The synergistic effect of dielectric barrier discharge plasma and phycocyanin on shelf life of Oncorhynchus mykiss rainbow fillets.

This study aimed to evaluate the efficacy of dielectric barrier discharge treatment (DBD) combined with phycocyanin pigment (PC) in extending the shelf life of Oncorhynchus mykiss rainbow fillets stored at 4 ± 0.1 °C. Microbiological, physicochemical, sensory and antioxidant properties were assessed over an 18-day storage period. The combined DBD and PC treatment significantly inhibited total viable counts and Psychrotrophic bacteria counts compared to the rest of the samples throughout storage. While Total Volatile Nitrogen concentrations remained below international standard until day 18, they exceeded this threshold in control sample by day 9. DBD treatment notably reduced Trimethylamine levels compared to controls (p < 0.05). PC and DBD combined inhibited DPPH and ABTS radical scavenging capacities by 80% and 85%, respectively, while demonstrating heightened iron-reducing antioxidant activity compared to controls. Analysis of 24 fatty acids indicated that PC mitigated DBD's adverse effects, yielding superior outcomes compared to controls. The ratio of n-3 to n-6 fatty acids in all samples met or fell below international standard. Thus, the combined use of DBD and PC shows promise in extending fillet shelf life by over 15 days at 4 °C.

Effect of ultrasound technique to improve quality of Iranian industrial honey by controlling crystallization process.

This experiment aimed to assess the effects of ultrasound techniques on the quality of Iranian industrial honey. Honey samples were subjected to ultrasound waves at different frequencies and various parameters. The results showed that both ultrasound treatments (30 or 42 kHz) changed the physical, biochemical, antioxidant, and antibacterial characteristics of honey. Ultrasound treatments at 20 or 45°C for 1, 5, or 10 min reduced moisture, acidity, sugars, ABTS levels, 5-hydroxymethylfurfural content, clostridium, aerobic mesophilic bacteria count, and osmophile count while increasing diastase, phenol, and proline levels. Ultrasound treatment of honey samples at 30 and 42 kHz and different temperatures for varying durations led to a decrease in acidity after 90 and 180 days. Treating honey samples with 42 kHz ultrasound at 45°C for 10 min led to a significant reduction in the amount of reducing sugar. Ultrasonication at different frequencies and temperatures led to higher levels of phenol, ABTS, and proline production, along with a considerable decrease in the total count of aerobic mesophilic bacteria. Our study unveils the potential of ultrasonication to enhance honey quality through multifaceted improvements. Treatment significantly augmented phenolic content and antioxidant capacity, opening avenues for novel honey preservation and quality enhancement strategies. Additionally, ultrasonication effectively controlled honey crystallization while simultaneously improving biochemical, antioxidant, and antibacterial properties. This demonstrates its potential as a comprehensive strategy for honey quality improvement.

Studying the impact of phycoerythrin on antioxidant and antimicrobial activity of the fresh rainbow trout fillets.

Marine cyanobacteria present a significant potential source of new bioactive compounds with vast structural diversity and relevant antimicrobial and antioxidant activities. Phycobiliproteins (PBPs) like phycocyanin (PC), phycoerythrin (PE), and water-soluble cyanobacterial photosynthetic pigments, have exhibited strong pharmacological activities and been used as natural food additives. In this study, phycoerythrin (PE) isolated from a marine strain of cyanobacterium Nostoc sp. Ft salt, was applied for the first time as a natural antimicrobial as well as an antioxidant to increase the shelf life of fresh rainbow trout i.e., (Oncorhynchus mykiss) fillets. Fresh trout fillets were marinated in analytical grade PE (3.9 µg/mL) prepared in citric acid (4 mg/mL), and stored at 4 °C and 8 °C for 21 days. Microbiological analysis, antioxidant activity and organoleptic evaluation of both control and treated fish fillets were then statistically compared. The results demonstrated noticeable (P < 0.05) differences in the microbial counts, antioxidant activity, and organoleptic characteristic values between PE-treated and non-treated groups. In addition, we observed that treating fresh fish fillets with a PE solution leads to a significant increase in shelf life by at least 14 days. Consequently, PE could be an alternative to synthetic chemical additives since it does not contain the potentially dangerous residues of the synthetic chemical additives and is thus healthier to the consumers.

Isolation, Identification, and Characterization of the Native Yeast Strains from Homemade Cheese to Assess their Eliminating Impact on the Aflatoxin B1 and M1 of the Simulated Gastrointestinal Fluid.

Background: The occurrence of aflatoxins in food products is a silent threat to human health worldwide. A range of strategies has been introduced to address the bioavailability of aflatoxins, which are considered microbial tools to provide a low-cost and promising approach. Objectives: The present study focused on the separation of yeast strains from the homemade cheese rind layer to investigate the ability of native yeasts to eliminate AB1 and AM1 from simulated gastrointestinal fluids. Material and Methods: Homemade cheese samples were prepared from different locations in Tehran provinces and yeast strains were isolated and identified through the biochemical methods and molecular analysis of internal transcribed spacer and D1/D2 domain of 26S rDNA regions. Isolated strains were screened using simulated gastrointestinal fluids, and the ability of yeast strains to absorb aflatoxin was evaluated. Results: Out of 13 strains, 7 yeast strains were not affected by 5 ppm AFM1 while 11 strains did not show any significant response to 5 mg.L-1 (ppm) of AFB1. On the other hand, 5 strains were able to successfully tolerate 20 ppm AFB1. Candidate yeasts showed different abilities to remove aflatoxins B1 and M1. In addition, C. lusitaniae, G. geotrichum, G. candidum, and C. sanyaensis exhibited a significant ability to detoxify aflatoxins from the gastrointestinal fluid, respectively. Conclusion: Our data suggest that yeast communities with essential effects on the quality of homemade cheese appear to be precise candidates for the potential elimination of aflatoxins from the gastrointestinal fluid.

Bio-nanocomposites as food packaging materials; the main production techniques and analytical parameters.

Today, the development of multifunctional and versatile packaging materials based on green ingredients has received a lot of attention from researchers and consumers due to their biodegradability, biocompatibility, sustainability, and renewable nature of biomaterials. These emerging packaging materials in addition to increasing the shelf life of food products (active packaging), informs the consumer about the freshness and spoilage of the product in real-time (smart packaging). The limitations reported for biopolymers-based packaging, such as hydrophilicity and poor mechanical resistance, can be modified and improved by combining biopolymers with various materials including nanomaterials, cross-linkers, bioactive compounds, and other polymers. Consequently, the use of innovative, high performance, and green bio-nanocomposites reveal a promising opportunity to replace conventional non-biodegradable petroleum-based plastics. Likewise, interest in making polymeric bio-nanocomposites for active and smart packaging purposes has been increased in response to a global request for more effective and safe food packaging systems. There are various factors affecting the quality of bio-nanocomposites, such as biomaterials type, additives like nanoparticles, foods type, storage conditions, and the approaches for their preparation. In this review paper, we aimed to discuss the main challenges of the techniques commonly employed to prepare polymeric bio-nanocomposites, including casting, melt mixing (extrusion), electrospinning, and polymerization techniques. The casting has captured scientists' interest more than other techniques, due to the easy handling. The extrusion methods showed a more industrial approach than other techniques in this field. The electrospinning process has attracted a lot of interest due to the production of fibrous membranes, able to encapsulate and stabilize bioactive molecules. The polymerization technique shows less interest amongst scientists due to its complicated conditions, its reaction-based process and the use of toxic and not green reactants and solvents. In conclusion, all techniques should be optimized based on relevant specific parameters to obtain bio-nanocomposites with notable mechanical behaviors, barrier and permeability properties, contact angle/wettability, uniform structures, low cost of production, environmental-friendly nature, migration and penetration, and biodegradability features.

Influence of chitosan nanoparticles and fennel essential oils (Foeniculum vulgare) on the shelf life of Huso huso fish fillets during the storage.

Fish and fishery products are important parts of the human diet, but the microbial, chemical, and physical deteriorations limit their shelf life. Using the modified atmospheric packaging system and edible coatings is one of the main procedures to improve the shelf life of fish. In this research, the effect of chitosan nanoparticles (CNPs) loaded with fennel essential oils along with modified atmosphere packaging (MAP) system on chemical, microbial, and sensorial properties of Huso huso fish fillets during storage at fridge were evaluated. The results showed that coating fish fillets with CNPs and fennel EO significantly reduced the peroxide value, total volatile nitrogen, and thiobarbituric acid value compared with the control samples. Microbial analyses showed a lower number of mesophilic, psychotropic, pseudomonas, and lactic acid bacteria in coated fillets compared with control and MAP packaging. Fish fillets coated with CNPs and EO showed high acceptability in all sensorial attribute through the storage. It can be concluded that using CNPs and fennel EO along with MAP packaging can enhance the shelf life for H. huso fillets up to 18 days in the fridge.