Development of a freshness indicator for monitoring the quality of beef during storage

ConvColor DL: Concatenated convolutional and handcrafted color features fusion for beef quality identification

Beef is an important food product in human nutrition. The evaluation of the quality and safety of this food product is a matter that needs attention. Non-destructive determination of beef quality by image processing methods shows great potential for food safety, as it helps prevent wastage. Traditionally, beef quality determination by image processing methods has been based on handcrafted color features. It is, however, difficult to determine meat quality based on the color space model alone. This study introduces an effective beef quality classification approach by concatenating learning-based global and handcrafted color features. According to experimental results, the convVGG16 + HLS + HSV + RGB + Bi-LSTM model achieved high performance values. This model's accuracy, precision, recall, F1-score, AUC, Jaccard index, and MCC values were 0.989, 0.990, 0.989, 0.990, 0.992, 0.979, and 0.983, respectively.

Development of a Freshness Indicator for Assessing the Quality of Packaged Pork Products during Refrigerated Storage

A pH-sensitive dye-based freshness indicator has been developed to monitor the quality status of pork neck through distinct color transitions, addressing a crucial need for improved food safety and real-time monitoring within the food industry. This system aims to boost consumer confidence and improve shelf-life estimates by offering transparent and immediate quality indicators. Aerobically packaged pork neck samples underwent accelerated testing at 25 °C for 36 h, followed by refrigeration experiments at typical distribution temperatures of 4 and 8 °C over 10 days. Measured pork neck quality parameters included total bacterial count (TBC), total volatile basic nitrogen (TVB-N), and pH levels. Visual observation and colorimetric analysis were used to assess the chromatic variations of the freshness indicator, which showed a significant shift from orange to green in response to the presence of TVB-N in the headspace of the pork packaging. The chromatic parameters of the freshness indicator exhibited a significant correlation with the pork quality values throughout the storage periods. The results highlight the ability of the freshness indicator to effectively convey quality information about pork through noticeable colorimetric changes.

Alizarin complexone modified UiO-66-NH2 as dual-mode colorimetric and fluorescence pH sensor for monitoring perishable food freshness

Food prone to spoilage has a huge food safety hazard, threatening people's health, so early detection of food spoilage is a continuous and urgent need. Herein, we developed a dual-mode response sensor, alizarin complexone@UiO-66-NH2, which can accurately detect pH. The sensor demonstrated significant changes in color from pale yellow to deep pink, while the fluorescence shifted from light blue to blue violet. Moreover, both UV absorption and fluorescence intensity showed a linear correlation with pH raging from 4.5 to 7.5. These results indicate that the sensor effectively responds to pH, making it suitable for detecting the freshness of perishable food. To put this into practice, we integrated the sensor with cellulose-based filter paper to determine the freshness of shrimp and beef, which was proved to be effective in assessing freshness. In the future, it can be combined with intelligent colorimetric and fluorescence instruments to achieve visual detection.

Efficiency of Electronic Nose in Detecting the Microbial Spoilage of Fresh Sardines (Sardinella longiceps)

The assessment of microbial spoilage in fresh fish is a major concern for the fish industry. This study aimed to evaluate the efficiency and reliability of an electronic nose (E-nose) to detect microbial spoilage of fresh sardines (Sardinella longiceps) by comparing its measurements with Total Bacterial Count (TBC), Hydrogen Sulfide (H2S) producing bacterial count and Trimethylamine Oxide (TMAO) reducing bacterial count after variable storage conditions. The samples were stored at 0 °C (0, 2, 4, 6, and 8 days) and 25 °C (0, 3, 6, and 9 h), while day 0 was used as a control. The E-nose measurements were analyzed by Principal Component Analysis (PCA), Linear Discriminant Analysis (LDA) and Artificial Neural Network (ANN). Microbial counts increased significantly and simultaneously with the changes in E-nose measurements during storage. The LDA and ANN showed a good classification of E-nose data for different storage times at two storage temperatures (0 °C and 25 °C) compared to PCA. It is expected as PCA is based on linear relationships between the factors, while ANN is based on non-linear relationships. Correlation coefficients between E-nose and TBC, TMAO-reducing bacterial and H2S-producing bacterial counts at 0 °C were 0.919, 0.960 and 0.915, respectively, whereas at 25 °C, the correlation coefficients were 0.859, 0.945 and 0.849, respectively. These positive correlations qualify the E-nose as an efficient and reliable device for detecting microbial spoilage of fish during storage.

Improvement of Microbial Quality, Physicochemical Properties, Fatty Acids Profile, and Shelf Life of Basa (Pangasius bocourti) Fillets during Chilling Storage Using Pepsin, Rosemary Oil, and Citric Acid

Meat discoloration, lipid oxidation, and undesirable texture are inevitable phenomena in basa fish fillets during storage, which in turn limits their exportation as well as decreases consumer acceptability. In addition, increasing consumers' requirements for high-quality, minimally processed, and ready-to-cook fish fillets with an extended shelf-life is a great challenge, particularly with lifestyle changes. Accordingly, this study aimed to improve the quality, lipid stability, fatty acid profile, and lipid nutritional quality indices (LNQI) of basa fish fillets during chilling storage at 4 °C for 15 days using pepsin enzyme (E, 0.1%), rosemary oil (R, 0.5%), citric acid (CA, 0.5%), and their combination (0.1% E + 0.5% R; 0.1% E + 0.5% CA; and 0.1% E + 0.5% R + 0.5% CA). Our results revealed that all treated samples exhibited a significant increase in protein content, a significant decrease in fat content, and a marked reduction in pH, total volatile base nitrogen (TVBN), thiobarbituric acid (TBA), free fatty acids, and shear force (SF) values in comparison to control ones. Moreover, significant improvements in sensory scores, color stability, fatty acid profile, LNQI, and microbial quality of all treated samples were observed. Such findings were more pronounced in samples treated with a mixture of pepsin, rosemary, and citric acid (TVBN: 2.04 vs. 6.52 mg%; TBA: 0.40 vs. 2.68 mg malonaldehyde/Kg; and SF: 8.58 vs. 19.51 Kgf). Based on the obtained results, there was an extension for the shelf life of all treated basa fish fillet samples, especially in samples treated with a mixture of pepsin, rosemary, and citric acids when compared with the control samples (˃15 days versus 10 days). Additionally, eucalyptol, camphor, isoborneol, and α-pinene are the main components of rosemary, with great antioxidant and antimicrobial activity. In conclusion, the mixture of pepsin, rosemary, and citric acid can be applied easily in the seafood industry and at the household level to provide ready-to-cook fish fillets of high quality with great health benefits.

Development of real time-pH sensitive intelligent indicators for monitoring chicken breast freshness/spoilage using real packaging practices

Real-real time CO2-sensitive freshness indicators, phenol red (PR) and bromothymol blue (BTB) dyes, in three-layer system using cellulose based binder was developed to determine the freshness/spoilage of chicken breast. The developed indicators were used to monitor chicken meat spoilage packaged in polyamide/polyethylene (PA/PE) pouches under air and 100% nitrogen (N2) at 4 °C for 10 days. Changes in the ΔE and ΔRGB values of the indicators, CO2/O2 gas composition of packs, and chemical (TVBN, pH, trimethylamine), microbial, and sensory quality parameters of chicken breast meat were analyzed. The visual color change in the PR-based indicator was insufficient for the consumer to detect the spoilage with the naked eye in both simulation and food trial. However, three stage color (dark blue-turquoise-green) change was occurred in BTB-based indicators, and the color transition in the spoilage level of CO2 (10-15% (v/v)) is supported by the physicochemical, microbiological and sensorial properties of the chicken breast. The shelf life of chicken breast under air was limited to 4 days, while the shelf life under 100% N2 was 6 days which are supported by the visual color change of BTB indicator. The BTB-based indicators were found promising on a real packaging conditions and could be adapted to industrial scale for monitoring real-time freshness/spoilage of poultry, ensuring food safety.

A Novel Indicator Based on Polyacrylamide Hydrogel and Bromocresol Green for Monitoring the Total Volatile Basic Nitrogen of Fish

An intelligent indicator was developed by immobilizing bromocresol green (BCG) within the polyacrylamide (PAAm) hydrogel matrix to monitor the total volatile basic nitrogen (TVB-N) content of fish. The FTIR analysis indicated that BCG was effectively incorporated into the PAAm through the formation of intermolecular hydrogen bonds. A thermogravimetric analysis (TGA) showed that the PAAm/BCG indicator had a mere 0.0074% acrylamide monomer residue, meanwhile, the addition of BCG improved the thermal stability of the indicator. In vapor tests with various concentrations of trimethylamine, the indicator performed similarly at both 4 °C and 25 °C. The total color difference values (ΔE) exhibited a significant linear response to TVB-N levels ranging from 4.29 to 30.80 mg/100 g at 4 °C (R2 = 0.98). Therefore, the PAAm/BCG indicator demonstrated stable and sensitive color changes based on pH variations and could be employed in smart packaging for real-time assessment of fish freshness.

Effect of different vacuum levels for beef brisket during cold storage: A microbiological and physicochemical analysis

Effect of packaging at different vacuum levels such as 7.2 Pa (99.99% vacuum), 30 kPa (70.39%), 70 kPa (30.91%), and 101.33 kPa (0%, atmospheric condition) using a specially designed airtight container on physicochemical and microbial properties of beef brisket cuts during cold storage was investigated. Dramatic pH increase was found only in air atmospheric packaging. Higher vacuum level yielded higher water holding capacity and lower volatile basic nitrogen (VBN), 2-thiobarbituric acid (TBA), and growth rate of aerobic bacteria and coliforms, whereas the fatty acid composition showed no difference among various vacuum levels. The highest vacuum level (7.2 Pa) yielded no increases in VBN, TBA, and coliform and the least increase in aerobe counts. For bacterial communities, higher vacuum levels yielded higher proportions of Leuconostoc, Carnobacterium, and lactobacilli belonging to the phylum Firmicutes and lower proportions of Pseudomonas belonging to the phylum Proteobacteria. Predictive curves for bacterial communities showed that just a little oxygen significantly affects the bacterial dominance based on different oxygen dependence of individual bacteria and their logarithmic changes by vacuum level.

Preparation of Nanopaper for Colorimetric Food Spoilage Indication

In this study, we are reporting the fabrication of a nanocellulose (NFC) paper-based food indicator for chicken breast spoilage detection by both visual color change observation and smartphone image analysis. The indicator consists of a nanocellulose paper (nanopaper) substrate and a pH-responsive dye, bromocresol green (BCG), that adsorbs on the nanopaper. The nanopaper is prepared through vacuum filtration and high-pressure compression. The nanopaper exhibits good optical transparency and strong mechanical strength. The color change from yellow to blue in the nanopaper indicator corresponding to an increase in the solution pH and chicken breast meat storage data were observed and analyzed, respectively. Further, we were able to use color differences determined by the RGB values from smartphone images to analyze the results, which indicates a simple, sensitive, and readily deployable approach toward the development of future smartphone-based food spoilage tests.

A polylactide based multifunctional hydrophobic film for tracking evaluation and maintaining beef freshness by an electrospinning technique

A nanofiber film was prepared by a facile electrospinning technique using polylactide (PLA), butterfly pea flower extract (BPA) and cinnamaldehyde (CIN). The as-prepared film shows the prominent antioxidative, antibacterial, colorimetric and hydrophobic properties so that the beef freshness can be monitored and maintained up to 6 days at 4 °C simultaneously. Besides, the nanofiber structure endows the film with a fast color responsiveness under acidic-alkaline atmospheres with different concentrations. Moreover, this film exhibits higher tensile strength (9.56 Mpa) than that of the pure PLA electrospinning film (4.40 Mpa). Especially the introduction of the BPA effectively boosts the antimicrobial ability of the CIN. The freshness, sub-freshness and spoilage levels of the beef can be easily testified by observing the color difference change of the film. So the polylactide based multifunctional film as an intelligent packaging has an excellent potential for the sub-freshness detection of meat.

Fish Freshness Indicator for Sensing Fish Quality during Storage

This study aims to develop a freshness indicator for fish products that changes color to indicate ammonia among volatile base compounds (TVB-N) generated during storage. Through an optimization experiment, we observed the indicator's color change relative to the ammonia concentration standard, finally selecting cresol red and bromocresol purple for the indicator mixture. In addition, eco-DEHCH and Breathron film were applied to the freshness indicator, considering environmental and economic values. For the storage experiment, Chub mackerel (Scomber japonicus), Spanish mackerel (Scomberomorus niphonius), and Largehead hairtail (Trichiurus lepturus) samples were stored at three different temperatures (4, 10, and 20 °C) for seven days, and we measured pH, TVB-N, total bacterial count, and ammonia content every 24 h. The pH-sensitive sensors' color changes monitor amine release, especially ammonia, from decomposing fish. The chromatic parameter ∆E value increased significantly with fish product storage periods. We confirmed that when the freshness limit and bacterial spoilage level were reached, the color of the indicator changed from yellow to black and sequentially changed to purple as the storage period increased. Therefore, a developed freshness indicator can be used for determining the quality of fish products quickly and non-destructively by reflecting the freshness and spoilage degree of fish products during storage.

Application of smart packaging for seafood: A comprehensive review

Nowadays, due to the changes in lifestyle and great interest of consumers in a healthy life, people have started increasing their seafood consumption. But due to their short shelf life, experts are looking for a new packaging called smart packaging (SMP) for seafood. There are different indicators/sensors in SMP; one of the effective indices is time-temperature, which can show consumers the best time of using seafood based on their shelf life and experienced temperature. Another one is radio-frequency identification (RFID) that is a transmission device that represents a separate form of the electronic information-based SMP systems. RFID does not belong to any of the categories of markers or sensors; it is an auto recognition system that applies cordless sensors to indicate segments and collect real-time information without manual interposition. This review covers the use of SMP in all marine foods, including fish, due to its high consumption and high content of polyunsaturated fatty acids, eicosapentaenoic acid (C20:5n-3) and docosahexaenoic acid (C22:6n-3), which are the considerable factors of n-3 polyunsaturated fatty acids for human.

Effects of the Aging Period and Method on the Physicochemical, Microbiological and Rheological Characteristics of Two Cuts of Charolais Beef

Wet-aging (WA) and dry-aging (DA) methods are usually used in the beef industry to satisfy the consumers' tastes; however, these methods are not suitable for all anatomical cuts. In this study, WA and DA were applied to improve the quality of two cuts of Charolais beef (Longissimus dorsi and Semitendinosus). For 60 days (i.e., 2 days, 15 days, 30 days and 60 days of sampling), a physicochemical, rheological, and microbiological analysis were performed at WA (vacuum packed; temperature of 4 ± 1 °C) and at DA (air velocity of 0.5 m/s; temperature of 1 ± 1 °C; relative humidity of 78 ± 10%) conditions. The results showed that the aging method influenced the aging loss (higher in the DA), cooking loss (higher in the WA), malondialdehyde concentration (higher in the DA) and fatty acid profile (few changes). No differences in the drip loss and color were observed, which decreased after 30 days of aging. The WBSF and TPA test values changed with increasing an aging time showing that the aging improved the tenderness of meat regardless of the aging method. Moreover, the aging method does not influence the microbiological profile. In conclusion, both WA and DA enhanced the quality of the different beef cuts, suggesting that an optimal method-time and aging combination could be pursued to reach the consumers' preferences.

Grape skin flour obtained from wine processing as an antioxidant in beef burgers

The objective of this study was to determine the best level of wine making by-product meal (WBM) as a natural antioxidant to replace butylhydroxytoluene (BHT) in beef burger stored at -20 °C for up to 120 days. The treatments consisted of control (basic formulation - BF, without antioxidant); BF with BHT; and BF with WBM0.5, WBM1.0, WBM1.5, and WBM2.0, with 0.5, 1.0, 1.5 and 2.0 g WBM/100 g BF, respectively. Up to 60 days of storage, the lipid oxidation value between BHT and WBM0.5 treatments did not differ and were lower than the values presented by the other treatments. On day 90 and 120, the lipid oxidation values of treatments BHT, WBM0.5, and WBM1.0 did not differ and were lower than the values presented by WBM1.5 and WBM2.0 treatments. Burgers from all treatments with WBM inclusion had crude fiber values above 3 g/100 g. WBM1.5 and WBM2.0 treatments had the worst scores for appearance, aroma, juiciness and tenderness, in addition to the highest cooking losses. WBM can be used at up to 1 g/100 g to replace BHT in frozen beef burgers. Higher levels of WBM inclusion increased lipid oxidation and negatively affected the sensory quality of burgers.

Effects of Aging Methods and Periods on Quality Characteristics of Beef

The objective of this study was to determine effects of aging methods (wet-aged, dry-aged, and packaged dry-aged) during 60 d on quality traits and microbial characteristics of beef. Wet-aged beef was packed by vacuum packaging and stored in a 4°C refrigerator. Dry-aged beef was used without packaging. Packaged dry-aged beef was packaged in commercial bags. Dry-aged and packaged dry-aged samples were stored in a meat ager at 2°C-4°C with 85%-90% relative humidity. Meat color, crust thickness, aging loss, cooking loss, Warner-Bratzler shear force (WBSF), texture profile analysis, Torrymeter, meat pH, water activity, volatile basic nitrogen (VBN), thiobarbituric acid reactant substances (TBARS), and microbial analysis were measured or performed every 15 d until 60 d of aging time. Meat color changed significantly with increasing aging time. Differences in meat color among aging methods were observed. Aging losses of dry-aged and packaged dry-aged samples were higher than those of wet-aged samples. Wet-aged beef showed higher cooking loss, but lower WBSF than dry-aged and packaged dry-aged beef. VBN and TBARS showed an increasing tendency with increasing aging time. Differences of VBN and TBARS among aging methods were found. Regarding microbial analysis, counts of yeasts and molds were different among aging methods at the initial aging time. Packaged dry-aged and dry-aged beef showed similar values or tendency. Significant changes occurred during aging in all aging methods. Packaged dry aging and dry aging could result in similar quality traits and microbial characteristics of beef.

Comparison of Superchilling and Supercooling on Extending the Fresh Quality of Beef Loin

This study compared the effects of superchilling and supercooling preservations for 15 days on the freshness and quality characteristics of beef loin. Beef freshness was evaluated by total aerobic count (TAC), total volatile basic nitrogen (TVB-N), and thiobarbituric acid reactive substances (TBARS), and instrumental color, drip loss, cooking loss, and texture profile analysis (TPA) were determined as quality parameters. All assays were compared with fresh control and normal chilling conditions (4 °C). The mean preservation temperatures of superchilling and supercooling were −3.9 °C and −2.1 °C, respectively. The freshness parameters indicated that both superchilling and supercooling extended the freshness of beef loin for 15 days, while chilled beef could not maintain the standard of freshness conditions. For quality parameters, there was no difference between the control and supercooling treatments, whereas superchilling exhibited higher drip loss and toughness compared to the control (p < 0.05). Therefore, this study demonstrated that supercooling was the best preservation technique to extend the freshness and quality of beef loin, but superchilling was not suitable to guarantee the quality of beef.

Meat 4.0: Principles and Applications of Industry 4.0 Technologies in the Meat Industry

Meat 4.0 refers to the application the fourth industrial revolution (Industry 4.0) technologies in the meat sector. Industry 4.0 components, such as robotics, Internet of Things, Big Data, augmented reality, cybersecurity, and blockchain, have recently transformed many industrial and manufacturing sectors, including agri-food sectors, such as the meat industry. The need for digitalised and automated solutions throughout the whole food supply chain has increased remarkably during the COVID-19 pandemic. This review will introduce the concept of Meat 4.0, highlight its main enablers, and provide an updated overview of recent developments and applications of Industry 4.0 innovations and advanced techniques in digital transformation and process automation of the meat industry. A particular focus will be put on the role of Meat 4.0 enablers in meat processing, preservation and analyses of quality, safety and authenticity. Our literature review shows that Industry 4.0 has significant potential to improve the way meat is processed, preserved, and analysed, reduce food waste and loss, develop safe meat products of high quality, and prevent meat fraud. Despite the current challenges, growing literature shows that the meat sector can be highly automated using smart technologies, such as robots and smart sensors based on spectroscopy and imaging technology.

Analysis of Food Storage Stability of Biodegradable Containers Made of Pork Skin Gelatin Polymer with Walnut Shell Powder

This study analyzes the food storage stability of biodegradable containers made of pork skin gelatin polymer. Packaging materials were prepared with different proportions of walnut shell powder, including 10% (W10), 20% (W20), and polyethylene packaging (PE) as a control. To analyze storage stability, parameters such as pH, thiobarbituric acid reactive substance (TBARS), volatile basic nitrogen (VBN), microbial population, and color were measured. The pH, yeast and mold, redness, and yellowness of W10 and W20 had no significant difference compared to those of PE in all storage periods (p > 0.05). The TBARS of W20 was shown to slowly increase compared to W10. The VBN concentration of W10 and W20 were significantly higher than that of PE in the first and second weeks, but there was no significant difference in the third week (p < 0.05). The total bacterial counts of W10 and W20 were significantly higher than that of PE during the first week (p < 0.05), but there was no significant difference thereafter (p > 0.05). The lightness values of W10 and W20 were significantly lower than that of PE in the second and third weeks (p < 0.05). These results indicated that biodegradable containers containing up to 20% walnut shell powder can substitute plastic packaging materials.

Development of freshness indicator for monitoring chicken breast quality and freshness during storage

An indicator for freshness and quality measurement was utilized to perceive changes in freshness quality while storing chicken breasts. Visible color changes of the indicator shows spoilage and freshness of the packaged products. In addition, changes in pH, volatile basic nitrogen (VBN), and Pseudomonas spp. were monitored. The color change sensor (ΔE) reflected the headspace pH during the chicken breasts' packaging process. After storing chicken breast at 20 °C for 24 h, the color change (ΔE) of the indicator for freshness and quality measurement changed. The color change (ΔE) values were correlated with quality characteristics such as sensory, microbiological, and chemical properties that were popularly used to settle the freshness of chicken breast. In conclusion, the results showed that the indicator for freshness and quality measurement was useful in settling the shelf life of chicken breast products by physicochemical changes and monitoring microbial safety.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-022-01034-x.

Development and Characterization of Bioactive Poly(butylene-succinate) Films Modified with Quercetin for Food Packaging Applications

The preparation of biodegradable active packaging materials is still a major challenge. Here, we report the fabrication and characterization of poly(butylene succinate)-based (PBS) films enriched with a natural polyphenolic antioxidant—quercetin. The PBS-based films with various quercetin content (0.05; 0.10; 0.25 and 0.50 pph on PBS) were prepared via a solvent casting method. Physical (optical, mechanical, thermal, moisture and water sorption, water vapor and UV–vis barrier) and biofunctional (antioxidant and antibacterial against Escherichia coli and Staphylococcus aureus) film properties were tested. The migration of quercetin into model food liquid systems was determined. As a result of quercetin addition, significant changes in color, opacity and UV-blocking effect were observed. The presence of the active substance did not significantly affect the thermal properties of the PBS matrix. However, the mechanical properties of the films were slightly decreased. The films exhibited excellent free radicals (DPPH, ABTS, O₂⁻) scavenging and some bactericidal activities. PBS-quercetin films with superior functional properties have many possibilities for active food packaging applications.

Freshness monitoring technology of fish products in intelligent packaging

Fish products are one of the preferred products in modern healthy diets, because they contain unqualified proteins, polyunsaturated fatty acids and a variety of vitamins and minerals. However, because of their vulnerability to deterioration, methods to maintain their freshness have attracted wide attention. Intelligent packaging can effectively monitor the quality and safety of fish products, provide warning, and has a great market and development potential. Therefore, this paper reviews the research progress of intelligent packaging technology used to monitor the freshness of fish products. The quality attributes of freshness of fish products are summarized. The classification, principle and latest application progress of three advanced technologies, indicator, sensor and radio frequency identification (RFID), are summarized. In addition, the advantages and disadvantages of the intelligent packaging technology for monitoring the freshness of products are discussed, and the current research results are summarized and prospected.