Effect of high molecular weight chitosan coating on quality and shelf life of refrigerated channel catfish fillets

The effect of pomegranate peel extract added as a natural preservative on the quality parameters of thornback ray (Raja clavata) sausages stored at +4°C

In this study, three different groups of sausages were produced from thornback ray (Raja clavata) without additives (control group), waste pomegranate peel extract (natural group), and ascorbic acid (synthetic group). Biochemical, physicochemical, and microbiological changes of sausages were examined under refrigerator conditions (+4°C), and the shelf life was determined. The best results in terms of nutritional and physicochemical values were obtained in sausages treated with pomegranate peel extract. All sausage groups were spoiled on the 15th day in terms of the total volatile basic nitrogen (TVB-N); however, the pomegranate peel extract group showed a more positive effect compared to the other sausage groups. However, this value was not considered because cartilaginous fish such as stingrays contain higher levels of nonprotein nitrogenous compounds. It was observed that microbial growth was less in the natural group and the antimicrobial effect of pomegranate peel extract was higher than that of ascorbic acid. In addition, it was determined that the pomegranate peel extract group extended the shelf life up to 6 days in terms of total viable count (TVC) and yeast/mold compared to the control and synthetic groups, respectively. This study showed that pomegranate peel extract has a better protective effect than ascorbic acid and it can be used as a natural additive in preserving the quality of seafood products.

Sustainable valorization approaches on crustacean wastes for the extraction of chitin, bioactive compounds and their applications - A review

The unscientific disposal of the most abundant crustacean wastes, especially those derived from marine sources, affects both the economy and the environment. Strategic waste collection and management is the need of the hour. Sustainable valorization approaches have played a crucial role in solving those issues as well as generating wealth from waste. The shellfishery wastes are rich in valuable bioactive compounds such as chitin, chitosan, minerals, carotenoids, lipids, and other amino acid derivatives. These value-added components possessed pleiotropic applications in different sectors viz., food, nutraceutical, cosmeceutical, agro-industrial, healthcare, and pharmaceutical sectors. The manuscript covers the recent status, scope of shellfishery management, and different bioactive compounds obtained from crustacean wastes. In addition, both sustainable and conventional routes of valorization approaches were discussed with their merits and demerits along with their combinations. The utilization of nano and microtechnology was also included in the discussion, as they have become prominent research areas in recent years. More importantly, the future perspectives of crustacean waste management and other potential valorization approaches that can be implemented on a large scale.

Effect of vacuum and modified atmosphere packaging on moisture state, quality, and microbial communities of grouper (Epinephelus coioides) fillets during cold storage

The study aimed to assess the impact of different packaging methods on the moisture state, quality, and microbial composition of grouper fillets. The grouper fillets were packaged under the following four conditions: vacuum packaging (VP), 70% CO2/30% N2 (MAP1); 60% CO2/30% N2/10% O2 (MAP2); 40% CO2/30% N2/30% O2 (MAP3). Physicochemical and microbiological parameters were evaluated during 21 days of cold storage. The result demonstrated that MAP was effective in inhibiting microbial growth and accumulation of total volatile basic nitrogen (TVB-N), while also maintaining the water-holding capacity (WHC) of grouper fillets. Additionally, MAP1 effectively inhibited lipid and protein oxidation and protected the secondary structure of myofibrils compared to MAP2 and MAP3, with MAP1 samples having the lowest thiobarbituric acid reactive substances (TBARS) value (0.009-0.04 MDA/kg) and carbonyl content (0.20-0.26 μmol/g) and the highest sulfhydryl content (0.25-0.49 μmol/g) during cold storage. The results of high-throughput sequencing revealed that the presence of oxygen in the packaging system significantly influenced bacterial succession. Over time, Carnobacterium gradually became the dominant genera of fillets stored in MAP, and the presence of oxygen in MAP2 and MAP3 accelerated this transition by 9 days, compared to MAP1. In contrast, Enterobacteriaceae and Carnobacterium were the main dominant genera in VP. Remarkably, Enterobacteriaceae were virtually absent in MAP2 and MAP3 during storage, suggesting that the presence of oxygen exerted a significant inhibitory effect on Enterobacteriaceae. This study provides valuable insights into the application of MAP in the preservation of grouper fillets.

Use of dill extracts as a natural preservative on shelf-life extension of rainbow trout croquettes during refrigerator storage

In this study, changes in quality parameters of rainbow trout croquettes treated with dill extracts obtained by brewing (BDA) and distillation (DDA) methods were investigated during 61 days of refrigerated storage (+2 ± 1°C). Physicochemical, microbial, and sensory parameters of the rainbow trout croquettes were analyzed once every 4 days. It was observed that the precooking process and additives influenced the nutrient composition and color change of the croquettes. Total volatile base nitrogen and thiobarbituric acid values did not exceed the limit values in any group during refrigerated storage and these values were found as 23.10 ± 0.89 mg/100 g and 3.13 ± 0.08 mg MDA/kg in the control group (C), 21.00 ± 0.92 mg/100 g and 2.77 ± 0.14 mg MDA/kg in BDA group, and 21.70 ± 0.92 mg/100 g and 2.85 ± 0.07 mg MDA/kg in DDA group, respectively. Extract treatments, especially DDA, resulted in a significant reduction in the counts of total aerobic mesophilic and psychotropic bacteria in trout croquettes compared to the control group. It was determined that the sensory scores of all croquette groups decreased during storage and the acceptability scores of the C, BDA, and DDA groups reached on the 33rd, 57th, and 61st days of storage, respectively. According to the results, this work demonstrated that the dill extracts both distilled and brewed can be used as a natural additive to improve the quality and extend the shelf life of rainbow trout croquettes.

Application of chitosan with different molecular weights in cartilage tissue engineering

Cartilage tissue engineering involves the invention of novel implantable cartilage replacement materials to help heal cartilage injuries that do not heal themselves, aiming to overcome the shortcomings of current clinical cartilage treatments. Chitosan has been widely used in cartilage tissue engineering because of its similar structure to glycine aminoglycan, which is widely distributed in connective tissues. The molecular weight, as an important structural parameter of chitosan, affects not only the method of chitosan composite scaffold preparation but also the effect on cartilage tissue healing. Thus, this review identifies methods for the preparation of chitosan composite scaffolds with low, medium and high molecular weights, as well as a range of chitosan molecular weights appropriate for cartilage tissue repair, by summarizing the application of different molecular weights of chitosan in cartilage repair in recent years.

Chitosan Coating Functionalized with Flaxseed Oil and Green Tea Extract as a Bio-Based Solution for Beef Preservation

Ecological and safe packaging solutions arise as pivotal points in the development of an integrated system for sustainable meat production. The aim of this study was to assess the effect of a combined chitosan (Ch) + green tea extract (GTE) + essential oil (thyme oil, TO; flaxseed oil, FO; or oregano oil, OO) coating on the safety and quality of vacuum-packaged beef during storage at 4 °C. An optimized bio-based coating formulation was selected (2% Ch + 2% GTE + 0.1% FO) to be applied to three fresh beef cuts (shoulder, Sh; knuckle, Kn; Striploin, St) based on its pH (5.8 ± 0.1), contact angle (22.3 ± 0.4°) and rheological parameters (viscosity = 0.05 Pa.s at shear rate > 20 s^-1). Shelf-life analysis showed that the Ch-GTE-FO coating delayed lipid oxidation and reduced total viable counts (TVC) and Enterobacteriaceae growth compared with uncoated beef samples over five days. In addition, Ch-GTE-FO coating decreased total color changes of beef samples (e.g., ∆E* = 9.84 and 3.94, for non-coated and coated Kn samples, respectively) for up to five days. The original textural parameters (hardness, adhesiveness and springiness) of beef cuts were maintained during storage when Ch-GTE-FO coating was applied. Based on the physicochemical and microbial characterization results, the combination of the Ch-GTE-FO coating developed was effective in preserving the quality of fresh beef cuts during refrigerated storage along with vacuum packaging.

Influence of corn starch based bio-active edible coating containing fumaric acid on the lipid quality and microbial shelf life of silver pomfret fish steaks stored at 4 °C

The present study aimed at assessing the impact of addition of fumaric acid (0.5%), as an active agent, in a corn starch (2%) based edible coating, on the lipid quality and microbial shelf life of silver pomfret (Pampus argenteus) fish steaks stored at 4 °C. Treating fish steaks with FA resulted in a bacteriostatic effect leading to reduced counts of total mesophilic and psychrotrophic bacteria, H2S producing bacteria and Pseudomonas spp. The total mesophilic bacterial count of uncoated control sample exceeded the permissible limit of 7 log cfu g-1 on 6th day and had the lowest microbial shelf life. FA incorporation in the CS coating improved the microbial stability of fish steaks resulting in a shelf life of 15 days. The outcomes of the study suggest that CS based coating is beneficial in delaying lipid oxidation as displayed by the lower TBA and PV values while FA is an effective agent for further increasing the preservative action of CS coating by significantly inhibiting microbial growth as well as lipid quality deterioration, which could be exploited by the seafood industry as an active packaging component.

Preparation of chitosan grafted caffeic acid coating and its effect on pompano (Trachinotus ovatus) preservation

BACKGROUND

The present study aimed to investigate the preservative effect of chitosan-caffeic acid grafts coating (CS-g-CA) on the quality and microbial characteristics of pompano (Trachinotus ovatus) during iced storage. CS-g-CA was prepared by a 1-(3-dimethylaminopropyl)-3-ethylcarbodiimidehydro/N-hydroxysuccinimide coupling reaction. The grafting of CS-g-CA was confirmed by UV-visible and Fourier-transform infrared spectra. Samples were treated with distilled water (control), chitosan (CS), caffeic acid (CA) and CS-g-CA for 10 min, respectively. Microbiological [total viable count (TVC), H₂ S-producing bacteria count, Pseudomonas bacteria count], physicochemical indicators [water holding capacity (WHC), cooking loss, pH, total volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA), texture profile analysis, free amino acids] and sensory evaluation were investigated during ice storage at 4 °C for up to 27 days.

RESULTS

The results showed that the antioxidant and antibacterial activities of CS could be improved by grafting CA onto CS. CS-g-CA coating could greatly slow down the speed of water loss and maintain WHC. Furthermore, CS-g-CA coating showed superior antibacterial activities by inhibiting the growth of TVC, delayed the decline of flavor amino acids and reduced sensory change. In addition, CS-g-CA coating reduced lipid oxidation and protein degradation as indicated by the decrease in TBA and TVB-N, possibly as a result of the addition of CA into CS membrane significantly improving the antioxidant activity of CS.

CONCLUSION

Compared with the control group, CS-g-CA coating had the optimal effect and could enhance the shelf-life of Trachinotus ovatus for at least another 9 days. © 2021 Society of Chemical Industry.

Analysis of Alternative Shelf Life-Extending Protocols and Their Effect on the Preservation of Seafood Products

Seafood is essential to a healthy and varied diet due to its highly nutritious characteristics. However, seafood products are highly perishable, which results in financial losses and quality concerns for consumers and the industry. Due to changes in consumer concerns, demand for healthy products has increased. New trends focusing on reducing synthetic preservatives require innovation and the application of additional or alternative strategies to extend the shelf life of this type of product. Currently, refrigeration and freezing storage are the most common methods for fish preservation. However, refrigeration alone cannot provide long shelf-life periods for fish, and freezing worsens sensorial characteristics and consumer interest. Therefore, the need to preserve seafood for long periods without exposing it to freezing temperatures exists. This review focuses on the application of other approaches to seafood products, such as biodegradable films and coating technology; superchilling; irradiation; high-pressure processing; hyperbaric storage; and biopreservation with lactic acid bacteria, bacteriocins, or bacteriophages. The efficiency of these techniques is discussed based on their impact on microbiological quality, sensorial degradation, and overall preservation of the product’s nutritional properties. Although these techniques are already known, their use in the industrial processing of seafood is not widespread. Thus, the novelty of this review is the aggregation of recent studies on shelf life extension approaches, which provide useful information for the selection of the most appropriate technology and procedures and industrial innovation. Despite the fact that all techniques inhibit or delay bacterial proliferation and product decay, an undesirable sensory impact may occur depending on the treatment conditions. Although no technique appears to replace refrigeration, the implementation of additional treatments in the seafood processing operation could reduce the need for freezing, extending the shelf life of fresh unfrozen products.

Application of Chitosan-Lignosulfonate Composite Coating Film in Grape Preservation and Study on the Difference in Metabolites in Fruit Wine

In order to solve the global problem of fruit rotting due to microbial infection and water loss after harvest, which leads to a large amount of food waste, this experiment uses degradable biological composite coating to prolong the preservation period of grapes. Chitosan (CH) and Lignosulfonate (LS) were used as Bio-based film materials, CH films, 1% CH/LS films and 2% CH/LS biomass composite films were synthesized by the classical casting method and applied to grape preservation packaging. Its preservation effect was tested by grape spoilage rate, water loss rate, hardness, soluble solids, titratable acid, and compared with plastic packaging material PE film. At the same time, 1H NMR technology combined with pattern recognition analysis (PCA) and partial least squares discriminant analysis (PLS-DA) was used to determine the nuclear magnetic resonance (NMR) of Cabernet Sauvignon, Chardonnay and Italian Riesling wines from the eastern foothills of Helan Mountain to explore the differences in metabolites of wine. The results of preservation showed that the grapes quality of CH films and 2% CH/LS coating package is better than the control group, the decay rates decreased from 37.71% to 21.63% and 18.36%, respectively, the hardness increased from 6.83 to 10.4 and 12.78 and the soluble solids increased from 2.1 in the control group to 3.0 and 3.2. In terms of wine metabolites, there are similar types of metabolites between cabernet Sauvignon dry red wine and Chardonnay and Italian Riesling dry white wine, but there are significant differences in content. The study found that 2% CH/LS coating package could not only reduce the spoilage rate of grapes, inhibit the consumption of soluble solids and titratable acids, but also effectively extend the shelf life of grapes by 6 days.

Formation, structure, properties of chitosan aspartate and metastable state of its solutions for obtaining nanoparticles

Chitosan (200 kDa) dissolution in an aqueous solution of L-aspartic acid, physicochemical properties and features of the resulting chitosan salt were studied by conductometry, potentiometry, viscometry, turbidimetry, IR and NMR spectroscopy, and X-ray diffractometry. Chitosan aspartate is a water-soluble hydrated polymorph exhibiting properties of a cationic polyelectrolyte with an effective macromolecular coil radius 60-75 nm. The specific conductivity, dielectric constant, viscosity and pH of the chitosan - L-aspartic acid - water system change over time after preparation due to counterion-polycation association to form ion pairs, multiplet structures, and their subsequent aggregation. As a result, nanoparticles (40-90 nm) are formed after ~24 h, microparticles (0.6-1.4 μm) are after ~48 h, and precipitation occurs after 72-96 h. The precipitated phase is a water-insoluble chitosan salt with a developed system of H-bonds and high crystallinity degree. Chitosan nanoparticles have high biocompatibility and the ability to accelerate the proliferative activity of epithelial cells. HYPOTHESIS: Ion pairs and multiplets are formed in the chitosan - L-aspartic acid - water system due to counterion association, which leads to phase segregation of the polymer substance at the level of nanoparticles and microparticles.

Effect of Molecular Weight and Nanoarchitecture of Chitosan and Polycaprolactone Electrospun Membranes on Physicochemical and Hemocompatible Properties for Possible Wound Dressing

Tissue engineering has focused on the development of biomaterials that emulate the native extracellular matrix. Therefore, the purpose of this research was oriented to the development of nanofibrillar bilayer membranes composed of polycaprolactone with low and medium molecular weight chitosan, evaluating their physicochemical and biological properties. Two-bilayer membranes were developed by an electrospinning technique considering the effect of chitosan molecular weight and parameter changes in the technique. Subsequently, the membranes were evaluated by scanning electron microscopy, Fourier transform spectroscopy, stress tests, permeability, contact angle, hemolysis evaluation, and an MTT test. From the results, it was found that changes in the electrospinning parameters and the molecular weight of chitosan influence the formation, fiber orientation, and nanoarchitecture of the membranes. Likewise, it was evidenced that a higher molecular weight of chitosan in the bilayer membranes increases the stiffness and favors polar anchor points. This increased Young's modulus, wettability, and permeability, which, in turn, influenced the reduction in the percentage of cell viability and hemolysis. It is concluded that the development of biomimetic bilayer nanofibrillar membranes modulate the physicochemical properties and improve the hemolytic behavior so they can be used as a hemocompatible biomaterial.

Effect of Chitosan Coating Incorporated with Artemisia fragrans Essential Oil on Fresh Chicken Meat during Refrigerated Storage

The present study was conducted to assess the impact of chitosan coating (1%) containing Artemisia fragrans essential oil (500, 1000, and 1500 ppm) as antioxidant and antimicrobial agent on the quality properties and shelf life of chicken fillets during refrigerated storage. After packaging meat samples, physicochemical, microbiological, and organoleptic attributes were evaluated at 0, 3, 6, 9, and 12 days at 4 °C. The results revealed that applied chitosan (CH) coating in combination with Artemisia fragrans essential oils (AFEOs) had no significant (p < 0.05) effects on proximate composition among treatments. The results showed that the incorporation of AFEOs into CH coating significantly reduced (p < 0.05) pH, thiobarbituric acid reactive substances (TBARS), and total volatile base nitrogen (TVB-N), especially for 1% CH coating + 1500 ppm AFEOs, with values at the end of storage of 5.58, 1.61, and 2.53, respectively. The coated samples also displayed higher phenolic compounds than those obtained by uncoated samples. Coated chicken meat had, significantly (p < 0.05), the highest inhibitory effects against microbial growth. The counts of TVC (total viable counts), coliforms, molds, and yeasts were significantly lower (p < 0.05) in 1% CH coating + 1500 ppm AFEOs fillets (5.32, 3.87, and 4.27 Log CFU/g, respectively) at day 12. Organoleptic attributes of coated samples also showed the highest overall acceptability scores than uncoated ones. Therefore, the incorporation of AFEOs into CH coating could be effectively used for improving stability and shelf life of chicken fillets during refrigerated storage.