To investigate the distribution of carboxymethyllysine (CML) in plant-based meat products and its toxic effects on zebrafish larvae, five representative commercially available plant-based meat products were selected. Liquid chromatography-mass spectrometry (LC-MS) was employed to analyze the CML content in these products and compare it with those of other product types. Zebrafish were used as a biological model to evaluate the acute embryonic toxicity and developmental toxicity of exogenous CML on zebrafish larvae. Results indicated CML concentrations in plant-based meat products ranged from 0.39 (prepared products and smoked and cooked products) to 35.36 mg/kg (deep-fried products), comparable to those of instant noodles, cereal products, and certain meat products. The median lethal concentration (LC₅₀) of CML at 96 hours post-fertilization (hpf) was 864.521 mg/L; it did not affect the survival of zebrafish embryos at concentrations ≤ 250 mg/L nor the hatching rate at concentrations ≤ 62.5 mg/L. CML concentrations ≥ 125 mg/L induced developmental malformations in zebrafish larvae. The estimated daily intake (EDI) of CML via plant-based meat consumption was assessed, indicating that CML levels were far below the threshold for causing developmental toxicity to zebrafish. These findings provide support for assessing the potential food safety of CML in plant-based meat and evaluating dietary exposure to this compound.

The effect of rosemary extract on the flavor characteristics and oxidative quality of dried Penaeus vannamei at different processing stages was explored employing an electronic tongue, an electronic nose, high performance liquid chromatography (HPLC), and gas chromatography-mass spectrometry (GC-MS). The results showed that rosemary extract significantly inhibited the carbonyl content and thiobarbituric acid reactive substances (TBARS) value of shrimp at the soaking, boiling, and drying stages (P < 0.05). Compared with the control group without the addition of rosemary extract, the shrimp with rosemary extract had a higher equivalent umami concentration (EUC) and a lower degradation rate of flavor nucleotides. The proportion of sweet amino acids in the rosemary treatment group was significantly higher, while the proportion of total bitter amino acids was significantly lower than that in the control group at the soaking, boiling, and drying stages (P < 0.05). The electronic nose results showed that the odor characteristics were similar between the groups with and without rosemary extract during the cooking stage. A total of 41 volatile flavor compounds were identified by GC-MS. Rosemary extract inhibited the generation of volatile flavor components including those responsible for the fishy odor such as trimethylamine at different processing stages, which may be related to the antioxidant activity of rosemary extract. Overall, rosemary extract shows good application prospects in improving the non-volatile flavor quality of shrimp when combined with thermal processing techniques.

The debittering effect of β-cyclodextrin, lactoferrin or flavourzyme at various concentrations on bone collagen peptide was evaluated by electronic tongue, color analysis and sensory evaluation. The debittering mechanism was elucidated by hydrophobicity, free amino acid content and Fourier transform infrared (FTIR) spectroscopy. Meanwhile, the impact of the different debittering methods on antioxidant properties of bone collagen peptide was explored in terms of total antioxidant capacity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity, and 2,2’-azinobis-(3-ethylbenzthiazoline-6-sulfonate) (ABTS) cation radical scavenging capacity. β-Cyclodextrin at 4 g/100 mL, lactoferrin at 5 g/100 mL and flavourzyme at 1.5 g/100 mL greatly reduced the bitterness of bone collagen peptide, and flavourzyme at 1.5 g/100 mL reduced it to the lowest level. In addition, surface hydrophobicity of all debittered samples was lower than that of the control group (P < 0.05). After debittering with β-cyclodextrin or lactoferrin, the content of hydrophobic free amino acids was significantly decreased, but increased after debittering with flavourzyme (P < 0.05), suggesting that the principles of these debittering methods are different. Compared with the other debittering methods, flavourzyme treatment significantly enhanced the antioxidant ability of bone collagen peptide (P < 0.05). Thus, flavourzyme treatment offers a potential approach for the production of bone collagen peptide with acceptable bitterness intensity and high antioxidant activity.

The effect of process and storage on the volatiles and odorant profile of Chinese dry sausage was evaluated, as well as its physicochemical parameters. Microbial esterification and wine (27.54%–43.35%), and lipid oxidation (11.30%–34.92%) played a key role in flavor profile during process and storage. A significant increase of each volatile was detected during process except gradual decrease of volatiles from spices, while a gradual decrease of each volatile was detected during storage except significant increase of volatiles from lipid oxidation and esterification. 15 and 6 odor-active compounds were respectively correlated (P < 0.05) with the process and storage time. Level of heptanal, 1-octen-3-ol, the ethyl of 2-methylbutanoic, 3-methylbutanoic, butanoic, benzoic, hexanoic, heptanoic, octanoic and decanoic acid were best discriminators of process stage, while (E)-2-nonenal, ethyl hexanoate, ethyl heptanoate, and methyl decanoate, were marker compounds of storage time. An objective method was established to evaluate the stages of process and storage for samples.

The effect of sodium chloride (NaCl) curing salt content on protein oxidation, lipid oxidation and lipolysis of Chinese dry sausage was investigated. Two groups Chinese dry sausages with 2% and 4% (m/m) salt content were studied. The degree of protein oxidation increased during the processes in two groups sausages, while the content of phospholipids decreased, neutral lipids and free fatty acids increased. The degree of protein oxidation, lipid oxidation and lipolysis in 4% NaCl content group was higher than those in 2% NaCl content group, while 4% NaCl content group has higher lipase activity. In conclusion, 4% NaCl may facilitate the protein oxidation, lipid hydrolysis and oxidation in Chinese dry sausage, and the protein oxidation had strong correlation with lipid oxidation and lipolysis. The results could provide a basis for improving the technology of industrial production.