Investigation on 3D printing of shrimp surimi under different printing parameters and thermal processing conditions.

Improving the printing accuracy and stability of shrimp surimi and finding appropriate printing parameters and suitable thermal processing method can help to develop high value-added 3D printing products of shrimp surimi. It was found that in order to make the 3D printing products of shrimp surimi have higher printing adaptability (printing accuracy and printing stability reach more than 97%), by choosing nozzle diameter of 1.20 mm and setting the printing height of the nozzle to 2.00 mm, the layers of the printed products were better fused with each other, and the printing accuracy of the products could be greatly improved; there was no uneven discharge and filament breakage when the nozzle moved at the speed of 30 mm/s; and the products were internally compact and had good stability when the printing filling rate was 80%. In addition, the deformation rates of steamed, boiled and deep-fried shrimp surimi products were significantly higher than those of oven-baked and microwaved shrimp surimi products (P < 0.05). Microwave heating had a greater effect on the deformation and color of shrimp surimi products, and was not favored by the evaluators. In terms of deformation rate, sensory score, and textural characteristic, the oven-baked thermal processing method was selected to obtain higher sensory evaluation scores and lower deformation rates of shrimp surimi 3D printed products. In the future, DIY design can be carried out in 3D printing products of shrimp surimi to meet the needs of different groups of people for modern food.

Two novel angiotensin-converting enzyme (ACE) and dipeptidyl peptidase IV (DPP-IV) inhibiting peptides from tilapia (Oreochromis mossambicus) skin and their molecular docking mechanism.

In the study, papain was used to hydrolyze tilapia (Oreochromis mossambicus) skin to obtain a tilapia skin hydrolysate (TSH) with dual angiotensin-converting enzyme (ACE) and dipeptidyl peptidase IV (DPP-IV) inhibitory activities. The resulting TSH was sequentially fractionated by ultrafiltration, size exclusion separation chromatography, and reverse-phase high-performance liquid chromatography. Its inhibitory effects on ACE and DPP-IV were determined by commercial reagent kits. Two peptides purified from TSH were identified as Gly-Pro-Leu-Gly-Ala-Leu (GPLGAL) and Lys-Pro-Ala-Gly-Asn (KPAGN) by the ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Inhibitory concentration (IC50) of GPLGAL on ACE and DPP-IV were 117.20 ± 1.69 and 187.10 ± 2.75 µM, respectively. IC50 of KPAGN on ACE and DPP-IV were 137.40 ± 2.33 and 259.20 ± 2.85 µM, respectively. The molecular simulation demonstrated that the binding affinities of GPLGAL to ACE and DPP-IV proteins were -8.5 and -7.4 kcal/mol, respectively, whereas those of KPAGN to ACE and DPP-IV proteins were -7.9 and -6.7 kcal/mol, respectively. GPLGAL interacted with 21 amino acid residues of the ACE active site, whereas KPAGN engaged with 19 amino acid residues. Additionally, GPLGAL interacted with 10 amino acid residues of the DPP-IV active site, whereas KPAGN engaged with 13 amino acid residues. The two peptides predominantly occupied the active sites of ACE (His513, Tyr523, and Ala354) and DPP-IV (Tyr662 and Arg125) through hydrogen bonding. This leads to the deactivation of ACE and DPP-IV. PRACTICAL APPLICATION: Accelerate tilapia skin development and high-value utilization; provide foundation for preparing the peptides with dual ACE and DPP-IV inhibiting activity.

Insight into the correlation of key taste substances and key volatile substances from shrimp heads at different temperatures.

This study aimed to investigate taste substances of shrimp heads stored at 20 °C, 4 °C, -3 °C, and - 18 °C, and the correlation between taste substances and 25 key volatile substances. Notably, samples stored at 20 °C showed significant changes in bitter amino acids and hypoxanthine, and quickly deteriorated. Samples stored at 4 °C for 14 d or - 3 °C for 30 d facilitated the development of umami amino acids, sweet amino acids, and IMP. Furthermore, samples stored at -18 °C for 30 d demonstrated no significant changes in taste profile. Changes in taste substances through quantitative analysis were consistent with changes in taste profile through e-tongue analysis. Based on the results of O2PLS (VIP > 1), Cys, Arg, Glu, Ser, Val, Ala, Ile, ADP, and IMP were correlated with 25 key volatile substances. This study provides fundamental data for the storage, transportation, and value-added utilization of shrimp heads.

Hypolipidemic and Anti-Obesity Effect of Anserine on Mice Orally Administered with High-Fat Diet via Regulating SREBP-1, NLRP3, and UCP-1.

To investigate the efficacy of anserine on antiobesity, C57BL/6 mice are orally administered with a high-fat diet (HFD) and different doses of anserine (60, 120, and 240 mg/kg/day) for 16 weeks. Body weight, lipid, and epididymal fat content in mice are measured, and their liver damage is observed. The results display that the body weight, epididymal fat content, and low-density lipoprotein cholesterol (LDL-C) content in anserine groups are decreased by 4.36-18.71%, 7.57-35.12%, and 24.32-44.40%, respectively. To further investigate the antiobesity mechanism of anserine, the expression of SREBP-1, NLRP3, NF-κB p65 (p65), and p-NF-κB p65 (p-p65) proteins in the liver and peroxisome proliferator-activated receptor gamma coactivator 1α (PGC1-α) and UCP-1 proteins in brown adipose tissue (BAT) is analyzed by Western blot. Results show that anserine can significantly decrease the expression of the NLRP3, p65, p-p65, and the SREBP-1 proteins and increase the expression of the PGC1-α and UCP-1 proteins. This study demonstrates that anserine lowered blood lipids and prevented obesity; its antiobesity mechanism may be related to the activation of brown fat by inflammation.

Investigation on 3D Printing of Shrimp Surimi Adding Three Edible Oils.

Three-dimensional (3D) printing provides a new method for innovative processing of shrimp surimi. However, there still exists a problem of uneven discharge during the 3D printing of surimi. The effects of different amounts of lard oil (LO), soybean oil (SO), and olive oil (OO) (0%, 2%, 4%, and 6%, respectively) added to shrimp surimi on the 3D printability of surimi were evaluated. The findings showed that with the increase in the added oil, the rheological properties, texture properties, water-holding capacity (WHC), and water distribution of surimi with the same kind of oil were significantly improved; the printing accuracy first increased and then decreased; and the printing stability showed an increasing trend (p < 0.05). The surimi with 4% oil had the highest printing adaptability (accuracy and stability). Different kinds of oil have different degrees of impact on the physical properties of surimi, thereby improving 3D-printing adaptability. Among all kinds of oil, LO had the best printing adaptability. In addition, according to various indicators and principal component analysis, adding 4% LO to shrimp surimi gave the best 3D-printing adaptability. But from the aspects of 3D printing properties and nutrition, adding 4% SO was more in line with the nutritional needs of contemporary people.

Effect of static magnetic field-assisted freezing at different temperatures on muscle quality of pacific white shrimp (Litopenaeus vannamei).

The effect of static magnetic field-assisted freezing (MF) at different temperatures (-35, -30, -25, and -20 °C) on the muscle quality of pacific white shrimp (Litopenaeus vannamei) was evaluated to investigate the possibility of energy saving by MF. The results showed that the -35 °C MF treatment increased the water-holding capacity of shrimp muscle, and maintained the wholeness of the microstructure compared to -35 °C immersion freezing (control group, IF). With the increase in freezing temperature in the MF treatments, the size of ice crystals gradually increased, and the sensory properties of shrimp decreased. The water-holding capacity, sensory properties, and water distribution of shrimp muscle subjected to MF at -25 °C were still no significantly different from those of the IF at -35 °C (P > 0.05). In summary, the utilization of MF enhanced the quality of frozen pacific white shrimp, which has the potential to provide energy saving benefits.

Effect of Liquid Nitrogen Freezing Temperature on the Muscle Quality of Litopenaeus vannamei.

The implications of different liquid nitrogen freezing (LNF) temperatures (-35 °C, -65 °C, -95 °C, and -125 °C) on the ice crystal and muscle quality of white shrimp (Litopenaeus vannamei) were investigated in this essay. The results showed that better muscle quality was maintained after LNF treatment compared to that after air blast freezing (AF) treatment. As the freezing temperature of liquid nitrogen decrease, the freezing speed accelerated, with the freezing speed of LNF at -125 °C being the fastest. However, an excessively fast freezing speed was not conducive to maintaining the quality of shrimp. Among all the freezing treatments, LNF at -95 °C led to the lowest thawing losses and cooking losses, and the highest L* values, indicating that LNF at -95 °C could keep the water holding capacity of frozen shrimp better than that with other freezing methods. At the same time, LNF at -95 °C resulted in higher water holding capacity, and hardness values for shrimps than those with other frozen treatments (p < 0.05). In addition, the results of the water distribution of shrimps showed that treatment with a -95 °C LNF reduced the migration rate of bound and free water. Meanwhile, the microstructural pores of shrimps in the -95 °C LNF group were smaller, indicating that the ice crystals generated during -95 °C LNF were relatively smaller than those generated via other frozen treatments. In conclusion, an appropriate LNF temperature (-95 °C) was beneficial for improving the quality of frozen shrimp, and avoiding freezing breakage.

The Preventive Mechanism of Anserine on Tert-Butyl Hydroperoxide-Induced Liver Injury in L-02 Cells via Regulating the Keap1-Nrf2 and JNK-Caspase-3 Signaling Pathways.

Anserine is a naturally occurring histidine dipeptide with significant antioxidant activities. This study aimed to investigate the preventive mechanism of anserine on tert-butyl hydroperoxide (TBHP)-induced liver damage in a normal human liver cell line (L-02 cells). The L-02 cells were pretreated with anserine (10, 20, and 40 mmol/L) and then induced with 400 µmol/L of TBHP for 4 h. The results showed that the survival rates of L-02 cells and the contents of GSH were significantly increased with the pretreatment of anserine; the activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the extracellular fluid were sharply decreased; and the formation of reactive oxygen species (ROS), nuclear fragmentation, and apoptosis were significantly inhibited. In addition, anserine could bind to the Kelch domain of Kelch-like ECH-associated protein 1 (Keap1) with a binding force of -7.2 kcal/mol; the protein expressions of nuclear factor-erythroid 2-related factor-2 (Nrf2), quinone oxidoreductase 1 (NQO1), heme oxygenase-1 (HO-1), and Bcl-2 were upregulated by anserine in TBHP-induced L-02 cells, with the downregulation of p-JNK and caspase-3. In conclusion, anserine might alleviated liver injury in L-02 cells via regulating related proteins in the Keap1-Nrf2 and JNK-Caspase-3 signaling pathways.

Biomimetic triumvirate nanogel complexes via peptide-polysaccharide-polyphenol self-assembly.

Self-assembled peptide and polysaccharide nanogels are excellent candidates for bioactive delivery vectors. However, there are still significant challenges in the application of nanogels as delivery tools for bioactive elements. This study aims to deliver, and control the release of a hydrophobic bioactive flavonoid hesperidin. Using the self-assembling peptide (SAP) Fmoc-FRGDF, extracellular matrix mimicking nanofibrils were fabricated, which were decorated and bolstered with immunomodulatory polysaccharide strands of fucoidan and infused with hesperidin. The mechanical properties, secondary structure, and microscopic morphologies of the composite hydrogels were characterized using rheometer, FTIR, XRD, and TEM, etc. The encapsulation efficiency (EE) and release behavior of hesperidin were determined. Coassembly of the SAP with fucoidan improved the mechanical properties (from 9.54 Pa of Fmoc-FRGDF hydrogel to 7735 Pa of coassembly hydrogel at 6 mg/mL fucoidan concentration), formed thicker nanofibril bundles at 4 and 6 mg/mL fucoidan concentration, improved the EE of hesperidin from 72.86 % of Fmoc-FRGDF hydrogel to over 90 % of coassembly hydrogels, and showed effectively controlled release of hesperidin in vitro. Intriguingly, the first order kinetic model predicted an enhanced hydrogel retention and release of hesperidin. This study revealed a new approach for bioengineered nanogels that could be used to stabilize and release hydrophobic payloads.

Insight into muscle quality of white shrimp (Litopenaeus vannamei) frozen with static magnetic-assisted freezing at different intensities.

The effects of magnetic field-assisted immersion freezing (MF) with different intensities (20, 40, 60, and 80 mT) on the freezing process and muscle quality of white shrimp (Litopenaeus vannamei) were studied in the present study. The results showed that, compared with immersion freezing (IF), 60 mT MF (MF-60) shortened the total freezing time, reduced thawing loss and cooking loss, and helped to maintain the water holding capacity and texture properties of frozen shrimp samples. In addition, the increase in the L* value of frozen shrimp samples was also inhibited by MF-60. The result of water distribution revealed that MF-60 reduced the mobility and loss of immobilized water and free water. The microstructure of MF-60 was characterized by smaller pores, indicating that MF-60 promoted the generation of fine ice crystals. Overall, MF-60 was beneficial in reducing ice crystal size and inhibiting the loss of shrimp muscle quality loss during the freezing process.

Effects of magnetic field-assisted immersion freezing at different magnetic field intensities on the muscle quality of golden pompano (Trachinotus ovatus).

This study evaluated the effects of magnetic field-assisted immersion freezing (MIF) with different magnetic field intensities (0, 20, 40, 60, and 80 mT) on the freezing curves, ice crystal area, microstructure, and physicochemical properties of golden pompano (Trachinotus ovatus) muscle. The result showed that, compared with refrigerator freezing (RF) and immersion freezing (MIF-0), magnetic fields prolonged the freezing time. However, the centrifugal loss and cooking loss of MIF-20 were 23.55 % and 29.18 % lower than those of MIF-0 group, respectively (P < 0.05). Low field-nuclear magnetic resonance results showed that MIF-20 group exhibited more homogeneous of water distribution and higher water content, the T22 was 20.59 % shorter than of MIF-0 (P < 0.05). Microscopic observations confirmed that the MIF-20 group had the smallest and the most evenly distribution of ice crystals. Therefore, MIF at 20 mT intensity can effectively improve the muscle qualities of frozen golden pompano.

The identification of three phospholipid species roles on the aroma formation of hot-air-dried shrimp (Litopenaeus vannamei) by gas chromatography-ion mobility spectrometry and gas chromatography- mass spectrometry.

Aroma is critical to the commercial acceptance of the hot-air-dried shrimp. The purpose of this study was to investigate the effect of phospholipid species with different fatty acid compositions on the aroma formation of dried shrimp. GC-IMS and GC-MS were used to obtain volatile fingerprints and volatile compound profiles, respectively. The results of GC-IMS and GC-MS indicated that the effect of phospholipids on the overall aroma of dried shrimp was related to the unsaturation of fatty acids constituting phospholipids, and fatty acids with higher unsaturation had a greater impact on the overall aroma of dried shrimp. Therefore, PC(C16:0/C18:2) had the greatest effect on the overall aroma of dried shrimp, followed by PE(C18:1/C18:1), and the lowest was PE(C18:0/C18:0). GC-MS results showed that phospholipids could promote the formation of aromatic compounds such as pyrazines and aldehydes in dried shrimp, and the magnitude of the effect of different phospholipids was highly positively correlated with the degree of unsaturation of fatty acids in phospholipids. PE(C18:0/C18:0) could significantly promote the formation of 2,3,5-trimethylpyrazine and 2-ethyl-3,5-dimethylpyrazine. PE(C18:1/C18:1) could importantly improve the formation of 2,5-dimethylpyrazine, 2-ethyl-5-methylpyrazine and 1-octen-3-ol. PC(C16:0/C18:2) could prominently increase the formation of 2,5-dimethylpyrazine, 2,3,5-trimethylpyrazine, 2-ethyl-5-methylpyrazine, 2-ethyl-3,6-dimethylpyrazine, benzaldehyde and 2-nonanone. Furthermore, three phospholipid species significantly inhibited the formation of trimethylamine.

Gelation Process Optimization of Shrimp Surimi Induced by Dense Phase Carbon Dioxide and Quality Evaluation of Gel.

Dense phase carbon dioxide (DPCD) is a new non-thermal method to induce surimi gel. However, the gel quality is affected by many factors, such as DPCD treatment time, temperature, and pressure, which makes it complicated to determine its operating parameters. Box-Behnken and backward linear regression were used to optimize the conditions (temperature, pressure, and treatment time) of DPCD-induced shrimp surimi gel formation, and a model between shrimp surimi gel strength and treatment conditions was developed and validated in the present study. Meanwhile, the heat-induced method was used as a control to analyze the effect of DPCD on the quality of shrimp surimi gel in the present study. The results showed that DPCD treatment affected the strength of shrimp surimi gel significantly, and the pressure of DPCD had the greatest influence on the gel strength of shrimp surimi, followed by time and temperature. When the processing pressure was 30 MPa, the temperature was 55 °C, and the treatment time was 60 min, the gel strength of the shrimp surimi was as high as 197.35 N·mm, which was not significantly different from the simulated value of 198.28 N mm (p > 0.05). The results of the gel quality properties showed that, compared with the heat-induced method, DPCD reduced the nutrient and quality loss of the shrimp surimi gel, and increased the gel strength and gel water-holding capacity. The results of low-field nuclear magnet resonance showed that DPCD increased the binding capacity of shrimp surimi to bound water and immobilized water, and reduced their losses. Gel microstructure further demonstrated that DPCD could improve shrimp surimi gelation properties, characterized by a finer and uniformly dense gel network structure. In summary, DPCD is a potential method for inducing shrimp surimi to form a suitable gel. The prediction model established in this study between DPCD treatment temperature, pressure, time, and gel strength can provide a reference for the production of shrimp surimi by DPCD.

Evaluation of Aroma Characteristics of Dried Shrimp (Litopenaeus vannamei) Prepared by Five Different Procedures.

Litopenaeus vannamei is one of the most popular shrimp species in the world and has been reported in studies on its dryness and flavor. However, the aroma characteristics of shrimps dried with different drying methods are compared in a unified way, and there are few reports on the difference in aroma of different shrimps dried. In order to clarify the difference in aroma characteristics of shrimp dried produced by different drying methods. In this study, blanched shrimp (BS) was used as a control to analyze the aroma characteristics of shrimp dried by five different procedures (SD-BFDP) samples, namely vacuum freeze-dried shrimp (VFDS), vacuum dried-shrimp (VDS), heat pump-dried shrimp (HPDS), hot air dried-shrimp (HADS) and microwave vacuum-dried shrimp (MVDS). An electronic nose (E-nose) was used to obtain the aroma fingerprint of SD-BFDP samples. Headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used for qualitative and quantitative analysis of volatile compounds in SD-BFDP samples. Partial least squares regression (PLSR) was used to analyze potential correlations between sensory attributes and aroma-active compounds (AACs). Partial least squares-discrimination analysis (PLS-DA) was used to screen for signature aroma compounds. The results of the E-nose showed that there were differences in the aroma fingerprints of the SD-BFDP samples, and the E-nose could distinguish the five kinds of SD-BFDP. The qualitative and quantitative results of GC-MS showed that the types and contents of the main volatile components of SD-BFDP samples were different. 15 AACs were screened from SD-BFDP based on odor activity value (OAV). The PLSR results showed good correlations between certain sensory attributes and the majority of AACs. PLS-DA results displayed that aroma attributes of SD-BFDP samples could be distinguished by six signature aroma compounds, including trimethylamine, 2,5-dimethylpyrazine, 2-ethyl-5-methylpyrazine, nonanal, 3-ethyl-2,5-dimethylpyrazine, and octanal. These research results reveal that shrimps dried in different procedures have unique aroma characteristics, which could provide a theoretical basis for the rapid identification of aroma attributes of dried shrimps in the future. From a flavor perspective, MVD is the best drying method.

Overexpression of Bacillus circulans alkaline protease in Bacillus subtilis and its potential application for recovery of protein from soybean dregs.

Proteases are important for decomposition of proteins to generate peptides or amino acids and have a broad range of applications in different industries. Herein, a gene encoding an alkaline protease (AprBcp) from Bacillus circulans R1 was cloned and bioinformatics analyzed. In addition, a series of strategies were applied to achieve high-level expression of AprBcp in Bacillus subtilis. The maximum activity of AprBcp reached 165,870 U/ml after 60 h fed-batch cultivation in 50 l bioreactor. The purified recombinant AprBcp exhibited maximum activity at 60°C and pH 10.0, and remained stable in the range from pH 8.0 to 11.0 and 30 to 45°C. Metal ions Ca2+, Mn2+, and Mg2+ could improve the stability of AprBcp. Furthermore, the recombinant AprBcp displayed great potential application on the recovery of protein from soybean dregs. The results of this study will provide an effective method to prepare AprBcp in B. subtilis and its potential application on utilization of soybean dregs.

Anserine beneficial effects in hyperuricemic rats by inhibiting XOD, regulating uric acid transporter and repairing hepatorenal injury.

This study aims to investigate the anti-hyperuricemia effect and mechanism of anserine in hyperuricemic rats. Hyperuricemic rats were induced with a combination of 750 mg per kg bw d potassium oxazinate (PO) and 200 mg per kg bw d hypoxanthine for a week, and the rats were separately orally administered anserine (20, 40, 80 mg kg-1) and allopurinol (10 mg kg-1) for three weeks. The results show that the content of serum uric acid (SUA) decreased by approximately 40% and 60% after the intervention of anserine and allopurinol, respectively. The activity of superoxide dismutase (SOD) was increased and the levels of malondialdehyde (MDA), alkaline phosphatase (ALP) and alanine aminotransferase (ALT) were significantly decreased in the anserine groups. After the administration of anserine, the contents of blood urea nitrogen (BUN) and creatinine (Cr) were reduced in the kidney, and the levels of the proinflammatory cytokines IL-1ß, IL-6ß, TNF-α and TGF-ß and inflammatory cell infiltration were reduced in both the liver and kidney. Moreover, the gene expressions of xanthine oxidase (XOD), renal urate transporter 1 (URAT1) and glucose transporter type 9 (GLUT9) were downregulated by anserine administration, and the gene expressions of ATP-binding cassette transporter G2 (ABCG2), organic anion transporter 1 (OAT1) and organic anion transporter 3 (OAT3) were upregulated at the same time. These findings suggest that hepatorenal injury was repaired by anserine, which further regulated the expression of hepatic XOD and renal URAT1, GLUT9, ABCG2, OAT1 and OAT3 to relieve hyperuricemia in rats.

Improvement of solubility, stability and antioxidant activity of carotenoids using deep eutectic solvent-based microemulsions.

Natural carotenoids have been widely used as colorants and antioxidants in process of food, medicine, and cosmetic. However, the carotenoids have low bioactivity in vivo due to poor water-solubility. To enhance the solubility, stability and antioxidant activity of carotenoids, novel microemulsions (MEs) composed with deep eutectic solvents (DESs), tween 80 and water were developed as alternatives to organic solvents. The phase diagrams and physicochemical properties (viscosity, pH, and diameter) of the DES-based MEs were investigated at different temperatures. Then the solubility distribution, storage stability and DPPH free radical-scavenging activity of three carotenoids (astaxanthin, astaxanthin ester and lutein) in the MEs were evaluated. Compared with ethanol, methanol, and acetone, all the DES-based MEs studied significantly enhanced the solubility of the carotenoids due to the stronger hydrogen bonding and Van der Waals interactions. The highest solubilities of 0.27, 473.63, and 12.50 mg/mL for astaxanthin, astaxanthin ester and lutein, respectively, were observed in the MEs containing DES (DL-menthol:acetic acid = 1:2) at 35 â„ƒ. Moreover, astaxanthin ester can be well preserved in the MEs containing DES (DL-menthol:octanoic acid = 1:2) with a half-life of more than 69 days. In addition, the DPPH scavenging capacities of the three carotenoids in all the MEs were higher than the organic solvents. The results revealed that the DES-based MEs with low viscosity (<0.2 Pa•s) and mild acidic pH (4-5) are potential solvents for natural carotenoids in food processing and storage, medicine making, as well as biomaterials processing.

The anti-fatigue effect of the Auxis thazard oligopeptide via modulation of the AMPK/PGC-1α pathway in mice.

The Auxis thazard oligopeptide (ATO) was obtained by papain digestion and ultrafiltration membrane separation, and its anti-fatigue effects and mechanisms were evaluated using animal experiments on Kunming mice. Compared with the negative control group, the ATO extended the time to exhaustion in mice in a forced swim test by 0.81-1.62 times. Liver glycogen levels were significantly increased by 0.6-1.63 times and muscle glycogen levels were increased by 9.52-10.02%; the levels of lactic acid (16.46-17.21%) and urea nitrogen (34.88-41.91%) decreased. The ATO also increased antioxidant activity, reduced malondialdehyde levels (18.00-35.79%) in the liver and myocardium, and increased the gene and protein expression of AMPK and PGC-1α in fatigued mice. These results indicate that the ATO exerts an anti-fatigue effect via improving energy metabolism and decreasing oxidative stress.

The Role of Amino Acids in the Formation of Aroma-Active Compounds during Shrimp Hot Air Drying by GC-MS and GC-IMS.

In the present paper, the role of amino acids of Penaeus vannamei was investigated in the formation of volatile substances during drying. The variations in volatile substances among samples with different moisture contents (raw, 45%, 30%, 15%, and 5%) were obtained by gas chromatography-ion mobility spectrometry (GC-IMS) and gas chromatography-mass spectrometry (GC-MS). The amino acid contents of the above samples were measured by the amino acid automatic analyzer. Correlation between pyrazines and the various amino acid contents was analyzed by the Pearson correlation coefficient. Their correlation was verified by conducting addition assays. The types and contents of volatile components increased significantly in samples with moisture contents between 30% and 5%. The most obvious increases in the type, content and odor activity value of pyrazines were observed in this range. Basic amino acids (Arg, Lys, and His) had a strong correlation with the formation of pyrazines. Addition assays verified that the addition of Arg and Lys increased the content of pyrazines in shrimp after drying.

Insight into the correlations among rheological behaviour, protein molecular structure and 3D printability during the processing of surimi from golden pompano (Trachinotus ovatus).

To investigate the 3D printability of surimi from golden pompano, the rheological properties, protein molecular structure, and 3D printability of food inks from every step of surimi processing were measured, and their correlations were analysed. The results showed that surimi from chopping (surimi-C), chopping with salt (surimi-CS) and setting (surimi-S) were suitable for 3D printing, among which surimi-CS had the best shape fidelity. The clustering analysis of variables revealed that the yield stress and AF could be used as indexes to characterize extrusion and deposition behaviour of surimi, respectively. The accuracy of 3D printing was affected by the extrusion property of the food ink, which was controlled by the ionic bond content. The stability of 3D printing was affected by the self-supporting capacity of the food ink, which was controlled by the hydrogen bond and hydrophobic interaction contents. The results provided theoretical guidance for developing 3D printing of surimi ingredients.