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The fishy odor of fish oil, a popular nutritional supplement, affects its quality as well as consumer acceptance and eating experience. An objective or scientific method for analyzing fish oil's olfactory characteristics is still lacking. This study examined anchovy oil to develop qualitative and quantitative approaches for identifying fishy odor components. Multiple fish oil refining samples were analyzed using gas chromatography-ion mobility spectrometry (GC-IMS). Due to their significant alterations during fish oil refining, low threshold values, and distinct olfactory properties, the unsaturated aldehydes (E)-2-pentenal and (E,E)-2,4-heptadienal and the unsaturated ketone 1-penten-3-one may contribute to the fishy odor. Among the chemicals, (E,E)-2,4-heptadienal was chosen as the marker for developing a method to quantify fishy odor and analyze deodorization samples using headspace solid-phase micro-extraction gas chromatography-mass spectrometry (HS-SPME-GC-MS). The quantitative study of fishy odor in fish oil is a pioneering approach that can help improve quality assurance and refining process. [ABSTRACT FROM AUTHOR]

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Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The quality of water has a great impact on the life of aquatic species. The frequency of algal proliferation has increased all over the world due to changes in the water quality factors of the water systems. This study determined the correlation between Uroglena americana (U. americana) and water quality factors. U. americana mainly proliferated in late April at the surface level of the source water when the water temperature was in the range of 15.8–17.9 °C. Water temperature was negatively correlated with U. americana throughout the sampling period. In spring, the dissolved nitrogen (DN), dissolved organic carbon (DOC), fluorescence substance (peaks 1, 2, 3, 4, and 5), and electrical conductivity (EC) were positively correlated with the U. americana whereas the pH, dissolved oxygen (DO), oxidative reduction potential (ORP), turbidity, color, and dissolved phosphorus (DP) were negatively correlated. The total bacteria (16S rDNA) of source water showed a strong positive correlation (r = 0.66 at p = 0.05) with U. americana. The proliferation of U. americana also could be influenced by the associated microalgae species of source water. The Peridinium and Asterionella species were negatively correlated with U. americana, whereas the Euglena, Chlamydomonas, and Nitzchia species were positively correlated; among them, Euglena sp showed a significant positive correlation (r = 0.90, at p = 0.01) with U. americana. The obtained results of this study could be applied to the source water quality management and the optimization of the operating conditions of drinking water treatment plants to ensure the quality of drinking water. [ABSTRACT FROM AUTHOR]

A boiled fish simulation system was constructed to explore the deodorization effect of main aroma compounds (MAC) on myofibrillar protein (MP) with main fishy compounds (MFC) during heating. The results showed that the MFC content of boiled fish was reduced by 63.10–78.10 % when boiled by heat-stable emulsions loading MAC. Specifically, adding linalool, anethole, and myrcene significantly elevated the free percentage of hexanal, heptanal, and 1-octen-3-ol after heating, while the free percentage of octanal and nonanal markedly increased by adding anethole and limonene. Molecular docking exhibited that MAC and MFC possessed co-binding sites with myosin. Linalool and anethole were competitively bound to MP through hydrophobic and hydrogen bonding sites, while myrcene and limonene were via hydrophobic interaction sites. Moreover, MAC-MP formed a relatively stable structure, exhibiting increased α-helix content and decreased surface hydrophobicity, which reduced the available sites for MFC binding, ultimately desorbed MFC (65.46 %–95.89 %). [Display omitted] • Heat-stable emulsions loaded with MAC markedly reduced fishy odor of fish fillets. • A simulation system mirroring the boiled fish preparation process was constructed. • MFC were desorbed 65.46 %–95.89 % by adding MAC. • MAC competitively bound to MP via hydrophobic and hydrogen bonding sites. • Hydrophobic interactions are the primary force between MP and MAC. [ABSTRACT FROM AUTHOR]

Processing is an indispensable technology in the preparation of Spirulina platensis (S. platensis). The key odorants in liquids, muds, and powders from S. platensis (NM and GZ) were characterized. A total of 90 odorants were identified and 41 odorants were sniffed with the flavor dilution (FD) factors ranging from 1 to 729. Among them, nonanal, decanal, d -limonene, β -cyclocitral, and β -ionone with FD factors ≥1 were detected in S. platensis during the whole processing stages. In addition, heptanal, (E , E)-2,4-nonadienal, trans -4,5-epoxy-(E)-2-decenal, 1-hepten-3-one, isophorone, 3-ethyl-2,5-dimethylpyrazine, and α -ionone exhibited higher odor activity values in powders; β -myrcene, methional, and S -methyl methanethiosulphonate were key odorants in muds; while trans -3-penten-2-ol was key odorant in liquids. Besides, the GZ-mud presented stronger earthy and fishy odor than NM - mud. S. platensis powders have the stronger grassy odor, roasted odor, and marine odor than S. platensis muds. Overall, drying process promotes the formation of aldehydes, heterocyclic compounds, and terpenoids. [Display omitted] • Aldehydes, pyrazines, and terpenoids in S. platensis powders increased during drying process. • S. platensis powders have the stronger grassy odor, roasted odor, and marine odor. • Acid and sulfides mainly imparted rancid and fishy odor to S. platensis muds. • GC-IMS distinguished S. platensis odor differences at different processing stages. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Home Economics of Japan is the property of Japan Society of Home Economics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To decrease the fishy odor of tilapia protein hydrolysates, this study investigated the flavor properties of fish protein hydrolysates (FPH) fermented by Hanseniaspora pseudoguilliermondii (FPHY), Lactobacillus plantarum 082 (FPHL) and combined fermentation (FPHLY). The thiobarbituric acid reactive substance (TBARS) values of FPHY (from 3.15 mg/L to 2.30 mg/L) and FPHL (from 2.89 mg/L to 1.29 mg/L) reduced by 26.98% and 55.36%, respectively. However, there were no obvious changes in amino acid composition. HS-SPME-GC-MS analysis showed that the main fishy components in FPH were hexanal and 1-octene-3-ol. Compared with FPHL, FPHY can produce more esters (1470.65 μg/mL), and the ester content was 352 times that of FPH (4.17 μg/mL) and 405 times that of FPHL (3.63 μg/mL). E-nose analysis, sensory evaluation and e-tongue analysis indicated that fermentation could decrease the bitterness of FPH, resulting in an improved taste. Therefore, H. pseudoguilliermondii fermentation could reduce the fishy odor and bitterness of FPH. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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. [ABSTRACT FROM AUTHOR]

The undesirable odor of crab meatballs was evident after boiling and cooling, high-voltage electrostatic field (HVEF), lysozyme and yeast extract (LY), and the combination (LYH) were all applied to pre-deodorize crab meatballs to estimate the effect in view of odor, pH, fat oxidation and protein oxidation. None of the tert-butylamine (1.58 ± 0.14 ng/g), (E, E)-2,4-Dodecadienal (18.52 ± 0.12 ng/g), 1-Octen-3-ol (13.51 ± 0.22 ng/g) and nonanal (681.55 ± 0.24 ng/g) in the control were detected in LYH group, while nonanal in HVEF and LY groups was reduced by 86.07% and 42.60%, respectively. Thirteen volatile substances with variable importance plot ≥1 contributed prominently to the odor of crab meatballs depended on partial least squares discrimination analysis. Protein oxidation of the pretreated crab meatballs was alleviated, as well as thiobarbituric acid reactive substances (TBARS) and lipoxygenase (LOX) activity, with the best inhibitory effect of LYH being 40.10% and 62.80% on the respective effects. The correlation analysis derived that fishy substances were significantly positively correlated with TBARS and pH. LYH was the optimal pre-deodorization, which involved promoting glycolysis and lactic acid bacteria colonization in the liquid medium, and inhibiting fat oxidation by affecting enzyme activity in HVEF. • Significant contributions of 13 volatiles to the typical odor of crab meatballs. • Optimal de-fishy: lysozyme, yeast extract with high-voltage electrostatic field. • The optimal de-fishy method inhibited fat oxidation and protein oxidation. • The optimal de-fishy method caused lower signal values for electronic nose sensors. [ABSTRACT FROM AUTHOR]

Kelp (Laminaria japonica) is an important marine resource with low cost and rich nutrition. However, its fishy odor has compromised consumer acceptance. In this study, the effects of fermentation with Lactobacillus plantarum FSB7, Pediococcus pentosaceus CICC 21862 and Saccharomyces cerevisiae SK1.008 on fishy notes in kelp was studied using gas chromatography-mass spectrometry (GC-MS), gas chromatography-ion mobility spectrometry (GC-IMS) and odor activity values (OAVs). Forty-four volatile organic compounds (VOCs) were identified in unfermented kelp, most of which were aldehydes, followed by alkanes, alcohols and ketones. Among them were 19 volatile compounds with OAV greater than one. Substances containing α,β-unsaturated carbonyl structure (1-Octen-3-one, (E,Z)-2,6-nonadienal, (E,E)-2,4-decadienal, etc.) are the main contributors to kelp fishy odor. The number of VOCs in kelp samples fermented by L. plantarum, P. pentosaceus and S. cerevisiae were decreased to 22, 24 and 34, respectively. GC-IMS shows that the fingerprint of the S. cerevisiae fermented sample had the most obvious changes. The disappearance of 1-octen-3-one and a 91% decrease in unsaturated aldehydes indicate that S. cerevisiae was the most effective, while L. plantarum and P. pentosaceus only reached 43–55%. The decrease in kelp fishy notes was related to the decrease in α,β-unsaturated carbonyl groups. The experimental results show that odor reduction with fermentation is feasible.

Lipid oxidation has a negative impact on application and stability of hydrolyzed collagen (HC) powder from fatty fish skin. This study aimed to produce fat-free HC powder from salmon skin via optimization of one-step hydrolysis using mixed proteases (papain and Alcalase) at different levels. Fat removal processes using disk stack centrifugal separator (DSCS) for various cycles and subsequent defatting of HC powder using isopropanol for different cycles were also investigated. One-step hydrolysis by mixed proteases (3% papain and 4% Alcalase) at pH 8 and 60 °C for 240 min provided HC with highest degree of hydrolysis. HC powder having fat removal with DSCS for 9 cycles showed the decreased fat content. HC powder subsequently defatted with isopropanol for 2 cycles (HC-C9/ISP2) had no fat content with lowest fishy odor intensity, peroxide value, and thiobarbituric acid reactive substances than those without defatting and with 1-cycle defatting. HC-C9/ISP2 had high L*-value (84.52) and high protein (94.72%). It contained peptides having molecular weight less than 3 kDa. Glycine and imino acids were dominant amino acid. HC-C9/ISP2 had Na, Ca, P, and lowered odorous constituents. Combined processes including hydrolysis and defatting could therefore render HC powder free of fat and negligible fishy odor.

• Pulse electric field (PEF) was used for pretreatment of seabass skin. • PEF before vacuum infusion (VI) with porcine pancreas lipase (PPL) was done. • VI with PPL process enhanced defatting of PEF-treated seabass skin. • PEF-VI-PPL-treated skin had lower lipid distribution than isopropanol-treated skin. • Hydrolyze collagen prepared from PEF-VI-PPL-treated skin had lower fishy odor/flavor. Lipid removal of Asian sea bass skin pretreated with pulsed electric field (PEF) at 24 kV/cm for 72 ms, followed by hydrolysis with porcine pancreas lipase (PPL) at 42.36 U/g skin dry matter with the aid of vacuum impregnation (VI) at various vacuum times (10, 15, 20 and 30 min) was investigated. The highest lipid reduction in PEF-treated skin was found at vacuum time of 20 min (p < 0.05). The efficacy of defatting was increased with increasing VI cycles (p < 0.05), in which lipids were eliminated by 97% when VI cycles of 4 were used. Also, the lipid content was lower than that found in sample treated with 30% isopropanol under the same VI condition (p < 0.05). Moreover, lipids extracted from PEF-VI-PPL treated skin had lower monounsaturated and polyunsaturated fatty acid contents as compared to other samples. Lower lipid distribution was noticeable in PEF-VI-PPL treated skin. When PEF-VI-PPL-treated skin was hydrolyzed using papain at 0.3 U/g dry skin matter, weak fishy odor/flavor of the resulting hydrolyzed collagen was observed, compared with other samples (p < 0.05). Additionally, there was the reduced abundance of volatile compounds. Thus, the use of PPL in conjunction with VI could remove lipid in PEF-treated skin effectively. [ABSTRACT FROM AUTHOR]

Fresh duck eggs normally have an unpleasant fishy odor when compared with eggs from other poultry. However, the cause of this unpleasant smell remains unknown. Besides, we have limited knowledge regarding the perception ability of this odor. Therefore, we aimed to identify the causative substances responsible for the fishy odor in duck eggs, and further evaluate the factors affecting the perception ability of this odor. We detected and quantified the volatile substances in the yolks of Jingjiang duck and Beijing duck eggs using headspace gas chromatography, and evaluated the fishy odor rating scores. We performed association studies on the relationship between the relative content of volatile substances and fishy odor rating scores. The fishy odor of egg yolks from different species/breeds was also characterized. Furthermore, we assessed the species/breeds of poultry eggs and the effects of gender and region of the evaluators on the fishy odor rating score by using an ordinal logistic regression model. Results showed that trimethylamine (TMA) is responsible for the fishy odor of duck eggs, which was confirmed with subsequent verification (P < 0.001). The fishy odor of duck eggs was stronger than that of chicken eggs; the fishy odor of Jingjiang duck eggs was the strongest. Results also indicated that the fishy odor perception ability was affected by the gender and region of the evaluators (P < 0.001). Overall, these data clarified that TMA imparted the fishy odor to duck eggs; factors such as gender and region may affect the fishy odor perception ability. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Defatting of seabass skins using pulsed electric field (PEF)‐assisted process at different electric field strengths (16 and 24 kV/cm) and times (36, 72, and 108 ms) in combination with porcine pancreas lipase (PPL) at 25 U/g dry matter was investigated. PEF‐treated skin at 24 kV/cm for 72 ms followed by PPL treatment removed 86.93% lipids. PEF‐treated skin was further optimized for lipid reduction by response surface methodology. Central composite design was adopted to establish treatments based on two independent variables, involving PPL concentration (30 to 55 U/g dry matter) and hydrolysis time (60 to 180 min). Second‐order polynomial model was used for predicting the response. The highest lipid removal (91.96 ± 1.70%) was attained when the optimal condition (42.36 PPL units/g dry skin matter for 139.78 min) was used. The experiment value was in accordance with the predicted value. PEF‐PPL‐treated skin had lower monounsaturated and polyunsaturated fatty acids than the solvent‐extracted skin (P < 0.05). When PEF‐PPL‐treated skin was hydrolyzed using papain at 0.30 U/g dry matter, lower fishy odor/flavor of resulting hydrolyzed collagen (PEF‐PPL‐HC) was found than other samples (P < 0.05). Lower total volatile compounds were also obtained in PEF‐PPL‐HC sample. Thus, the use of PEF pretreatment along with PPL before papain hydrolysis effectively prevented the formation of fishy odor/flavor in hydrolyzed collagen from seabass skin. Practical Application: Fishy odor/flavor caused by lipid oxidation of fish skin hydrolysates limits their applications in foods. Defatting process is the significant step for skin pretreatment. Although several methods could remove lipids from fish skins, either by lipase or solvent extraction, fishy odor/flavor is still detected in hydrolysate. Pulsed electric field‐assisted process in combination with porcine lipase is another approach that can be used to enhance efficiency via electroporation, causing the loosened skin matrix and facilitating the migration of lipase into the skin. Consequently, the resulting hydrolysate might have the lowered fishy odor/flavor and could be used in foods, especially for fortification. [ABSTRACT FROM AUTHOR]

Disgusting fishy odor problems have become a major concern in drinking water quality, and are commonly related to algal proliferation in source water. Unlike the typical musty/earthy odorants 2-methylisoborneol (MIB) and geosmin, identification of the corresponding fishy odorants is still a big challenge. In this study, two species of fishy-odor-producing algae, Ochromonas sp. and Cryptomonas ovate , were cultured to explore the odor production characteristics and typical odorants. When algae were ruptured in the stationary and decline phases, fishy odor intensities of 4 to 8 characterized by FPA were produced. However, some frequently reported aldehydes that could cause fishy odor, including n-hexanal, 2-octenal, heptanal, 2,4-heptanal and 2,4-decadienal, were not detected in either of the cultured algae. The possible fishy odor-causing compounds were further identified by combining gas chromatography-olfactometry (GC-O/MS) and comprehensive two-dimensional gas chromatography (GC × GC-TOFMS) using retention indices (RIs). From GC-O/MS analysis, twelve and six olfactometry peaks with various odor characteristics were identified in Ochromonas sp. and Cryptomonas ovate , respectively, of which three and two olfactometry peaks showed fishy odor characteristics. 2-Nonenal, 2,4-octadienal, fluorene and 2-tetradecanone were identified as fishy odorants in Ochromonas sp., and 1-octen-3-ol, 6-methyl-5-hepten-2-one, 1-octen-3-one, 2-nonenal and 2,4-octadienal were identified in Cryptomonas ovate. Other identified compounds, including butyl butanoate (fragrant odor), ionone (fragrant odor), bis (2-chloroisopropyl) ether (chemical odor) etc., did not show fishy features. Therefore, the fishy odor might be a synthetic and comprehensive odor, which resulted from the combination of different odorants and their synergistic effects. The results of this study will be helpful for understanding fishy odor problems, which will provide support for fishy odor management and control in the drinking water industry. Unlabelled Image • Seven possible fishy odorants are first identified in two algae culture. • Fishy odor is aggravated while algal cells ruptured. • Fishy odor is synthetic from combination of different odorants. [ABSTRACT FROM AUTHOR]

Fishy odor has become one of the most often encountered aesthetic water quality problems in drinking water. While fresh water algae living in colder water can produce offensive fishy odors, their environmental behaviors remain poorly understood. In this study, two chrysophyte species (Synura uvella and Ochromonas sp.), which are often associated with fishy odor events, were selected to investigate the effect of temperature (8, 16, and 24 °C) and light intensity (10, 41, and 185 μmol photons m−2 s−1) on algal growth and odorant production. Five polyunsaturated aldehyde derivatives, including 2,4-heptadienal, 2-octenal, 2,4-octadienal, 2,4-decadienal, and 2,4,7-dectridienal, were identified as fishy/cod liver oil/fatty/rancid descriptors in the cultures of the two algae based on gas chromatography-olfactometry-mass spectrometry and comprehensive two-dimensional gas chromatography mass spectrometry. While biomass yield increased with the increase in temperature for both species, significantly higher odorant yields (production of odorants per cell) were obtained at 8 °C. The total odorant production and cell yield of the odorants decreased with the increase in light intensity from 10 to 185 μmol photons m−2 s−1. The biodegradation half-lives for the released odorants were 6–10 h at 8 °C and 2–4 h at 24 °C, whereas the volatilization half-lives were 36–97 d at 8 °C and 6–17 d at 24 °C, suggesting that temperature-dependent biodegradation was an important factor controlling the fate of fishy compounds in aquatic environments. The results of this study will help clarify why most fishy odor events occur in cooler seasons, and provide knowledge related to cold water persistence for the management of fishy odor problems associated with algae. Image 1 • 2,4-heptadienal, 2-octenal, 2,4-octadienal, 2,4-decadienal and 2,4,7-dectridienal were identified as the fishy odorants. • Lower temperature and light intensity increased the total production and cell yield of the odorants. • Biodegradation is an important process for odorants loss. [ABSTRACT FROM AUTHOR]

Abstract Coir pith is a highly potential adsorbent for adsorbing trimethylamine (TMA). It harbors a higher adsorption capacity for TMA compared to commercial activated carbon (CAC). It was found that lignin and holocellulose extracted from coir pith played an important role in TMA adsorption. Lignin itself had the highest TMA adsorption capacity (269.01 mg/g) followed by holocellulose (75.43 mg/g), coir pith (14.3 mg/g) and CAC (10.26 mg/g), respectively. The pseudo-first- and second orders were applied to the kinetic data. For the adsorption of TMA by coir pith, the best fit was achieved by the pseudo-second order. Thermodynamic studies showed an endothermic and physico-chemical adsorption process between TMA and the coir pith. TMA desorption study suggested that only 14%–47% of TMA was desorbed with distilled water. In addition, Fourier transform-infrared (FT-IR) spectra showed that C–H bond (methyl group), C–O bond from phenolic alcohol and C–O bond from tertiary alcohol in lignin and holocellulose were involved in TMA adsorption. Coir pith-based filter showed high TMA adsorption efficiency (98%) and kept constant for more than 48 days in a continuous system. Pilot scale experiment, coir pith beads filter could be succesfully applied as a packing material for TMA removal. Therefore, coir pith can be used as a promising packing material for TMA treatment at contaminated site. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Fishy odor was always generated in hairtail fish balls, decreasing the quality and reducing commercial acceptance. Improving the flavor of hairtail fish balls is a challenge in recent seafood industry. Extracts from sage leaves, oregano leaves and grape seeds (SOG) were proved to be effective in reducing the fishy odor in hairtail fish balls. The primary antioxidants were catechin, epicatechin and rosmarinic acid in SOG with the antioxidant capacity of 0.09 ± 0.01 mg gallic acid equivalents (GAE)/mL. Gas chromatography mass spectrometry (GC-MS) showed that about 50% volatility off-flavor compounds including aldehydes, ketones, alcohols and hydrocarbons, were reduced by the application of SOG. Inhibition of fishy odor by SOG was directly related with the reduced thiobarbituric acid reactive substances value (TBARs value) and total volatile basic nitrogen (TVB-N), which was likely due to the decreased lipid oxidation and bacteria growth, respectively. These results suggested the beneficial potential for SOG in inhibiting fishy odor formation and improving flavor of hairtail fish balls during storage. Highlights • The SOG was rich in polyphenols with antioxidant and antimicrobial properties. • The SOG treatment of hairtail fish balls significantly inhibited fishy odor generation during storage at 4 °C. • The SOG treatment reduced changes in TBARs value, pH, TVB-N and TMCs of hairtail fish balls during storage at 4 °C. [ABSTRACT FROM AUTHOR]

[Display omitted] • The fishy odors from the origin and formation to elimination were summarized. • The characteristic odorants were aldehydes, alcohols, and amines. • Lipid oxidation was the main formation pathway of fishy compounds. • Regulation techniques of flavor involve masking, eliminating, and conversion. Fishy odor in aquatic products has a significant impact on the purchasing decisions of consumers. The production of aquatic products is a complex process involving culture, processing, transportation, and storage, which contribute to decreases in flavor and quality. This review systematically summarizes the fishy odor composition, identification methods, generation mechanism, and elimination methods of fishy odor compounds from their origin and formation to their elimination. Fishy odor compounds include aldehydes (hexanal, heptanal, and nonanal), alcohols (1-octen-3-ol), sulfur-containing compounds (dimethyl sulfide), and amines (trimethylamine). The mechanism of action of various factors affecting fishy odor is revealed, including environmental factors, enzymatic reactions, lipid oxidation, protein degradation, and microbial metabolism. Furthermore, the control and removal of fishy odor are briefly summarized and discussed, including masking, elimination, and conversion. This study provides a theoretical basis from source to elimination for achieving targeted regulation of the flavor of aquatic products, promoting industrial innovation and upgrading. [ABSTRACT FROM AUTHOR]

Fishy odor, as an offensive and unpleasant odor, could occur in drinking water source with poor nutrition, it is usually considered to be associated with odor-producing microalgae. However, the specific relations among fishy odor, fishy odorants and responsible microalgae were not elucidated comprehensively. In this paper, the odor-causing compounds generated from six microalgae with fishy odor characteristic, isolated in drinking water source Tongyu River, were identified simultaneously. The sensory evaluation result indicated that Tongyu River was principally related to fishy odor (odor intensity 6.5–7.6). Correspondingly, seven, nine, seven, six, seven and seven olfactory detection peaks (ODP) were screened by combining data of GC/O/MS and GC/GC/TOFMS in Cyclotella, Cryptomonas ovate, Melosira, Dinobryon sp. , Synedra and Ochromonas sp. , which were isolated in Tongyu River and cultured in laboratory. Totally twenty odor-causing compounds, including hexanal, 2-hexenal, 3-hexen-1-ol, heptanal, 1-octen-3-one, 2,4-heptadienal, 2-tetradecanone, 3,5-octadien-2-one, octanal, 1-octen-3-ol, 2-octenal, nonanal, 2,4-octadienal, 2-nonenal, decanal, 2,6-nonadienal, 2-decenal, undecanal, 2,4-decadienal and dodecanal, were screened and identified in all isolated microalgae. Additionally, fishy odor intensity for all identified microalgae increased obviously as microalgae cell number increased and microalgae cell ruptured in cultivation cycles through pearson and spearman correlation analysis. For the first time, twenty odor-causing compounds associating with fishy odor were recognized from six isolated microalgae, which would provide more scientific basis and theoretical support for preventing and treating fishy odor episode of drinking water source. [Display omitted] • Six fishy odor-producing microalgae were separated from water source. • Twenty odorants were identified in six cultured microalgae simultaneously. • Fishy odor increased while odor-producing microalgae cells ruptured. [ABSTRACT FROM AUTHOR]

Abstract The physicochemical properties and fishy odor of gelatin from splendid squid skins as influenced by drying method were investigated. Gelatins obtained from freeze drying (FG) and spray drying with inlet temperatures of 160 (S160), 180 (S180) and 200 °C (S200) were characterized. All samples had α- and β-chains as the predominant constituents. The lightness decreased and samples became more yellowish and reddish as spray drying inlet temperature increased (P < 0.05). FG showed the highest gel strength, followed by S160, S200 and S180 (P < 0.05). FG also had the highest band intensity of α- and β-chains. Fourier transform infrared spectra of spray dried samples showed the highest loss of triple-helix structure. Spray dried gelatin showed higher solubility than freeze dried gelatin (P < 0.05). Fishy odor was more intense in FG compared to those obtained using spray drying (P < 0.05). Fishy odor intensity decreased as drying temperature increased (P < 0.05) and this was in agreement with the lower values observed for thiobarbituric acid reactive substances, peroxides and volatile compounds including aldehydes, ketones, and alcohols. The results showed that spray drying is a potential means for production of gelatin from splendid squid skins with minimal fishy odor. Highlights • Drying methods affected the properties and fishy odor of gelatin from squid skin. • Fishy odor was less intense in spray dried than in freeze dried gelatin. • Spray drying had a negative impact on gel strength and color of gelatin. [ABSTRACT FROM AUTHOR]

The odor-active substances in a fish soup cooked with scallions, ginger, and cooking wine were extracted by solid-phase micro-extraction and analyzed by gas chromatography-olfactometry-mass spectrometry. The results of sensory evaluation indicate that the three seasonings--scallions, ginger, and cooking wine--reduced the fishy odor. Further, the effect of cooking wine or scallions was better than ginger. The main odorants of scallions, ginger, and cooking wine that reduced the fishy odor by masking the odor were detected. The main odorants in the scallions-treated sample were isovaleraldehyde, nonanal, alloaromadendrene, and dipropyl disulfide. The main odorants in the ginger-treated sample were sesquiterpenes, olefins, aldehydes, alcohols, and ketones. The main odorants in the cooking wine-treated sample were (E)-2-heptenal, decanal, copaene, and terpinen-4-ol. [ABSTRACT FROM AUTHOR]

Trimethylamine (TMA) contamination produces a strong 'fishy' odor and can cause pathological changes in humans. By screening native microorganisms from Sansevieria kirkii exposed to 100 ppm TMA, it was shown that endophytic bacteria number 1 (EN1) and number 2 (EN2) have a higher TMA tolerance and removal capacity than other bacteria species in a closed system. In addition, EN1 and EN2 demonstrated the ability to produce high quantities of indole-3-acetic acid (IAA) and use 1-aminocyclopropane-1-carboxylic acid (ACC), which is found normally in plant growth-promoting bacteria (PGPB). Moreover, 16S ribosomal DNA (rDNA) sequences of EN1 and EN2 identification showed that EN1 and EN2 was the same bacteria species, Bacillus cereus. B. cereus EN1 was chosen to apply with S. kirkii to remove TMA in a plant capsule, which was compared to control conditions. It was found that 500 g of soil with S. kirkii inoculated with B. cereus EN1 had a higher TMA removal efficiency than other conditions. Moreover, the flow rate of TMA-contaminated gas was varied (0.03-1 L min) to calculate the loading rate and elimination capacity. The maximum loading rate of 500 g soil with B. cereus EN1-inoculated S. kirkii was 2500 mg m h, while other conditions showed only around 250-750 mg m h. Therefore, a plant capsule with B. cereus EN1-inoculated S. kirkii had the potential to be applied in TMA-contaminated air. [ABSTRACT FROM AUTHOR]

• XAD-16 resin column chromatography could enrich antiplatelet peptides and deodorize. • pH value of loading sample had a great impact on the peptides separation. • The antiplatelet peptides containing PG/OG lied in 20% ethanol fraction at pH 6.0. • The 20% ethanol fraction had a weakest fishy odor. Enrichment of antiplatelet peptides from silver carp skin collagen hydrolysates (CH) was studied using macroporous resins. Static adsorption showed that XAD-16 resin was the suitable resin due to its high adsorption capacity. The dynamic desorption of CH was studied on XAD-16 resin by ethanol gradient elution. Interestingly, pH value of loading sample had a great impact on the peptides separation. Results revealed that the yield and the antiplatelet activity of Ethl-20% fraction were highest at loading sample pH 6.0. The antiplatelet peptides were enriched in the 20% ethanol fraction with IC 50 2.03 mg/mL compared to IC 50 of CH, 4.7 mg/mL. Besides, the Ethl-20% fraction had a weakest fishy odor. Moreover, a series of peptides containing Hyp-Gly or Pro-Gly were identified from Ethl-20% fraction, which contributed to the antiplatelet activities. This study provided a simple and efficient method for large-scale separation enrichment of antiplatelet peptides as functional foods from CH. [ABSTRACT FROM AUTHOR]

Yellow River source water has long suffered from odor problems in winter. In this study, odor characteristics, potential odorants, and algae in the source water of six cities (Lanzhou, Yinchuan, Hohhot, Zhengzhou, Jinan and Dongying) along the Yellow River were determined in winter (February to March 2014). According to flavor profile analysis (FPA), moderate to strong fishy odors occurred in all cities, except for Lanzhou. At the same time, mild earthy/musty odors and septic/swampy odors were also detected. The strong fishy odor (FPA intensity, 8.5) in Yinchuan was attributed to the abnormal growth of Dinobryon (cell density, 5.7 × 10 4 cells/mL), while the fishy odors in Hohhot, Zhengzhou, Jinan, and Dongying might be caused by Melosira and Cyclotella, Cryptomonas, Dinobryon , and Synedra, respectively. Unsaturated aldehydes, which have been reported to cause fishy odors, were not detected in all samples. However, some saturated aldehydes, including hexanal, heptanal, nonanal, decanal, and benzaldehyde, were detected with a total concentration range of 690 ng/L to 2166 ng/L, and might have partly contributed to the fishy odors. In addition, 2-MIB (5.77–21.12 ng/L) and geosmin (2.26–9.73 ng/L) were responsible for the earthy/musty odors in the Yellow River source waters, and dimethyl disulfide (648.2 ng/L) was responsible for the rancid/swampy odor (FPA intensity, 8.0) episode in Yinchuan. This is a comprehensive study reporting on the occurrence and possible reasons for the odor issues in the Yellow River source water during winter. [ABSTRACT FROM AUTHOR]

Removal of trimethylamine (TMA) by 10 different livingSansevieriaspp. and their dried leaf materials was studied. The results showed that livingSansevieria kirkiiwas the most effective plant whileSansevieria masonianawas the least effective in TMA removal. Two major pathways were involved in stomata opening and epicuticular wax on the leaf surface. In the presence of TMA, the stomata opening inSansevieriaspp. was induced, which enhanced TMA removal under light conditions. Dried leaf powders ofSansevieriaspp. adsorbed TMA through their waxes. Therefore, both living and non-livingSansevieriaspp. can be effectively used for removal of TMA. [ABSTRACT FROM PUBLISHER]

Off-flavors, characterized by a fishy odor, are emitted during the heating of rapeseed oil in a fryer. In order to study the headspace composition of degraded rapeseed oil, and more specifically the compounds responsible for the fishy odor, four headspace techniques were evaluated: Static headspace (SHS), headspace trap (HS Trap), headspace solid phase microextraction (HS-SPME), and headspace sorptive extraction (HSSE) coupled to gas chromatography-mass spectrometry (GC-MS). The selected model compounds to develop the headspace methods were 1-penten-3-one, 1-octen-3-one, and E,Z-2,6-nonadienal as known fishy odor markers. Extraction conditions for the four techniques were optimized and evaluated in terms of repeatability and sensitivity. They were then applied to the analysis of real samples of degraded rapeseed oil. SHS was not suitable for the analysis of odorant volatile compounds because of LOD values lower than those required for a quantitative analysis of the target compounds. Concerning HS-SPME and HSSE, a discrimination against the more volatile compounds was observed. Finally, HS Trap-GC-MS was considered the most appropriate technique for the analysis of the headspace of rapeseed oil in this study with LOD values less than 2 μg/L for the three target compounds. More than 60 compounds were identified by HS Trap-GC-MS and two compounds responsible for the fishy odor could be detected. The evolution of the relative areas of these compounds was reported for fresh oil and rapeseed oil degraded by 1, 5, and 10 heating cycles. Practical applications: The characterization of the volatile compounds responsible for the fishy odor is a key industrial issue. Moreover, the developed method with HS-Trap could be used to quantify several volatile compounds characteristic of the degradation of rapeseed oil, and to evaluate the possible effect of antioxidants on oils. Rapeseed oil is edible oil containing a substantial amount of omega 3, but the heating of this oil leads to the formation of off-flavors, characterized by a fishy odor. The characterization of these off-flavors is a key industrial issue, and different headspace techniques can be considered to study the molecules present in the headspace of degraded rapeseed oil. [ABSTRACT FROM AUTHOR]

From screening 23 plant species, it was found that Pterocarpus indicus (C) and Sansevieria trifasciata (crassulacean acid metabolism (CAM)) were the most effective in polar gaseous trimethylamine (TMA) uptake, reaching up to 90 % uptake of initial TMA (100 ppm) within 8 h, and could remove TMA at cycles 1-4 without affecting photosystem II (PSII) photochemistry. Up to 55 and 45 % of TMA was taken up by S. trifasciata stomata and leaf epicuticular wax, respectively. During cycles 1-4, interestingly, S. trifasciata changed its stomata apertures, which was directly induced by gaseous TMA and light treatments. In contrast, for P. indicus the leaf epicuticular wax and stem were the major pathways of TMA removal, followed by stomata; these pathways accounted for 46, 46, and 8 %, respectively, of TMA removal percentages. Fatty acids, particularly tetradecanoic (C) acid and octadecanoic (C) acid, were found to be the main cuticular wax components in both plants, and were associated with TMA removal ability. Moreover, the plants could degrade TMA via multiple metabolic pathways associated with carbon/nitrogen interactions. In CAM plants, one of the crucial pathways enabled 78 % of TMA to be transformed directly to dimethylamine (DMA) and methylamine (MA), which differed from C plant pathways. Various metabolites were also produced for further detoxification and mineralization so that TMA was completely degraded by plants. [ABSTRACT FROM AUTHOR]