Sensory odour profiling and lipid oxidation status of fish oil and microencapsulated fish oil

The aroma transformation of Japanese sea bass (Lateolabrax japonicas) through endogenous enzyme incubation during the lag phase of attached microorganisms

Endogenous enzymes play a crucial role in determining fish product aroma. However, the attached microorganisms can promote enzyme production, making it challenging to identify specific aromatic compounds resulting from endogenous enzymes. Thus, we investigated the aroma transformation of Japanese sea bass through enzymatic incubation by controlling attached microorganisms during the lag phase. Our results demonstrate that enzymatic incubation significantly enhances grassy and sweet notes while reducing fishy odors. These changes in aroma are associated with increased levels of 10 volatile compounds and decreased levels of 3 volatile compounds. Among them, previous studies have reported enzyme reaction pathways for octanal, 1-nonanal, vanillin, indole, linalool, geraniol, citral, and 6-methyl-5-hepten-2-one; however, the enzymatic reaction pathways for germacrene D, beta-caryophyllene, pristane, 1-tetradecene and trans-beta-ocimene remain unclear. These findings provide novel insights for further study to elucidate the impact of endogenous enzymes on fish product aromas.

Strategies to reduce fishy odor in aquatic products: Focusing on formation mechanism and mitigation means

Aquatic products, integral to human diets, often bear a distinct fishy odor that diminishes their appeal. Currently, the formation mechanisms of these odoriferous compounds are not fully understood, complicating their effective control. This review aims to provide a comprehensive overview of key fishy compounds, with a focus on their formation mechanisms and innovative methods for controlling fishy odors. Fishy odors in aquatic products arise not only from the surrounding environment but also from endogenous transformations due to lipid autoxidation, enzymatic reactions, degradation of trimethylamine oxide, and Strecker degradation. Methods such as sensory masking, adsorbent and biomaterial adsorption, nanoliposome encapsulation, heat treatment, vacuum treatment, chemical reactions, and biological metabolic transformations have been developed to control fishy odors. Investigating the formation mechanisms of fishy odors will provide solid foundational knowledge that can inspire creative approaches to controlling these unpleasant odors.

Sensory Wheel and Lexicon for the Description of Cold-Pressed Hemp Seed Oil

Cold-pressed hemp seed oil (CP-HSO) has become available on the market and is gaining popularity mainly for its appeal and nutritional profile. The sensory quality largely depends on seed quality and processing as well as oil storage conditions. Given the "native" nature of the product, obtained by cold-pressing, the development of a standardized methodology to evaluate and describe the sensory quality of HSOs is of the utmost importance. To this aim, 16 commercial HSOs were evaluated, covering the main differences in brands and sales channels. A trained panel developed a vocabulary to describe the HSO profile consisting of 44 attributes, and a practical sensory wheel was proposed to classify attributes in different clusters and according to sensory modality. A sensory profile sheet was developed including two color descriptors (yellow, green), seven main positive (sunflower/pumpkin seeds, nutty, toasted nutty, hay, sweet, bitter, and pungent), several secondary positive (herbs, coffee, tobacco, etc.), four main defects (rancid, paint, burnt, and fish), and other secondary negative descriptors (boiled vegetables, cucumber, etc.). Subsequently, specific training of the panelists was carried out, and a satisfactory performance level was reached. This study represents the first attempt to standardize the sensory quality and terminology of HSO.

3D printing based on meat materials: Challenges and opportunities

Three-dimensional (3D) printing, as an emerging technology, is driving great progress in the food industry. In the meat field, 3D printing is expected to replace the traditional food industry and solve the problems of raw material waste and food contamination. Nevertheless, the application of 3D printing in meat still faces many challenges. The rheological properties of the ink, such as shear thinning behavior, viscosity, and yield stress, are critical in determining whether it can be printed smoothly and ensuring the quality of the product. Meat materials are complex multi-phase colloidal systems with unique fibrous structures that cannot be printed directly, and improving the printability of meat colloids mainly limits meat printing. The complexity of meat colloidal systems determines the different heat requirements. In addition, at this stage, the functionality of the printer and the formulation of a single nutritional and organoleptic properties limit the implementation and application of 3D printing. Moreover, the development of cultured meat, the full application of by-products, and the emergence of new technologies provides opportunities for the application of 3D printing in the meat industry. This review highlights the current challenges and opportunities for the application of 3D printing in meat to provide new ideas for the development of 3D printing.

Identification of off-flavor compounds and deodorizing of cattle by-products

An unnatural flavor in a food or drink product caused by the presence of undesirable compounds due to contamination or deterioration is called off-flavor. This study determined the characteristics of cattle by-products off-flavor (heart, liver, lung, rumen, and intestine). We identified 25, 34, 26, 22, and 26 volatile compounds from the heart, liver, lung, rumen, and intestine, respectively, in the bovine via headspace solid-phase microextraction/gas chromatography-mass spectrometry (HS-SPME/GC-MS). Based on the relative odor activity value (ROAV ≥ 1), 16 volatile compounds were labeled as characteristic off-flavor by principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA). The compounds involved in the characteristic off-flavor in bovine heart were E,E-2,4-nonadienal, E,E-2,4-decadien-1-al, hexanal, (E)-2-octenal, and decyl aldehyde. In the bovine liver, the off-flavor compounds were 1-nonanol, ethyl hexanoate, 2-octanone, and dodecyl aldehyde and in bovine lung 3-heptylacrolein was the off-flavor compound. In bovine rumen, heptaldehyde, octanal, p-cresol, and 1-nonanal were off-flavor compounds, and lastly, 1-octen-3-ol and E-2-nonenal were off-flavor compounds with bovine intestine. The cattle by-products were deodorized by shallot-ginger extract masking, baker's yeast fermentation, active dry yeast + β-cyclodextrin (β-CD) composite, and ultrasound + chitosan composite. The above 16 labeled characteristic compounds decreased in concentration. The ultrasound + chitosan composite method showed a significantly better effect than the other methods (p < .05). The aim of this study was to determine the characteristic flavor information of cattle by-products and provide idea on how to improve the flavor by various deodorization methods. PRACTICAL APPLICATIONS: This study investigated the volatile flavor compounds of cattle by-products from five organs (heart, liver, lung, rumen, and intestine) by headspace solid-phase microextraction/gas chromatography-mass spectrometry (HS-SPME/GC-MS). The 16 volatile compounds were labeled as the major characteristic off-flavor compounds by relative odor activity values and principal component analysis. Four different deodorization methods were adopted, and among them, ultrasound + chitosan composite method showed best results. This study has provided useful information about the characteristic off-flavor compounds and suggests how to improve the flavor of cattle by-products through various deodorization methods.

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.

Efficacy of n-3 fatty acid supplementation on rheumatoid arthritis' disease activity indicators: a systematic review and meta-analysis of randomized placebo-controlled trials

Theoretical evidence and previous studies suggest that oralnutrient supplementation (ONS) with n-3 fatty acids for rheumatoid arthritis (RA) has the potential to lower disease activity indicators and non-steroidal anti-inflammatory drug (NSAID) uptake. A systematic search was conducted on five databases/registries from inception until May 23, 2021 with the aim to identify randomized placebo-controlled trials comparing n-3 supplements to placebo on disease-specific outcomes. A total of 23 studies matched the criteria (PROSPERO: CRD42019137041). Pooled analyses revealed that n-3 ONS provided a small effect in reducing pain [standardized mean difference (SMD): -0.16, 95% confidence intervals (CI): -0.40 to 0.09], and tender (SMD: -0.20, 95% CI: -0.46 to 0.05) and swollen joint count (SMD: -0.10, 95% CI: -0.28 to 0.07). In sensitivity analyses, there was a small effect in the reduction of NSAIDs intake (SMD: -0.22, 95% CI: -0.90 to 0.46), and c-reactive protein was reduced only by 0.21 mg/dL (95% CI: -0.75 to 0.33). Similar findings were observed regarding other objective/subjective outcomes. The certainty of the evidence was mostly of "very low/low" quality. Overall, n-3 ONS in RA might have a limited clinical benefit. Previous findings suggesting a reduction in NSAID intake may have been biased from the inadequate blinding of interventions.

Olfactory and gustatory disorders caused by COVID-19: How to regain the pleasure of eating?

Background

Recently, anosmia and ageusia (and their variations) have been reported as frequent symptoms of COVID-19. Olfactory and gustatory stimuli are essential in the perception and pleasure of eating. Disorders in sensory perception may influence appetite and the intake of necessary nutrients when recovering from COVID-19. In this short commentary, taste and smell disorders were reported and correlated for the first time with food science.

Scope and approach

The objective of this short commentary is to report that taste and smell disorders resulted from COVID-19 may impact eating pleasure and nutrition. It also points out important technologies and trends that can be considered and improved in future studies.

Key findings and conclusions

Firmer food textures can stimulate the trigeminal nerve, and more vibrant colors are able to increase the modulation of brain metabolism, stimulating pleasure. Allied to this, encapsulation technology enables the production of new food formulations, producing agonist and antagonist agents to trigger or block specific sensations. Therefore, opportunities and innovations in the food industry are wide and multidisciplinary discussions are needed.

Protection of menhaden oil from oxidation in Pickering emulsion-based delivery systems with α-lactalbumin-chitosan colloidal nanoparticle

In this study, α-lactalbumin-chitosan (ALA-CHI) colloidal nanoparticles were spontaneously formed mainly through electrostatic interactions for stabilizing Pickering emulsion loaded with health-beneficial but unstable menhaden oil. The oxidative stability of menhaden oil was supposed to be significantly enhanced with Pickering emulsion-based delivery systems with ALA-CHI colloidal particles. The film of ALA-CHI colloidal nanoparticles had higher surface hydrophobicity than ALA at pH 5.0, and 6.5. A near-neutral wettability (89.6°) of ALA-CHI nanoparticles was observed at pH 5.0. Stable Pickering emulsions (60% menhaden oil fraction, w/w) were successfully fabricated with only 0.12% (w/w) of ALA-CHI nanoparticles. Pickering emulsions exhibited superior storage, heat, and centrifugation stability. The formation of gel-like structures was confirmed by rheological results. The viscosity and storage modulus in the frequency range of 0.1 to 10 Hz with a 1.0% strain exhibited remarkable increases with increasing colloidal particle concentration or oil fraction. Increasing oil fractions from 20% to 60% (w/w) or colloidal particle concentrations 0.12% to 2.40% (w/w) can pronouncedly facilitate the inhibition of lipid oxidation, as confirmed by detecting the formation of primary and secondary oxidation products.

Microparticles loaded with fish oil: stability studies, food application and sensory evaluation

AIM

Evaluate the stability of microparticles loaded with fish oil produced by spray drying, spray chilling and by the combination of these techniques (double-shell) and use the microparticles for food application.

METHODS

Samples were stored for 180 days at 6 °C and 24 °C (75% RH). Performed investigations included encapsulation efficiency, moisture content, aw, size (laser scattering), colour (L*, a*, b*), polyunsaturated fatty acids (PUFAs) (GC), thermal behaviour (DSC) and crystalline structure (XRD).

RESULTS

Double-shell microparticles containing 26 wt% core material, 22.74 ± 0.02 µm (D0.5) and 2.05 ± 0.03 span index, 1.262 ± 0.026 wt% moisture content and 0.240 ± 0.001 of aw had PUFAs retention higher than 90 wt% during storage at 6 °C without changes in crystalline structure (β'-type crystals) and melting temperature (54 °C). The sensory evaluation suggested low fish oil release in oral phase digestion.

CONCLUSIONS

Double-shell microparticles were effective to protect and deliver PUFAs.

Starch-based materials encapsulating food ingredients: Recent advances in fabrication methods and applications

Encapsulation systems have gained significant interest in designing innovative foods, as they allow for the protection and delivery of food ingredients that have health benefits but are unstable during processing, storage and in the upper gastrointestinal tract. Starch is widely available, cheap, biodegradable, edible, and easy to be modified, thus highly suitable for the development of encapsulants. Much efforts have been made to fabricate various types of porous starch and starch particles using different techniques (e.g. enzymatic hydrolysis, aggregation, emulsification, electrohydrodynamic process, supercritical fluid process, and post-processing drying). Such starch-based systems can load, protect, and deliver various food ingredients (e.g. fatty acids, phenolic compounds, carotenoids, flavors, essential oils, irons, vitamins, probiotics, bacteriocins, co-enzymes, and caffeine), exhibiting great potentials in developing foods with tailored flavor, nutrition, sensory properties, and shelf-life. This review surveys recent advances in different aspects of starch-based encapsulation systems including their forms, manufacturing techniques, and applications in foods.

Fish Oil Microcapsules as Omega-3 Enrichment Strategy: Changes in Volatile Compounds of Meat Products during Storage and Cooking

This work aims to analyze the effects of processing and storage on the volatile compound profile of different meat products enriched in ω-3 polyunsaturated fatty acids (PUFA). Monolayered (Mo) and multilayered (Mu) microcapsules of fish oil were tested. The profiles of volatile compounds were analyzed by solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS). The enrichment with Mo significantly increases the abundance of volatile compounds from lipid oxidation and markers of ω-3 PUFA oxidation, which may be related to the multilayer structure of chitosan–maltodextrin in Mu that achieves greater fish oil protection than the simple coating of maltodextrin in Mo. Besides, the changes in volatile compounds during storage depends on the type of fish oil microcapsules and the meat products, having an increased abundance of ω-3 PUFA oxidation markers in dry-cured sausages added with Mo. However, the enrichment of these meat products with Mo and Mu does not modify the usual variations in the volatile compound profile during culinary cooking. Thus, the addition of multilayer fish oil microcapsules may be a suitable option for enrichment of meat products in ω-3 PUFA without modifying the abundance of volatile compounds, including oxidation markers.

A systematic review and meta-analysis of fish oil encapsulation within different micro/nanocarriers

Fish oil is one of the most important sources of omega 3 polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid and docosahexaenoic acid which are the most important PUFAs with several health benefits. However, PUFAs are prone to oxidation and have a poor water solubility which limits the use of fish oils into food formulations. Encapsulation techniques can be applied to overcome these challenges. There is a large number of published micro/nanoencapsulation papers, where each of them contains a limited number of wall materials, feed formulation, encapsulation technique, and storage conditions. Therefore, without systematic evaluation of the data extracted from available studies, the design of functional foods containing fish oil would not be very successful. The objective of this systematic review is a meta-analysis of published researches on the nano/microencapsulation of fish oil. A comprehensive literature search was performed between 1 October and 31 December 2019 with encapsulation, fish oil, and oxidative stability keywords. Overall, 39 qualified articles were selected for the statistical analysis. Based on the technique used for encapsulation, the fish oil-loaded carriers were classified into four main groups: (a) spray-dried particles; (b) freeze-dried particles; (c) electrospun fibers and electrosprayed capsules; and (d) other carriers prepared by supercritical antisolvent, gelation, liposomes, spray-freeze drying, and transglutaminase catalyzed cross-linking. The three most frequent methods applied for fish oil encapsulation were spray drying (42.86%), freeze drying (21.43%), and electrohydrodynamic (19.04%) methods, respectively. Averagely, the best encapsulation efficiency was obtained for electrohydrodynamic processes. Also, the combination of polysaccharide-protein based wall materials provided the best performance in terms of fish oil encapsulation efficiency.

Effect of Omega-3 Microcapsules Addition on the Profile of Volatile Compounds in Enriched Dry-Cured and Cooked Sausages

The main goal of the present study was evaluating the effect of enriching meat products (cooked (C-SAU) and dry-cured sausages (D-SAU)) with monolayered (Mo) and multilayered (Mu) fish oil microcapsules on the profile of volatile compounds, with special interest in lipid oxidation markers. For that, Solid-Phase Microextraction (SPME) and Gas Chromatography-Mass Spectrometry (GC-MS) were used. Significant differences were found in the volatile compound profile between Mo and Mu, which was been reflected in the meat samples. Thus, in general, volatile compounds from lipid oxidation have shown higher abundance in Mo and C-SAU and D-SAU enriched with this type of microcapsule, indicating that the wall of Mu (chitosan-maltodextrine) might protect the encapsulated bioactive compounds more effectively than that of Mo (maltodextrine). However, this finding is not reflected in the results of previous studies evaluating the sensory perception and oxidation stability of C-SAU and D-SAU, but it should be considered since unhealthy oxidation products can be formed in the enriched meat products with Mo. Thus, the addition of Mu as an omega-3 vehicle for enriching meat products may be indicated.

Optimization and Analysis of Acid Treated Trimethylamine using Surface Response and Gas Chromatography Analytical Methods

Background:

Trimethylamine (TMA) is a nitrogenous base aliphatic organic compound accounting for the odor of rotten fish and it is used as an indicator for analyzing the quality of fish products.

Introduction:

Extraction procedures and analytical methods including colorimetric and Gas- Chromatography (GC) can quantify the TMA contents of fish products after pre-treatment with basic solutions. However, the extraction procedure and analytical methods for acid-treated samples are not known, despite the majority of fish products being preserved using acid preservatives.

Methods:

The methodologies used included solid-phase micro-extraction of TMA followed by its quantification by a GC-based analytical method. An analysis of response surface methodology was also conducted to verify the optimum conditions for TMA detection in acid-treated liquid samples affected by factors including trapping time, temperature, and stirring speed.

Results:

The results obtained from this study showed that the optimum conditions for the best yield of TMA extraction are 20 min of trapping, emission at 55°C, and stirring at 400 rpm. The validation of the developed method was carried out using rotten fish after acid treatment. Acid treatment decreased TMA by up to 73.01%, however, when adding NaOH solution of the same volume to the samples, TMA increased similar to the control group.

Conclusion:

Here, we report a simple, sensitive, and rapid extraction procedure. A GC-based analytical method was developed for the analysis of TMA from the acid-treated sample. The developed extraction procedure and analytical methods were optimized and validated, which could be helpful for the extraction of TMA without damaging the sample.

Evaluating the use of fish oil microcapsules as omega-3 vehicle in cooked and dry-cured sausages as affected by their processing, storage and cooking

This work evaluated the use of monolayered (Mo) and multilayered (Mu) fish oil microcapsules as vehicles of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in cooked and dry-cured meat products as affected by the storage and culinary heating or dry-cured processing. Proximate composition, oxidation, EPA and DHA quantity, acceptability and morphology were evaluated. Mo and Mu microcapsules increased the quantity of EPA and DHA, leading to cooked and dry-cured products susceptible to be labeled as "source of omega-3 fatty acids", without influencing physico-chemical characteristics, oxidative stability, acceptability or usual changes that take place during the culinary heating or dry-cured processing. The storage at refrigeration influenced on usual modifications on lipid oxidation and hedonic scores, but overall quality of the meat products enriched seems not to be impaired after storing. Thus, it could be indicated the viability of Mo and Mu as vehicles to enrich meat products subjected to low and high temperature for manufacturing, storage at refrigeration and culinary heating.

Application of Plackett-Burman Design in Screening of Natural Antioxidants Suitable for Anchovy Oil

Considering the safety of synthetic antioxidants, more and more natural antioxidants have been developed and utilized in foods. This study aimed to screen out a natural antioxidant combination from many antioxidants, which could significantly affect the oxidation stability of anchovy oil, while Plackett–Burman design (PBD) methodology was employed in this screening. According to the statistical results of this design, sesamol, dihydromyricetin, teapolyphenol, and rosemary acid were four significant parameters on the oxidation stability of anchovy oil. Moreover, dihydromyricetin presented the best antioxidant effect among nine kinds of selected antioxidants when they were used alone in anchovy oil. Meanwhile, a combination including sesamol (0.02%), teapolyphenol (0.02%). and rosemary acid (0.02%) was adopted, and its antioxidant ability was similar to that of tert-butylhydroquinone (TBHQ). Additionally, phytic acid as a synergist was used and combined with sesamol, and the antioxidant ability of this combination was better than that of TBHQ. This study presented a reference for the industrial applications of natural antioxidants and synergists in anchovy oil.

Flash Profile as an effective method for assessment of odor profile in three different fishes

Fish has a high nutritional value and its regular consumption is associated with lower probabilities of cardiovascular diseases. Brazilians are characterized as low fish consumers, and the fish odor significantly affects the consumer acceptance or rejection. Grass carp, catfish and pacu are three fishes with high potential of farming in the Southwestern region of Paraná, Brazil, and worldwide. The characterization of their odor profile using the Flash Profile technique is the focus of this study. With assessors selected for odor analysis, the assessment of samples of the three species of fish was carried out in two stages (1) generation of attributes using the Grid method and (2) evaluation of the fish samples, according to attributes individually selected, with 9 cm unstructured and anchored scales. The data was processed by using generalized procrustes analysis. A total of 19 selected assessors were able to recognize and describe the stimuli perceived by the different substances. The terminology surveyed revealed the term "fishy" as the most cited, followed by "pond water", "fat" and "rancid". Flash Profile provided a precise odor characterization and discrimination with quantitative differences among the fishes. Pacu was the species related to the terms earth, fat, plant, fridge and wood. Earth, viscera, putrid, fat, burnt oil, blood, fishy odor and acid characterized the catfish, related to the most negative descriptors. Grass carp was associated to the terms pond water, fishy odor, rancidity, fat and grass.

Effective Prevention of Oxidative Deterioration of Fish Oil: Focus on Flavor Deterioration

Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), both abundant in fish oil, are known to have significant biochemical and physiological effects primarily linked to the improvement of human health, especially cardiovascular and brain health. However, the incorporation of fish oil into foods and beverages is often challenging, as fish oil is very easily oxidized and can cause undesirable flavors. This review discusses this rapid formation of the fishy and metallic off-flavors, focusing especially on an early stage of fish oil oxidation. Although oxidative stability and quality of commercialized fish oil have improved over the past few years, there is a still a problem with its application: Flavor deterioration can be found even at very low oxidation levels. This review also notes the effective way to inhibit the formation of the volatile compounds responsible for the flavor deterioration.

Sensory description of marine oils through development of a sensory wheel and vocabulary

The Omega-3 industry lacks a defined methodology and a vocabulary for evaluating the sensory quality of marine oils. This study was conducted to identify the sensory descriptors of marine oils and organize them in a sensory wheel for use as a tool in quality assessment. Samples of marine oils were collected from six of the largest producers of omega-3 products in Norway. The oils were selected to cover as much variation in sensory characteristics as possible, i.e. oils with different fatty acid content originating from different species. Oils were evaluated by six industry expert panels and one trained sensory panel to build up a vocabulary through a series of language sessions. A total of 184 aroma (odor by nose), flavor, taste and mouthfeel descriptors were generated. A sensory wheel based on 60 selected descriptors grouped together in 21 defined categories was created to form a graphical presentation of the sensory vocabulary. A selection of the oil samples was also evaluated by a trained sensory panel using descriptive analysis. Chemical analysis showed a positive correlation between primary and secondary oxidation products and sensory properties such as rancidity, chemical flavor and process flavor and a negative correlation between primary oxidation products and acidic. This research is a first step towards the broader objective of standardizing the sensory terminology related to marine oils.

Thermo-Oxidative Stability Evaluation of Bullfrog (Rana catesbeiana Shaw) Oil

Bullfrog oil (BO), a natural product obtained from recycling of adipose tissue from the amphibian Rana catesbeiana Shaw, has been recently evaluated as a therapeutic activity ingredient. This work aimed to evaluate the long-term and accelerated thermal oxidative stabilities of this product, which is a promising raw material for emulsion technology development. BO was extracted from amphibian adipose tissue at 70 °C with a yield of 60% ± 0.9%. Its main fatty acid compounds were oleic (30.0%) and eicosapentaenoic (17.6%) acids. Using titration techniques, BO showed peroxide, acid, iodine and saponification indices of 1.92 mEq·O₂/kg, 2.95 mg·KOH/g oil, 104.2 g I₂/100 g oil and 171.2 mg·KOH/g oil, respectively. In order to improve the accelerated oxidative stability of BO, synthetic antioxidants butylhydroxytoluene (BHT) and buthylhydroxyanisole (BHA) were used. The addition of BHT increased the oxidation induction time compared to the pure oil, or the oil containing BHA. From the results, the best oil-antioxidant mixture and concentration to increase the oxidative stability and allow the oil to be a stable raw material for formulation purposes was derived.

α-Tocopheryl linolenate solid lipid nanoparticles for the encapsulation, protection, and release of the omega-3 polyunsaturated fatty acid: in vitro anti-melanoma activity evaluation

The main target of this study was the preparation, characterization and antioxidant activity evaluation of α-tocopheryl linolenate based solid lipid nanoparticles (SLNs-TL), able to incorporate omega-3 α-linolenic acid, useful for the treatment of melanoma, a type of skin cancer. In particular, α-linolenic acid was successfully derivatized with α-tocopherol and the obtained compound was characterized by Fourier transform infrared (FT-IR) and by ¹H NMR to confirm the ester linkage. Both the empty SLNs-TL that SLNs-TL-LIN, containing omega-3-linolenic acid, were prepared through the technique of the microemulsion. The nanoparticles were characterized for entrapment efficiency, size and shape. Their antioxidant activity was investigated in rat liver microsomal membranes in inhibiting the lipid peroxidation induced by tert-butyl hydroperoxide (tert-BOOH), which endogenously produces alkoxyl radicals by Fenton reactions. The obtained results indicate that the α-tocopherol, linked by ester bond to α-linolenic acid, maintains an excellent antioxidant activity. The encapsulation efficiency was equal to 77% and the polydispersity index 0.198 indicating a good dimensional distribution. Furthermore, the nanoparticles were tested in vitro for their cytotoxic activity against human melanoma cancer cell line C32. Both empty SLNs-TL and loaded SLNs-TL-LIN showed a high biological activity, being more effective than α-linolenic acid and α-tocopherol. The results indicated that these nanoparticles could provide the delivery and the protection of unstable molecules, such as α-linolenic acid, from degradation induced by mechanisms of oxidative stress.

Physicochemical and sensory characterization of refined and deodorized tuna (Thunnus albacares) by-product oil obtained by enzymatic hydrolysis

In this study, the effects of chemical refining and deodorization on fatty acid profiles and physicochemical and sensory characteristics of the tuna by-product oil obtained by enzymatic hydrolysis were evaluated. Enzymatic extraction was conducted for 120 min at 60 °C and pH 6.5 using Alcalase at an enzyme-substrate ratio of 1:200 w/w. The chemical refining of crude oil consisted of degumming, neutralization, washing, drying, bleaching, and deodorization; deodorization was conducted at different temperatures and processing times. Although chemical refining was successful, temperature and chemical reagents favored the removal of polyunsaturated fatty acids (PUFA) from the oil. Aroma attributes of fishy odor, frying odor, and rancid odor predominantly contributed to the sensory evaluation of the product. Deodorization conditions of 160 °C for 1h and 200 °C for 1h were recommended for the tuna by-product oil, which is rich in PUFA.

Thermal and oxidative stability of Atlantic salmon oil (Salmo salar L.) and complexation with β-cyclodextrin

The thermal and oxidative stability of Atlantic salmon oil (Salmo salar L.) as well as its β-cyclodextrin (β-CD) complexation ability has been verified for the first time. The main omega-3 fatty acids, EPA and DHA, were significantly degraded, even at 50 °C. Their relative concentrations decrease from 6.1% for EPA and 4.1% for DHA to 1.7% and 1.5% after degradation at 150 °C, respectively. On the other hand, the relative concentrations of monounsaturated and saturated fatty acids remained constant or slightly increased by a few percent after degradation (e.g., from 10.7% to 12.9% for palmitic acid). Co-crystallization of ASO with β-CD at a host–guest ratio of 1:1 and 3:1 from an ethanol–water mixture and kneading methods has been used for the preparation of β-CD/ASO complexes. The analysis of the complexes by thermogravimetry, differential scanning calorimetry (DSC), and Karl Fischer titration (KFT) as well as the decrease of the “strongly-retained” water content confirm the formation of the inclusion compound. Furthermore, the DSC parameters correlate well with the KFT kinetic data for β-CD/ASO complexes.

Phytosterol structured algae oil nanoemulsions and powders: improving antioxidant and flavor properties

Phytosterol structured algae oil nanoemulsions and powders were obtained using a one-pot sonification strategy and followed by spray-drying. β-Sitosterol and γ-oryzanol co-structured microencapsulation is a technique for burying fishy odor and preventing oil oxidation.

Off-flavour masking of secondary lipid oxidation products by pea dextrin

The aim of the present study was to evaluate the off-flavour masking potential of pea dextrin (PD) in emulsions rich in ω-3 and ω-6-fatty acids in comparison with maltodextrin (MD) and 2-hydroxypropyl-β-cyclodextrin (HPBCD). After optimisation of the homogenisation procedure, stable emulsions were prepared and stored for up to eight weeks. The development of six secondary lipid oxidation products: propanal, 1-penten-3-one, 1-penten-3-ol, hexanal, (E,E)-2,4-heptadienal and (E,Z)-2,6-nonadienal, was monitored via headspace gas chromatography after solid-phase microextraction. Sensory evaluation of the emulsions was performed by a trained panel. PD already showed masking properties for propanal, 1-penten-3-one, hexanal and (E,E)-2,4-heptadienal during validation of the gas chromatographic analysis, but not for 1-penten-3-ol or (E,Z)-2,6-nonadienal. During storage, the course of lipid oxidation was similar in all emulsions as concluded from the hydroperoxide value. Results from the sensory evaluation confirmed a masking of rancid off-flavour. In conclusion, pea dextrin is suitable for masking off-flavour resulting from early stages of lipid oxidation.

Nano- and microdelivery systems for marine bioactive lipids

There is an increasing body of evidence of the positive impact of several marine lipids on human health. These compounds, which include ω-3 polyunsaturated fatty acids, have been shown to improve blood lipid profiles and exert anti-inflammatory and cardioprotective effects. The high instability of these compounds to oxidative deterioration and their hydrophobicity have a drastic impact in their pharmacokinetics. Thus, the bioavailability of these compounds may be affected, resulting in their inability to reach the target sites at effective concentrations. In this regard, micro/nanoparticles can offer a wide range of solutions that can prevent the degradation of targeted molecules, increase their absorption, uptake and bioavailability. In this work we will present the options currently available concerning micro- and nanodelivery systems for marine lipids; with emphasis on micro/nanoparticles; such as micro/nanocapsules and emulsions. A wide range of bottom-up approaches using casein, chitosan, cyclodextrins, among others; will be discussed.