Giovanni M. Turchini

Effects of alternative dietary lipid sources on performance, tissue chemical composition, mitochondrial fatty acid oxidation capabilities and sensory characteristics in brown trout (Salmo trutta L.)

The efficiency of five dietary lipid sources (fish oil as control—C; canola oil—CO; poultry fat—PF; pork lard—PL; and oleine oil—OO) were evaluated in juvenile brown trout (58.4±0.7 g) in an experiment conducted over 70 days at 14.6±0.4 °C. The best growth was observed in fish fed the C diet whereas the PL diet fed fish had the best feed utilization. Significant differences in carcass and muscle proximate composition, but not in liver, were noted among fish fed the different dietary treatments. The fatty acid composition of muscle largely reflected that of the diets, while total cholesterol was not affected. The atherogenicity and the thrombogenicity qualities of the trout flesh were modified by the lipid sources. Sensory analysis did not show any significant differences among the cooked fillets with respect to dietary treatments, while in uncooked products, some significant differences were observed. The carnitine palmitoyltransferase I and II (CPT-I and CPT-II) activities of liver and white muscle were assayed for a better understanding of the potential β-oxidation capability of the different dietary lipid sources. The hepatic, but not white muscle CPT-I and CPT-II activities were affected by dietary treatments. This study showed that alternative lipid sources could be used effectively for oil coating extruded diets for brown trout.

Fish Oil Replacement and Alternative Lipid Sources in Aquaculture Feeds

Fish Oils in Aquaculture: In Retrospect Sena S. De Silva, David S. Francis, and Albert G. J. Tacon Lipids in Aquafeeds J. Gordon Bell and Wolfgang Koppe The Worlds Oils and Fats Frank D. Gunstone Palm Oil and Saturated Fatty Acid-Rich Vegetable Oils Wing-Keong Ng and Veronique Gibon Soybean Oil and Other n-6 Polyunsaturated Fatty Acid-Rich Vegetable Oils Paul B. Brown and Steven D. Hart Rapeseed (Canola) Oil and Other Monounsaturated Fatty Acid-Rich Vegetable Oils Giovanni M. Turchini and Rodney J. Mailer n-3 Polyunsaturated Fatty Acid-Rich Vegetable Oils and Blends Douglas R. Tocher, David S. Francis, and Keith Coupland Terrestrial Animal Fats Dominique P. Bureau and David L. Meeker Alternative Marine Resources Rolf-Erik Olsen, Rune Waagbo, Webjorn Melle, Einar Ringo,and Santosh P. Lall New Alternative n-3 Long-Chain Polyunsaturated Fatty Acid-Rich Oil Sources Matthew R. Miller, Peter D. Nichols, and Chris G. Carter Minor Components in Fish Oil and Alternative Oils with Potential Physiological Effect Jana Pickova, Sabine Sampels, and Marc Berntsen Fish Oil Replacement in Starter, Grow-Out, and Finishing Feeds for Farmed Aquatic Animals Brett D. Glencross and Giovanni M. Turchini The Effects of Fish Oil Replacement on Lipid Metabolism of Fish Bente E. Torstensen and Douglas R. Tocher Welfare and Health of Fish Fed Vegetable Oils as Alternative Lipid Sources to Fish Oil Daniel Montero and Marisol Izquierdo The Effects of Fish Oil Replacement on Nutritional and Organoleptic Qualities of Farmed Fish Grethe Rosenlund, Genevieve Corraze, Marisol Izquierdo, and Bente E. Torstensen Index

Fatty acid metabolism (desaturation, elongation and β-oxidation) in rainbow trout fed fish oil- or linseed oil-based diets

In consideration of economical and environmental concerns, fish oil (FO) substitution in aquaculture is the focus of many fish nutritionists. The most stringent drawback of FO replacement in aquafeeds is the consequential modification to the final fatty acid (FA) make-up of the fish fillet. However, it is envisaged that a solution may be achieved through a better understanding of fish FA metabolism. Therefore, the present study investigated the fate of individual dietary FA in rainbow trout (Oncorhynchus mykiss) fed a FO-based diet (rich in 20 : 5n-3) or a linseed oil-based diet (LO; rich in 18 : 3n-3). The study demonstrated that much of the 18 : 3n-3 content from the LO diet was oxidised and, despite the significantly increased accretion of Delta-6 and Delta-5 desaturated FA, a 2- and 3-fold reduction in the fish body content of 20 : 5n-3 and 22 : 6n-3, respectively, compared with the FO-fed fish, was recorded. The accretion of longer-chain FA was unaffected by the dietary treatments, while there was a greater net disappearance of FA provided in dietary surplus. SFA and MUFA recorded a net accretion of FA produced ex novo. In the fish fed the FO diet, the majority of dietary 20 : 5n-3 was accumulated (53.8 %), some was oxidised (14.7 %) and a large proportion (31.6 %) was elongated and desaturated up to 22 : 6n-3. In the fish fed the LO diet, the majority of dietary 18 : 3n-3 was accumulated (58.1 %), a large proportion was oxidised (29.5 %) and a limited amount (12.4 %) was bio-converted to longer and more unsaturated homologues.

Fish Oil Diet Associated with Acute Reperfusion Related Hemorrhage, and with Reduced Stroke-Related Sickness Behaviors and Motor Impairment

Ischemic stroke is associated with motor impairment and increased incidence of affective disorders such as anxiety/clinical depression. In non-stroke populations, successful management of such disorders and symptoms has been reported following diet supplementation with long chain omega-3-polyunsaturated-fatty-acids (PUFAs). However, the potential protective effects of PUFA supplementation on affective behaviors after experimentally induced stroke and sham surgery have not been examined previously. This study investigated the behavioral effects of PUFA supplementation over a 6-week period following either middle cerebral artery occlusion or sham surgery in the hooded-Wistar rat. The PUFA diet supplied during the acclimation period prior to surgery was found to be associated with an increased risk of acute hemorrhage following the reperfusion component of the surgery. In surviving animals, PUFA supplementation did not influence infarct size as determined 6 weeks after surgery, but did decrease omega-6-fatty-acid levels, moderate sickness behaviors, acute motor impairment, and longer-term locomotor hyperactivity and depression/anxiety-like behavior.

Responsible aquaculture and trophic level implications to global fish supply.

Hunger and malnutrition remain among the most devastating problems facing the worlds poor and needy, and continue to dominate the health and well-being of the worlds poorest nations. Moreover, there are growing doubts as to the long-term sustainability of many existing food production systems, including capture fisheries and aquaculture, to meet the future increasing global demands. Of the different agricultural food production systems, aquaculture (the farming of aquatic animals and plants) is widely viewed as an important weapon in the global fight against malnutrition and poverty, particularly within developing countries where over 93% of global production is currently produced, providing in most instances an affordable and a much needed source of high quality animal protein, lipids, and other essential nutrients. The current article compares for the first time the development and growth of the aquaculture sector and capture fisheries by analyzing production by mean trophic level. Whereas marine capture fisheries have been feeding the world on high trophic level carnivorous fish species since mankind has been fishing the oceans, aquaculture production within developing countries has focused, by and large, on the production of lower trophic level species. However, like capture fisheries, aquaculture focus within economically developed countries has been essentially on the culture of high value-, high trophic level-carnivorous species. The long term sustainability of these production systems is questionable unless the industry can reduce its dependence upon capture fisheries for sourcing raw materials for feed formulation and seed inputs. In line with above, the article calls for the urgent need for all countries to adopt and adhere to the principles and guidelines for responsible aquaculture of the FAO Code of Conduct for Responsible Fisheries.

Alien Species in Aquaculture and Biodiversity: A Paradox in Food Production

Abstract Aquaculture is seen as an alternative to meeting the widening gap in global rising demand and decreasing supply for aquatic food products. Asia, the epicenter of the global aquaculture industry, accounts for over 90% of the global aquaculture production quantity and about 80% of the value. Asian aquaculture, as with global aquaculture, is dependent to a significant extent on alien species, as is the case for all the major food crops and husbanded terrestrial animals. However, voluntary and or accidental introduction of exotic aquatic species (alien species) is known to negatively impact local biodiversity. In this relatively young food production industry, mitigating the dependence on alien species, and thereby minimizing potential negative impacts on biodiversity, is an imperative for a sustainable future. In this context an attempt is made in this synthesis to understand such phenomena, especially with reference to Asian inland finfish, the mainstay of global aquaculture production. It is pointed out that there is potential for aquaculture, which is becoming an increasingly important food production process, not to follow the past path of terrestrial food crops and husbanded animals in regard to their negative influences on biodiversity.

A Whole Body, In Vivo, Fatty Acid Balance Method to Quantify PUFA Metabolism (Desaturation, Elongation and Beta-oxidation)

Currently there are several contrasting methods utilized for estimating elongation and desaturation of fatty acids and their general metabolism. The majority of these methods involve an ex vivo approach, requiring expensive and sophisticated equipment, likely to result in considerable variation in enzyme activity between and within species. In the present paper we introduce a further development of the whole-body fatty acid balance method for the estimation of the elongation and desaturation of fatty acids. This method though receiving considerable attention because of its simplicity and reliability has yet to be presented in detail. Theoretically, the whole-body fatty acid balance method can potentially be applied to any organism and requires little more than a gas chromatography unit for fatty acid analysis and elementary calculations. As such in this paper we attempt to spell out in detail the theoretical basis and the methods of application drawing specific examples. Using the present method it is possible to measure the fate of individual fatty acids towards desaturation, elongation and oxidation and calculate the elongase, Δ-6 desaturase and Δ-5 desaturase activities.

Traceability issues in fishery and aquaculture products

Nowadays availability and international trade of fish and seafood are strongly influenced by food safety norms. Several European Directives have introduced safety standards into the chain for fisheries and aquaculture products with the concept ‘from farm to fork’, usually based on the Codex Alimentarius provisions. A labelling regulation for fishery and aquaculture products came into effect in the European Union in 2001, requiring identification of the official commercial and scientific name, the origin of the fish and its production method (farmed or wild). This regulation aims to provide consumers with a minimum of information on characteristics of such products and is enforced in Italy by Ministry of Agriculture Decree No. 27.03.02 on the labelling of fish products. In addition, in Regulation No. 178/2002, which lays down procedures in the matter of food safety and establishment of the European Food Safety Authority, the Commission defines traceability as ‘the ability to trace and follow a food, feed, foodproducing animal or substance intended to be or expected to be incorporated into a food or feed, through all stages of production, processing and distribution’. As a consequence of these regulations, various labelling schemes from producers and distributors are now in place for fish products. These aim to promote resource sustainability, distinction of quality and product safety. Typically, such producer’s or distributor’s labels inform the consumer as to which aquaculture techniques have been used and which type of feed or raw materials have been used in the feed formulation. New interest in organic fish products or ‘natural’ fish products is also particularly intense in aquaculture, although current schemes tend to be complex and expensive and, so far, a ‘physiological’ incompatibility between aquaculture and organic production of fish seems to exist. Consumers are increasingly interested in ‘natural’ or wild fish products. This results from a decreased confidence in the quality and safety of farmed fish, especially that produced in other countries, as well as concern about environmentally friendly production methods. Unfortunately, recent food scares (i.e. BSE) and the malpractices of some food

The Health Benefit of Seafood

Due to the continuous demand on the part of consumers for high-quality healthy food, primary animal production systems are trying to reduce the impact of some risk factors on human health. The available technologies for farmers to reach this goal seem to lie in genetic improvement and the improvement of feeding and management practices. To date many nutritional theories have focused their attention on the numerous health implications of the fatty acid profile of the diet; in particular the relationship between saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), long-chain polyunsaturated fatty acids (PUFA) of both the n-3 and n-6 categories, seems to play a major role. An important feature of polyunsaturated fatty acids, in particular n-3 fatty acids, is their role in the prevention and modulation of certain diseases that are common in industrialized countries. These are the following (Pike, 1999): (i) impaired development of brain and visual acuity (reduced intellectual capacity in infants, aggression and depression); (ii) neurological dysfunction, including visual symptoms; (iii) inflammatory and autoimmune disorders (rheumatoid arthritis, psoriasis, ulcerative colitis, asthma); (iv) coronary heart disease (restenosis, cardiac arrhythmias); (v) mild hypertension (high blood pressure). As shown in numerous studies, coronary heart diseases (CHD) are largely influenced by dietary habits in correlation with the characteristic lipid profile. Pike (1999) reported interesting data about the characterization of the lipids in the human diet in relationship to the incidence of cardiac and coronary pathologies. He observed that in the last two centuries, with the continuous increase in the consumption of total lipids and SFA and the parallel diminution of the assumption of PUFA and n-3 fatty acids, a remarkable increase of the percentage incidence of cardiovascular pathologies has been recorded. It is known that CHD are caused by obstruction of the coronary vessels by the formation of atheromi or thrombi and, as suggested by Ulbricht and Southgate (1991), it seems that CHD can be influenced by seven dietary factors that

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.