Extraction of specific egg yolk antibodies and application in chitosan coating: effect on microbial and sensory properties of rainbow trout fillet during chilled storage

Polypropylene/Poly(butylene adipate-co-terephthalate) Breathing Film for Inhibiting Pseudomonas and Maintaining Microbial Communities and Postharvest Quality of Allium mongolicum Regel during Storage

Allium mongolicum Regel (A. mongolicum) is a healthy edible plant but highly perishable with a short shelf life of 1-2 d. Modified atmosphere packaging (MAP) could inhibit the postharvest senescence and decay of the vegetables. Thus, the aim of this study was to apply MAP with different gas permeabilities to the storage of A. mongolicum and evaluate its effects on maintaining microbial communities and the postharvest quality of A. mongolicum. The results showed that polypropylene/poly(butylene adipate-co-terephthalate) (PP/PBAT, abbreviated as PAT) MAP was suitable for the storage of A. mongolicum by establishing an optimal atmosphere of 0.5-0.6% O2 and 6.2-7.1% CO2 in the bag. It could delay the postharvest senescence of A. mongolicum and maintain its quality by slowing down its respiration rate and weight loss, reducing cell membrane permeability and lipid peroxidation, maintaining the cell wall, and reducing infection and the growth of microorganisms. However, A. mongolicum in HPT was more perishable than that in PAT during storage. Pseudomonas was found to be the main spoilage bacteria, and they could also be effectively inhibited by PAT-MAP. The next-generation sequencing results also showed the growth of Escherichia-Shigella, Clostridium sensu stricto 1, Streptococcus, Aureobasidium, Didymella, and Fusarium, responsible for A. mongolicum decay or human disease, was well inhibited by PAT-MAP. The results suggested that PAT-MAP could be used to maintain microbial diversity and the postharvest quality of A. mongolicum under cold storage conditions. It provided a feasible solution for the preservation, food quality, and safety control of A. mongolicum.

Edible packaging systems for enhancing the sensory quality of animal-derived foods

Maintaining the sensory quality of animal-derived foods from paddock to plate is a big challenge due to their fatty acid profile and susceptibility to oxidative changes and microbial spoilage. Preventive measures are taken by manufacturers and retailers to offset the adverse effects of storage to present animal foods to consumers with their best sensory attributes. The use of edible packaging systems is one of the emerging strategies that has recently attracted the attention of researchers and food processors. However, a review that specifically covers the edible packaging systems focused on improving the sensory quality of animal-derived foods is missing in the literature. Therefore, the objective of this review is to discuss in detail various edible packaging systems currently available and their mechanisms for enhancing the sensory properties of animal-derived foods. The review includes the findings of recent papers published during the last 5 years and summarises the novel materials and bioactive agents.

The Quality Analysis and Deterioration Mechanism of Liquid Egg White during Storage

The quality of liquid egg white (LEW) during storage is critical for the development of the egg industry. In order to effectively control its storage quality, the effects of packaging materials and storage conditions on the quality of LEW were investigated. High-throughput sequencing (HTS) was applied to explore changes in bacterial population proportions and microflora in the spoilage of LEW. The shelf life of LEW packaged with glass (LEW-PG), plastic (LEW-PP), and tinplate (LEW-PT) was preliminarily determined to be 8, 5, and 7 days, respectively. LEW-PG possessed superior sensory scores (65) and L values (87.5), and a lower growth rate of total volatile basic nitrogen (TVB-N) content among the three samples on the last day of shelf life, and was chosen for further study. During 24 days of storage, the sensory scores of the LEW-PG in 10 °C and 4 °C groups decreased by 32.7% and 25.7%, respectively. There was no significant difference in foaming properties of LEW-PG between the 10 °C and 4 °C groups (p > 0.05). HTS analysis showed that the abundance of species composition in the 10 °C samples was higher than that in the 4 °C samples, though the latter possessed a higher community diversity. At the genus level, the dominant bacteria in the 10 °C group were Pseudomonas (21.79%), others (19.21%), and Escherichia (11.21%), while others (37.5%), Escherichia (30.40%), and Bifidobacterium (17.72%) were highly abundant in the 4 °C samples. It is hoped that this study could provide theoretical support for quality control of LEW during storage.

Protective effect of chitosan-loaded nanoemulsion containing Zataria multiflora Boiss and Bunium persicum Boiss essential oils as coating on lipid and protein oxidation in chill stored turkey breast fillets

The present study was conducted to evaluate the lipid and protein oxidation responses of cold stored turkey meat using chitosan-contained nanoemulsions supplemented with the essential oils of two aromatic plants including Zataria multiflora Boiss and Bunium persicum Boiss. Chemical traits such as total volatile basic nitrogen (TVB-N), peroxide value (PV), thiobarbituric reactive substances (TBARs), free fatty acids (FFA), fatty acid composition and TC (total carbonyl) of samples were carried out at 4°C. Moreover, their pH and sensory properties were also determined at the same conditions. The initial value of the TVB-N (2.24 mg N/100 g) reached 20.81 mg N/100 g. TVB-N values achieved for all meat samples were lower than the highest acceptable limit (28-29 mg N/100 g). In all the treatments, PV and TBARs values were increased until day 10, and afterward a decrease was observed until day 20 of storage. TBARs values of the samples (mg MDA/kg) ranged from 1.97 ± 0.04 to 4.48 ± 0.39 in CNE + ZEO 1% to 2.72 ± 0.32 to 6.66 ± 0.21 in CON at zero time and day 5, respectively. FFA and TC were enhanced at a slower rate in the treated samples. The most efficient treatment against chemical deterioration was found to be CNE + ZEO 1%. Chitosan and sonicated chitosan treatments had the highest color score and lowest odor score at zero time. The obtained results suggested coating turkey meat fillets with ZEO and BEO as an effective strategy to delay at their chemical deterioration. PRACTICAL APPLICATION: The spoilage risk of fresh products is higher than other foods. Turkey meat spoils because of biological reactions such as the oxidation of lipids and protein, the action of endogenous enzymes, and the metabolic activities of microorganisms that end in a short shelf life. The oxidation of lipids not only reduces or retards, but also inhibits by edible coatings. Edible coatings formed from bioactive compounds would effectively provide possibility of active compounds onto surface of minimally processed foods. Therefore, application chitosan-loaded nanoemulsion coating containing Zataria multiflora Boiss and Bunium persicum Boiss essential oils is recommended in food industry especially for poultry industry to increase the chemistry and sensory quality of turkey breast fillets.

Chitosan-loaded nanoemulsion containing Zataria Multiflora Boiss and Bunium persicum Boiss essential oils as edible coatings: Its impact on microbial quality of turkey meat and fate of inoculated pathogens

This study was targeted to investigate the effect of chitosan-loaded nanoemulsion enriched with two types of essential oils on the microbial quality of turkey meat. To this end, the effects of essential oils of Zataria Multiflora Boiss (ZEO) and Bunium persicum Boiss (BEO) were evaluated at two concentrations (0.5% and 1% (w/v)) during 18 days of storage at 4 °C. Initially, in vitro evaluations were performed on the prepared nanoemulsions, namely essential oil nanoemulsions and chitosan-loaded nanoemulsions containing essential oils, using micro-dilution method and agar diffusion methods, respectively. Meat samples were analyzed for microbial indicators and inoculated salmonella Enteritidis, and Listeria monocytogenes during 3-day intervals. The highest reduction rate of total viable bacteria (2.06 log CFU/g), total psychrophilic (2.59 log CFU/g), Pseudomonas spp. (2.07 log CFU/g), Enterobacteriaceae (2.51 log CFU/g), lactic acid bacteria (2.51 log CFU/g), and yeast and mold count (2.10 log CFU/g) were observed in chitosan-loaded nanoemulsion containing ZEO 1%, in comparison with control samples. Moreover, the shelf life significantly increased due to the application of chitosan-loaded nanoemulsions (15-18 days), compared to that of the control group (6 days). Therefore, the edible chitosan-based nanoemulsion could play an effective role in the preservation of the microbial qualities of turkey meat.

Preparation, physicochemical and preservation properties of Ti/ZnO/in situ SiOx chitosan composite coatings

BACKGROUND

Among nanomaterials, Ti and ZnO nanoparticles are often chosen as preservation materials because of their antibacterial properties. Chitosan, as a natural biopolymer, has potential because of its abundance, compatibility and antibacterial properties. To improve the physicochemical and preservation properties of in situ SiOx chitosan (CS) composite coating, Ti/ZnO/SiOx CS composite coatings were prepared with Ti-doped ZnO (Ti/ZnO) nanorods and nanoballs. The composite coating structures were characterized by Fourier transform infrared, X-ray diffraction and scanning electron microscopy, and their physicochemical and preservation properties were determined simultaneously.

RESULTS

The results show that the Ti/ZnO nanoparticles are beneficial to homogeneous dispersion of in situ synthesized nano SiOx in the CS coating, and that Ti/ZnO nanoballs have better dispersion than Ti/ZnO nanorods. Moreover, strong hydrogen bonds are formed among Ti/ZnO nanoparticles and in situ synthesized nano SiOx and CS molecules, and the primary structure of CS is disorganized. Thereby, the gas permeabilities and mechanical properties of the CS coatings are improved due to modification of Ti/ZnO nanoparticles, and the Ti/ZnO nanoballs/SiOx CS composite coating is optimal. The preservation properties of the CS coatings on Sciaenops ocellatus are significantly improved, and those of Ti/ZnO/in situ SiOx CS composite coatings are superior.

CONCLUSION

The preservation properties of the CS composite coatings on S. ocellatus are significant, and the Ti/ZnO nanoballs/SiOx CS composite coating is even better. Therefore, the co-modification method of in situ nanoparticles and antibacterial nanoparticles may be a promising method to improve the preservation properties of CS coatings. © 2019 Society of Chemical Industry.

Rainbow trout fillet biopreservation by edible chitosan-based coating containing egg yolk antibody (IgY) and lycopene

The aim of the study was to investigate the effect of the extracted egg yolk antibody along with lycopene on the chemical quality of the rainbow trout fillet during 16 days of refrigeration storage. Chickens were immunized against Pseudomonas fluorescens (P. fluorescens), Shewanella putrefaciens (S. putrefaciens) and total spoilage bacteria and their eggs were collected for the isolation of egg yolk antibodies. Then fish fillets were immersed in chitosan-based coating solutions, containing lycopene and extracted antibodies, and analyzed for lipid oxidation changes (peroxide, thiobarbituric acid, free fatty acid and fatty acid profile), physico-chemical properties (pH and water holding capacity), and sensory evaluation, during 16 days of refrigeration storage. Results showed that chitosan solutions with lycopene or IgY could significantly (p < 0.05) increase the oxidative stability of lipids in fish fillets; although, combinational use of lycopene and IgY showed a higher effect on delaying the rate of lipid oxidation. Significant differences were also observed between treatments contained combination of chitosan, antibody and lycopene with the control group, regarding pH and WHC. Saturated fatty acids increased in all treatments, although the changes in the treatments containing lycopene and antibody were significantly (p < 0.05) lower than the control group. Hence the addition of egg yolk antibody and lycopene in coating solution are good bio-preservatives for seafood products as it improves sensory attributes and prevents lipid oxidation.