Evaluating shelf life and anti-browning of shrimp by chitosan-coated nanoliposome loaded with licorice root extract.

Chitosan coating containing nanoliposomes loaded with licorice root extract was prepared to investigate shrimp's shelf life and anti-browning function during 20 days of ice storage. 1% licorice root hydroethanolic extract (LHE) was encapsulated in nanoliposomes or coated with chitosan, and then the shrimp were immersed in coating solutions. LHE treatment had the lowest browning indices (5 and 1.02), TBA (0.32 mg MDA/kg), and FFA (0.01%). Chitosan-coated LHE treatment (Ch-LHE) showed the best performance for TVN, microbial counts, and discoloration. PV, WHC, and cook loss in the treatment with LHE nanoliposome coated with chitosan (Ch-N-LHE) were measured at acceptable levels of 0.53 meq/kg, 86.12%, and 15.06%, respectively. Experiments showed that pure or encapsulated LHE is an effective method for increasing the quality and preventing the browning of shrimp. Additionally, due to its cost-effectiveness and health benefits, it can be an effective natural substitute for sodium metabisulfite at the global export level.

Controlled Hypothermic Storage for Lung Preservation: Leaving the Ice Age Behind.

Controlled hypothermic storage (CHS) is a recent advance in lung transplantation (LTx) allowing preservation at temperatures higher than those achieved with traditional ice storage. The mechanisms explaining the benefits of CHS compared to conventional static ice storage (SIS) remain unclear and clinical data on safety and feasibility of lung CHS are limited. Therefore, we aimed to provide a focus review on animal experiments, molecular mechanisms, CHS devices, current clinical experience, and potential future benefits of CHS. Rabbit, canine and porcine experiments showed superior lung physiology after prolonged storage at 10°C vs. ≤4°C. In recent molecular analyses of lung CHS, better protection of mitochondrial health and higher levels of antioxidative metabolites were observed. The acquired insights into the underlying mechanisms and development of CHS devices allowed clinical application and research using CHS for lung preservation. The initial findings are promising; however, further data collection and analysis are required to draw more robust conclusions. Extended lung preservation with CHS may provide benefits to both recipients and healthcare personnel. Reduced time pressure between procurement and transplantation introduces flexibility allowing better decision-making and overnight bridging by delaying transplantation to daytime without compromising outcome.

Utilization of Carbon-Based Nanomaterials and Plate-Fin Networks in a Cold PCM Container with Application in Air Conditioning of Buildings.

Cold energy storage devices are widely used for coping with the mismatch between thermal energy production and demand. These devices can store cold thermal energy and return it when required. Besides the countless advantages of these devices, their freezing rate is sluggish, therefore researchers are continuously searching for techniques to improve their operating speed. This paper tries to address this problem by simultaneously combining a network of plate fins and various types of carbon-based nanomaterials (NMs) in a series of complex computational fluid dynamics (CFD) simulations that are validated by published experimental results. Horizontal, vertical, and the combination of these two plate-fin arrangements are tested and compared to the base model. Subsequently, several carbon-based NMs, including SWCNT, MWCNT, and graphene-oxide NMs are utilized to further improve the process. The influence of these fin networks, nanoparticle types, and their volume- and mass-based concentrations within the PCM container are studied and discussed. According to the results, carbon-based NMs exhibit superior performance compared to metal-oxide NMs, so that at identical NM volume and mass fractions, MWCNT particles present a 2.77% and 17.72% faster freezing rate than the CuO particles. The combination of plate-fin network and MWCNT particles is a promising technique that can expedite the ice formation rate by up to 70.14%.

Compound Heat Transfer Augmentation of a Shell-and-Coil Ice Storage Unit with Metal-Oxide Nano Additives and Connecting Plates.

Due to the high enthalpy of fusion in water, ice storage systems are known as one of the best cold thermal energy storage systems. The phase change material used in these systems is water, thus it is inexpensive, accessible, and completely eco-friendly. However, despite the numerous advantages of these systems, the phase change process in them is time-consuming and this leads to difficulties in their practical application. To solve this problem, the addition of nanomaterials can be helpful. This study aims to investigate the compound heat transfer enhancement of a cylindrical-shaped unit equipped with double helically coiled coolant tubes using connecting plates and nano additives as heat transfer augmentation methods. Complex three-dimensional numerical simulations are carried out here to assess the best heat exchanger material as well as the impact of various nanoparticle types, including alumina, copper oxide, and titania, and their concentrations in the PCM side of the ice storage unit. The influence of these parameters is discussed on the charging rate and the temperature evolution factor in these systems. The results suggest that using nano additives, as well as the connecting plates, together is a promising way to enhance the solidification rate by up to 29.9%.

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.

Vibrational spectroscopy and biochemical changes in silver carp as related to quality of washed mince.

BACKGROUND: Biochemical and protein conformational changes in silver carp occurred during ice storage, affecting the physico-chemical and textural properties of its washed mince. Fourier-transform infrared spectroscopy (FTIR) and FT Raman could offer insightful molecular-level information that could be related to the freshness of fish and textural properties of washed mince. RESULTS: The K value increased from 15.8% to 85.0% after 14 days on ice. The surface hydrophobicity of silver carp muscle proteins increased during ice storage, and its thrice-washed mince showed the same trend. The yield and textural properties of washed mince continually decreased as the storage time was extended. Fourier-transform infrared spectroscopy revealed that, as storage time increased, the α-helix content of mince decreased, while the ß sheet content increased. Prolonged ice storage led to the exposure of buried aromatic amino acid residues and an increase in disulfide interchanges in mince and washed mince. Changes in the ∑ß sheet structure and Raman intensity at 828 cm-1 observed in mince correlated well with the K value. The α-helix content and Raman intensity of raw washed mince at 621 and 828 cm-1 showed a strong correlation with its textural properties. CONCLUSION: Silver carp should be processed to surimi within 7 days of ice storage to obtain a reasonably good yield and gel texture. Infrared and Raman spectroscopy can possibly be utilized to monitor freshness quality and protein conformational changes in silver carp and to estimate the textural properties of washed mince as affected by freshness. © 2019 Society of Chemical Industry.

Nanoencapsulated essential oils embedded in ice improve the quality and shelf life of fresh whole seabream stored on ice.

Ice containing essential oils (EOs) nanoencapsulated in ß-cyclodextrins (ß-CD) (named as EOs+ß-CD ice) was used for stunning/slaughtering by hypothermia in ice slurry, and for ice storage of gilthead seabream. Clove essential oil (CEO) was used at fish stunning/slaughtering, while ice storage of whole fish was performed using a combination of carvacrol, bergamot and grapefruit EOs (CBG). Inclusion complexes CBG+ß-CD were characterized, and antimicrobial effect was also evaluated. The kneading method used to form inclusion complexes with CBG showed a good complexation efficiency. Microbial, physical-chemical and sensory analyses were carried out to assess the quality changes of fresh whole seabream during ice storage at 2 °C for 17 days. Results (microbial, chemical and sensorial) indicated that seabream stunning/slaughtering and storage using EOs+ß-CD ice (in low doses of 15 mg/kg ice for stunning, and 50 mg/kg ice for ice storage) improved the quality of fresh fish and extended the shelf-life up to 4 days.

Effect of ε-polylysine and ice storage on microbiota composition and quality of Pacific white shrimp (Litopenaeus vannamei) stored at 0 °C.

This study evaluated the effects of ε-Polylysine and ice storage on microbiota composition and quality attributes of Pacific white shrimp stored at 0 °C. The sensorial shelf-life of control, 0.1% ε-Polylysine treated group, and ice stored group were 5, 8, and 7 days, respectively. Microbiota composition was explored by the Illumina-MiSeq high throughput sequencing targeting of 16S rRNA genes. At the time of sensory rejection, Pseudoalteromonas, followed by Candidatus Bacilloplama and Psychromonas, were the dominant microbiota in spoiled control samples on day 5. However, 0.1% ε-Polylysine inhibited the growth of Pseudoalteromonas and Psychromonas. Consequently, Candidatus Bacilloplama followed by Aliivibrio became the dominant microbiota in the ε-Polylysine treated group on day 8. Meanwhile, Aliivibrio, followed by Moritella and Pseudoalteromonas were the dominant microbiota in ice stored samples on day 7. Furthermore, due to the modulating effect of ε-Polylysine and ice storage on microbiota, chemical changes of the treated groups were slower, which was reflected as lower concentrations of total volatile basic nitrogen, putrescine, cadaverine, and hypoxanthine, and higher contents of inosine 5'-monophosphate and hypoxanthine riboside at the end of storage. In conclusion, ε-Polylysine and ice storage altered the microbiota composition and delayed quality deterioration of Pacific white shrimp.

Effects of slightly acidic electrolyzed water ice and grapefruit seed extract ice on shelf life of brown sole (Pleuronectes herzensteini).

The effects of slightly acidic electrolyzed water ice (SAEW-ice) and grapefruit seed extract ice (GSE-ice) on changes in brown sole quality during storage were determined using microbial, chemical, and sensory analyses to prolong the shelf life of brown sole. Microbiological analyses showed that GSE-ice storage was more effective for inhibiting the growth of total plate count, Pseudomonas, and H2S-producing bacteria than SAEW-ice storage. Chemical indexes of brown sole showed that SAEW-ice and GSE-ice storage extended the shelf life of fish compared with TW-ice. Sensory scores following GSE-ice storage were higher than those following storage under the other conditions. Taken together, the present study indicated that the quality of brown sole was maintained for 9-10 days in TW-ice, and 11-12 days in SAEW-ice and 12-13 days in GSE-ice. Therefore, ice storage using SAEW-ice and GSE-ice effectively extended the shelf life of brown sole.

Antioxidant and antimicrobial properties of grape and papaya seed extracts and their application on the preservation of Indian mackerel (Rastrelliger kanagurta) during ice storage.

Antioxidant properties of grape (GSE) and papaya seed extracts (PSE) were tested in vitro at varied concentrations and growth inhibition were seen against gram positive and gram negative bacteria by disc diffusion method. The results revealed that GSE contain four times higher phenolic and six folds higher flavonoid content than PSE. The antioxidant properties of GSE and PSE showed dose dependent activities and were comparatively much higher in GSE. Linoleic acid model of GSE and PSE displayed 67.67 and 46.43 % of inhibition respectively at 500 mg/L. The effect of dip treatment by GSE and PSE at a concentration of 500 and 1000 mg/L respectively on the quality changes of Indian mackerel (Rastrelliger kanagurta) in iced condition were assessed using chemical, microbiological and sensory parameters along with chilled whole control (CWC). The inhibition of primary and secondary lipid oxidation products by GSE at 500 mg/L was comparable to BHT at 200 mg/L. GSE exhibited higher antimicrobial activity on gram-positive strains compared to PSE and reduced the formation of volatile bases significantly. On the day of sensory rejection for CWC, the formation of trimethylamine and total volatile base nitrogen were reduced by 32.27 and 31.85 % in GSE samples and 19.01 and 24.70 % in PSE samples respectively. The dip treatment of GSE increased the shelflife of mackerel up to 15 days, PSE by 12 and 9 days for CWC during ice storage. Therefore, it can be concluded that, GSE can be used as a promising natural preservative and a substitute to the synthetic counterparts.

Differential role of endogenous cathepsin and microorganism in texture softening of ice-stored grass carp (Ctenopharyngodon idella) fillets.

BACKGROUND: Texture deterioration often negatively affects sensory attributes and commercial values of ice-stored fish fillets. The mechanism of softening of fish fillets during chilling storage is not fully resolved. Grass carp is a predominant freshwater fish species in China. The objective of the present study was to investigate the differential role of endogenous cathepsin and microorganisms in texture softening of ice-stored grass carp fillets. RESULTS: The fillets were immersed in either NaN3 solution to reduce microbial activity or in iodoacetic acid solution to exclude cathepsin activity before ice storage. Treatment with NaN3 reduced microbial load of fillets below 2 log CFU g(-1) muscle during the entire storage period, and had no significant influence on the cathepsin activity and proteolysis. But the shear force of fillets treated with NaN3 decreased by 66% after 21 days of storage. Meanwhile, treatment with iodoacetic acid inactivated cathepsin B and B + L but did not significantly affect the microbial growth of fillets. Compared to NaN3 treatment, iodoacetic acid effectively alleviated softening and inhibited the increase in TCA-soluble peptides during storage. CONCLUSION: This study demonstrated that proteolysis induced by endogenous cathepsins, rather than microorganisms, plays an important role in texture softening of ice-stored grass carp fillets. © 2015 Society of Chemical Industry.

Citrus peel extract incorporated ice cubes to protect the quality of common pandora: Fish storage in ice with citrus.

The objective of this study was to investigate the effects of ice with albedo and flavedo fragments of Citrus (Grapefruit (Citrus paradisi) and Bitter orange (Citrus aurantium L.)) extracts on the quality of common pandora (Pagellus erythrinus). Concentrated citrus extracts were diluted with distilled water (1/100 w/v) before making of ice. The ice cubes were spread on each layer of fishes and stored at 0 °C for 15 days. The pH value showed a regular increase in all samples. TVB-N levels of bitter orange treatment groups were recorded lower than the other groups reaching to 25.11 ± 0.02 mg/100 g at the end of the storage. The TMA-N values of bitter orange treatment groups were lower than that of control and grapefruit treatment groups. In terms of TBARS value, alteration was observed in the control samples and this value significantly (p < 0.01) increased from 0.101 ± 0.011 mg MA/kg to 0.495 ± 0.083 mg MA/kg, while remained lower in the citrus extracts treatment groups at the end of storage since their antioxidant capacity. The oxidation was suppressed in citrus extracts treatment groups, especially in bitter orange flavedo treatment. The results showed the bitter orange albedo and bitter orange flavedo extracts in combination with ice storage have more effectiveness in controlling the biochemical indices in common pandora.

Biochemical, textural, microbiological and sensory attributes of gutted and ungutted sutchi catfish (Pangasianodon hypophthalmus) stored in ice.

Pangasianodon hypophthalmus (sutchi catfish) is a fresh water catfish extensively being cultured in the South East Asian countries in the recent years. The present study provides the first report on the effects of gutting on the quality characteristics of aquacultured sutchi catfish stored in ice. pH of whole ungutted and gutted catfish didn't show significant difference (p > 0.05) during ice storage period. Total Volatile Base Nitrogen (TVB-N), Alpha Amino Nitrogen (AAN), Free Fatty Acids (FFA) and Thio Barbituric Acid Reactive Substance (TBARS) were lower in gutted fish compared to whole ungutted fish at any particular day during ice storage. However, gutted fish expressed higher rate of primary lipid oxidation than ungutted fish. Textural degradation of the fish muscle as indicated by hardness, cohesiveness, springiness and chewiness was lower in gutted fish. Results of sensory evaluation revealed that gutting has significantly improved the sensory quality of the fish. However, microbiological analysis revealed higher Total Plate Count (TPC) and Enterobactereaceae count in gutted fish. The shelf life of gutted and whole ungutted sutchi cat fish as determined by microbiological analysis was 16-18 days and 18-20 days respectively while storage in ice.

Microbiological evolution of gilthead sea bream (Sparus aurata) in Canary Islands during ice storage.

This study analyses the microbiological changes with traditional methods for total mesophilic aerobic, psychrotrophic, Aeromonas sp., Pseudomonas sp., Shewanella putrefaciens, Enterobacteriaceae, sulfide-reducing Clostridium and Photobacterium phosphoreum in muscle, skin and gills of whole ungutted gilthead sea bream (Sparus aurata) stored in ice during 18 days. The muscle tissue showed the minor grade of contamination, followed by the skin and the gills, with statistic significance (p < 0.001). The most prominent microorganisms in the different tissues and at the end of the storage were Pseudomonas sp. (7.76, 10.11 and 10.40 log CFU/g), Aeromonas sp. (7.49, 8.24 and 9.02 log CFU/g) and S. putrefaciens (8.05, 7.49 and 8.05 log CFU/g) in sea bream harvested in the temperate water of the Canary Islands. The results obtained from this study can contribute to the improvement of microbiological knowledge of gilthead sea bream (Sparus aurata) by determining the evolution of microorganisms responsible for spoilage and their counts in different tissues such as muscle, skin, and gills during iced storage.

Effect of ice storage on the functional properties of proteins from a few species of fresh water fish (Indian major carps) with special emphasis on gel forming ability.

In the present study the effect of ice storage on physico-chemical and functional properties of proteins from Indian major carps with special emphasis on gel forming ability have been assessed for a period of 22 days. The solubility profile of proteins in high ionic strength buffer and calcium adenosine triphosphatase (ATPase) enzyme activity reduced significantly (p < 0.05), while that of total volatile base nitrogen (TVB-N) increased significantly (p < 0.05) at the end of 22 days of ice storage. The major protein fraction showed association-dissociation-denaturation phenomenon during ice storage as revealed by gel filtration profile and viscosity measurements. The gel forming ability of three fish species both in fresh and during different periods of ice storage was assessed by measuring the gel strength of heat induced gel. Among the three species the gel strength of the gel obtained from Catla catla and Cirrhinus mrigala was higher (586 and 561 g.cm) than the gel obtained from Labeo rohita (395 g.cm) in fresh condition. The gel forming ability of three species was significantly affected (p < 0.05) during ice storage. The TVB-N values of fish meat as a function of ice storage was within the prescribed limit up to 17 days of the ice storage.

Effect of ante-mortem hypoxia on the physicochemical and functional properties of white shrimp (Litopenaeus vannamei) muscle stored on ice.

The effect of ante-mortem hypoxia on the physicochemical and functional properties of raw and cooked white shrimp was studied. Hue angle was greater (p ≤ 0.05) for stressed raw shrimp compared to control (greener color); whereas a lower angle was detected for cooked stressed shrimp (redder/orange coloration). In addition, hue angle increased (p ≤ 0.05) over the ice storage period for control and stressed shrimp (raw and/or cooked). Muscle hardness and shear force showed no differences when comparing control and stressed shrimp (raw and/or cooked). However, during ice storage, shear force increased (p ≤ 0.05) by 22% and 9% for control and stressed raw shrimp, respectively; in contrast, shear force and muscle hardness decreased for cooked shrimp (p ≤ 0.05). Control showed more (p ≤ 0.05) elasticity than stressed cooked shrimp. Stressed raw shrimp showed a water holding capacity 10.8% lower (p ≤ 0.05) than control. However, during the storage, water holding capacity increased (p ≤ 0.05) reaching similar values to control after day 4. Muscle protein solubility of stressed shrimp was 31% lower than control; however, no differences (p > 0.05) were observed after the second day. The thermal stability of myosin (T max) showed differences (p ≤ 0.05) among control and stressed shrimp, whereas no differences for ΔH were observed. Results showed the influence of ante-mortem hypoxia on the physicochemical and functional properties of white shrimp muscle.