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Fish represent one of the most perishable food groups. Therefore, it is important to find viable alternatives that contribute to the preservation of quality and increase the shelf life of fishery products, and one alternative is to use natural extracts with antimicrobial activity. The objective of this study was to determine the effect of a natural extract prepared with garlic (NGE) on the quality and shelf life of tilapia fillets stored on ice for 18 days. For this purpose, NGE was prepared by homogenizing peeled garlic cloves with distilled water, which were then centrifuged to obtain the extract (NGE); then, the fish fillets were immersed in the extract and were coated in NGE. The fillets with NGE were packed in high-density polyethylene bags and stored in crushed ice for 18 days. The adenosine 5′-triphosphate (ATP) and degradation products, K-value, color, texture, water holding capacity, pH, total mesophilic count, and total volatile bases (TVB-N) were monitored during storage. The ATP content, K-value, pH, total microbial count, and TVB-N changed with respect to ice storage time, and the results between fillets with NGE and control fillets differed. In conclusion, the application of NGE increased the shelf life of fillets stored on ice by 6 days, obtaining a shelf life of 18 days on ice, which shows its potential to improve the utilization of the species.

Fishing products are characterized for being highly perishable; therefore, preservation methods are used to retain freshness and quality and extend shelf life. One of the factors that most impact the loss of freshness, quality, and shelf life is storage temperature. This study evaluated the effect of storage temperature (0 ºC and 5 °C) on the quality and shelf life of tilapia (Oreochromis niloticus) muscle during 20 days of storage. Adenosine 5’-triphosphate (ATP) and related compounds, K-value, pH, color, texture, water holding capacity (WHC), total volatile bases (TVB-N), and total count of mesophilic microorganisms were monitored. Both time and storage temperature had a significant effect (P < 0.05) on the K-value, TVB-N, and total count of mesophilic microorganisms. The overall results of this study indicated that the edible quality of tilapia muscle was affected by storage temperature, observing a shelf life of 16 days at 0°C and 8 days at 5 ºC.

During the harvest, processing, and distribution of avocado (Persea americana Mill.), a large amount of waste (peel, seed, and pulp) is produced, which has proven to have antioxidant properties and this by-product might be used as input within the food production chain. This study evaluates the lipid oxidation, antioxidant capacity and phenolic compounds of two pastes made with avocado by-products (with seed: PS and without seed: PWS) during 60 d stored under refrigeration. On the results obtained, an analysis of variance (ANOVA) was performed, followed by the Tukey’s test (p ≤ 0.05). The lipid oxidation was controlled in both pastes and was even reduced during storage. In the PS, the antioxidant capacity declined, although it remained high and very similar to the PWS towards the end of the storage. The concentration of phenolic acids increased during most of the time of storage. Although PWS displayed better results with two of the analyses performed, both pastes were considered to have important antioxidant characteristics, which remained during the refrigerated storage. Due to this, its potential use in the production of foods is inferred, particularly for animals such as cattle, pigs, in aquaculture, or even in the cosmetics industry.

This study describes the preparation and characterization of eggplant peel extract-loaded electrospun gelatin nanofiber and study of its in vitro release. Results obtained by scanning electron microscopy (SEM) and transmission electronic microscopy (TEM) micrograph revealed that eggplant peel extract-loaded electrospun gelatin nanofiber is in nanometric range with an average diameter 606.7 ± 184.5 and 643.6 ± 186.7 nm for 20 and 33.3 mg mL

El objetivo de la presente investigación fue evaluar el efecto de la temperatura de almacenamiento (0 y 5ºC) sobre los principales metabolitos y parámetros relacionados con el rigor mortis del músculo de tilapia (Oreochromis niloticus). Se evaluó el índice de rigor (IR), adenosina 5´-trifosfato (ATP), glucógeno, ácido láctico, pH y textura. El análisis del IR se realizó durante 266 h de almacenamiento a las dos temperaturas, mientras que el resto de los parámetros se monitorearon al tiempo 0 y a las 48 h de almacenamiento en ambas temperaturas. Se encontró que tanto la temperatura como el tiempo de almacenamiento presentaron un efecto significativo sobre el IR, siendo más pronunciado a 5°C en comparación al de 0°C.ABSTRACTThe aim of this research was to evaluate the effect of storage temperature (0 and 5°C) on the main metabolites and related parameters to rigor mortis in muscle of tilapia (Oreochromis niloticus). The rigor index (IR), adenosine 5’-triphosphate (ATP), glycogen, lactic acid, pH and texture were evaluated. The IR analysis was performed during 266 hours of storage at the two temperatures, while the rest of the parameters were monitored at 0 and at 48 hours of storage at both temperatures. It was found that both temperature and storage time, had a significant effect on IR, being more pronounced at 5°C compared to 0°C.

El presente trabajo de investigación determinó el efecto de la temperatura estable y oscilante del agua de mar a tres diferentes niveles (21, 24 y 28°C), sobre la condición fisiológica de la almeja mano de león Nodipecten subnodosus. Para ello, se evaluaron los siguientes indicadores fisiológicos: contenido de adenosina trifosfato (ATP), glucógeno y carbohidratos totales, así como índice de rendimiento muscular (IRM) y carga energética adenilada (CEA), los cuales se determinaron en el músculo abductor de organismos extraídos directamente de la laguna y después de la aplicación de los tratamientos. Se encontró que, en el experimento, las concentraciones de ATP, contenido de glucógeno, carbohidratos totales, e IRM disminuyeron significantemente (P

The aim of this study was to evaluate the effects of chitosan-tomato plant extract (C-TPE) edible coating (EC) applications on the physicochemical, microbiological, sensory and antioxidant capacity of chicken during storage. Edible coatings prepared with chitosan 1%, acetic acid 1%, glycerol and TPE (0.1 and 0.3%) were tested. The slices were submerged for 1 minute in different treatments (T1: C 1%; T2: C 1% + TPE 0.1%; T3: C 1% + TPE 0.3%; T4: control) and stored at 4 °C. At the end of the storage period, the treatments exhibited the greatest physicochemical and microbiological effects in the slices, reducing the microbial population relative to the control. The T2 treatment exhibited the highest antioxidant capacity, total phenolic content and overall acceptance. The results demonstrate that the application of C with the addition of a natural extract, such as those from the tomato plant, can be an alternative method for preserving chicken meat.

Collagen is the major connective tissue (CT) protein and one of the main constituents of the jumbo squid (Dosidicus gigas). Therefore, physicochemical changes of pepsin-solubilized collagen (PSC) and insoluble collagen (IC) were studied after cooking (100°C/30 min) of muscle (mantle, fins, and arms). Different pyridinoline (Pyr) contents (the major cross-linking molecule in collagen fibers) were found in the fresh muscle of the three anatomical regions. After the cooking process, a decrease from 10 to 30% in the thermal resistance of collagen was observed, depending on the anatomical region and fraction evaluated. Furthermore, the electrophoretic profile, Fourier transform infrared (FTIR) spectroscopy, and the amino-acid profile revealed that structural changes occurred in the two different collagen fractions caused by the thermal process, and the changes were greater in the mantle. Under the conditions applied in this study, collagen fractions from the squid arms showed more stability during the cooking process due to the high cross-linking degree of their fibers.

The giant squid (Dosidicus gigas) has been proposed as raw material to obtain myofibrillar protein concentrates. However, it has been observed that colloidal systems formed from squid proteins have limited stability. Therefore, the isolation and characterization of the actomyosin-paramyosin isolated (API) complex were performed, because they are the main proteins to which functionality has been attributed.; Results: Densitogram analysis revealed 45% of actin, 38% of myosin and 17% of paramyosin. The amino acid profile indicates a higher proportion of acidic amino acids, which gives a higher negative charge; this was supported by the zeta potential. Total sulfhydryl (TSH) content was lower compared with proteins of other aquatic species.; Conclusion: The higher percentage of actin in relation to myosin, the presence of paramyosin, as well as the low content of sulfhydryl groups, could comprise the main causes of the low technological functional property of proteins from D. gigas mantle. © 2017 Society of Chemical Industry.; © 2017 Society of Chemical Industry.

The antibacterial activity of low-density polyethylene/adhesive resin (10%)/epigallocatechin gallate (0.03, 0.5, 5, and 10%) extrusion cast films were evaluated against Staphylococcus aureus (gram positive) and Pseudomonas sp. (gram negative) via direct contact and in solid and liquid culture media. The epigallocatechin gallate concentration in the active films was established per the in vitro antibacterial analysis of pure epigallocatechin gallate against S. aureus and Pseudomonas sp. The epigallocatechin gallate migration profile and concentration required to inhibit bacterial growth in broth were determined. In addition, the effects of epigallocatechin gallate and adhesive resin on the mechanical, color, and thermal film properties were investigated. The results indicate that pure epigallocatechin gallate inhibited the growth of both bacteria. However, only the films with 10 wt% epigallocatechin gallate (with and without adhesive resin) induced morphological changes and inhibited the growth of S. aureus (p

Chitosan was functionalized with epigallocatechin gallate (EGCG) by a free radical-induced grafting procedure, which was carried out by a redox pair (ascorbic acid/hydrogen peroxide) as the radical initiator. The successful preparation of EGCG grafted-chitosan was verified by spectroscopic (UV, FTIR and XPS) and thermal (DSC and TGA) analyses. The degree of grafting of phenolic compounds onto the chitosan was determined by the Folin-Ciocalteu procedure. Additionally, the biological activities (antioxidant and antibacterial) of pure EGCG, blank chitosan and EGCG grafted-chitosan were evaluated. The spectroscopic and thermal results indicate chitosan functionalization with EGCG; the EGCG content was 25.8mg/g of EGCG grafted-chitosan. The antibacterial activity of the EGCG grafted-chitosan was increased compared to pure EGCG or blank chitosan against S. aureus and Pseudomonas sp. (p

The aim of this study was to evaluate the effectiveness of chitosan&ndash, tomato plant extract (C-TPE) edible coating (EC) on the physicochemical, microbiological, sensory, and antioxidant capacity changes of pork during storage. Edible coatings prepared with chitosan 1%, acetic acid 1%, glycerol, and TPE (0.1% and 0.3%) were tested. Slices of pork were submerged in different treatments (T1: C 1%, T2: C 1% + TPE 0.1%, T3: C 1% + TPE 0.3%, T4: control) and stored at 4 &deg, C. The different treatments showed the best results in physicochemical and microbiological analyses, with reduced microbial population relative to the control. The highest antioxidant capacity and total phenolic content were shown in T3, and the overall acceptance was better in T2. The results show that the application of C with the addition of natural extracts, such as the tomato plant with antioxidant and antimicrobial properties, can be an alternative method for preserving pork.

Chymotrypsin was purified from jumbo squid hepatopancreas (HP) with 2.4-fold and yield 1.9%, and characterized with a molecular weight of 31 kDa, as estimated by sodium dodecyl sulfatepolyacrylamide gel electrophoresis (SDS-PAGE). Chymotrypsin effect over collagen extracted from the mantle, fins and arms of the jumbo squid was evaluated. The enzyme exhibited the maximum activity at pH 7 and 65°C using Suc-Ala-Ala-Pro-Phe-p-nitroanilide (SAAPNA) as a substrate and it was identified using the specific inhibitors N-tosyl-L-phenylalaninechloromethyl ketone (TPCK) and phenyl methyl sulfonyl fluoride (PMSF), showing residual activities of 6% and 0%, respectively. Furthermore, high activity was observed in the pH range of 4.0 to 8.0. Purified enzyme showed a moderate in vitro activity using muscle collagen as a substrate. Although further research is needed, the results suggest that the enzyme has a potential application where acidic or slightly alkaline conditions are needed.

The antimicrobial activity of films made of poly(l-lactic acid)/poly(l-lactic acid) grafted maleic anhydride(copolymer)/epigallocatechin gallate(EGCG) blend was determined. The effect of epigallocatechin gallate incorporation (0.03, 0.5, 5, and 10 wt%) as a natural antibacterial was determined by direct contact, solid and liquid culture media. The film antimicrobial activity was evaluated against two bacteria (gram-negative: Pseudomonas spp.; gram-positive: Staphylococcus aureus). The copolymer was prepared and characterized by Fourier transform infrared analysis and Molau test. Furthermore, the degree of grafting was determined. The epigallocatechin gallate migration profile through the films were determined and the minimum epigallocatechin gallate concentration in films required to show antibacterial activity was evaluated. The results showed that only the films with 10 wt% epigallocatechin gallate significantly affected ( p

Summary Jumbo squid (Dosidicus gigas) is characterised by its low commercial value, lean and white meat without bones or scales and high muscular yield. Therefore, it is an attractive species for the production of protein concentrates. However, the gelling ability of squid proteins is low due to the inherent characteristics of the proteins. Different hydrocolloids can be used to improve the gelling ability, where pH and concentration of the hydrocolloids are very important to stablish. Therefore, this study aimed to obtain a protein concentrate from Dosidicus gigas and evaluate the effect of pH and chitosan concentration on its gelation and conformational changes. Treatment at pH 7.0 with 2% chitosan improved the water-holding capacity, elasticity and agglomeration according to the Z potential; it also improved the thermal stability and gelling according to the dynamic oscillatory measurements and differential scanning calorimetry. This information demonstrates that chitosan incorporation plays an important role in gel formation and improves the gelling capacity of squid proteins without affecting the brightness and whiteness, important parameters for this product.

Different studies on obtaining protein concentrates or surimi from giant squid ( Dosidicus gigas) have reported that soft gels are obtained in comparison with other fish species. Therefore, the aim of this research was to investigate the effect of the setting (30 and 60 °C, for 0, 30, 60, and 90 min) on the gelling capacity as a possible alternative to improve the textural characteristics of the gels. Treatments at 60 °C (G4, G5, and G6) had a higher percentage of insoluble protein, while the electrophoretic profile showed the presence of high molecular weight (HMW) aggregates, as well as the decrease of myosin, paramyosin and actin bands as the incubation time was increased. Likewise, these systems presented a lower content of total sulfhydryl (TSH), which is attributed to the formation of disulfide bridges. The texture profile analysis (TPA) showed that the setting application affected the different parameters evaluated (strength, elasticity, and cohesiveness). Setting as pretreatment did not prove to be a good alternative for the gelling of proteins from giant squid mantle, since the control treatment (no setting) was that which exhibited better textural characteristics.

The products of fishing are highly perishable foods. Thus, it is necessary to seek viable alternatives that help to preserve product freshness and quality and to increase its shelf life. One of these alternatives is the use of extracts with antimicrobial activity obtained from plants, such as tomato, which has been observed to present compounds with antimicrobial activity. The objective of this work was to determine the effect of an extract obtained from the tomato plant and incorporated into an edible chitosan coating on the quality and shelf life of the sierra fish fillet stored on ice for 15 days. For the latter, an extract was prepared with dehydrated tomato plants, which was incorporated by immersion alone or in combination with an edible chitosan-based coating in sierra fish fillets. The following treatments were applied: C (Chitosan), TPE (Tomato Plant Extract), TPE-C (TPE-Chitosan), and control (without chitosan and extract). Color, pH, WHC, ATP-related compounds, and K value were monitored during 15 days of storage on ice. Likewise, the total count of mesophiles was determined. The results indicated that treatments C, TPE, and TPE-C were significantly different (p<0.05) from lot control in terms of the concentration of ATP-related compounds, K value, pH, and total mesophilic count. We concluded that application of the extract alone or in combination with chitosan allows for the improvement of the quality and shelf life of the sierra fish fillet.

Gelling ability is attributed to myosin, which is the main myofibrillar protein. Therefore, its integrity is very important. However, a gel with good textural characteristics and stability depends on the inherent characteristics of its proteins, as well as on external factors (primarily temperature, pH, protein concentration and added salt). The best gels from aquatic organism proteins are obtained at a pH value of approximately 7.0. However, the concentration of salt is often variable. In contrast, when proteins are recovered using acid/alkaline dissolution, gels with good textural characteristics are obtained without salt. Hydrophobic interactions, disulfide bonds, hydrogen bonds, and electrostatic interactions are the main interactions that stabilize the protein gel. Thus, this review focuses on the study of the main factors involved in protein gelation, as well as on the extraction method effect on the gelling capacity of proteins from aquatic organisms.

Jumbo squid (Dosidicus gigas) is an underutilized fishery resource in the Gulf of California. Jumbo squid muscle could potentially be utilized to manufacture protein concentrates to be used as a base for surimi or as a food ingredient. However, the main problem is the low gelling ability of these protein concentrates compared those of with fish species. Consequently, the present study evaluated the effects of pH and the NaCl concentration on the gelling properties of protein concentrates from squid mantle. According to texture profile analysis, improved gelling properties were obtained at pH 6.0 and 1% of NaCl. During the sol-gel transition, decreased surface hydrophobicity that corresponded to an increased intensity of α-helix structures was detected. Moreover, the total sulfhydryl content decreased during gel formation. Viscoelasticity and water holding capacity analyses showed the formation of a more structured gel at pH 7.0. The higher enthalpy and denaturation temperature detected by differential sca...

Two protein concentrates from jumbo squid fins (Dosidicus gigas) were elaborated. One of them was obtained via alkaline dissolution and subsequent isoelectric precipitation (alkaline protein concentrate [APC]) and the other was obtained via the traditional method (neutral protein concentrate [NCP]). The electrophoretic profile of the APC showed that the myosin heavy chain band disappeared, mainly due to the denaturation induced by alkaline solubilization or activation of alkaline protease. Concerning the quality of the gels, the folding test showed that gels obtained using APC were better than those obtained using NPC, but a texture profile analysis detected fracture in the APC gels. Regarding the interfacial properties, low emulsifying capacity was observed for both protein concentrates, and the APC was better than the NPC. Additionally, the foaming properties were excellent for both concentrates and were significantly better for APC. Therefore, the alkaline solubilization process for fin squid was suitable for the production of functional protein concentrates. Practical Applications One of the challenges of the fishing industry is to achieve an integral use of fishing resources. Jumbo squid is an abundant resource in Northwest Mexico and its by-products generate a great of waste, which are an environmental problem. Viscera, heads and fins are the main waste of jumbo squid. Fins are about 10% of the total animal; therefore, their exploitation is a good option for this industry. Hence, this study compares and evaluates the functional properties of the protein concentrates obtained from squid fins via alkaline dissolution and subsequent isoelectric precipitation and the conventional methodology (water washing muscle) to determine the most feasible method of obtaining protein concentrates from squid fins.

In the present work the myosin molecule from jumbo squid mantle (Dosidicus gigas) was isolated and characterized with the aim to evaluate the influence of ionic strength on its gelling properties. It was found that the myosin molecule possesses different chemical and structural characteristics than other vertebrates and invertebrates species, such as some cephalopods, which might explain differences in gelation in comparison to those from other organisms. A lower content of total sulfhydryl groups (TSH) possibly caused an improvement in the myosin molecule flexibility when the ionic strength increased (p ˂ 0.05). The aforementioned possibly affected (p ˂ 0.05) the enzyme activity, surface hydrophobicity, viscosity and RSH groups. The results demonstrate that the myosin molecule from jumbo squid is structurally different from the rest of the marine species.

Modification of pH and NaCl concentration changed the physicochemical properties of sarcoplasmic proteins (SP) from jumbo squid mantle and consequently their functional properties. Better results of emulsifying activity index (EAI) and foam capacity (FC) were exhibited at pH 11 in NaCl absence due to higher solubility. But better emulsifying stability index (ESI) was obtained at pH 11 in 0.5 M NaCl, while, foaming stability (FS) was better at pH near to isoelectric point (pI). These results suggest that SP from jumbo squid may be a promising ingredient, whose functional properties can be manipulated by changing pH and NaCl concentration.

The effect of two commercialin vivotransport methods (cardboard boxes and ixtle sacks) on the physiological condition of Japanese oyster (Crassostrea gigas) was evaluated. Total carbohydrates, glycogen, adenosine 5′-triphosphate (ATP) and related products, adenylate energy charge (AEC), and pH of transported oysters in simulated conditions were determined. The results showed that the ATP initial concentration was low from the beginning of the experiment, and AEC decreased in both transport methods. With respect to the total carbohydrates and glycogen, the samples maintained in cardboard box and ixtle sack decreased during transport, respectively. Similarly, significant changes in pH were observed for both methods. Our results showed that physiologically the bestin vivotransporting method for Japanese oyster is in cardboard boxes.

Chitosan films (CF) with cinnamon bark oil (CO) incorporated at 0% (control), 0.25%, 0.5%, and 1.0% v/v were prepared by an emulsion method. The films were characterized based on their physical properties (solubility, water vapor permeability, optical property, and microstructure) and antioxidant properties (DPPH, ABTS, and its protective effects on human erythrocytes). The results showed that the incorporation of 0.5 and 1.0% of CO into the CF significantly decreased its solubility to 22% of the control (p<0.05). The water vapor permeability of the CF-CO was significantly reduced to 40% with low concentrations of CO (0.25%) incorporated into the CF. In general, the films presented a yellow coloration and an increase in transparency with the incorporation of CO into the CF. It was also observed that the incorporation of CO increased the antioxidant activity between 6.0-fold and 14.5-fold compared to the control, and the protective capacity against erythrocyte hemolysis increased by as much as 80%.

Postmortem biochemical and microbiological changes in loricariid catfish (Pterygoplichthys disjunctivus) muscle were evaluated during ice storage for 20 days. Values of pH remained stable for 15 days (7.4 ± 0.2), and total volatile base-nitrogen (TVB-N) remained under acceptable limits throughout storage, with a final value of 25.2 ± 3.3 mg N/100 g muscle at Day 20. Adenosine-5´-triphosphate (ATP) and derivatives followed a postmortem degradation pattern similar to other species, with the K-value being the best freshness loss indicator. Biochemical and microbiological changes indicated that the shelf life of iced loricariid catfish muscle was 15 days under optimal (0°C) storage conditions.

Myofibrillar protein are the principally responsible of gelling properties in fishery resource, hence, during protein concentrate or isolated proteins preparation, sarcoplasmic protein are discarded; however, myofibrillar protein can support low levels of sarcoplasmic proteins without affecting the gelling property. Therefore, the aim of this study was to gradually remove sarcoplasmic proteins from giant squid mantle by means of different ionic strengths (I). Solutions of NaCl with different ionic strengths (I=0.0, 0.1, and 0.3) were used to obtain 3 protein concentrates. The electrophoretic profile in SDS-PAGE showed differences in protein removal with a high solubility of mantle proteins. The texture profile analysis showed that hardness increased in mantle protein washed with higher I. The total reactive sulfhydryls showed significant changes (p

Postmortem changes in blue shrimp (Litopenaeus stylirostris) muscle were studied on the basis of biochemical, chemical, physical, and microbiological changes during an 18 day storage period at 0°C. Adenosine 5′-triphosphate (ATP) content, breakdown products, K-value, pH, trimethylamine nitrogen (TMA-N), total volatile basic nitrogen (TVB-N), water holding capacity (WHC), color, and texture (shear force) changes were examined. Also, total mesophilic and psychrophilic bacterial counts were measured. K-value increased linearly (r2 = 0.98) from an initial value of 1.37 ± 0.59 to 59.42 ± 6.05% at Day 18. Spoilage indicators TVB-N and TMA-N increased from 29.56 ± 1.33 and 0.69 ± 0.25 to 39.04 and 2.04 ± 0.59 mg of N/100 g at Day 18, respectively; meanwhile, the total viable counts of mesophilic and psychrophilic bacteria increased from 3.48 ± 0.44 and 2.61 ± 0.29 log CFU/g to 6.27 ± 0.21 and 7.14 ± 0.39 log CFU/g, respectively, which indicated spoilage at the end of the storage period. The pH, texture, WHC, and...

The effect of season and storage at three temperatures (0, 5 and 10 °C) was evaluated on the main metabolites and parameters related to rigor mortis . Adenosine 5′-triphosphate (ATP), lactic acid, octopine, pH and sarcomere length in the adductor muscle of lion's paw scallop Nodipecten subnodosus were determined. Seasonality influenced the initial values of ATP, octopine and pH, however, no effect was noticed during storage, since a similar effect for the three temperatures evaluated in the four seasons was observed. A lower ATP concentration was found during storage at 0 °C than that found in muscle stored at 5 and 10 °C. According to the analyses of lactic acid, octopine and pH, the muscle acidification during rigor mortis was independent of lactic acid production. The greater sarcomere lengths for all seasons were in agreement with the highest ATP concentrations, corresponding to the samples stored at 5 and 10 °C. Therefore, according to the level of myofibrillar contraction, rigor mortis was lower at 5 and 10 °C storage in the four seasons. Hence, it is concluded that the seasonality did not show a significant impact on metabolite and parameter values related to rigor mortis during storage, and that 5 °C is the best storage temperature for the adductor muscles during the initial stage of rigor mortis and then reduce it to 0 °C, if it is focused to the fresh market.

According to the World Health Organization, cancer is the main cause of mortality worldwide; thus, the search of chemopreventive compounds to prevent the disease has become a priority. White shrimp (Litopenaeus vannamei) has been reported as a source of compounds with chemopreventive activities. In this study, shrimp lipids were extracted and then fractionated in order to isolate those compounds responsible for the antimutagenic activity. The antimutagenic activity was assessed by the inhibition of the mutagenic effect of aflatoxin B1on TA98 and TA100Salmonellatester strains using the Ames test. Methanolic fraction was responsible for the highest antimutagenic activity (95.6 and 95.9% for TA98 and TA100, resp.) and was further separated into fifteen different subfractions (M1–M15). Fraction M8 exerted the highest inhibition of AFB1mutation (96.5 and 101.6% for TA98 and TA100, resp.) and, after further fractionation, four subfractions M8a, M8b, M8c, and M8d were obtained. Data from1H and13C NMR, and mass spectrometry analysis of fraction M8a (the one with the highest antimutagenic activity), suggest that the compound responsible for its antimutagenicity is an apocarotenoid.

A protein concentrate from jumbo squid (Dosidicus gigas) was produced under alkaline conditions. Solubility, recovery of proteins, electrophoretic profile, as well as changes in the pattern of solubility of proteins recovered were determined. In the gels, its capability (functional–technological) was evaluated in terms of texture profile analysis, folding test, water holding capacity, and color attributes. The alkaline treatment promoted the autolysis of myosin heavy chain; however, the alkaline concentrate showed better gel formation ability compared with the mantle, resulting in gel strength of 11.83 ± 0.66 and 21.53 ± 2.95 N · cm at 75% and 90% compression, respectively. Nevertheless, the gels prepared from protein concentrate showed a low water holding capacity (38.1 ± 0.1%), while the folding test showed gels grade C-A and C-B for protein concentrate and mantle, respectively. Se elaboro un concentrado proteico a partir de calamar gigante (Dosidicus gigas) bajo condiciones alcalinas. Se monitoreo la s...

Ray fish were caught, filleted, and stored in ice. Fillets were analysed for 18 days to determine the chemical, biochemical and physical changes and their relation to the muscle eating quality. Trimethylamine (TMA-N), total volatile bases (TVB-N), ATP content and breakdown products, K value, pH, texture, water-holding capacity (WHC) and colour changes were monitored. At the beginning of the study, the ray fish muscle showed a low concentration of ATP and a high value of inosine 5′-monophosphate (IMP). Regarding to the signs of freshness and deterioration, K value presented an exponential increase (r2 = 0.95) with an initial value of 4.7% and a final value of 47.5%. Furthermore, the TBV-N and TMA-N significantly increased (P

The most important cephalopod resource in the northwestern area of Mexico is the jumbo squid whose postmortem biochemical behavior has been studied in detail. Adenosine triphosphate (ATP) degradation in this organism is different than the other species because of the fast degradation of adenosine monophosphate (AMP) metabolite in mantle. In this research, AMP deaminase from jumbo squid mantle was partially characterized. The enzyme showed an optimum behavior at 50 °C, the enzyme lost more than 90% of its activity within 15 min from 55 to 60 °C, and the enzyme remained stable for 30 min from 10 to 50 °C. It was also stable within the pH range of 3.0–5.0 and exhibited an optimum activity at pH 4.5. Enzyme was strongly activated by Mg+2 and weakly activated by Ca+2. ATP was an excellent activator even in a low concentration, while adenosine diphosphate (ADP) did it at higher concentrations. These results suggest that enzyme might be regulated by the adenylate energy charge.

The biochemical, chemical and physical postmortem changes and their relation to the cazon muscle eating quality were studied during an 18 day storage period at 0 °C (ice). Content of ATP and breakdown products, K value, pH, trimethylamine (TMA-N), total volatile bases (TVB-N), water-holding capacity (WHC), colour and texture changes were examined. At the beginning of the study, the cazon muscle showed a low concentration of ATP and a high value of IMP. Regarding to the signs of freshness and deterioration, K value presented a linear increase (r2 = 0.97) with an initial value of 1.05% and a final value of 58.9%. The TBV-N and TMA-N significantly increased (P < 0.05). As for the physical analysis whereas the pH and the WHC changed (P < 0.05); texture was not affected (P < 0.05). The overall results of this study indicated that the edible quality of cazon fish muscle was maintained during at least 18 days of ice storage.

Pacific Lion’s Paw Scallop meats were dried at 50, 60, and 70 °C after pretreatment in citric acid at pH 3 during zero (control), one, and three hours. Immersion in the acid solution reduced the scallop pH from 6.20 to 5.99 (1 h) and 5.88 (3 h) and directly affected the drying times. At 50 °C drying times were 22, 10 and 8.5 h, at 60 °C they were 15, 9.5 and 8 h, and at 70 °C they were 13, 8 and 6 h for control, 1 h, and 3 h of acid treatment. Drying times were considerably reduced as acid immersion time increased. The drying temperature had no significant effect (p ⩾ 0.05) on colour and texture, whereas the acid treatment had a significant effect (p

Postmortem biochemical, chemical, and physical changes of the adductor muscle of Pacific lions-paw scallop were studied during a 15-day storage period at 0 °C (ice). Content of ATP and breakdown products, K value, pH, trimethylamine, total volatile bases, water-holding capacity, colour, and texture changes were examined. K value increased logarithmically (r2 = 0.95) from an initial value of 40.3–79.7% on day 15. The spoilage indicators trimethylamine and total volatile bases increased from 15.6 to 30.7 and 1.3 to 6.8 mg N/100 g of sample, respectively, which indicated spoilage at the end of the storage period. Texture, colour, and pH were not affected; however, water-holding capacity decreased significantly, from 96.0% on day 1 to 86.0% on day 15. Overall results indicated that quality of Pacific lions-paw scallop adductor muscle was maintained during at least 12 days of ice storage.

Several freshness and spoilage indicators were monitored to characterize the postmortem biochemistry of giant squid (Dosidicus gigas) mantle muscle. Squid samples were obtained directly from the sea and kept at 0 degrees C during a 15-d storage period. Data at zero time were obtained from cryogenically frozen samples at time of capture. The adenosine 5'-triphosphate (ATP) degradation followed a different pattern as compared with that from fish species. ATP was almost completely depleted at 24-h postcatch from 6.54 to

The spiny lobster, Panulirus interruptus, is a valuable crustacean and most of its production is marketed live. In the northern fisheries of Baja California, Mexico, the animals are exposed to short-term emersion at different air temperatures during the live marketing procedures. This work evaluates the effect of short-term emersion (up to 10 h) at two air temperatures (7ºC and 20ºC) and of a 2-h recovery period on ATP, its related metabolites and some muscle quality parameters. Survival was 100% after all emersion times. No significant differences were found either in the adenylic energetic charge or in the levels of ATP and its related metabolites. The highest concentrations were found for AMP, IMP and INO, while ATP had the lowest levels. Muscle quality parameters such as water holding capacity and shear force remained similar to the control values. Although pH decreased slightly with emersion, it was very close to the control values after the 2-h recovery period. The overall results suggest that P. interruptus may perform physiological compensatory work after 10 h emersion even at 20ºC without significantly affecting the muscle quality.