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ReportReport

    Report

    Identification of Health and Nutritional Benefits

    of New Zealand Aquaculture Seafood’s

    For: Aquaculture New Zealand

    Level 1 Wakatu House

    Montgomery Square

    Nelson

    From: Grant MacDonald, PhD

    Food Scientist

    MacDonald and Associates Ltd

    Nelson

    Tuesday, 6 April 20102

    Contents

    1.SUMMARY ..................................................................................................... 3

    2.INTRODUCTION ...........................................................................................7

    3. BRIEF DESCRIPTION OF SOME NUTRITIONALLY FUNCTIONAL AND

    BIOACTIVECOMPONENTSINSEAFOOD’S ......................................................9

    3.1 PROTEINS AND BIOLOGICALLY ACTIVE

    PEPTIDES ....................................................................... 9

    3.2 LONG CHAIN POLYUNSATURATED FATTY

    ACIDS ....................................................................... 10

    3.3

    MINERALS ...................................................................................................................

    ......... 12

    3.4 VITAMINS AND

    COENZYMES ................................................................................................... 13

    3.5 CAROTENOIDS AND OTHER COLOURED

    COMPOUNDS ............................................................... 13

    3.6 OTHER POSSIBLE BIOACTIVE

    COMPONENTS ............................................................................ 14

    4. REVIEW OF AVAILABLE INFORMATION ON NEW ZEALAND

    AQUACULTURE

    SPECIES ................................................................................................................

    ................. 15

    4.1 SOURCES OF NUTRITIONAL

    INFORMATION ............................................................................... 15

    4.2 SUMMARY OF NUTRITIONAL

    INFORMATION .............................................................................. 15

    4.3 SUMMARY FOR NEW ZEALAND KING

    SALMON .......................................................................... 17

    4.3.1 Effect of cooking on salmon nutritional

    characteristics ................................................ 19

    4.4 SUMMARY FOR GREENSHELL

    MUSSELS .................................................................................. 20

    4.4.1 Seasonal changes in composition of Greenshell

    mussels ........................................... 22

    4.5 SUMMARY FOR PACIFIC

    OYSTERS .......................................................................................... 25

    4.5.1 Seasonal changes in composition of Pacific

    oysters ................................................... 26

    4.6 SUMMARY FOR BLUE

    MUSSELS .............................................................................................. 27

    5. NUTRITIONAL EFFECTS OF FOOD

    PROCESSING............................................................. 28

    6. IDENTIFY MARKETING MESSAGES FOR

    PROMOTION..................................................... 30

    6.1 MAKING NUTRITION

    CLAIMS ................................................................................................... 30

    6.2 MAKING HEALTH

    CLAIMS........................................................................................................ 31

    6.3 A STRATEGY

    FORWARD ......................................................................................................... 31

    7. IDENTIFY GAPS IN

    INFORMATION ...................................................................................... 33

    REFERENCES.......................................................................................................

    ......................... 34

    APPENDIX 1. VITAMIN AND MINERAL

    RECOMMENDATIONS................................................. 40

    1. Summary

    The ability to identify healthy components in a food and to promote this information to enable consumers to make healthy food choices can be a powerful marketing tool. In a wider context, when applied to whole populations as a public health measure, making healthier food choices can prevent disease and provide exceptional value in that the cost of modifying diet is minimal.Significant health benefits from modest fish consumption have been observed. A recent metaanalysis study found that people who ate fish at least once a week significantly reduced the risk of cardiovascular disease (CVD) by 15%. There was a dose-response relation between fish consumption and lower CVD mortality, with 7% lower CVD mortality rates with an increased consumption of 20g/day of fish (lean and fatty fish).

     The health aspects of seafood have primarily, and since the discovery of the low incidence of CVD in Greenland Eskimos, been linked to high intakes of marine omega-3 polyunsaturated fatty acids in particular eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 20:6n-3). Possible contributions from other functional components, such as proteins, taurine, selenium, calcium and other minerals, vitamins, coenzymes and antioxidants have at least partly been neglected.

    The aims of this report are to 1) identify healthy components and nutritional benefits of New Zealand aquacultured seafood’s, specifically New Zealand king salmon (Oncorhynchus tshawytscha), Greenshell mussels (Perna canaliculus), Pacific oysters (Crassostrea gigas) and blue mussels (Mytilus edulis aoteanus), and 2) to identify benefits that could be used to promote these seafood’s. Any gaps in

information will also be highlighted.

    New Zealand king salmon One to two 150g servings per week of New Zealand king salmon would supply sufficient omega-3’s for an average person’s needs. For a

    person with existing CVD a higher intake of omega-3’s of 1g/day has been shown to

    be beneficial, and or people with rheumatoid arthritis about 3g/day omega-3’s are

    recommended. Consequently, eating New Zealand king salmon more often per week would help supply sufficient omega-3’s in the diet and may be a healthy alternative.

    There is some evidence to show there is a link between the combination of high omega-3’s, high selenium, taurine and astaxanthin in salmon to provide strong anti-inflammatory effects in humans, but more work needs to be published to provide more scientific evidence. 4There is also some evidence to show that when salmon muscle tissue is digested biologically active peptides are produced that can have beneficial health effects. However, although there is evidence to show that eating fish regularly will reduce CVD and other diseases, the link is probably not yet strong enough to make direct health claims for New Zealand king salmon.

    With a fat content of 34.7g per 150g serving the salmon is quite high in fat and would provide about 87% of the RDI for fat of 40g/day, as well as about 20% of the energy required per day. However, many people have energy requirements greater than the reference 8400kJ/day (2000kcal/day). Also, to put the 40g per day in context with actual current fat consumption, the daily per capita availability of fat in the Oceania nations in 1990 was 138g (mainly from meat), which comprised 38% of the dietary energy, a level considered too high for optimum health. In 1995 the median fat

    intake for Australians aged 19 years and over was 74.5g per day. Replacing meat in a meal, with its high saturated fatty acid content, with salmon would be a healthy alternative.

    The level of cholesterol in New Zealand king salmon, with 72mg per serving, may be of concern to some consumers. However, recent research has shown that dietary cholesterol has a relatively small effect on plasma (blood) cholesterol, although an intake of less than 300mg per day cholesterol is usually advised.

    The omega-3 fatty acids in New Zealand king salmon were very stable and are

    well preserved during different cooking methods (poaching, steaming, microwaving, pan frying, oven baking and deep frying), although there can be some uptake of the frying oil by the fillet when deep frying. It is possible that the high levels of natural antioxidants in the salmon flesh, such as astaxanthin and vitamin E, help protect the omega-3 fatty acids during cooking. Greenshell mussels A 100g serving of steamed Greenshell mussels is a good source of protein and would supply about 30% of the daily requirement for an adult. They are also a low fat, low calorie food. However, because their lipids are high in omega-3 fatty acids they are a very good source of omega-3’s, with a very good DHA to EPA ratio and low omega-6 content. Greenshell

    mussels are also a very good source of a number of essential minerals, such as selenium, iodine and iron, consumption of which can have significant health implications. For example, selenium is implicated in antioxidant and immune functions in the body and perhaps a reduction in CVD. A deficiency of iodine and iron have been linked to widespread health disorders in various parts of the world.

    In addition to the high omega-3 content, and high content of selenium, Greenshell mussels also contain a number of other bioactive components such as taurine, glycogen, chondroitin sulphate, polyphenols and carotenoids from female mussels that will contribute to antioxidant activity and will have other health implications. Digestion of Greenshell mussels may also give rise to bioactive 5

    peptides. Little information has been published about these bioactives and the health properties of steamed Greenshell mussels. However, it is not surprising that for the last 30 years dried Greenshell mussel powder has been sold as a health supplement for its anti-inflammatory

    properties and the treatment of arthritis in humans and in animals. This product originally arose from observations of the low incidence of arthritis in segments of the New Zealand population that consumed significant quantities of Greenshell mussels.

    Most of the focus in Greenshell mussel powder supplements has been on the health properties of the mussel oil in the powder which is high in EPA, DHA and other omega-3’s with little emphasis on these other components that have also been shown to have antioxidant and health properties.

    Pacific oysters A 100g serving of raw Pacific oysters is a good source of protein and would supply about 20% of the daily requirement for an adult. They are also a low fat, low calorie food. However, similarly to Greenshell mussels, because their lipids are high in omega-3 fatty acids they are a very good source of omega-3’s. There

    is no published data on the specific polyunsaturated fatty acids or relative ratio of omega-3 to omega-6 in New Zealand Pacific oysters.

    Similarly to Greenshell mussels, Pacific oysters are also a very good source of essential minerals, such as selenium, zinc, copper, iodine, iron, manganese, as well as vitamin B12. Pacific oysters are also a good source of phosphorus, magnesium, niacin and vitamin C and contain significant amounts of glycogen and taurine. Although no New Zealand data is available for the later two bioactives.

    Blue musselsUntil recently there was little commercial interest in developing products and markets for New Zealand blue mussels, therefore there is little published data available for general proximate analysis and other nutritional components. Using overseas data, cooked blue mussels (Mytilus edulis sp.) are appreciated as a good source of vitamin C, thiamine, riboflavin, folate, phosphorus and zinc and as a very good source of protein, vitamin B12, iron, manganese and selenium. The relatively high level of cholesterol (56mg/100g cooked meat) may be a concern to some consumers.

    From this summary of published data it is evident that for New Zealand king salmon, Greenshell mussels and Pacific oysters there is sufficient information to be able to make some nutrition claims in specific markets. Especially with respect to omega-3 content, protein content and minerals such as selenium, iron, iodine, as well as for some vitamins.

    In the US the FDA have determined that if a seafood has greater than 130mg EPA and/or DHA in a daily serving then a label nutrition claim can be made. A single serving of New Zealand king salmon, Greenshell mussels and Pacific oysters will easily meet these criteria.6 A strategy forward There is little doubt that increased consumption of products made from the seafoods discussed in this report would have significant health benefits for most people in the general population and for some

    diseased segments of the population the benefits would be even greater (e.g. CVD, diabetes and arthritis affected people). The encouragement for increased consumption of seafood would be an important public health initiative.

    It is probable that these health benefits will arise not from one specific bioactive component of the seafood but from a number of them and from interactions between bioactive components affecting multiple physiological pathways and sites in the body. These interactions between bioactive components and the body are very complex and can be very powerful. It follows that making specific health claims about a food can also be a complex and difficult process, especially since claims need to be backed up with positive human experimental data.An alternative to making health claims about New Zealand aquacultured products would be to support and help publish research on the links between consuming New Zealand seafood’s and specific health outcomes. Publicising this research will improve brand value over the long-term. A concomitant outcome would be the spin-off of specific nutraceutical products from the New Zealand aquaculture industry.

    Although New Zealand has a good database of the nutritional components in its aquacultured seafoods there are significant gaps in knowledge. Some of these gaps have arisen from a lack of priority, such as for basic information on blue mussel composition and changes with season. While other gaps are due to increased knowledge of the importance of under-researched nutritional components, such as taurine, vitamin D and some minerals, and their interactions with other components.

    Little effort has been spent in identifying other sources of antioxidants, such as polyphenols from mussels and oysters. There is a need for research to quantify the antioxidant contribution from New Zealand seafoods.

    The greatest gap in information however, is in the area of the links between consumption of New Zealand aquacultured seafoods and their benefits for human health. The fact that even a modest seafood consumption (or modest increase) can lead to significant health benefits for a population needs to be developed beyond just the contribution of high omega-3 consumption to include contributions from other functional components. Because of the potential for national health benefits and

    consequent reduction in health costs, this work would support justification for increased consumption of seafoods as a national health priority.7

    2. Introduction

    Scientific and technical developments in seafood have led to an increasing awareness among consumers that dietary source and degree of processing is important for their health, to such an extent that in some markets there is an increasing reluctance to pay more for products not perceived as offering significant health benefits. As a consequence, the ability to identify healthy components in a food and to promote this information to enable consumers to make healthy food choices can be a powerful marketing tool. In a wider context, when applied to whole populations as a public health measure, making healthier food choices can prevent disease and provide exceptional value in that the cost of modifying diet is minimal.With the rise in food nutrition and health claims there has also been an increasing wariness about some of the claims by both consumers and regulatory authorities (Todd 2009; Anon 2010a; Anon 2010b; Hamburg 2010). Consequently, to increase market value over the long-term there is a need to ensure that any promotion is supported by good nutritional and compositional information.

    To make health claims about a nutrient or ingredient in a food requires a more rigorous approach. For example, the US FDA has set-up an evidence-based review system for evaluating health claims (Anon 2009). The process for gathering sufficient evidence to support a health claim is discussed in detail by Finley (2005). In the EU, when making a voluntary nutrition or health claim you must comply with the requirements of European Regulation (EC) No 1924/2006 on nutrition and health claims made on food (see

    http://eurlex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:32006R1924R(01):EN:NOT).

    A nutrition claim is any claim which states, suggests or implies that a food has particular beneficial nutritional properties due to the presence, absence, increased or reduced levels of energy or of a particular nutrient or other substance, and includes

claims such as “source of calcium”, “low fat”, high fibre” and “reduced salt”. These

    claims must be substantiated by generally accepted scientific evidence. A health claim is any claim that states, suggests or implies that a relationship exists between a food category, a food or one of its constituents and health. This would include claims such as “calcium helps build strong bones”. More general claims such as “good for you” may also be health claims, and the regulation takes these into account.

    To date, most effort has been spent on determining basic nutritional information for foods, such as proximate analyses (moisture, protein, carbohydrate, lipids and minerals), vitamins (e.g. watersoluble B and C vitamins, folate and oil-soluble vitamins A, D, E, K) and minerals. And although New Zealand has an extensive database of seafood compositional data (Vlieg 1984; Vlieg 1985; Vlieg 1985; Vlieg 1988; Vlieg and Body 1988; Vlieg, Body et al. 1988; Vlieg 1990; Vlieg, Body et al. 1991; Vlieg, Lee et al. 1991; MacDonald, Hall et al. 2000; MacDonald, Hall et al. 2002; Lesperance, Clark et al. 2009), there is still great scope for identifying bioactive compounds in 8seafood’s to create value by changing markets perception of the quality and value of New Zealand’s aquaculture products.

    There has been growing interest in the health-promoting role of certain foods above their traditional nutritional value. Thus, research efforts to identify functional and bioactive components from many natural foods, including seafood’s, have been increased. Significant health benefits from modest fish consumption have been observed. A recent meta-analysis study found that people who ate fish at least once a week significantly reduced the risk of cardiovascular disease (CVD) by 15% (He,

    Song et al. 2004). There was a dose-response relation between fish consumption and lower CVD mortality, with 7% lower CVD mortality rates with an increased consumption of 20g/day of fish (lean and fatty fish).The health aspects of seafood have primarily, and since the discovery of the low incidence of CVD in Greenland Eskimos, been linked to high intakes of marine omega-3 polyunsaturated fatty acids in particular eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 20:6n-3)(Dyerberg, Bang et al. 1978). Possible contributions from other functional components, such as taurine and selenium, have at least partly been neglected

(Elvevoll, Eilertsen et al. 2008).

    There are many components in fish that may protect against CVD. Fish is rich in omega-3 fatty acids, calcium, selenium, vitamin D, taurine and Coenzyme Q10 (Savige 2001). In other studies marine low molecule weight components with antioxidative effects, such as tocopherols, Coenzyme Q10, selenium and also taurine have attracted special attention due to their possible prevention of low-density lipoprotein oxidation. In recent studies the link between the levels of polyphenol antioxidants in mussels and reducing plasma lipids, for lowering cholesterol and other health benefits has been suggested (Leontowicz, Leontowicz et al. 2008). Section 3 gives a brief introduction to each component and its significance to seafood’s.

    Farmed seafood’s are natural products and can be subject to normal seasonal variations in composition that can affect nutritional functional properties. An increased understanding of these compositional variations would be worthwhile so that reasonable average compositional data can be used by the industry for labelling and for health claims. The aims of this report are to 1) identify healthy components and nutritional benefits of New Zealand aquacultured seafood’s, specifically New Zealand king salmon (Oncorhynchus tshawytscha), Greenshell mussels (Perna canaliculus), Pacific oysters (Crassostrea gigas) and blue mussels (Mytilus edulis aoteanus), and 2) to identify benefits that could be used to promote these seafood’s. Any gaps in information will also be highlighted.9

    3. Brief description of some nutritionally functional and bioactive components in seafood’s

    3.1 Proteins and biologically active peptides

    Proteins

    Seafood’s are considered a valuable source of proteins. Fish muscle protein is generally rich in lysine, the sulphur-containing amino acids and threonine, which are limiting amino acids in cerealbased diets. Therefore, increasing the proportion of marine fish in the diet of people where cereals are the main protein source, is an effective way to improve their nutritional status. This is also why fishmeal and other fish products (e.g. silage) are valued as components in animal feeds.

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