Growth and product quality of European eel (Anguilla anguilla) as affected by dietary protein and lipid sources

A 12-week feeding trial was undertaken to evaluate the effects of partial replacement of marine raw materials in the diet with soybean meal and beef tallow on growth and product quality of European eel (Anguilla anguilla ). Based on growth, feed efficiency and chemical composition, soybean meal was found to be an unsuitable ingredient for eel diets as a substitute for fishmeal (25% on a protein basis), probably because of the low digestibility of its carbohydrate content. However, beef tallow can be used to replace 50% of fish oil without reduction in growth, provided that digestible carbohydrates are present in the diet. No major effects of protein and lipid sources in the diet were found on fillet chemical composition. Sensory analysis revealed no significant differences between fish fed the control and the experimental diets, with the exception of salty taste which was significantly higher in fish fed combined soybean meal and beef tallow compared with fish fed the control diet.

Biometric, nutritional and organoleptic changes in intensively farmed Murray Cod (Maccullochella peelii peelii) purged for different time periods

A period of purging before harvesting is common practice in intensive aquaculture to eliminate any possible off flavours from the fish. The present study was conducted to evaluate the biometrical, nutritional and sensory changes in intensively farmed Murray cod (Maccullochella peelii peelii) after 0, 2 and 4 weeks of purging. After the main biometric parameters were recorded, fish were analysed for proximate, fatty acid composition and flavour volatile compounds. A consumer preference test (triangle test) was also conducted to identify sensorial differences that may affect the consumer acceptability of the product.

Fish purged for 2 and 4 weeks had a significant weight loss of 4.1% and 9.1%, respectively, compared to unpurged fish, whilst perivisceral fat content did not change. The concentration of saturated (SFA), monounsaturated (MUFA) and highly unsaturated (HUFA) fatty acids were not significantly affected by purging time, while polyunsaturated fatty acids (PUFA), n − 3 and n − 3 HUFA were significantly higher (P < 0.05) in purged fish compared to unpurged fish. Consumers were able to detect differences between the purged and unpurged fish (P < 0.05) preferring the taste of the purged fish. However, consumers were unable to distinguish between fish purged for 2 and 4 weeks.

This study showed that a 2 weeks purging period was necessary and sufficient to ameliorate the final organoleptic quality of farmed Murray cod. With such a strategy the nutritional qualities of edible flesh are improved while the unavoidable body weight loss is limited.

Lipid characterisation of different tissues and fillet portions of intensively farmed Murray Cod Maccullochella peelii peelii

Although many studies have focused on the lipid and fatty acids composition of farmed fish, no many have investigated their deposition pattern in different portions of the fillet. Previous studies, mainly on salmonids, have shown that lipids distribution varies greatly depending on the species, portion and type of muscle, but nevertheless, there is not accurate description of its deposition pattern in many fish, in particular in warm water, freshwater carnivorous species. Murray cod is the largest Australian native freshwater carnivorous fish and supports a small but well established and fast growing industry. The objective of this study was therefore to determine if there was any difference in lipid and fatty acid in different tissues such as muscle, liver and perivisceral fat and in different portions of the fillet of farmed Murray cod.

Three size fish (small, medium and large), all fed the same commercial diet, were selected from a commercial intensive farm. The left fillet of each fish was sectioned into nine portions, according to muscle lines and main anatomical features. The nine portions as well as whole right fillet, liver and perivisceral fat were analysed for proximate and fatty acid composition (Table 1).

Differences in lipid content were found amongst different portions of the fillet, with the dorsal/cranial portion (P1) recording the lowest and the more ventral/caudal portion (P8) recording the highest (P<0.05) value. The latter also recorded the highest amount of monounsaturated fatty acid (MUFA) and the lowest of polyunsaturated fatty acids (PUFA), arachidonic acid, 20:4n-6 (ArA), docosahexaenoic acid, 22:6n-3, (DHA) and n3/n6 ratio. In general, lipid content in the different fillet portions was inversely correlated to PUFA and directly to MUFA. Saturated fatty acid (SFA) and eicosapentaenoic acid, 20:5n-3 (EPA) did not show any discernible trend and were similar throughout, while significant differences of DHA and ArA content were observed. This study shows that lipid deposition in Murray cod varies remarkably and that different fatty acids are deposited at different rates. The results of this study show how different adjacent portions can be and therefore attention need to be paid when conducting chemical, nutritional and sensorial analyses on Murray cod.

Translating text into motion : performance analysis for singers and directors

The study proposes a method of interpretation, which gives the contemporary singer-actor and director a method of performance analysis considering both the visual and the auditory aspects of vocal performance. The analysis begins with an analysis of the structure, which maps out the key ideas and translates them into main states of mind. The text analysis is followed by an analysis of the musical treatment of the text, also scanning for extra dramatic meaning inherent in vocal line and musical accompaniment. The so isolated dramatic ideas in text and musical structure and content are finally discussed in terms of their physical aspects, using the system of gesture as practiced by actors and singers before, during and beyond the Baroque period. The method is exemplified by the obbligato recitative "In quali eccessi" from Donna Elvira’s scene in the second act of the opera "Don Giovanni" by L. Da Ponte and W. A. Mozart. The musical example includes gestural notation and a table gestural notation symbols.

Bio-economical and ethical impacts of alien finfish culture in European inland waters

Since 1989, and in comparison to the global trend, inland aquaculture production of European finfish has declined. To date, the yearly European freshwater aquaculture production is 371,727 tons, valued at over US$1 billion. Indigenous species accounted for less than one-third of the production, whereas alien species (a species that has been moved beyond its natural range of distribution) accounts for the remainder. However, in general, indigenous species command a higher market price. Currently, food quality and food safety are leading concerns of consumers, and European consumers are also becoming alert to environmentally detrimental practices. Therefore, to aim at economic sustainability, the sector needs to satisfy consumer expectations of environmentally friendly practices. It is believed that farming alien finfish species can threaten local biodiversity through escapes, and this represents a current environmental concern relative to aquaculture. In this context, an attempt is made in this paper to understand and quantify the impacts of alien finfish cultivation in European inland waters, and to suggest remedial measures.

Fatty acid composition and volatile compounds of caviar from farmed white sturgeon (Acipenser transmontanus)

The present study was conducted to characterize caviar obtained from farmed white sturgeons (Acipenser transmontanus) subjected to different dietary treatments. Twenty caviar samples from fish fed two experimental diets containing different dietary lipid sources have been analysed for chemical composition, fatty acids and flavour volatile compounds. Fatty acid make up of caviar was only minimally influenced by dietary fatty acid composition. Irrespective of dietary treatments, palmitic acid (16:0) and oleic acid (OA, 18:1 n-9) were the most abundant fatty acid followed by docosahexaenoic acid (DHA, 22:6 n-3) and eicopentaenoic (EPA, 20:5 n-3).

Thirty-three volatile compounds were isolated using simultaneous distillation–extraction (SDE) and identified by GC–MS. The largest group of volatiles were represented by aldehydes with 20 compounds, representing the 60% of the total volatiles. n-Alkanals, 2-alkenals and 2,4-alkadienals are largely the main responsible for a wide range of flavours in caviar from farmed white surgeon

Towards understanding the impacts of the pet food industry on world fish and seafood supplies

The status of wild capture fisheries has induced many fisheries and conservation scientists to express concerns about the concept of using forage fish after reduction to fishmeal and fish oil, as feed for farmed animals, particularly in aquaculture. However, a very large quantity of forage fish is being also used untransformed (fresh or frozen) globally for other purposes, such as the pet food industry. So far, no attempts have been made to estimate this quantum, and have been omitted in previous fishmeal and fish oil exploitation surveys. On the basis of recently released data on the Australian importation of fresh or frozen fish for the canned cat food industry, here we show that the estimated amount of raw fishery products directly utilized by the cat food industry equates to 2.48 million metric tonnes per year. This estimate, plus the previously reported global fishmeal consumption for the production of dry pet food suggest that 13.5% of the total 39.0 million tonnes of wild caught forage fish is used for purposes other than human food production. This study attempts to bring forth information on the direct use of fresh or frozen forage fish in the pet food sector that appears to have received little attention to this date and that needs to be considered in the global debate on the ethical nature of current practices on the use of forage fish, a limited biological resource.

Biometric, nutritional and sensory changes in intensively farmed Murray cod (Maccullochella peelii peelii, Mitchell) following different purging times

A period of purging before harvesting is common practice in intensive aquaculture to eliminate any possible off flavours from the fish. The present study was conducted to evaluate the biometrical, nutritional and sensory changes in intensively farmed Murray cod (Maccullochella peelii peelii) after 0, 2 and 4 weeks of purging. After the main biometric parameters were recorded, fish were analysed for proximate, fatty acid composition and flavour volatile compounds. A consumer preference test (triangle test) was also conducted to identify sensorial differences that may affect the consumer acceptability of the product.

Fish purged for 2 and 4 weeks had a significant weight loss of 4.1% and 9.1%, respectively, compared to unpurged fish, whilst perivisceral fat content did not change. The concentration of saturated (SFA), monounsaturated (MUFA) and highly unsaturated (HUFA) fatty acids were not significantly affected by purging time, while polyunsaturated fatty acids (PUFA), n − 3 and n − 3 HUFA were significantly higher (P < 0.05) in purged fish compared to unpurged fish. Consumers were able to detect differences between the purged and unpurged fish (P < 0.05) preferring the taste of the purged fish. However, consumers were unable to distinguish between fish purged for 2 and 4 weeks.

This study showed that a 2 weeks purging period was necessary and sufficient to ameliorate the final organoleptic quality of farmed Murray cod. With such a strategy the nutritional qualities of edible flesh are improved while the unavoidable body weight loss is limited.

Effects of starvation and water quality on the purging process of farmed Murray cod ( Maccullochella peelii peelii )

The aim of this study was to determine the effects of starvation and water quality during the purging process on the biometric parameters, fatty acids, and flavor volatiles of Murray cod farmed in a recirculation system. Market size Murray cod, at the end of the grow-out stage, were divided into eight treatments. The treatments were either fed/starved (F or S) and kept in clean water (CW: CWF2, CWS2, CWF4, and CWS4) or fed/starved and kept in recycled water (RW: RWF2, RWS2, RWF4, and RWS4) for either 2 or 4 weeks. Fish were sampled at 0, 2, and 4 week intervals. Food deprivation was responsible for a significant (P < 0.05) weight loss compared to that of fed treatments. The same was observed for the condition factor (K), hepatosomatic index (HSI), and dress-out percentage (DP). No significant changes were, however, observed in the visceral fat index (VFI). Saturated fatty acids (SFA) were highest in RWF4 and lowest in CWS4 (P < 0.05), while monounsaturated fatty acids (MUFA) were lowest in CWF4 (P < 0.05). Starvation did not affect the flavor volatile compounds, which were mainly affected by changes in water quality. Specifically, total aldehyde (% w/w) content was significantly (P < 0.05) affected by water quality, but the time of purging was not responsible for any noteworthy differences. This study was able to separate the effects of starvation and water quality, in the purging process, on the final eating quality of farmed market size Murray cod. It is concluded that because of the inevitable weight loss during starvation, Murray cod should be fed during the purging stage but kept in clean water and deprived of food only for the time necessary to empty the gastro-intestinal tract.

Maternity waiting homes in Southern Lao PDR : the unique 'silk home'

The concept of maternity waiting homes (MWH) has a long history spanning over 100 years. The research reported here was conducted in the Thateng District of Sekong Province in southern Lao People’s Democratic Republic (PDR) to establish whether the MWH concept would be affordable, accessible, and most importantly acceptable, as a strategy to improve maternal outcomes in the remote communities of Thateng with a high proportion of the population from ethnic minority groups. The research suggested that there were major barriers to minority ethnic groups using existing maternal health services (reflected in very low usage of trained birth attendants and hospitals and clinics) in Thateng. Unless MWH are adapted to overcome these potential barriers, such initiatives will suffer the same fate as existing maternal facilities. Consequently, the Lao iteration of the concept, as operationalized in the Silk Homes project in southern Lao PDR is unique in combining maternal and infant health services with opportunities for micro credit and income generating activities and allowing non-harmful traditional practices to co-exist alongside modern medical protocols. These innovative approaches to the MWH concept address the major economic, social and cultural barriers to usage of safe birthing options in remote communities of southern Lao PDR.