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In order to develop a healthy food with easily absorbable nutrients for the elderly, functional ready-to-eat seafood based on restructured fish fillets (from undervalued fish species) and encapsulated fish oil was prepared and assessed. Four restructured fish products (raw fillet, RF and raw fillet with encapsulated material incorporation, RF+, and fried fillet, CF and fried fillet with encapsulated material incorporation, CF+) were tested. The study entailed characterising lipid fraction and determining lipid and fatty acid (FA) bioaccessibility. Frying increased the weight of the n6 polyunsaturated FA (PUFA) content, from 3.9–5.1% to 6.8–10.2%. PUFA concentration decreased from 32.6–45.0 (RF and CF) to 28.3–34.4% (RF+ and CF+). Regarding bioaccessibility, the n3/n6 PUFA ratios were lowered in RF and RF+ and augmented in CF and CF+. To meet the EPA + DHA RDI and derive potential benefits for the elderly, two servings of RF, RF+ and CF+ and three servings of CF per week would suffice by ignoring bioaccessibility. However, based on bioaccessibility, 12 servings of RF and 6 servings of RF+ and CF contrast with only 2 servings of CF+. CF+ would be an excellent choice for enhancing n3 PUFA intake, thus representing a way of valorising undervalued marine resources through innovative functional food.

Burgos-type cheese is an ultrafiltered soft fresh cheese widely commercialized in Spain. Its structural behavior against external forces is of great importance for the dairy industry, since consumer acceptance depends mainly on texture. In the present study, dynamic and static oscillatory shear rheological analyses of 15 commercial Burgos-type fresh cheeses of different composition, brand and species were carried out to determine the relationship between cheese characteristics and rheological properties. Cheeses were differentiated mainly based on their fat:protein (F:P) ratio into 3 groups: low (L, F:P ≤ 0.1), medium (M, 0.1 < F:P < 0.9) and high (H, F:P ≥ 0.9). H cheeses showed higher complex modulus (G*0, 4131 ± 1238 Pa) when compared to L (2366 ± 1825 Pa), mainly related to cheese protein levels. L cheeses presented higher compliance (13.0 ± 4.5 × 10−4 Pa-1) than H (6.5 ± 3.3 × 10−4 Pa-1), indicating differences in the cohesiveness of the cheese matrix. The present research shows that low amplitude shear analysis together with creep-recovery assays would be complementary tools suitable for the rheological characterization of Burgos-type fresh cheeses and that their F:P ratio has a strong impact on cheese final structure.

The role of chitosan nanoparticles on the rheological behaviour, antioxidant properties and lipid digestibility of vinaigrettes was investigated in comparison with a protonated chitosan polymer. Nanoparticles were produced using different concentrations of tripolyphosphate (TPP) and acetic acid. The lower ionic concentrations were used to encapsulate a fish protein hydrolysate. Rotatory tests produced shear-thinning behaviour in the different nanoparticle suspensions. The vinaigrettes with addition of both chitosan and nanoparticles exhibited a stationary shear-thinning flow with viscoelastic characteristics of weak gels. The presence of chitosan nanoparticles in the emulsified oil phase produced a three-dimensional network with higher energy stability in the case of hydrolysate-loaded nanoparticles. Both chitosan and chitosan nanoparticles increased the radical scavenging capacity of vinaigrettes, but not the ferric ion reducing power. Addition of empty or hydrolysate-loaded nanoparticles reduced lipid digestion in vinaigrettes to a greater extent than chitosan (≈45% with nanoparticles; 33% with chitosan).

Atlantic horse mackerel (Trachurus trachurus) fillets were coated by gallic acid and chitosan solutions, including chitosan nanoparticles, and fish quality and shelf life were assessed during chilled storage for 13 days. All chitosan-containing coatings decreased microorganisms’ growth in more than 2 log cycles up to late storage stages; however, those with chitosan nanoparticles resulted to be more effective, probably due to a greater contact surface with fish muscle. Furthermore, the lowest total volatile basic nitrogen (TVB-N) values, as well as pH values below 7, were found for horse mackerel fillets coated by those solutions with chitosan nanoparticles. Additionally, horse mackerel fillets coated by solutions with chitosan nanoparticles also showed the lowest thiobarbituric acid reactive substances (TBARS) values, maybe owing to a more sustained release of gallic acid. In this regard, it is worth noting that, although gallic acid solution showed no antimicrobial activity, this prevented lipid oxidation and, therefore, preserved color and texture during the chilling storage.

Encapsulation in polymer NPs (NPs) is a well-recognized way to improve the oral bioavailability of hydrophobic and hydrophilic compounds by enhancing their solubility in aqueous medium, to protect them from acid and enzymatic degradation in the gastrointestinal tract, and to favour their permeability across the mucosal membranes. Nanostructures rather than larger delivery systems are also proposed to encapsulate prebiotics, probiotics and natural antimicrobial compounds, as they allow greater penetration of the mucous layer, as well as lower and longer dosages. The NPs with mucoadhesive capacity are designed specifically to increase the residence time at the intestinal absorption sites due to their ability to adhere to the intestinal mucosa. However, they should also be able to penetrate through the mucosa to reach the enterocytes or intestinal absorptive cells. By using the appropriate materials, the size and surface properties of NPs can be routed towards a particular mucus-interaction mechanism. Polymer NPs are widely employed for oral delivery applications in the pharmaceutical industry, since their surface properties are easily tunable to improve mucoadhesive capacity and mucus penetrating ability. Due to their biodegradability, biocompatibility and non-toxicity, biopolymer NPs have gained interest in recent years as mucoadhesive delivery systems for potential food applications. This review aims to promote attention to the use of food-grade biopolymer NPs to increase the bioavailability of natural compounds based on their mucoadhesive potential, and to facilitate the delivery of prebiotics, probiotics and antimicrobials along the gastrointestinal tract. This also includes a previous brief introduction to the complex mucoadhesion mechanism and common evaluation methods for determining mucoadhesiveness in nanoparticulate systems.

This study aimed to microencapsulate protein hydrolysates from stripped weakfish (Cynoscion guatucupa) industrial byproducts produced by Alcalase (HA) and Protamex (HP) by spray drying, using maltodextrin as wall material. The physicochemical characteristics, and in vitro antioxidant and Angiotensin-I converting enzyme-inhibitory activities were evaluated during storage. Both microencapsulated hydrolysates showed spherical shape (~3.6 µm particle diameter), low water activity (<0.155) during storage and reduced hygroscopicity (~30%) compared to the free hydrolysate. Infrared spectroscopy evidenced the maltodextrin-hydrolysate interaction. Based on the in vitro results, nematoid C. elegans in L1 larval stage were treated with free and microencapsulated HP, which demonstrated a protective effect on nematoid exposed to oxidative stress (survival ~ 13% control, 77% free HP, and 85% microencapsulated HP) and improved their growth and reproduction rate. Thus, microencapsulation appears to be a good alternative to maintain hydrolysates stability during storage, showing bioactivity in C. elegans.

The aim of the present work was to fortify yogurt by adding a stripped weakfish (Cynoscion guatucupa) protein hydrolysate obtained with the enzyme Protamex and microencapsulated by spray drying, using maltodextrin (MD) as wall material. The effects on the physicochemical properties, syneresis, texture, viscoelasticity, antioxidant and ACE inhibitory activities of yogurt after 1 and 7 days of storage were evaluated. In addition, microbiological and sensory analyses were performed. Four yogurt formulations were prepared: control yogurt (without additives, YC), yogurt with MD (2.1%, YMD), with the free hydrolysate (1.4%, YH) and the microencapsulated hydrolysate (3.5%, YHEn). Yogurts to which free and microencapsulated hydrolysates were added presented similar characteristics, such as a slight reduction in pH and increased acidity, with a greater tendency to present a yellow color compared with the control yogurt. Moreover, they showed less syneresis, the lowest value being that of YHEn, which also showed a slight increase in cohesiveness and greater rheological stability after one week of storage. All yogurts showed high counts of the microorganisms used as starters. The hydrolysate presence in both forms resulted in yogurts with antioxidant activity and potent ACE-inhibitory activity, which were maintained after 7 days of storage. The incorporation of the hydrolysate in the microencapsulated form presented greater advantages than the direct incorporation, since encapsulation masked the fishy flavor of the hydrolysate, resulting in stable and sensorily acceptable yogurts with antioxidant and ACE inhibitory activities.

In this study, chitosan nanoparticles (CNPs) were prepared by the ionic gelation technique with tripolyphosphate (TPP), and the effect of CNP composition and physicochemical characteristics were evaluated. After the synthesis optimization, CNPs were used as carriers for a fish protein hydrolysate (FPH) with bioactive properties (CNPH). The physicochemical characteristics, antioxidant capacity and antimicrobial, antihypertensive and emulsifier properties of unloaded and loaded CNPs in a food system model were studied. CNPH showed a uniform particle distribution, size ~200 nm, high stability (zeta potential around 30 mV), radical scavenging activity and increased antimicrobial activity against Staphylococcus aureus, Shigella sonnei and Aeromonas hydrophila. Additionally, CNPH showed an angiotensin I-converting enzyme (ACE)-inhibitory activity of 63.6% and, when added to a food emulsion model, this system containing CNPs, with or without FHP, exhibited improved food emulsion stability. Thus, CNPs were able to carry the FPH while maintaining their bioactive properties and can be an alternative to the delivery of bioactive peptides with potential as an emulsion stabilizer for food applications.

The ability of compounds of natural origin (black, white, red, and green tea extracts, phytic acid) to inhibit TMAO-demethylase enzyme was assayed. Black tea and phytic acid exerted the highest inhibiting activities, similar to the already known inhibitor sodium citrate. Hake minces incorporating these three compounds were prepared and stored frozen (150 days, –12 °C). TMAO-demethylase enzyme was partially inhibited (lower enzyme activity, reduction of formaldehyde accumulation). The study of physicochemical properties of the minces (salt-soluble proteins, water holding capacity, structural water associated with myofibrils) pointed to evident protein aggregation and loss of functionality when phytic acid was added, whereas black tea and sodium citrate did not have a negative effect. Consequently, the salt-ground mince with phytic acid showed worse viscoelastic properties than the others. In conclusion, black tea polyphenols and sodium citrate can be used as additives to inhibit TMAO-demethylase enzyme during frozen storage of fish minces.

The influence of different melanosis-inhibiting formulations on sensory parameters, texture, water holding capacity and microbiological properties of frozen deep-water rose shrimp (Parapenaeus longirostris) was evaluated throughout 6 months of storage at −18 °C. Eight formulations were tested: three of them containing 4-hexylresorcinol (4-HR, 0.05, 0.1 and 0.25%, w/v) in combination with organic acids (citric, ascorbic and acetic) and chelating agents (ethylenediaminetetraacetic acid and di-sodium di-hydrogen pyrophosphate); four commercial formulae based on sulphites (alone or accompanied by gluconic acid, chitosan or glucose), and a commercial blend based on 4-HR and NaCl. Non-treated shrimp were used as control. 4-HR-based treatments, as well as the joint use of sulphites and d-gluconic acid, were very effective in preventing melanosis during storage without affecting sensory parameters. All formulations assayed did not alter the water holding capacity of muscle protein during frozen storage. In general terms, shrimp hardness increased after a melanosis-inhibiting blend treatment and remained more or less constant during storage. From the microbiological point of view, experimental formulations with 4-HR reduced the total microbiota after treatment, especially at 0.1% (w/w). After 6 months of frozen storage, for most microbial groups studied counts were lower than the limit of detection, except in shrimp treated with the commercial 4-HR-based formulation, where counts were close to 3 log cfu/g. The melanosis-inhibiting blends assayed were useful to preserve sensory, functional and microbial quality in shrimp after six months of frozen storage.

Films with appropriate mechanical properties and low permeability are very important for food packages. The aim of this research was to develop and characterize the ternary films made from chitosan (CH), poly(vinyl alcohol) (PVA), and fish gelatin (FG) at different blend compositions (50/50/0, 40/40/20, 35/35/30, 30/30/40, and 25/25/50, CH/PVA/FG) via a simple casting method. Stress-strain curves showed that the incorporation of 20% FG into the films made them tougher as well as making them more elastic; optimum ternary films were obtained using CH/PVA/FG ratio of 40/40/20, giving maximum values of TS and EAB as 41.93 ± 3.24 MPa and 133.13 ± 13.23%, respectively. The water vapor permeability (WVP) values of the ternary films were in the range of 0.686–0.818 g mm/kPa h m2. With increasing FG content, the WVP of the films increased to some extent, whereas the water solubility was reduced up to 23%. Water absorption increased with increasing FG concentration up to 874%. Meanwhile, the ultraviolet–visible-light barrier of the resultant ternary films was significantly improved with the addition of FG; at the same time, an increase in FG concentrations also made the films more opaque and improved their thermal stability. FT-IR spectra showed interactions through hydrogen bonding between the polar groups of FG and hydroxyl moieties of CH and PVA in the blends, which enhanced the compatibility between the three polymers. X-ray diffraction analysis suggested compatibility among the polymeric-blends, and changes of the surface of the films was confirmed by SEM and AFM analyses. The obtained results suggested the effectiveness of blending approach in improving the compatibility of polymers and overall functionality of films.

Unwanted catches are an under-utilised marine resource. The European Union Regulation 1380/2013 introduces the obligation to land unwanted catches, creating the need to find an economically viable solution for the exploitation of these species that cannot be used for direct human consumption. Fishing discards, by their own condition, are constituted by a variable number and proportion of species whose composition changes with seasonality, fishing area, etc. At the industrial level, this heterogeneity is a limitation to valorise this precious resource by means of the elaboration of restructured products. Therefore, the design of standardized formulas for obtaining fishery products from them, to which technological and/or functional ingredients can be added, is a promising way to valorise and take advantage of this resource. The objective of this work was to evaluate the functional effect of a product made from different underutilised fish species and leaves of a halophyte plant (sea fennel) in mice. The animals were fed with the functional product or with standard diet during one month. Different blood parameters and composition of the intestinal microbiota were then analysed. The consumption of the functional product increased the iron levels in blood. Moreover, the total cholesterol levels lowered significantly, while the glucose levels decreased. On the other hand, the study of the intestinal microbiota indicates a tendency to increase the percentage of Bacteroids in groups that consumed fish protein as opposed to the control. To conclude, this product has shown an important functional effect in mice, and further studies should be performed on humans to confirm its functionality.

Sea aster (Aster tripolium) is a halophyte plant that is confined in its distribution to salt marshes, estuaries and occasionally to inland salt works. The fleshy leaves have a sweet taste, but they are scarcely consumed. Sea aster could be used as crop plant for human consumption in a future. Moreover, this plant is a rich source of polyphenols with significant nutraceutical benefits to humans. In this work, leaves of sea aster collected at the northeast coast of Spain were characterized. The water, fiber and fat content were 92 1 and 0.2%. The lipid fraction was mainly composed of omega-3 fatty acids A relevant amount of iron was found. The amount of heavy metals was lower than 1 ppm. The amino acid profile showed abundance of glycine, aspartic and glutamic acid, and alanine Studies in Caco2 and HTP1 cell lines revealed the absence of cytotoxicity even at concentration of 7.5%.The polyphenolic extract obtained from stems and leaves showed relevant antioxidant activity. Moreover, the extract showed ability to produce inhibition of different enzymes with an important role in different human disorders: Angiotensin-Converting enzyme (ACE, implicated in the control of blood pressure), Dipeptidyl-Peptidase IV (DPP-IV, for maintenance of normal glucose homeostasis) and Prolyl Endopeptidase (PEP, involved in cognitive disorders). The half maximal inhibitory concentration (IC50) was used to measure the potency of the extract in inhibiting the enzyme activity. The obtained results were 0.73 mg/ml (ACE), 0.92 mg/ml (DPP-IV) and 1.29 mg/ml (PEP). The proximal composition suggest that sea aster has potential to be used for human consumption. In addition, its leaves and stems are a source of bioactive polyphenols with potential activity against various chronic diseases. Its use as nutraceutical, cosmeceutical, and pharmaceutical molecules should be explored for specific applications.

Protein by-products from Stripped weakfish (Cynoscion guatucupa) were hydrolysated (5% degree of hydrolysis) using Alcalase or Protamex. The cytotoxicity, and its antioxidant and ACE-inhibitory activities before and after a simulated in vitro gastrointestinal digestion, as well as its bioaccessibility, were determined. Both hydrolysates had similar values of 2,2´-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activity (ABTS), although Protamex hydrolysate attained higher values in ferric-reducing antioxidant power (RP) and greater antihypertensive capacity. After digestion (4 h), ABTS values remained constant. However, RP values decreased over time, which was reflected in lower bioaccessibility. Cell line assays of Caco2 showed that hydrolysates were not cytotoxic. Then, the chitosan nanoparticles loaded with Protamex hydrolysate was carried out in order to protect it from a possible loss of activity and to be able to control release. The size of the resultant particles were < 200 nm, potential Z >30 mV with encapsulation efficiency of 43%. As for the antioxidant activity (ABTS), the results revealed a gradual and controlled release of the peptide from the nanoparticle, which varied according to the amount of crosslinking agent. Likewise, the hydrolysate maintained its antihypertensive activity once nanoencapsulated. In order to evaluate their potential application, the nanoparticles were incorporated into a model emulsion or a real mayonnaise-type system. Emulsions with nanoparticles retain a higher lipid content at the pH of the emulsion (3.3), and to a greater extent at pH 7.5, 37ºC (intestinal conditions), while an increase in the release of peptides from charged nanoparticles was also observed. In the real system (mayonnaise), the nanoparticles conferred a good consistency, with similar stability and less lipid release.

Although the consumption of algae in the western diet is increasingly growing, the main use of these is to obtain their polymers, which in the case of brown algae, such as Laminaria, are mainly alginates, fucoidan and laminaran. During the extraction process of polysaccharides, other compounds are usually removed, which constitute a bioactive potential of great interest, as they are usually proteins, polyphenols and carotenoids in variable proportion according to species. The OBJECTIVE of this work is the integral use of Laminaria digitata, through the extraction of alginate, and the by-products generated, such a proteins, which are extracted as hydrolysates. The hydrolysate encapsulation in nanoliposomes of phosphatidylcholine and their stabilization with sodium alginate by means of drying methods (atomization and lyophilization) is also intended, as a model of application. Sodium alginate was extracted from Laminaria digitata with a yield of 66%. The by-products were used to obtain a hydrolysate with antioxidant and antihypertensive properties, which could be encapsulated with high encapsulation efficiency in soy phosphatidylcholine liposomes. The cellular viability of the Laminaria hydrolysate and the liposome loaded with hydrolysate in CaCo 2 and THP 1 cell lines was 100% in all the tested concentrations. These liposomes were stabilized by coating with the extracted sodium alginate by using one of the two processes: lyophilization or atomization. The atomization proved to be more suitable for desiccation and preservation of the liposomal particle properties. Of the coated liposomes, the atomized ones were slightly smaller than the lyophilized ones. Both liposomes showed high stability at different pH during one week stored in refrigeration, with very electronegative Z potential values.

The application of nanoparticles and nanostructures in meat and fishery products is relatively recent and is arousing increasing interest. Nanostructure magnifies the properties with respect to traditional compounds (which are larger), owing to the greater surface area exposed and the small size, facilitating greater accessibility in food. There are many different kinds of nanoparticles and nanostructures; for example, they may use metals or substances of vegetable or animal origin, such as chitosan structures. Otherwise, the application of natural compounds to maintain product quality is increasingly demanded, but the sensory characteristics of the products limit their use. Encapsulation by nanovesicles (emulsions and liposomes) of these compounds is a good strategy to mitigate their sensory characteristics while allowing progressive release of the bioactive agent to exert its action. This is the case with essential oil nanoemulsions. Liposomes entrapping bioactive compounds of many different kinds could be ingredients for the design of functional food products, while they improve the nutritional value because of their high-quantity polyunsaturated fatty acid, but they can also be used in the food industry for a large diversity of technological purposes. Meat and fishery product packaging can be improved by nanotechnology in aspects concerning the improvement of physicochemical properties and the design of active and intelligent packages. With regard to the use of nanobiosensors, often, they are mere prototypes, but no doubt, they will soon be implemented in industrial quality control because they present high sensitivity, repeatability, and quickness. They are mainly applied to guarantee species identification and to detect compounds and microorganisms.

A shrimp extract (SME) obtained from the mild-acid demineralization treatment of shrimp shells to produce chitosan was collected. It was mainly composed of fat (≈73%), protein (≈19%), and ash (≈9%) and contained considerable amounts of calcium (≈1.9 g/100 g), astaxanthin (≈30 mg/100 g) and unsaturated fatty acids (≈27% MUFA, ≈39% PUFA). The SME was used in combination with chitosan for wrapping raw salmon to produce a ready-to-eat product enriched in calcium. No significant changes in hardness were found, as compared to the unwrapped salmon. Estimated intakes of bioaccessible calcium increased significantly by 3.6-fold, whereas intake of bioaccessible fat was reduced by 15%. SFA were the main fatty acid group reduced (≈80%), whereas MUFA and PUFA were only reduced by ≈20% each. Total viable counts, pseudomonads, enterobacteria, and specific fish spoilers were reduced by 2–4 log CFU/g in wrapped sample during the chilled storage period (19 days).

Soy phosphatidylcholine liposomes encapsulating increasing concentrations of two sea fennel extracts (aqueous and ethanolic) prepared by ultrasonication were freeze-dried, using glycerol as lyoprotectant. Particle properties, water dispersibility, colour, thermal properties and antioxidant capacity (radical scavenging capacity, ferric ion reducing power, Folin-reactive substances) of the liposomal preparations were determined. The freeze-drying process caused an overall increase in particle size and polydispersity index, while the zeta-potential became more electronegative. Both sea fennel extracts were rich in chlorogenic acid (42.61 and 58.48 mg/g for the aqueous and ethanolic extracts, respectively) and showed great antioxidant activity. Vitamin C was identified in the aqueous extract, whereas rutin and rosmarinic acid in the ethanolic one. The entrapment efficiency, determined in the liposomes prepared at the highest extract concentration, was 65.6% and 49.1% for the aqueous extract and the ethanolic extract, respectively. The liposomal antioxidant activity and total phenolic content followed a linear increasing tendency as a result of increasing the extract concentration, irrespective of the type of extract. Higher antioxidant activity was found in the liposomes loaded with the ethanolic extract, in a clear relationship to the greater amount of highly antioxidant phenolic compounds extracted, and also to their lower entrapment efficiency, which caused a greater amount of extract to remain outside the liposome. Both extracts were suitable for producing liposomes with antioxidant properties which could be dried and used to design functional foods.

A shrimp peptide fraction (ST1) with biological activity (ABTS radical scavenging capacity, angiotensin-converting enzyme and dipeptidyl-peptidase-IV inhibitory activities), was encapsulated in partially purified soy phosphatidylcholine nanoliposomes (L-ST1) using glycerol to preserve the bilayer during the film-forming dehydration step. The z-average, zeta potential and encapsulation efficiency of L-ST1 were, respectively, 99.98 nm, −53.87 mV and 52.37%. Transmisssion Electron Microscopy images showed that the liposomes incorporated in sodium caseinate films caused film matrix disruption, but vesicle structure was well preserved and uniformly distributed along the film matrix. The films with liposomes became more water soluble, adhesive and mucoadhesive, with no changes in thickness or transparency. The film showed a very favourable taste perception, regardless the presence or type of liposomes, while the buccal dissolution was faster with the films carrying the liposomes. The film could be used in different food designs without distorting the sensory acceptance of the final product.

The aim of this work was to assess the effect of several melanosis-inhibiting formulations on quality of deepwater pink shrimp (Parapenaeus longirostris) during storage. The formulations tested were as follows: one containing 4-hexylresorcinol (0.1%) in combination with organic acids (citric, ascorbic and acetic) and chelating agents (ethylenediaminetetraacetic acid [EDTA] and di-sodium di-hydrogen pyrophosphate [PPi]); a commercial formula based on sulphites (3%), and another formulation containing a mixture of chitosan (0.3%) and commercial sulphites. Non-treated shrimp were used as control. The 4-hexylresorcinol-based formulation was more effective than 3% of commercial sulphite solutions in preventing melanosis. This treatment prolonged the sensory acceptability of shrimp by up to six days in ice storage. During chilled storage, the treatment with the 4-hexylresorcinol-based formula inhibited the growth of microorganisms by 1.5–2 log cycles as compared to commercial sulphites, especially HS-producers and pseudomonads. At the end of the experimental period, TVB-N levels were slightly higher in the lot treated with 4-hexylresorcinol (33 mg/100 mg) and reflected greater endogenous enzymatic activity, since the counts of the spoiler microorganisms remained around log 5 cfu/g or even lower. In general, the incorporation of chitosan to sulphites did not improve or produce a marked effect on shrimps during storage. During the sensory analysis, the panellists rated all the lots very similar, although the 4-hexylresorcinol formulation was the only one with a neutral odour at the end of the period. The 4-hexylresorcinol-based formulation induced yellow-green colorations to some extent in the cephalothorax, possibly due to the effect of organic acids and chelants, while the rest of the lots presented greyish/blackish colorations. Therefore, the formulation based on 4-hexylresorcinol may safely substitute traditional sulphites to improve the quality of fresh shrimp and prol