Volatile Basic Nitrogen Values Research Articles

Edible Coating Based on Alginate Nanoparticles Containing Menthol and Zataria multiflora Essential Oil: Effect on the Shelf Life of Chicken Thigh in the Refrigerator.

Chicken thigh is a popular and widely consumed meat product. However, its high moisture content and susceptibility to microbial spoilage limit its shelf life. To address this issue, we investigated the efficacy of an edible coating based on alginate nanoparticles (AlgNPs) containing menthol, Zataria multiflora essential oil (EO), or their combination for extending the shelf life of chicken thigh. The nanoparticles were prepared through ionic gelation methods; their particle size was obtained as 87-205 nm with PDI values of < 0.3 and SPAN values of < 1. The AlgNPs containing both menthol and the EO showed the most potent antimicrobial activity (the lowest counts of pseudomonas, aerobic mesophilic, and yeast-mold), during cold storage. This coating treatment showed also the highest antioxidant activities, with the lowest thiobarbituric acid reactive substances (TBARS), pH and total volatile basic nitrogen (TVBN) values. Moreover, this coating significantly (p < 0.05) showed the highest sensory quality of chicken thighs, as evidenced by the higher sensory scores for texture, odor, color, and overall acceptability. Therefore, the edible coating based on AlgNPs containing menthol and Z. multiflora EO is an effective and promising approach for extending the shelf life of chicken thighs.

Development of a Novel Colorimetric pH Biosensor Based on A-Motif Structures for Rapid Food Freshness Monitoring and Spoilage Detection.

Accurate methods for assessing food freshness through colorimetric pH response play a critical role in determining food spoilage and ensuring food quality standards. This study introduces a novel unlabeled DNA sequence, poly-dA20, designed to exploit the colorimetric properties of both the single strand and the fold-back A-motif structure in conjunction with gold nanoparticles (AuNPs) under varying pH conditions. When exposed to storage temperatures of 4 °C and 25 °C, the color variations in the AuNP solution, influenced by pH level changes in mutton and sea bass samples' different storage periods, are easily discernible to the naked eye within a minute. The ratio of UV absorption values at 527 nm and 700 nm (A527/A700) demonstrates a strong linear correlation with both the storage duration and pH of the food samples. Furthermore, a comprehensive analysis combining the total volatile basic nitrogen (TVB-N) value with the A527/A700 ratio is employed for precise assessment of food freshness. The innovative pH-responsive sensing strategy not only provides a new approach for on-site food freshness and spoilage detection systems but also serves as a valuable tool for pH-related biological detection in clinical diagnostic applications.

Carvacrol-loaded emulsions stabilized by soy protein isolate/chitosan oligosaccharide conjugates improved the quality of refrigerated sea bass (Lateolabrax maculatus).

In this study, the soybean protein isolate / chitosan oligosaccharide (SPI/COS) conjugates were developed using glycosylation and used as a stabilizer of carvacrol-loaded emulsions for refrigerating sea bass (Lateolabrax maculatus). The results of Fourier transform infrared spectroscopy and fluorescence spectroscopy showed that COS modified the secondary and tertiary structure of SPI by covalent binding. The SPI/COS conjugate with a mass ratio of SPI and COS of 4:1 (SPI/COS-4) exhibited high glycosylation degree, great water solubility and better emulsification properties. Carvacrol-loaded emulsion stabilized by the SPI/COS-4 (CE-SPI/COS-4) had nanoscale droplet size and remained stable during 40days of storage. SPI/COS-4 aqueous solution (SPI/COS) and CE-SPI/COS-4 aqueous solution (CE-SPI/COS) in the form of immersion were applied to investigate their preservation effects on sea bass, with sterile water as control check (CK). Sea bass were stored at 4°C and quality assessments of fish were performed periodically for up to 21days, which included microbiological and physicochemical analysis. As suggested by microbiological analysis, CE-SPI/COS treatment could significantly inhibit the bacterial growth. The low total volatile basic nitrogen value, thiobarbituric acid value and K-value indicated that CE-SPI/COS greatly retarded protein and lipid oxidation in fish and significantly suppress the degradation of nucleotide. Moreover, fish treated with CE-SPI/COS had minimal color variation and water loss, and maintained hardness, adhesiveness, chewiness, and resilience of fish to the highest degree. Therefore, emulsions stabilized with SPI/COS conjugates may be employed as a potential strategy for the quality maintenance of sea bass.

Effects of Red Vinasse on Physicochemical Qualities of Blue Round Scad (Decapterus maruadsi) During Storage, and Shelf Life Prediction.

A fish processed with red vinasse is a type of Fujian cuisine with regional characteristics. In order to monitor the effect of red vinasse on storage quality and shelf life of blue round scad (Decapterus maruadsi) during storage, the changes in fat content, thiobarbituric acid reactive substances (TBARS), composition of polyunsaturated fatty acids (PUFAs), pH value, texture, and sensory quality were studied at different storage temperatures (4 °C, 25 °C, and 37 °C). By analyzing the correlation between changes in sensory qualities and physical and chemical indexes, a first-order kinetic model and the Arrhenius equation were used to build a shelf-life prediction model for blue round scad during storage. The results showed that processing with red vinasse can significantly reduce the malondialdehyde (MDA) production and the decrease in PUFAs, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (p < 0.05) during storage. Based on partial least squares regression (PLSR), the storage temperature and time have a significant impact on the PUFA composition in blue round scad, which changed less when the samples were stored at 4 °C and 25 °C, and they had better nutritional composition of fatty acids at lower temperatures. Among the PUFAs, DHA (C22:6n-3) and EPA (C20:5n-3) had higher relative contents and significantly decreased during storage (p < 0.05). Additionally, the processing with red vinasse can slow down the increase in total volatile basic nitrogen (TVB-N) value and pH of blue round scad, maintain the appropriate hardness, elasticity, cohesion and chewability, and improve the overall sensory quality of the fish. In addition, according to the results of model prediction based on TBARS value, the storage shelf life of blue round scad with red vinasse added was 55 d, 2.7 d and 28 h at 4 °C, 25 °C and 37 °C, respectively. The accuracy of the forecast model was high, and the relative errors of the measured values and predicted values were less than 10%. Thus, it not only provided a theoretical basis for the processing and application of red vinasse to Chinese traditional food, but also provided innovative ideas for the safe storage and high-value utilization of blue round scad.

Development of konjac glucomannan-based active-intelligent emulsion films loaded with different curcumin-metal chelates: Stability, antioxidant, fresh-keeping and freshness detection properties

The aim of this study was to develop konjac glucomannan (KGM)-based active-intelligent emulsion films loaded with different curcumin-metal chelates, where six types of films were prepared and their corresponding properties were investigated. The FTIR and XRD results showed that curcumin chelated with metal ions successfully. Moreover, curcumin-Ca chelate had the best thermal stability and antioxidant activity with the DPPH and ABTS radical-scavenging activity values of 38.28 % and 22.79 %, respectively. Furthermore, the results of microstructure and contact angle showed that chelation with metal ions improved the interfacial interactions between curcumin-metal chelates and film matrix. Interestingly, KGM-based active-intelligent emulsion films loaded with curcumin-Ca chelate (Type IV film) displayed the best thermal stability with the highest temperature of maximum weight loss at 380 °C, the best mechanical property, the highest total phenol content (17.31 mg gallic acid/g film), as well as the best antioxidant activity with DPPH and ABTS radical-scavenging activity values of 69.24 % and 58.66 %, respectively, and the best antibacterial activity. Consequently, Type IV film was used for the fresh-keeping and freshness detection of pork. The results showed that the pork packaged with Type IV film displayed excellent fresh-keeping properties, including reducing the increase rate of volatile basic nitrogen (TVB-N) and pH values and the decrease rate of hardness and elasticity of pork during storage time. Meanwhile, the color of Type IV film gradually changed from yellow to red. Therefore, this study suggested that KGM-based active-intelligent emulsion films have great potential application in the fresh-keeping and freshness detection of fresh meat.

Monitoring Meat Freshness with Intelligent Colorimetric Labels Containing Red Cabbage Anthocyanins Copigmented with Gelatin and Gallic Acid.

Polyvinyl alcohol (PVA)-based pH-responsive color indicators were developed using red cabbage anthocyanin (Anth) copigmented with gelatin and gallic acid (GA). The indicator prepared with gelatin and GA (GA/gelatin/Anth/PVA) was highly resistant to light exposure. GA/gelatin/Anth/PVA exhibited distinct color changes in pH 2-11 buffer solutions and stable color indication in acidic and neutral solid systems (pH 2 and 7) at 97% relative humidity. GA/gelatin/Anth/PVA exhibited the highest sensitivity to dimethylamine, followed by ammonia and trimethylamine. The addition of gelatin and GA facilitated hydrogen bonding, which enhanced thermal stability and water solubility without compromising tensile properties. A color change from purple to blue signaled spoilage when total volatile basic nitrogen values for beef and squid reached 21.0 and 37.8 mg/100 g, respectively. The GA/gelatin/Anth/PVA indicator shows potential for indicating the freshness of raw beef.

Controlling the quality of Patinopecten yessoensis from the perspective of the ultrasound and ferulic acid influences.

In this study, the effects of ultrasound combined with ferulic acid (FA) on the quality of the Yesso scallop (Patinopecten yessoensis) adductor muscles (SAM) during refrigerated storage were investigated. The results demonstrated that the combined treatment with 350W ultrasound and FA (UFA) significantly delayed enzyme activities and microbial growth in SAM tissues compared to FA treatment alone. After 6 days of cold storage, samples treated with UFA exhibited higher hardness (2850g), lower thiobarbituric acid reactive substances (TBARS=9.35 MDA mg/g SAM), and lower total volatile basic nitrogen (TVB-N=19.75mg/100g SAM) values compared to control and FA-treated samples. Consequently, UFA treatment prolonged the shelf life of SAM by 3 days during storage at 4°C. Based on scanning electron microscopy and low-field nuclear magnetic resonance data, these findings are attributed to UFA treatment not only reducing the degradation of SAM tissue network structure but also minimizing water loss. PRACTICAL APPLICATION: Scallop adductor muscle (SAM) is commonly considered a delicacy owing to its unique mouthfeel and delicious taste. However, owing to its high moisture content and high levels of various nutrients, SAM has a short shelf life. In this work, a combination of ultrasound with ferulic acid (UFA) has been found to have effective preservation effects on SAM during refrigerated storage. Our study findings pave the way for a potential approach to maintain scallop quality during processing and storage. Moreover, our study also provides some theoretical basis for using and promoting these technologies in aquatic products.

A novel fluorescence platform for portable and visual monitoring of meat freshness

Biogenic amines (BAs) are crucial markers of meat spoilage. Developing practical and effective BAs detection methods is essential for monitoring meat freshness and ensuring daily consumption safety. This study prepared several naphthalene-based fluorescent compounds to visually monitor meat freshness in real-time. These probes show a colorimetric fluorescence response to putrescine and cadaverine (typical spoilage indicators) through nucleophilic addition/elimination reaction. The detectability of these probes can be optimized by altering the electronegativity and substitution position of the recognition group. Among these compounds, 2-((6-(4-(diphenylamino)phenyl)naphthalen-2-yl)methylene)malono nitrile (TNMA) demonstrated exceptional sensing performance toward putrescine and cadaverine, including high-contrast fluorescence color transition (red to blue), rapid response times (∼30 s), high selectivity and sensitivity (detection limit for putrescine: 2.69 ppm, cadaverine: 6.11 ppm). Furthermore, the B/R values of TNMA test strips output by RGB analysis presented a linear correlation with total volatile basic nitrogen (TVBN, an international standard for evaluating food spoilage) values in pork. Based on this correlation, we utilized smartphone applications to construct an intelligent evaluation system, enabling visual monitoring of pork, chicken, and shrimp freshness under various storage conditions. The TNMA-based system offers a reliable platform for real-time, portable and visual monitoring of meat freshness for consumers and suppliers in the food industry.

Microbial composition of spoiled irradiated ready-to-eat chicken feet and their spoilage characteristics

The spoilage of irradiated ready-to-eat chicken feet (RTECF) seriously affects the food's quality, resulting in package swelling and off-flavors, both of which are highly undesirable to stakeholders and consumers. To investigate the spoilage characteristics of irradiated RTECF and the microorganisms responsible for the spoilage and swelling, the changes in physicochemical properties, microbial community, and volatile organic compounds (VOCs) between normal and spoiled RTECF were evaluated. Compared with normal samples, the spoiled RTECF showed a higher pH value and total volatile basic nitrogen (TVB-N) value, lower color value, and texture features (P < 0.05). Acinetobacter, Pseudomonas, Lactobacillus, and Candida were the dominant genera responsible for RTECF spoilage as confirmed through both culture-dependent methods and high-throughput sequencing (HTS). The results of the verification for gas-producing strains showed that Lactobacillus brevis could cause RTECF packaging to swell. A total of 20 key VOCs were identified using headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results of Pearson correlation analysis (|r|>0.8, P < 0.05) showed that 12 dominant core microbial genera had a significant effect on the flavor of RTECF before and after spoilage. This study provides a theoretical reference for solving the problem of RTECF spoilage and improving the overall quality of RTECF products.

A Self‐Calibrating Sensing Platform Based on Amine‐Responsive Excitation Wavelength‐Dependent Fluorescent Polymers for Real‐Time and Visual Detection of Food Freshness

AbstractAccurate assessment of food freshness is critical to maintaining human health. However, the complex environment of food usually leads to false‐positive measurements result. Therefore, the development of sensing platforms with self‐calibration for accurate detection of food freshness in complex environments is essential. Here, using the green fluorescence‐emitting FITC‐ene and the red fluorescence‐emitting DBA‐ene‐Eu3+ as fluorescent units, fluorescent polymeric materials P1‐P4 with excitation wavelength‐dependent (254 and 365 nm, matched with standard UV lamp) emission are prepared. P1‐P4 responded rapidly to biogenic amines (BAs). Among them, P3 exhibits the widest linear range, and the most noticeable fluorescence color change (from orange‐red to yellow‐green) under 254 nm excitation and enhanced green fluorescence under 365 nm excitation. The changes of P3‐prepared labels at different excitation wavelengths can be utilized to rapidly evaluate the food's freshness. Furthermore, by using a smartphone to read the Red/Green/Blue values of the labels, the total volatile basic nitrogen (TVBN) values can be output to quantitatively evaluate the food freshness, and the output TVBN values at different excitation wavelengths are utilized for mutual calibration to improve the accuracy of the estimation results. This self‐calibrating sensing platform is fast and nondestructive, which provides an effective method for the accurate evaluation of food freshness.

Quality non-destructive sorting of large yellow croaker based on image recognition

The YOLOv7 algorithm was used to establish a fast and non-destructive quality identification model for large yellow croaker (Larimichthys crocea) in this study. The cross multi-head attention mechanism in the swin transformer was incorporated into the neck of YOLOv7 architecture to enhance the recognition performance. The freshness classification model based on the total volatile basic nitrogen value was evaluated by freshness indicators, visual features, and texture profile analysis (TPA). The findings indicated that the enhanced model achieved an accuracy rate of 98.6% in freshness classification, which was higher than 85.6% of the original model. Visual features (fish-eye plumpness and turbidity) were highly correlated with all freshness indexes (all above 0.8). The accuracy of freshness discrimination in different lighting environments was also greater than 90%. These results collectively indicate the potential for the eye region images to serve as a reliable indicator for the sorting of freshness in large yellow croakers.

Impact of Packaging Methods Coupled with High Barrier Packaging Loaded with TiO2 on the Preservation of Chilled Pork.

This study investigated the impact of packaging methods coupled with high barrier packaging loaded with titanium dioxide (TiO2) on the quality of chilled pork. The experiment consisted of three treatment groups: air packaging (AP), vacuum packaging (VP), and vacuum antibacterial packaging (VAP). Changes in total viable count (TVC), pH value, total volatile basic nitrogen (TVB-N) value, sensory attributes, and water holding capacity of pork were analyzed at 0, 3, 6, 9, and 12 d. TVC of the VAP group was 5.85 Log CFU/g at 12 d, which was lower than that of AP (6.95 Log CFU/g) and VP (5.93 Log CFU/g). The antibacterial film incorporating TiO2 effectively inhibited microorganism growth. The VAP group exhibited the lowest pH value and TVB-N value among all the treatment groups at this time. The findings demonstrated that the application of VAP effectively preserved the sensory attributes of pork, the hardness, cohesiveness and adhesiveness of pork in VAP group were significantly superior than those in AP group (p<0.05), but not significantly compared with VP group. On the 12 d, the CIE a* value of pork in VAP group was significantly higher (p<0.05). This exhibited that VAP could effectively maintain the freshness of chilled pork and extend the shelf life for 3 d compared to the AP group. These findings provide empirical evidence to support the practical implementation of TiO2-loaded packaging film in the food industry.

Effect of Paprika Powder on the Antioxidant Capacity of Emulsion-Type Sausages.

Antioxidant activity of freeze-dried paprika powder and storage properties of emulsion-type pork sausages containing diverse concentrations of this powder (0%, 1%, 2%, and 3%) were analyzed. Antioxidant activities of red and yellow paprika powders were analyzed by evaluating their 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferric reducing antioxidant power (FRAP), total phenol content (TPC), and total flavonoid content (TFC). The yellow paprika powder exhibited remarkably higher DPPH radical scavenging activity, FRAP values, and TPC than the red paprika powder (p<0.05), while TFC showed no remarkable difference between them (p>0.05). Storage properties of sausages containing the yellow paprika powder were analyzed by evaluating their water holding capacity, cooking yield, and thiobarbituric acid reactive substance (TBARS), and volatile basic nitrogen (VBN) values. The 3% yellow paprika powder group showed remarkably higher water-holding capacity and cooking yield compared to the 0% group (p<0.05). TBARS values were remarkably lower in the 2% and 3% yellow paprika powder groups than in the 0% group at all weeks (p<0.05). VBN value was remarkably lower in the 3% yellow paprika powder group than in the 0% group at all weeks (p<0.05). Overall, addition of 3% yellow paprika powder improved the storage properties of emulsion-type sausages.

Evaluation of fish meal freshness using a metal-oxide semiconductor electronic nose combined with the long short-term memory feature extraction method.

To improve the classification and regression performance of the total volatile basic nitrogen (TVB-N) and acid value (AV) of different freshness fish meal samples detected by a metal-oxide semiconductor electronic nose (MOS e-nose), 402 original features, 62 manually extracted features, manually extracted and selected features by the RFRFE method, and the features extracted by the long short-term memory (LSTM) network were used as inputs to identify the freshness. The classification performance of the freshness grades and the estimation performance of the TVB-N and AV values of fish meal with different freshness were compared. According to the sensor response curve, preprocessing and feature extraction steps were first applied to the original data. Then, five classification algorithms and four regression algorithms were used for modeling. The results showed that a total of 30 features were extracted using the LSTM network, and the number of extracted features was significantly reduced. In the classification, the highest accuracy rate of 95.4% was obtained using the support vector machine method. In the regression, the least squares support vector regression method obtained the best root mean square error (RMSE). The coefficient of determination (R2), RMSE, and relative standard deviation (RSD) between the predicted value of TVBN and the actual value were 0.963, 11.01, and 7.9%, respectively. The R2, RMSE, and RSD between the predicted value of AV and the actual value were 0.972, 0.170, and 6.05%, respectively. The LSTM feature extraction method provided a new method and reference for feature extraction using an E-nose to identify other animal-derived material samples.

Development of active hydrogel absorbent pads based on sodium alginate/potassium-doped carbon dots for chilled pork preservation

In this study, potassium-doped carbon dots (K-CDs) were added to sodium alginate (NaAlg) hydrogel to yield high-strength, antibacterial, antioxidant NaAlg hydrogel absorbent pads (NaAlg/K-CDs) to absorb chilled pork exudate during storage. The results revealed that the swelling rates of the NaAlg/K-CDs peaked at 3286.83%, a figure exceeding that of the commercial absorbent pads. Based on the bacterial diversity and richness results, Pseudomonas aeruginosa (P. aeruginosa) was evidently the dominant spoilage organism during chilled pork storage. On storage day 6, the P. aeruginosa population in the NaAlg/K-CDs hydrogel absorbent pad group was 82% of that in the control group. The total volatile basic nitrogen (TVB-N) value of the NaAlg/K-CDs group remained lower than 0.15 mg/g on day 8. The pH, TVB-N, total viable count (TVC), cooking loss, and volatile odour values of the chilled pork in the NaAlg/K-CDs hydrogel absorbent pad group were significantly lower than those in other absorbent pad groups. Moreover, the colour change and shear force values of the chilled pork in the NaAlg/K-CDs hydrogel absorbent pad group were lower than those in the control and wood fiber paper absorbent pad groups. These results indicate that the shelf life of the NaAlg/K-CDs-packaged chilled pork was extended by 2 days compared with that of the control. Therefore, the NaAlg/K-CDs hydrogel absorbent pads potentially inhibited microbial growth and improved the storage quality of chilled pork. This study provides an alternative solution against traditional chilled pork absorbent pads, further promoting the advancement of fresh meat preservation techniques.

Application of Ulva lactuca polysaccharide in the preservation of refrigerated of Lateolabrax maculatus fillets

This study aimed to explore the use of Ulva lactuca polysaccharide (ULP) as a preservative for perch (Lateolabrax maculatus) fillets stored under refrigeration at 4 °C. Fresh perch fillets were treated with ULP (7–10 kDa) and potassium sorbate, respectively, to evaluate their effectiveness in inhibiting bacterial growth and maintain freshness. A 0.5% ULP solution significantly decreased the pH value, total volatile basic nitrogen value, thiobarbituric acid value, and total bacterial count of perch fillets. ULP solution delayed the changes in whiteness and texture of fillets, as well as protein degradation. The acute toxicity experiment further evaluates the safety and reliability of ULP. Simultaneously, utilizing 16S rRNA techniques, the ULP solution inhibited microorganisms known for their strong spoilage capabilities, such as Pseudomonas, Actinetobacter, and Shewanella. Microorganisms with a weaker ability to cause corruption became the dominant bacteria, such as Acetobacter, Lactobacillus, and Faecalibacterium, thereby exerting a degree of inhibition against spoilage.

Combined Effect of an Active AgIon® Absorbent Pad and a Chitosan Coating on the Preservation of Fresh Beef.

In the present study, the combined effect of an AgIon® antimicrobial absorbent (Ζ) pad and a chitosan coating (C) on the preservation of fresh beef stored aerobically at 5 °C was investigated. Microbiological, physicochemical, and sensory attributes were monitored for up to 10 days of storage. The microbiological data indicated that the C and chitosan coating plus absorbent pad (CZ) treatments were the most efficient in reducing total viable counts (TVC) by 4.09 and 3.53 log cfu/g compared to the control W and Z treatments on day 4 of storage (p < 0.05). An analogous reduction in the counts of the other microbial groups monitored was recorded. pH values were ca. 5.7 for treatments W and Z and 5.45 for treatments C and CZ on day 4 of storage (p < 0.05). The total volatile basic nitrogen (TVB-N) values remained <20 mg/100 g for all treatments on day 4 and for treatments C and CZ on day 10 of storage. The total color difference values decreased (p < 0.05) during storage for treatments W and Z, but remained constant for treatments C and CZ. Based on sensory, microbiological and physico-chemical data, beef shelf life was ca ^# + 3 days for samples W and Z and at least 10 + 3 days for samples C and CZ. Between the two antimicrobial treatments, chitosan was considerably more effective than the AgIon® antimicrobial absorbent pad, which showed practically no antimicrobial activity in direct contact with beef meat.

The effect of carvacrol, thymol, eugenol and α-terpineol in combination with vacuum packaging on quality indicators of anchovy fillets

Food safety issues associated with the increased use of synthetic and chemicals preservatives agents are receiving increasing attention. The utilisation of natural resources may provide a potential and advisable alternative to chemical preservatives in the seafood industry. This research study focused on the impacts of pure bioactive compounds (carvacrol, thymol, eugenol, and α-terpineol) on the sensory and microbiological (total viable count, TVC) and chemical qualities (total volatile basic nitrogen (TVB-N) value, thiobarbituric acid (TBA), free fatty acid (FFA), and peroxide value (PV)) of vacuumed packaged anchovy (Engraulis encrasicolus) fillets during the refrigerated storage period. This study also evaluated the potential effect of bioactive compounds on biogenic amines (BAs) and ammonia (AMN) production in fish samples. Sensory investigations revealed that the control had an 8-day shelf life, that of the carvacrol and α-terpineol treatment was 15 days, and that of the thymol and eugenol treatment was 19 days. The application of bioactive compound on fish had a positive impact on the preservation of its oxidative stability through the reduction of TBA, FFA, and PV values as well as enhancement of the microbiological quality in comparision to the control. The use of pure bioactive compounds resulted in the reduction of the accumulation of BAs and AMN in anchovy fillets during 22 days of storage. The results exhibited that the pure bioactive compounds mainly eugenol and thymol, can increase the shelf life of anchovy. Therefore, they can be used by seafood industries as preservative agents due to their good antimicrobial and antioxidant activities.

Development of active packaging material based on polycaprolactone/hydroxypropyl methylcellulose nanofibers containing carbon dot nanoparticles for meat preservation

This work demonstrates the feasibility of using a combination of biodegradable polycaprolactone (PCL) and natural-based hydroxypropyl methylcellulose (HPMC) polymers containing carbon dots (CDs) for food packaging applications. CDs were synthesized using the insoluble portion of Zedo gum. The 5% and 15% concentrations of bare Zedo CDs (Z-CD) and nitrogen and sulfur co-doped CDs (TZ-CD) were chosen for incorporation into PCL/HPMC nanofibers (NFs). The PCL/HPMC/Z-CD15% and PCL/HPMC/TZ-CD15% demonstrated improved tensile strength (12.88 and 15.01 MPa), water solubility (30.20 and 42.36%), and water vapor transmittance (0.62 and 0.71 g mm/m2 h kPa)), respectively. When comparing the release of CDs in 10%, 50%, and 95% ethanolic solutions, it was found that TZ-CD released more rapidly than Z-CD from NFs in all three simulants. The CDs-added NFs exhibited potent antioxidant activity (80.5%). More significant antimicrobial activity against S. aureus was observed compared to E. coli. Additionally, reductions in total volatile basic nitrogen and thiobarbituric acid values indicated that beef covered with PCL/HPMC/TZ-CD15% and PCL/HPMC/Z-CD15% NFs had an extended shelf life of more than five days. In conclusion, PCL/HPMC/Z-CD15% and PCL/HPMC/TZ-CD15% NFs can be used as promising biodegradable packaging materials to enhance the shelf life of meat products.

Inhibition of protein denaturation and oxidation of prepared shrimp paste by sturgeon skin collagen peptide

This study investigated the cryoprotective effect of different concentrations (0.5%, 1.0%, 1.5%, 2.0%, and 2.5%) of sturgeon skin collagen peptides (CPs) on the changes in protein denaturation, oxidation, and overall quality of prepared shrimp paste during 180 d cryopreservation. Compared with phosphates and sorbitol, higher concentrations (>1.5%) of CPs minimized the denaturation and oxidation of protein with higher protein solubility, thermal transition enthalpy, and less carbonyl formation. Meanwhile, the decrease of hydrogen and ionic bonding was inhibited accompanied by less thawing loss and cooking loss. Compared with sorbitol, CPs at all concentrations contributed to less antioxidant effect in retarding the lipid oxidation after 180 d, however still exhibited lower thiobarbituric acid values than the control. The freshness of the 2.5% CPs group and sorbitol group was well maintained with the total volatile basic nitrogen value kept under 20 mg/100 g. Furthermore, a compact and less-aggregated gel matrix was observed during frozen storage. These findings indicate that CPs posed dose-dependent cryoprotective effects on shrimp paste, representing it as a comparable alternative to polyphosphates or sorbitol for seafood cryopreservation.