Effects of deodorization by powdered activated carbon, β-cyclodextrin and yeast on odor and functional properties of tiger puffer (Takifugu rubripes) skin gelatin

Structural characterization of glutaraldehyde crosslinked starch-based nanofibrous film and adsorption improvement for oyster peptide flavor

The inferior hydrophobicity and mechanical properties of starch-based nanofibrous films significantly restrict their practical application. In view of this, this study prepared octenylsuccinylated starch-pullulan nanofibrous films using electrospinning and glutaraldehyde (GTA) gas-phase crosslinking. After GTA crosslinking, the starch-based nanofibrous films remained white, randomly oriented, smooth, and droplet-free. As the crosslinking time increased from 0 h to 24 h, the mean fibrous diameter augmented from 157.34 nm to 238.66 nm, and the water contact angle rose from 24.30° to 52.49°. Meanwhile, their tensile strength and thermal stability grew, and the mean pore area and elongation at break abated with changes in function groups. The crosslinked starch-based nanofibrous films exhibited an enhanced adsorption capacity for alcohols, ethers, esters, hydrocarbons, and N-compounds of oyster peptides. Correlation analysis shows that the adsorption capacity of the starch-based nanofibrous films was positively correlated with mean fibrous diameter and water contact angle and negatively correlated with mean pore area. These results provide a theoretical basis for the practical application of crosslinked starch-based nanofibrous film materials in deodorization.

Hyaluronic acid-based multifunctional bio-active coating integrated with cinnamaldehyde/hydroxypropyl-β-cyclodextrin inclusion complex for fruit preservation

Natural preservatives such as cinnamaldehyde (CIN) are garnering increasing interest to replace their synthetic counterparts in maintaining fruit freshness and safety. However, their long-term effectiveness and widespread application have been greatly limited due to high volatility and potent aroma. To address these challenges, we developed a viable and simple strategy to prepare a multifunctional active coating for fruit preservation by incorporating host-guest inclusion complex of CIN and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) CIN@HP-β-CD into hyaluronic acid (HA), a natural polysaccharide with exceptional film-forming properties. The as-prepared HA/CIN@HP-β-CD coatings exhibited universal surface affinity, excellent antimicrobial performance, and satisfactory antioxidant properties with no potential toxicity. Release kinetic studies have demonstrated that CIN in the coating is continuously and slowly released. Furthermore, freshness preservation experiments on bananas and fresh-cut apples demonstrated that the developed coating is effective in preserving the color of fruit, decreasing the weight loss rate, preventing the microorganism's growth, and significantly extending the period of freshness, exhibiting the potential for application in fruit preservation.

Exploring the versatility of carbohydrates in surimi and surimi products: novel applications and future perspectives

Carbohydrate is one kind of the most important additives in the production of surimi and surimi products, mainly due to its wide range of sources and superior functionality. In recent years, new carbohydrates (oligosaccharides and polysaccharides) have been gradually applied in the production of surimi and surimi products which is mainly driven by consumer requirement on nutritional and the flavors or taste quality and producer requirement on extending the shelf life, like low calorie intake, dietary fiber enrichment, rich taste and improvement of antioxidant properties. Besides anti-freezing and improvement in gelling ability, novel functionalities have been explored such as fat substitution, improving flavor, antibacterial effect, antioxidant effect and improving three-dimensional printability. With an in-depth study of the mechanism of carbohydrate improving the qualities of surimi and surimi products, the application of carbohydrates in surimi would be more effective. Therefore, this review summarizes the new carbohydrates applied in the processing of surimi and surimi products, and their novel functionalities. Additionally, progress of the research on the mechanism of carbohydrate improving the qualities of surimi is also reviewed. © 2023 Society of Chemical Industry.

Effect of seasonal variation and farming systems on the properties of Nile tilapia gelatin extracted from scales

Although fish gelatin has become a research hotspot in recent years, researchers and manufacturers are still looking for high-quality sources of fish galatin to meet the commercial demand for safer gelatin.became This study aimed to evaluate the impact of seasonal variation and farming systems on the properties of gelatin extracted from Nile tilapia scales. Gelatin extracted from farmed tilapia had lowest impurities, higher clarity as well as desirable color characteristics (L* = 65.95 and a* = -0.33). The protein and fat composition of Wild (91.00 ± 0.00c) and 1.94 ± 0.05a respectively were higher than farmed gelatin of protein (91.00 ± 0.00c) and fat (0.84 ± 0.08b) but gelatin from the farmed type were clearer (98.30 ± 0.28a) than wild type (94.60 ± 0.28b). In addition, the XRD analysis confirmed its amorphous structure (2θ = 11°, 21°. 29°, and 31°). The gelatin extracted from wild tilapia showed an average yield of 1.98 % and good physicochemical and functional properties. Furthermore, FTIR indicated a strong bond positioned in the amide I region (1650.88 cm-1) of the wild tilapia gelatin. Partial Least Square (PLS) confirmed that viscosity is positively correlated with melting temperature upon a unit change in gelatin yield. This work highlights the significance of farming systems and seasonal variation in extraction conditions and great parameter to comprehensively navigate the functional, biochemical, and physical properties of Nile tilapia gelatin for broadening both food and non-food industrial appliactions.

Modified Structural and Functional Properties of Fish Gelatin by Glycosylation with Galacto-Oligosaccharides

This study aimed to investigate the effects of galacto-oligogalactose (GOS) glycosylation on the structural and functional properties of fish gelatin (FG). Results showed that with the increase of glycosylation time, grafting degree and browning increased, and new protein bands with increased molecular weight were observed by SDS-PAGE. Structural analysis showed that glycosylation reduced intrinsic fluorescence intensity and increased surface hydrophobicity of FG. FTIR analysis showed α-helix content decreased while random coil content increased in glycosylated FG. Emulsion activity index and emulsion stability index along with foam activity and foam stability were significantly elevated in GOS-4 and GOS-8, but FG glycosylated longer than 12 h exhibited less pronounced improvement. Glycosylated FG showed lower gel strength than control. The results indicate that moderate glycosylation could be applied to improve interfacial properties of FG.

Effects of ethanol pretreatment on osteogenic activity and off-flavors in blue mussel (Mytilus edulis L.) enzymatic hydrolysates

Aquatic protein hydrolysates have many biological activities, but the off-flavor seriously decreases their commercial acceptability. Therefore, it is important to invest in finding an effective deodorization of aquatic hydrolysates that do not affect activities. In this study, ethanol pretreatment of mussel was applied to establish a new method to deodorize the blue mussel (Mytilus edulis L.) hydrolysates. LC-MS and GC-MS analysis results showed that 87.34% of fatty acids, 83.94% of aldehydes, most volatile flavor compounds including aldehydes, ketones, alcohols, acids, and hydrocarbons were decreased after ethanol pretreatment. Besides, it was found that the enzymatic hydrolysates of mussel with or without ethanol pretreatment showed high osteogenic activity, which induced an increase of 33.65 ± 4.36% and 31.77 ± 5.45% in MC3T3-E1 cell growth. These results suggest that ethanol pretreatment has beneficial potential for improving the flavor aspects of blue mussel peptides which may have the potential to stimulate bone regeneration and formation.

Monitoring the Aroma Compound Profiles in the Microbial Fermentation of Seaweeds and Their Effects on Sensory Perception

Seaweeds have a variety of biological activities, and their aromatic characteristics could play an important role in consumer acceptance. Here, changes in aroma compounds were monitored during microbial fermentation, and those most likely to affect sensory perception were identified. Ulva sp. and Laminaria sp. were fermented and generally recognized as safe microorganisms, and the profile of volatile compounds in the fermented seaweeds was investigated using headspace solid-phase microextraction with gas chromatography–mass spectrometry. Volatile compounds, including ketones, aldehydes, alcohols, and acids, were identified during seaweed fermentation. Compared with lactic acid bacteria fermentation, Bacillus subtilis fermentation could enhance the total ketone amount in seaweeds. Saccharomyces cerevisiae fermentation could also enhance the alcohol content in seaweeds. Principal component analysis of volatile compounds revealed that fermenting seaweeds with B. subtilis or S. cerevisiae could reduce aldehyde contents and boost ketone and alcohol contents, respectively, as expected. The odor of the fermented seaweeds was described by using GC–olfactometry, and B. subtilis and S. cerevisiae fermentations could enhance pleasant odors and reduce unpleasant odors. These results can support the capability of fermentation to improve the aromatic profile of seaweeds.

Effect of β-cyclodextrin deodorization on the volatile chemicals and functional properties of three types of gelatins

The exploration of deodorization is important for the application of gelatin in food industry. In this work, the effect of β-cyclodextrin (β-CD) deodorization on the volatile chemicals and functional properties of three types of gelatins (commercial porcine skin gelatin, cold water fish skin gelatin, and Chinese longsnout catfish skin gelatin) were studied. The results suggested the odors of commercial gelatins were significantly less than home-extracted gelatins. The β-CD deodorization efficiency was dependent on both β-CD concentration and volatile chemical. (E)-2-Octenal (C8H14O), 1-octen-3-ol (C8H16O), 2-pentyl-furan (C9H14O), and hentriacontane (C17H36) could be deodorized at low β-CD concentration (even at 2 mg/mL). The best β-CD deodorization concentration for 66.7 mg/mL of Chinese longsnout catfish skin gelatin was 30 mg/mL. β-CD addition could not change the gel forming ability and emulsion activity of gelatins, whereas it had different and concentration-dependent effects on the emulsion stability of gelatins. β-CD addition had no obvious effects on the droplet sizes, droplet coalescence and liquid-gel transition behaviors, but had different effects on the creaming of the emulsions stabilized by three types of gelatins. The encapsulation of β-carotene did not significantly change the droplet trimodal size distribution and liquid-gel transition of fish oil-loaded emulsions. However, β-carotene might delay the droplet coalescence. The creaming stability of β-carotene/fish oil-loaded gelatin/β-CD-stabilized emulsions was dependent on the gelatins, β-CD, and β-carotene. Finally, the β-carotene retention in the emulsions was dependent not on β-CD addition but on the nature of the gelatins. These results provided useful information to understand the molecular deodorization behaviors and explore the deodorization of emulsifiers for food emulsions.

Molecular cloning, and optimized production and characterization of recombinant cyclodextrin glucanotransferase from Bacillus sp. T1

Cyclodextrin glucosyltransferase (CGTase) is an enzyme which degrades starch to produce cyclodextrins (CDs). In this study, the β-CGTase producing strain T1 was identified as Bacillus sp. by its morphological characteristics and 16S rDNA sequence analysis. The cgt-T1 gene was cloned and expressed in Escherichia coli. CGTase-T1 was purified by Ni-nitrilotriacetic acid agarose column and the molecular weight was determined as approximately 75 kDa using SDS-PAGE analysis. For the expression of soluble proteins, the optimal induction conditions were 10 h at 25 °C with OD₆₀₀ at 0.8. The purified CGTase-T1 exhibited maximum activity with an optimal pH and temperature of 6.0 and 65 °C. The enzyme was stable in a pH range of 7.0-10.0, retaining over 85% relative activity for 1 h. CGTase-T1 activity can be significantly enhanced by adding 1 mM Ba²⁺. Using a soluble starch substrate, the kinetic parameters were revealed with K _M and k _cat/K _M values of 2.75 mg mL^-1 and 1253.97 s^-1 mL mg^-1, respectively. Additionally, the four enzyme activities of CGTase-T1 were determined. The highest conversion rate to CDs (40.9%) was achieved from soluble starch after 8 h of enzyme reaction, where mainly β-CD was produced (79.1% of the total CDs yield), indicating that CGTase-T1 potentially has industrial application prospect.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13205-022-03111-8.

Deodorizing effects of rosemary extract on silver carp (Hypophthalmichthys molitrix) and determination of its deodorizing components

Fishy odor in fish products severely influences both eating quality and commercial acceptability, and natural plant extracts, particularly spices, have recently become popular for the removal of fishy odor. This study aimed to explore the potential of rosemary extract for the deodorization of silver carp (Hypophthalmichthys molitrix), as well as to identify the deodorizing components in rosemary extract. Results showed that all of the spice extracts used in this study (ginger, garlic, angelica dahurica, fennel, rosemary, nutmeg, white cardamom, cinnamon, star anise, and bay leaf) significantly reduced the fishy odor value of silver carp, among which rosemary extract was most effective, decreasing the fishy odor value by about 58%. Gas chromatography-mass spectrometry analysis and sensory evaluation showed that the fishy odor value and concentrations of the fishy odor-active compounds were significantly reduced by the application of rosemary extract. However, the lower the total phenolic content of rosemary extract, the poorer the deodorizing effects against silver carp, suggesting that the deodorizing effect was primarily driven by polyphenols. Fourteen phenolic compounds were measured in rosemary extract, and three individual phenolic compounds (rosmarinic acid [RA], carnosic acid [CA], and carnosol [CS]) were chosen for deodorizing experiment. Sensory detection results and changes of contents of volatile showed that these three phenolic compounds are effective at removing the fishy odor. These results suggest that polyphenols are the main deodorizing components, and RA, CA, and CS are the main deodorizing active compounds in rosemary extract. PRACTICAL APPLICATION: The results of this study may provide a new way to determine the deodorizing components of spice extracts. Moreover, it can provide guidance for further research in investigating the deodorizing mechanism of sipce extracts.

Interaction between Negatively Charged Fish Gelatin and Cyclodextrin in Aqueous Solution: Characteristics and Formation Mechanism

The effect that ratios of fish gelatin (FG) to α/β/γ cyclodextrins (α, β, γCDs) had on the phase behavior of a concentrated biopolymer mixture were comparatively investigated. This showed that the formed biopolymer mixture had the highest gel strength at ratios of FG–CD = 90:10. FG could interact with CDs to form stable soluble complexes with lower values of turbidity, particle size and ζ-potential. All of the FG–CD mixture solutions exhibited pseudo-plastic behaviors, and FG–αCD samples had the highest viscosity values than others. The addition of CDs could unfold FG molecules and make conformation transitions of FG from a random coil to β-turn, leading to the environmental change of hydrophobic residues and presenting higher fluorescence intensity, especially for βCDs. FTIR results revealed that the formation of intermolecular hydrogen bonds between FG and CD could change the secondary structure of FG. These findings might help further apply FG–CD complexes in designing new food matrixes.

Effect of Collagen Peptide-Chelated Zinc Nanoparticles From Pufferfish Skin on Zinc Bioavailability in Rats

Small-molecular-weight collagen peptides (CPs) with high zinc-chelating ability were extracted from pufferfish skin. Chelation of CPs with zinc was performed to prepare novel CP-chelated zinc (CP-Zn) nanoparticles. CP-Zn nanoparticles were spherical, regular, and well dispersed with an average size of ∼100 nm. The zeta potential assay was used to explore the stability of CP-Zn nanoparticles. CP-Zn nanoparticles were much more stable in the pH range of 3-8. The structural properties of CP-Zn nanoparticles were characterized by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry, Fourier transform infrared spectroscopy, and ¹H nuclear magnetic resonance spectroscopy. The results indicated that CPs were chelated with Zn ions through the amino nitrogen and oxygen atoms from the carboxyl groups. Furthermore, the animal experiment results showed that CP-Zn nanoparticles were more effective in improving zinc bioavailability of Zn-deficient rats than zinc gluconate and zinc sulfate. The study demonstrated that CP-Zn nanoparticles were ideal for zinc supplementation.

Removal of the fishy malodor from Bangia fusco-purpurea via fermentation of Saccharomyces cerevisiae, Acetobacter pasteurianus, and Lactobacillus plantarum

The present study aims to evaluate the deodorization of Bangia fusco-purpurea using microorganism fermentation with commercial starter cultures of Saccharomyces cerevisiae, Acetobacter pasteurianus, and Lactobacillus plantarum. The results showed the fermentation with S. cerevisiae, A. pasteurianus, and L. plantarum resulted in significantly decreases (p < .05) of the fishy malodor in B. fusco-purpurea. Among the three strains, S. cerevisiae was the best for reducing the fishy malodor. The optimal inoculum size and fermentation time were 0.2% and 4 hr, respectively. After the fermentation with the S. cerevisiae, the content of 1-octen-3-ol, (E)-2-octen-1-ol, hexanal, non-(2E)-enal, (E,E)-2,4-decadienal, 3,5-octadien-2-one, and 2-pentyl-furan were hard to be detected in the seaweed, whereas increases were observed in the concentrations of 2-butyl-1-octanol, cedrol, diisobutyl phthalate, and 2,4-di-t-butylphenol. The odor active value analysis indicated the removal of fishy odor was related to the reduction, dehydrogenation, and deformylating oxygenation of hexanal, nonanal, non-(2E)-enal, and (E,E)-2,4-decadienal and esterification of 1-octen-3-ol and (E)-2-octen-1-ol. Our findings provide a technical and scientific basis for the removal of fishy odor from B. fusco-purpurea. PRACTICAL APPLICATIONS: Bangia fusco-purpurea is a seaweed that can reduce the risks of cardiovascular and chronic metabolic diseases in human body. However, the seaweed has a strong fishy malodor, which largely declines consumer's acceptance. In this study, the commercial starters of Saccharomyces cerevisiae, Acetobacter pasteurianus, and Lactobacillus plantarum were shown to reduce the fishy malodor in B. fusco-purpurea via fermentation. After the fermentation with the microorganisms especially with the S. cerevisiae, the fishy malodor significantly reduced, and the overall aroma acceptance of B. fusco-purpurea products greatly improved. Therefore, this study provides a technical basis for the removal of fishy odor from B. fusco-purpurea and processing value-added products from it and facilitating its health benefits for human.

Development of a New Deodorization Method of Herring Milt Hydrolysate: Impacts of pH, Stirring with Nitrogen and Deaerator Treatment on the Odorous Content

Herring milt hydrolysate (HMH) presents the disadvantage of being associated with an unpleasant smell limiting its use. Thus, to develop a new effective and easy-to-use deodorization method, this research aimed to deepen the knowledge regarding the impacts of pH (pH 7 vs. pH 10), overnight stirring with nitrogen (+N vs. −N) and deaerator treatment (+D vs. −D) on the odorous content of HMH. This latter included dimethylamine (DMA), trimethylamine (TMA), trimethylamine oxide (TMAO) and the most potent odor-active compounds of HMH. Results showed that pH had a huge impact on the targeted compounds resulting in higher detected concentrations of DMA, TMA and TMAO at pH 10 than at pH 7 (p < 0.05) while the opposite trend was observed for the most potent odor-active compounds of HMH (p < 0.05). Moreover, independently of the pH condition, the overnight stirring with or without nitrogen had no impact (p > 0.05). Finally, the deaerator treatment was more effective to remove TMA and DMA at pH 10 than at pH 7 (p < 0.05) while the opposite trend was observed for the most potent odor-active compounds (p < 0.05). Sensory analysis confirmed that the application of pH 10 −N +D and pH 7 −N +D + alkalization pH 10 conditions led to the least odorous products (p < 0.05).

Onion Peel Powder as an Antioxidant-Rich Material for Sausages Prepared from Mechanically Separated Fish Meat

Mechanically separated fish meat (MSFM) can be used for the manufacturing of ready-to-eat products, such as sausages; however, it is highly perishable. Several plant by-products, including onion peel, which is rich in polyphenol antioxidants, can be added to food to extend shelf life. This study investigated the effects of the addition of onion peel powder (OPP) to sausage made from MSFM. Sausages were divided into four groups with different amounts of added OPP: 0% (control), 1%, 2%, and 3%. Cooked sausages were stored for 28 days at 5 °C. Samples were analyzed for thiobarbituric acid reactive substances, antioxidant activity, total polyphenol content, pH, and organoleptic properties. The addition of OPP significantly increased antioxidant activity and total polyphenol content and decreased pH, indicating acidic nature of OPP. Polyphenols from OPP effectively suppressed lipid oxidation. A 1–2% addition of OPP enhanced sensory properties. After the 28-day storage, the control samples received the lowest sensory score, due to the presence of a strong fishy odor, which was not present in samples with OPP. HPLC–MS/MS analysis revealed that quercetin is the most dominant compound in OPP. Overall, the results indicate that the addition of OPP in amounts of 1–2% can extend shelf life, without the deterioration of sensory properties.

Oleogel-structured composite for the stabilization of ω3 fatty acids in fish oil

The fish oil is encapsulated in a multi-compartment system featuring β-cyclodextrin complexation within whey protein isolate (WPI) coated oleogel particles.