acid, and glycine residues were the main binding sites. All results suggested that PNE might be a potential candidate to improve the quality of salted meat in the food industry. PRACTICAL APPLICATION: The quality deterioration of meat may not only affect its further processing and consumption but also may lead to some food safety problems. In present study, PNE exhibited the fine capability to inhibit the oxidation of meat, while it could ameliorate the texture, color, and physicochemical properties of meat due to its tightly interaction with myofibrillar protein. All result suggested that PNE could be potentially utilized to improve the quality of meat in food industry.

Effect of roasting temperature on lipid and protein oxidation and amino acid residue side chain modification of beef patties

Beef is rich in nutrients and is one of the most important ingredients in the world. But in the process of cooking and heating, the nutrients of beef will change to varying degrees. How temperature affects the oxidation of lipids and proteins in beef, and the modification of amino acid residues is unclear. This study intended to heat beef at different roasting temperatures (150 °C, 190 °C, 230 °C, 270 °C, 310 °C), measure parameter including colour, peroxide value (PV), thiobarbituric acid-reactive substances (TBARS), thiol and carbonyl content, protein solubility, tryptophan and Schiff base content, protein molecular weight distribution and modification of amino acid residues to discussed the effects of different temperatures on the lipid and protein oxidation of beef patties, as well as the modification of amino acid residues. The results showed that the values of L* and b* increased with the temperature increased, and the values of a* decreased. With the increase of temperature, the lipid oxidation indexes PV and TBARS, Schiff base and carbonyl content also increased, and the thiol content and protein solubility decreased significantly (p < 0.001). SDS-PAGE showed that the band of myosin heavy chain (MHC, 220 kDa) was significantly degraded, while the band of actin (42 kDa) was still clearly visible. The analysis of UPLC-MS/MS results found that the aromatic amino acid residues in all samples were oxidized to a certain extent, especially tryptophan. Other oxidative modifications, including α-amiooadipic acid (AAA), hydroxyethyl lysine (CEL) and malondialdehyde (MDA), were only present in roasted samples and not in raw meat. The results suggested that lipid oxidation and protein oxidation were closely related to colour parameters. The oxidation of proteins and lipids was aggravated at higher temperature. Amino acid side chains were also modified at high temperature, and this change was particularly evident in aromatic amino acids. These results provided new insights for the oxidation of proteins and lipids of beef and the modification level of amino acid residues under high temperature conditions, which will help us to improve the cooking quality of meat foods.

Effect of flavonoids from Lycium barbarum leaves on the oxidation of myofibrillar proteins in minced mutton during chilled storage

Herein, we report the effect of flavonoids from Lycium barbarum leaves (LBLF) on myofibrillar proteins (MP) in minced mutton during chilled storage (4 ± 1 ℃). High performance liquid chromatography (HPLC) analysis showed that the total flavonoid content in LBLF was 322.0 mg/g, of which the rutin content was 297.6 mg/g. The effect of 0.5%, 1.0%, and 1.5% LBLF on the structure and thermodynamic properties of MP in minced mutton was studied systematically. Tyrosine and tryptophan of MP samples treated with LBLF were converted from an exposed state to an embedded state. The interaction between LBLF and MP quenched the internal fluorescence, and improved the thermal stability of MP. The addition of LBLF significantly reduced the carbonyl and sulfhydryl contents of MP (p < 0.05), and decreased the surface hydrophobicity of MP in a dose-dependent manner. Our results indicate that LBLF can combine with free radicals produced by protein oxidation, block the free radical oxidation chain reaction, and inhibit the oxidation of MP. Therefore, LBLF may have great potential as a natural antioxidant in meats and meat products during chilled storage. PRACTICAL APPLICATION: Lycium barbarum is widely distributed in China, especially in Qinghai and Ningxia. The results of this study suggest that flavonoids extracted from L. barbarum leaves may be an effective natural antioxidant for the preservation of meats and meat products.

Assessment the influence of salt and polyphosphate on protein oxidation and Nε-(carboxymethyl)lysine and Nε-(carboxyethyl)lysine formation in roasted beef patties

The impact of NaCl and tripolyphosphate (TPP)/pyrophosphate (PP) on protein oxidation and Nε-(carboxymethyl)lysine (CML) and Nε-(carboxyethyl)lysine (CEL) formation in roasted beef patties was investigated. The content of CML and CEL in patties treated with salts was approximately 1.1-1.7 and 1.2-3.2 times higher than that of the control samples, respectively. An increase in salt content caused higher oxidation of tryptophan and protein carbonylation with a decrease in Schiff bases (P < 0.05) and a slight decrease in lipid oxidation (P < 0.05). Significant correlations (P < 0.05) between CML, CEL, and protein oxidation measurements was found. The higher salts content, causing less cooking loss and higher moisture content, significantly correlated (P < 0.05) with CML, CEL content, and protein oxidation of the patties. The increase in CML and CEL content and protein oxidation in roasted patties with salts might be related to the pro-oxidation of salts, and also partly due to the temperature changes caused by the water-holding capacity of salts.