Sustainable Food Supply Chains

Abstract

The effects of washing on the chemical composition, gel-forming ability and color of Monterey sardine mince were investigated. Recoveries were 41.5, 46.3 and 52.1% for solids and 49.9, 52.7 and 59.9% for protein using washing ratios of 1:20, 1:15 and 1:10, respectively. No differences were detected among the washing treatments except for gel cohesiveness as measured by texture profile analysis. Large variations in muscle composition were observed at different months of harvesting which could preclude the effect of washing on the characteristics of the mince. Results showed that washed mince possesses an excellent gel-forming ability, suggesting that sardine could be used for surimi processing.     

Characterization of Physicochemical Attributes and Muscle Protein Quality of Blue Catfish (Ictalurus furcatus) in Chesapeake Bay

ABSTRACT

Physicochemical attributes of Chesapeake Bay’s blue catfish and quality of muscle protein isolates (PIs) as influenced by storage condition and extraction methods were investigated. All fish were within the maximum consumable size limit. Those obtained during the autumn/winter and in Year 2 were larger with firmer fillets than their counterparts during the spring/summer and in Year 1. Protein was the predominant nutrient component. Protein extraction yield ranged from 35.3 ± 1.4% to 47.0 ± 5.1%, and β-sheet was the predominant secondary structure for all fish PIs. Salt-extracted PIs were whiter and had higher water holding capacity at neutral and alkali environments. The results of this study support the use of Chesapeake Bay blue catfish and muscle protein for potential value-added application.     

Exposure to seawater stimulates lipid mobilization from depot tissues of juvenile coho (Oncorhynchus kisutch) and chinook (O. tshawytscha) salmon

Tissue lipid content and lipolytic enzyme activity was determined in selected tissues of coho salmon,Oncorhynchus kisutch, at various developmental stages (freshwater parr, freshwater smolt, seawater smolt, and seawater stunt) and in tissues of coho salmon and chinook salmon,O. tshawytscha, exposed to seawater periodically during smoltification. Among developmental groups, total lipid concentration of liver and dark muscle was highest in freshwater (FW) parr. Lipid concentration in both liver and dark muscle was significantly lower in FW smolts, seawater (SW) smolts and SW stunts; no difference was observed among these groups. Alterations in lipid composition were reflected in depot triacylglycerol lipase activity. FW smolts, SW smolts and SW stunts displayed significantly higher lipase activity than FW parr in each of the tissues examined (live, dark muscle and mesenteric fat). Early in smoltification (March, April), exposure to seawater results in enhanced lipid depletion from liver, dark muscle and mesenteric fat, both 30 and 60 days after exposure, compared to FW controls. This depletion was accompanied by increased liver (March and April) dark muscle (March) and mesenteric fat (March) lipase activity. Later in smoltification (May), salinity-induced alterations in lipid metabolism were not observed. These results indicate that exposure to seawater stimulates lipid depletion in juvenile salmon and that the depletion can be explained, in part, by increased depot lipase activity. Furthermore, these data confirm that metabolic dysfunction is associated with stunting.     

Seasonal gonadal changes in the clam, Paphia laterisulca

The seasonal gonadal changes in the edible clam, Paphia laterisulca, from the Kalbadevi Estuary at Ratnagiri were studied for the period from May 1972 to April 1973 with the help of fresh gonad smears and histological study. The observations of gonad smears revealed the probable commencement of spawning between September and April from the occurrence of spent gonads. Male and female clams were present in almost equal numbers throughout the year.Histological details revealed that the clam P. laterisulca has a prolonged spawning period extending from mid-September to the end of March with two peaks, the first in October–November and the second in February–March. Lysis of the ripe gametes in both sexes for 2.5 months preceding spawning was observed. The second spawning peak was followed by regression in the gonads.Active gametogenesis was observed in May and June (33.5°C and 30.0°C), and again in December and January (21.5°C and 26.0°C) in clams that had spawned during the first spawning peak.The spawning stimulus in Paphia laterisulca appeared to be the sudden increase in salinity (from 4.1 to 22.5‰) in September in the Kalbadevi Estuary.     

The influence of anaerobic muscle activity,maturation and season on the flesh quality of farmed turbot

In order to test seasonal, rearing, maturing and anaerobic muscle activity effect on the flesh quality of turbot (Scophthalmus maximus) a total of 80 farmed turbot from three different strains from reared under natural or continuous light were killed by a percussive blow to the head in November (winter, Icelandic strain), March (spring, Portuguese strain) and June (summer, domesticated strain (France turbot)). To test the effect of anaerobic muscle activity, 10 fish were on each occasion pre rigor filleted, where one fillet was used as a control, while the other fillet was electrically stimulated using a squared 5 Hz, 10 V pulsed DC for 3 min. All pre rigor fillets were measured for pH, weighed, wrapped in aluminum foil and stored in polystyrene boxes with ice. After 7 days of storage the fillets were measured instrumentally for pH, drip loss, colour (CIE L* a* b*) and texture properties such as hardness and shear force, while fillet shrinkage and colour (RBG) were evaluated with computer imaging on photographs from a standard lightbox. Results showed that softness of the flesh was mainly influenced by factors associated with growth, such as season, photoperiod and maturation. Anaerobic muscle activity simulated with electrical stimulation caused an increase in drip loss (<1%) and loss of shear force (<4%), but had no effect on hardness or fillet shrinkage. Computer imaging revealed that muscle contractions related to the electrical stimulus forced out blood from the fillet causing less reddishness for the entire storage period. We conclude that a pH drop upon slaughter associated with anaerobic muscle activity has a minor effect on the flesh quality in the short run, while seasonal/alternatively genetic effects are predominant.     

The reproductive biology of the baby clam, Marcia opima, from two geographically separated areas of India

A study of the reproductive cycle of the baby clam, Marcia opima (Gmelin) was conducted at two sites along the southeast (Tuticorin Bay) and southwest (Ashtamudi estuary) coast of India from December 1998 to January 2000. Histological evidence showed that baby clam from both the sites showed two spawning seasons. First spawning season was recorded from May to July in the southeast coast. In the southwest coast, the first spawning season was observed through March to May. A second spawning season from September to December was recorded in both the coasts. In the southeast coast, minimum and maximum condition indices were obtained in January 2000 and April 1999 respectively and decreased from May to June and November to January, signifying the two spawning periods. Most of the animals were either in spent or indeterminate gonadal stage from May to August and November to January indicating the active spawning during that months in the southeast coast.     

Thermal ecology of subadult and adult muskellunge in a thermally enriched reservoir

The movement of adult muskellunge, Esox masquinongy Mitchill, has been investigated in a variety of systems, but temperature selection by muskellunge has not been examined where well‐oxygenated waters were available over a range of temperatures for much of the year. Thirty subadult and adult muskellunge tagged internally with temperature‐sensing radio tags were tracked from March 2010 to March 2011 in a Tennessee reservoir. Mean tag temperatures were 18.9 °C in spring (March to May), 22.1 °C in summer (June to August), 16.5 °C in autumn and 9.8 °C in winter (December to February). When the greatest range in water temperatures was available (7.1–33.3 °C; May to early August 2010), their realised thermal niche (mean ± 1 SD) was 22.3 °C ± 1.8; the realised thermal niche was affected by fish size (smaller fish selected slightly warmer temperatures) but not sex. An electric generating steam plant discharging warm water resumed operation in January 2011, and most (86%) tagged fish occupied the plume where temperatures were ≈10 °C warmer than ambient water temperatures. No mortalities were observed 15 days later when plant operations ceased. Their affinity for the heated plume prompted concerns that muskellunge will be too easily exploited when the plant operates during winter.     

Age, growth and life history of gunnel, Pholis fangi, in the Yellow Sea

We examined the formation of annuli by marginal observations on otoliths of gunnel (Pholis fangi) in the Yellow Sea to validate the age determination method and to derive the growth equation covering from larval to adult stages. Gunnels, ranging from 46 to 173 mm in total length, were collected by a bag net fishery from the western coastal waters off Korea from November 1998 to October 1999. Marginal observations indicated that the translucent zone (annual mark) on adult otolith was formed during the winter, whereas the opaque zone was formed during the summer. However, a translucent zone was formed between May and June in juvenile otoliths. This false ring was formed when the fish transited from the inshore pelagic life of larvae to the offshore bottom life of juveniles. The observed maximum age was 58 months. Using observed length-at-monthly age, growth in length was expressed by von Bertalanffy growth curve; L_t = 144.0 (1 − e^{−0.11 (t+0.43)}). P. fangi spawned in winter recruit to inshore, and grow quickly in the nursery habitats in spring. Gunnel inhabit the bottom offshore area during the summer season, and reappear inshore thereafter.     

Feeding ecology and habitat of the threespine stickleback, Gasterosteus aculeatus microcephalus, in a remnant population of northwestern Baja California, México

Abstract – The feeding ecology and habitat of the threespine stickleback ( Gasterosteus aculeatus microcephalus Girard, 1854) was studied from November 1996 to May 1997 in a remnant population of northwestern Baja California, México. The analysis of the stomach content of 179 individuals (25 to 56 mm standard length [SL]) showed a diet dominated by cyclopoid copepods (43.8%) and chironomid larvae (39.1%). Diet in relation to size and sex of the fish was dominated by copepods in autumn and winter and by chironomid larvae during spring. Diet overlap (Schoener's index) was significant (≥60%) between fish size-classes in January, March and April and between sexes for most sampling months. The average size of prey consumed was independent of fish mouth size. The feeding strategy of the threespine stickleback shifted from opportunist in winter to specialist in spring.     

Study on the potential of suspended longline mariculture of the scallop Chlamys farreri in offshore areas

The growth and survival of the scallop Chlamys farreri exposed to different initial densities were evaluated in culture systems from inshore and offshore areas of Sungo Bay, China, from May 2007 to March 2008. Water quality data (e.g. temperature, salinity, current speed, chlorophyll a and total particulate material) were measured concurrently. The C. farreri reached the market size after 10 months of cultivation. Average survival rates for the same initial densities were lower in the inshore area than those in the offshore area. Survival rates also were inversely proportional to the initial densities. Scallops in offshore area with initial densities of 20 and 30 individuals per disc resulted in significantly greater shell heights, soft tissue weights and muscle weight compared with the other experimental groups. Tissue weight increased rapidly from May to September. However, scallops in offshore area had a second growth peak during October to November. Scallops in the offshore area had higher growth and survival rates, which may be attributed to high water current speed resulting in increased food supplies. Results indicate that the scallop C. farreri has an aquaculture potential in offshore cultivation systems.     

Reproductive condition of the pearl oyster, Pinctada imbricata, Röding, in Port Stephens, New South Wales, Australia

In an investigation of the potential for pearl production in New South Wales (NSW), Australia, changes in the physical and reproductive condition of the pearl oyster, Pinctada imbricata, were monitored for over 2 years. Using wild oysters gathered from close to the southern extent of the species' range in Port Stephens, NSW, a series of macroscopic and histological observations were made. Reproductive activity in P. imbricata was greatest from late spring to early autumn with oysters in poor reproductive condition during winter. Peaks in reproductive indices occurred in November 1998, March 1999, December 1999 and April 2000. Four indices of physiological condition were used: shell growth, byssal attachment, mantle thickness and mucoprotien layer. With the exception of the thickness and extent of the mucoprotein layer, these indices either showed little variation or the variation that occurred was not related to seasonal or reproductive changes. Changes in the mucoprotein layer were correlated with water temperature and suggest that this layer is metabolized during periods of high demand such as during gonadogenesis. Collectors deployed at two sites in Port Stephens demonstrated that spatfall occurs largely in the months of December and January following the spring and early summer peaks in reproductive activity (November 1998 and December 1999). Spatfall was not observed following the autumnal peaks (March 1999 and April 2000) in reproductive activity. Overall, reproductive patterns in P. imbricata are poorly suited to spat supply in Port Stephens. Farmers require spat in early spring (September) to allow maximum use of the ‘growing’ season (September–May). Reproductively capable oysters are not available from the wild until September and quantity of natural spatfall is too variable and occurs too late in the season (December–January). As a result, oysters are being conditioned in the hatchery in July, spawned in August and spat are supplied to farmers in mid September.     

Comparison of Collagen Distribution and Muscle Structure Between Cultured Amberjack (Seriola dumerili) and Cultured Yellowtail (Seriola quinqueradiata)

ABSTRACT

The collagen distribution in cultured specimens of amberjack and yellowtail were assessed by histochemical observation in relation to the meat texture of the fish. Major structural alteration was observed in the level of pericellular connective tissue of yellowtail that had higher muscle lipid content; these changes are likely to be associated with the large-scale changes in muscle firmness resulting from the weakening of the cellular binding force. However, lipid deposition was limited to the myocommata in amberjack muscle; lipid deposition was not observed in the pericellular connective tissue, which is the likely reason why amberjack maintained firmer meat texture.     

Seasonal variations in muscle growth dynamics and selected quality attributes in Atlantic halibut (Hippoglossus hippoglossus L.) fed dietary lipids containing soybean and/or herring oil under different rearing regimes

Atlantic halibut (Hippoglossus hippoglossus), 1630 ± 510 g at the start of the experiment were reared in tanks for 1 year and subjected to three different environmental regimes; Continuous light and Constant temperature (CC), Natural light and Constant temperature (NC) or Natural light and Ambient temperature (NA). Two diets were fed, where 50% of the dietary lipids were either herring oil or soybean oil supplemented. The fish were sampled in May, August and November the first year, and February and May the following year. The CC groups grew better than the NC and NA groups from May to November, and as a result had a significantly (p < 0.05) higher weight by the end of the experiment. This difference did however not affect muscle fibre size distribution, or the chosen muscle quality attributes texture, fat content, water or fat loss of the fillet. These quality attributes were influenced by season and body weight, whereas diet had no significant effect. The NA group had lower fat content of the fillet than the other environmental regimes in August, November and May_end, and fat content increased with increasing fish weight. Water and fat losses were lowest in November and February. The diet influenced the fatty acid profile of the musculature; the triacylglycerol fraction reflecting the dietary treatment while the polar fraction was less influenced by diet. The hardness of the fillet was not influenced by the environmental regimes, but by season, and hardness was at its lowest in August, and increased towards the following spring. The muscle fibre distribution varied only with season, and neither treatment nor diet had any effect on the muscle growth dynamics. Recruitment of new fibres seemed mainly to occur during winter, signified by maximum occurrence of fibres < 500 μm² by the end of the experiment in May.     

Functional and Biochemical Characterization of Proteins Remaining in Solution After Isoelectric Precipitation

ABSTRACT

The resulting supernatant from the isoelectric precipitation of “sawdust” from Cape hake portioning and blue whiting muscle was concentrated by ultrafiltration and the retentate spray-dried. Two main peaks corresponding to molecular weights of 15 kDa and 65 kDa were detected in the supernatant from both raw materials; in the retentate the main proteins had approximately 18 kDa and 73 kDa, and some proteins with 59 kDa were detected in the permeate. The protein content was 74.0% and 70.0% for hake by-products and blue whiting, respectively. Dried proteins had relatively low emulsifying and foaming capacity but high foaming stability and were whitish in color. Hydrophobicity and sulphydryl content were similar to those from other protein sources.     

Actions of epinephrine on the contractility of fast and slow skeletal muscle fibres in teleosts

Fast and slow muscle fibers were isolated from the myotomes of atlantic cod (Gadus morhua L.) and sculpin (Myoxocephalus scorpius L.). Epinephrine was found to have no effect on twitch or sub-tetanic contractions in fast muscle fibres. Isoprenaline (10^–6M) had no effect on the contractility of slow muscle fibres. In contrast, epinephrine elicited a dose-dependent decrease in the half-time for twitch relaxation (t_1/2r), and in most cases a decrease in twitch amplitude. The maximum decrease in t_1/2r was around 5–20% of control values (at 10^–6M epinephrine), with a half maximal response at about 30 nmol l^–1. Responses to epinephrine were unaffected by propranolol and reversed by phentolamine, consistent with the stimulation of -adrenoreceptors. 10^–6M epinephrine produced a rise in cAMP levels from 1.8 to 3.1 pmol mg dry wt^–1 in cod slow fibres. However, the cellular mechanism underlying the action of epinephrine is unclear since forskolin, a potent activator of adenylate cyclase activity, where it has been investigated, was found to increase not decrease twitch duration and amplitude. The responses of fast and slow fibres to epinephrine and its antagonists were similar in summer (13°C) and winter acclimatized (5–6°C) sculpin.It is suggested that epinephrine may act to modulate the active state of slow muscle fibres at high cruising speeds and thereby increase swimming performance.     

Antioxidant Properties of Scomber japonicus Hydrolysates Prepared by Enzymatic Hydrolysis

The antioxidant properties of the Pacific chub mackerel (Scomber japonicus) muscle protein hydrolysates prepared by enzymatic hydrolysis were investigated. After enzyme hydrolysis at 50°C for 60 min, more than 80% of the S. japonicus muscle protein was hydrolyzed. The highest 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity (71.69%) occurred in whole muscle protein hydrolysates treated at 50°C for 30 min with Protamex, and the highest 2,2?-azino-bis(3-ethylbenzothiazolin-6-sulfonic acid) (ABTS) radical-scavenging activity (95.39%) was observed in white muscle protein hydrolysates treated at 50°C for 30 min with Neutrase. The highest superoxide dismutase (SOD)-like activity (32.84%) was recorded in white muscle protein hydrolysates treated at 50°C for 120 min with Protamex. Changes in the molecular weight distribution of S. japonicus muscle proteins after enzymatic hydrolysis were observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). A robust and a convenient enzyme hydrolysis technique for obtaining S. japonicus muscle protein hydrolysates with useful biological activities, within a short time (<2 h) is proposed.     

Impact of wind stress anomalies on the seasonal pattern of southern rock lobster (Jasus edwardsii) settlement in South Australia

Quantified estimates of southern rock lobster (Jasus edwardii) puerulus settlement have been undertaken in the Southern Zone fishery of South Australia since the early 1990s. An analysis of mean monthly puerulus settlement indices from 1995 to 2007 in three monitoring sites revealed a strong seasonal correlation (r > 0.94 between sites) in settlement patterns. Settlement was highest during the winter months of June, July and August with peak settlement in all sites occurring in July. A reduced secondary settlement occurred during February and March. Seasonal trends were correlated with monthly wind stress and direction data in order to investigate possible environmental drivers of settlement. Using monthly averages of wind stress, it was hypothesized that strong along‐shore wind‐stress anomalies (ASWSA) prior to peak settlement would influence puerulus indices. Maximum ASWSA over the December–May period prior to maximum settlement was therefore examined. The results showed significant correlations (P < 0.1, r = 0.51–0.90) between wind stress and puerulus settlement in all but one site. We suggest that storm events, in combination with onshore surface drift during the period of settlement, are the principal physical oceanographic mechanisms influencing settlement patterns within the Southern Zone rock lobster fishery of South Australia.     

Growth and condition index of mussel Mytilus galloprovincialis in experimental integrated aquaculture

Integrating mussel and finfish aquaculture has been recognized as a way to increase profits and decrease environmental impacts of finfish aquaculture, but not enough is known about the effects of finfish aquaculture on mussel growth. Here we present a pilot study aimed at determining how distance from finfish aquaculture affects mussel growth. To this end, we measured growth and condition index of mussel (Mytilus galloprovincialis) at three different distances (0, 60 and 700 m) from finfish aquaculture in the eastern Adriatic Sea. There was a statistically significant difference in growth of tagged mussels with respect to site. Average measured lengths of mussels at sites 1, 2 and 3 after the 10 months of the experiment were 57.60, 62.73 and 58.66 mm. Mussels grew fastest from March to May, and slowest from July to September, regardless of their position. Condition index showed spatial and temporal variations with higher values during fall and winter (∼23), and lower values during spring and summer (∼20). Our results show that production cycle in areas traditionally considered suboptimal for aquaculture can be equivalent to the cycle in areas traditionally considered optimal for mussel aquaculture if mussel aquaculture is integrated with finfish aquaculture.     

Effect of triploidy on muscle cellularity and flesh quality of turbot (Scophthalmus maximus)

Production of triploid turbot is a relevant goal for the aquaculture industry due to the benefits associated with their sterility and growth. In order for a better understanding of the final quality of the species, muscle cellularity and quality parameters of the flesh were studied in seven diploid and seven triploid turbot after sexual maturation. White muscle cellularity was evaluated throughout white muscle cross‐sectional area from the epaxial left muscle section of each fish. To ascertain the flesh quality, several physico‐chemical parameters (moisture, ash, protein, total fat, fatty acids and minerals) were analysed, and textural mechanical properties (springiness, hardness, chewiness, cohesiveness, gumminess and adhesiveness) were determined objectively with a texturometer. Muscle cellularity was different between both groups, such that muscle fibre density was higher for diploid specimens (P < 0.001) and muscle fibres diameters were higher for triploids (P < 0.001). Both ploidy groups showed no significant differences in moisture, ash, protein and total fat content (P > 0.05). All textural properties analysed showed no significant differences between both ploidy groups (P > 0.05). In both ploidy groups, fibre density and fibre diameter showed no significant correlations (P > 0.05) with textural parameters such as springiness, cohesiveness, chewiness and adhesiveness. Ploidy did not affect fatty acid composition, with the exception of eicosapentaenoic acid (C_20:5ω3) which was higher in the triploid group. No significant differences (P > 0.05) existed between diploid and triploid turbot in content of all minerals analysed. According to our results, the ploidy status determines significant variations on muscle cellularity but does not influence the flesh quality of the turbot.     

Microbial Growth Models in Gilthead Sea Bream (Sparus aurata) Stored in Ice

ABSTRACT

This study analyzes microbiological changes in whole, ungutted farmed gilthead sea bream (Sparus aurata) stored for an 18-day period in ice using traditional methods for mesophilic aerobic bacteria, psychrotrophic, Pseudomonas spp., Aeromonas spp., Shewanella putrefaciens, Enterobacteriaceae, sulphide-reducing Clostridium (Clostridia), and Photobacterium phosphoreum in muscle, skin, and gills, evaluating their seasonal differentiation. Two different statistical models were used to analyze microbiological growth. Simultaneously, physicochemical parameters such as the temperature, pH, biological oxygen demand (BOD), total dissolved solids, salinity, ammonia nitrogen, and total phosphorus content of growing waters were analyzed. The results showed that by the end of the storage time, specific spoilage bacteria (SSB) such as Pseudomonas spp., Aeromonas spp., and S. putrefaciens as H₂S-producing bacteria were dominant in sea bream harvested in temperate water in the Canary Islands. Muscle tissue had the least contamination, followed by skin and gills. The values of the analyzed seawater parameters were constant during the four seasons, except that the temperature showed a small difference between winter and summer. Seasonal effects were observed among the fish analyzed, suggesting that the lower levels of contamination detected in winter may have been due to the slight difference observed in water temperature in that season.