Current Challenges for the Aquatic Products Processing Industry E-Book
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- Herausgeber: John Wiley & Sons
- Kategorie: Fachliteratur
- Sprache: Englisch
This book offers a state-of-the-art analysis on the main challenges facing the aquatic products processing industry. The topics explored are particularly relevant to the issues faced by European consumers and processors, but the information provided within this book can be widely extrapolated. This book should be helpful for processors, fish traders, consumers, scientists and students. The first chapter is dedicated to the sociological definition of "fish" and consumers' perceptions. The following chapters deal with the notions of quality sensu lato, biological risks and their control, as well as the risks linked to the pollution of oceans and ecosystems by microplastics. Two types of processes and processed products - smoked fish and surimi products - which are of great economic importance to the European market, are also presented. The process of adding value to co-products, including the "blue biorefinery" and the innovative pH-shift technology are also covered in this book.
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Table of Contents
Cover
Table of Contents
Title Page
Copyright Page
Preface
1 Consumer Perceptions of “Fish” Food
1.1. Introduction
1.2. Thinking about fish
1.3. Eating fish
1.4. Reconnecting with the fish animal?
1.5. Conclusion
1.6. References
2 Fish Quality and Freshness
2.1. Introduction
2.2. Factors that affect the sensory quality
2.3. The use of sensory measurements in the quality control in the fish industry
2.4. References
3 Nutritional Value of Finfish
3.1. Introduction
3.2. Nutritional value of finfish
3.3. Future trends
3.4. References
4 Fish Traceability and Authenticity
4.1. Introduction
4.2. Seafood traceability
4.3. Analytical methods for the control of seafood traceability and authenticity
4.4. Needs and developments to improved traceability and authenticity for fish industries
4.5. References
5 Bacterial Risks and Biopreservation of Seafood Products
5.1. Introduction
5.2. Microbiota, microbial risk and product quality
5.3. Biopreservation of seafood products
5.4. Conclusion
5.5. References
6 Fish Parasites and Associated Risks
6.1. Introduction
6.2. Prevalence and significance of parasitosis for the sector
6.3. Emerging parasitosis
6.4. The special case of aquaculture species
6.5. Allergies related to the presence of parasites
6.6. The legislative framework for consumer protection or regulatory requirements for parasites in aquatic products
6.7. Methods for the detection of parasites and mainly nematode larvae
6.8. Identification of parasites
6.9. Prevention and control of parasite risk
6.10. Future perspectives and approaches
6.11. References
7 Microplastics
7.1. What are microplastics?
7.2. Analysis of microplastics in seafood
7.3. Contamination status in consumed marine species
7.4. Contamination status in processed products containing fish
7.5. Importance of risk assessment in the context of microplastic contamination
7.6. Concluding remarks
7.7. Acknowledgements
7.8. Appendix: List of consumed species for which microplastic contamination has been documented
7.9. References
8 Smoking: A Flavoring and Preservation Technique
8.1. Introduction
8.2. Role of the main manufacturing steps
8.3. Factors influencing conservation
8.4. The different technologies of salting – drying – smoking
8.5. Conclusion
8.6. Acknowledgements
8.7. References
9 Surimi and Derived Products
9.1. Introduction
9.2. Surimi sources
9.3. Manufacture of surimi
9.4. pH shift process
9.5. Mechanism of gel formation
9.6. Waste management, food-grade coproducts and other materials
9.7. Surimi seafood products
9.8. References
10 Little or Underutilized Marine Resources
10.1. What resources are not or hardly used in the fishing industry?
10.2. The opportunities
10.3. Products and processes
10.4. Synthesis of extracted products from marine co-products
10.5. Conclusion
10.6. References
11 Biorefinery of Underutilized Marine Resources Using the pH-Shift Technology
11.1. Introduction
11.2. Multiple-product blue biorefinery
11.3. pH-shift technology and its fractionation principles as a biorefinery tool
11.4. Isolation of functional proteins using the pH-shift technology
11.5. Cold extraction of fish oil parallel with gel-forming proteins
11.6. Collagen extraction using the pH-shift technology
11.7. Conclusions and future prospects
11.8. References
List of Authors
Index
End User License Agreement
List of Tables
Chapter 2
Table 2.1. Estimated shelf life for some fish species (Martinsdóttír et al. 20...
Table 2.2. Quality index scheme for whole farmed salmon (Salmo salar) (Martins...
Chapter 3
Table 3.1. Proximate chemical composition of finfish species (g 100 g–1) and c...
Table 3.2. Total SFAs, MUFAs, PUFAs, EPA and DHA as the % of total fatty acids...
Table 3.3. Elemental profile of finfish species (mg 100 g
–1
)
Chapter 5
Table 5.1. Microbiota from different seafood products determined by metabarcod...
Table 5.2. Safety criteria for seafood products from Regulation (EC) No. 2073/...
Chapter 6
Table 6.1. Advantages and disadvantages of methods for detecting Anisakidae la...
Chapter 7
Table 7.1. Levels of microplastic contamination identified in the literature d...
Chapter 10
Table 10.1. Average composition of fish co-products
Table 10.2. Presentation of co-product and finished product volumes in France ...
Table 10.3. Average composition of a fish collagen
Table 10.4. Presentation of possible products from co-products according to ma...
Chapter 11
Table 11.1. Overview of example by-products used for protein isolation using t...
List of Illustrations
Chapter 2
Figure 2.1. Factors affecting the sensory quality
Figure 2.2. Fish muscle
Figure 2.3. The fish chain from catch to consumer with control points and the ...
Figure 2.4. Use of QIM in estimating past and remaining storage time
Chapter 4
Figure 4.1. Phylogenetic tree showing the Thunnus species and other genera, li...
Figure 4.2. PCR-ELISA steps. The designed probe (1) is linked to a biotin mole...
Figure 4.3. RPA-LFDA detection of the common octopus (Octopus vulgaris). Posit...
Chapter 7
Figure 7.1. Illustration of the main polymers produced and examples of manufac...
Figure 7.2. Examples of categorization of plastic waste size classes, nanoplas...
Figure 7.3. Picture of various particles, including microplastics observed in ...
Figure 7.4. Aggregated data on sample size, percentage of intake, average numb...
Figure 7.5. Schematic representation of the three major pathways of exposure t...
Chapter 8
Figure 8.1. Manufacturing diagram
Figure 8.2. Manual dry salt salting
Figure 8.3. Air-conditioned drying-smoking chamber
Figure 8.4. Self-combustion smoke generator
Figure 8.5. Frictional smoke generator
Chapter 10
Figure 10.1. Distribution of fishmeal use
Figure 10.2. Fishmeal production flowchart
Figure 10.3. Description of the process steps for refining and purifying fish ...
Figure 10.4. Production diagram of fish enzymatic hydrolysates
Figure 10.5. Distribution curve of the molecular profiles of the hydrolysate b...
Figure 10.6. Oil, powder and liquid hydrolysates of fish co-products (source: ...
Figure 10.7. Mechanical belt or screw separator for fish pulp extraction (sour...
Chapter 11
Figure 11.1. Schematic overview of a potential blue biorefinery approach for f...
Figure 11.2. Schematic overview of the classic pH-shift process for fractionat...
Figure 11.3. A cold process for parallel isolation of fish oil and gel-forming...
Figure 11.4. Schematic overview of the process suggested for sequential isolat...
Guide
Cover Page
Table of Contents
Title Page
Copyright Page
Preface
Begin Reading
List of Authors
Index
WILEY END USER LICENSE AGREEMENT
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SCIENCES
Agronomy and Food Science,Field Directors – Jack Legrand and Gilles Trystram
Food Chains, Subject Heads – Thomas Croguennec,Catherine Renard, Véronique Verrez-Bagnis,Sylvie Chevallier and Véronique Sante-Lhoutellier
Current Challenges for the Aquatic Products Processing Industry
Coordinated by
Véronique Verrez-Bagnis
First published 2023 in Great Britain and the United States by ISTE Ltd and John Wiley & Sons, Inc.
Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be reproduced, stored or transmitted, in any form or by any means, with the prior permission in writing of the publishers, or in the case of reprographic reproduction in accordance with the terms and licenses issued by the CLA. Enquiries concerning reproduction outside these terms should be sent to the publishers at the undermentioned address:
ISTE Ltd27-37 St George’s RoadLondon SW19 4EUUK
www.iste.co.uk
John Wiley & Sons, Inc.111 River StreetHoboken, NJ 07030USA
www.wiley.com
© ISTE Ltd 2023The rights of Véronique Verrez-Bagnis to be identified as the author of this work have been asserted by her in accordance with the Copyright, Designs and Patents Act 1988.
Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s), contributor(s) or editor(s) and do not necessarily reflect the views of ISTE Group.
Library of Congress Control Number: 2023942087
British Library Cataloguing-in-Publication DataA CIP record for this book is available from the British LibraryISBN 978-1-78945-149-8
ERC code:LS8 Ecology, Evolution and Environmental Biology LS8_11 Marine biology and ecologyLS9 Applied Life Sciences, Biotechnology, and Molecular and Biosystems Engineering LS9_3 Applied animal sciences (including animal breeding, veterinary sciences, animal husbandry, animal welfare, aquaculture, fisheries, insect gene drive) LS9_5 Food sciences (including food technology, food safety, nutrition)
Preface
Véronique VERREZ-BAGNIS
Ifremer, Nantes, France
In terms of food, fish is one of the most appreciated among consumers due to its image as a healthy product. In fact, fish is a food with a high nutritional value, being rich in proteins, vitamins and essential amino acids. Fatty fish also provide polyunsaturated fatty acids which cannot be synthesized by humans.
The latest FAO State of Fisheries and Aquaculture report shows the growing role of the aquatic product sector in the global economy and in human nutrition. Indeed, according to 2018 figures, the global production of marine and freshwater products (fish and shellfish) is estimated at 179 million tons, including 82 million tons of aquaculture products, worth USD 401 billion. Since the 1960s, global per capita seafood consumption has increased from 9 kg (live weight equivalent) to 20.5 kg in 2018.
Fish is a very perishable foodstuff, undergoing an alteration of its organoleptic properties due to chemical degradation linked to a significant bacterial development, and to the action of enzymes present in fish (proteases, TMOase, lipases, etc.). In order to extend the shelf life of fish, the development of efficient processing treatments has progressed on a rather large scale. Next to the methods traditionally used, such as salting and drying, fermentation, marinating or smoking, refrigeration and especially freezing have enabled the distribution and sales in areas farther from the coast and have upset the whole sector with the advent of factory ships and the construction of new supply, processing and marketing channels. Fish is currently one of the most globalized foodstuffs.
Like any agri-food sector, the fishery and aquaculture industry is constantly changing. Indeed, the management methods of fisheries are evolving and must be improved so that the exploited stocks can be reconstituted and support a sustainable management of fisheries and ecosystems. Consumption habits are also changing (e.g. the recent craze by Westerners for raw products such as sushi). Technological and physical treatments, as well as biological treatments, are evolving to ensure the safety of food products. Public policies and associated regulations are very often amended.
Although this book is part of the SCIENCES collection and is intended to provide an overview of the vast field of the aquatic product industry, our purpose is to focus on the main current challenges of the aquatic product processing industry. The issues addressed are somewhat more related to the problems of European consumers and processors, with Europe importing 40% of total world imports in fishery and aquaculture products. However, the information provided in this book can be widely extrapolated and useful to any reader interested in these subjects, whether a processor, a fishmonger, a consumer, a scientist or a student.
Thus, in this book, the first chapter is dedicated to the sociological definition of the “fish” as food and the perceptions of this product by consumers. The following chapters deal with the notions of quality sensu lato (Chapters 2–4), then with biological risks (Chapters 5 and 6) and those related to the pollution of oceans and ecosystems by microplastics (Chapter 7). Two types of processes and processed products which are very important for the European market (smoked products and surimi-based products – Chapters 8 and 9) are then addressed. Chapters 10 and 11 talk about valorization of by-products of the processing industry, including the “blue biorefinery”, and the innovative pH-shift technology that plays a central role in splitting up poorly valorized resources into high value-added products.
April 2023
1Consumer Perceptions of “Fish” Food
GERVAISE DEBUCQUET
Audencia Business School, Nantes, France
1.1. Introduction
Due to being omnivores (Fischler 1990), humans are both obliged to diversify food sources to satisfy nutritional needs and the willingness of choosing these sources to vary the pleasures provided by the act of eating. These choices are made according to the availability of food, individual expectations, as well as the more or less affirmed prescriptions of social and cultural groups. In all cultures, animal foods are the subject of the strongest prescriptions, which can lead to prohibitions, avoidance or the expression of simple aversions. Indeed, animal products have always been the object of beliefs and myths and have thus crystallized a certain number of fears (Vialles 1998; Ferrières 2002) due to a form of magical thinking inherent in the act of incorporation (Rozin et al. 1986). Thus, incorporating the meat of an animal implies, in addition to ingesting its nutritional components, ingesting, more or less consciously, its symbolic attributes (Douglas 2005). In the continuity of Hippocrates’ thought, we can say that “one is what one eats” by virtue of these two mechanisms.
Incorporating fish into diets is therefore symbolically incorporating the real and supposed, imagined properties of the animal as well as of the sea (Fischler 1994); this gives rise to a symbolic equivalence between the sea, fish and those who eat them (Corbin 2005) and to a particular place for fish in collective representations. In fact, animals, depending on their nature and their origin – terrestrial, marine, lake or river – have, from time immemorial and in various socio-cultural spaces, conveyed contrasting imaginations and representations, which determine what is edible and what is a food taboo (Leach 1980). In the order of food, the lexical oppositions between “fish” and “flesh (associated with meat)” reveal the distinction between what comes from the aquatic environment and what comes from other environments (Vialles 1998). As a result, land, animal, meat and fish, regardless of their nutritional profile, are not completely interchangeable for committed eaters.
Questioning the reasons for eating fish reveals, even today, some of the specificities of this singular food and, through it, of the fish animal, questioned since antiquity, endowed with a particular status in the Judeo–Christian era and finally, reconsidered more recently in the light of dietetic and ecological imperatives.
1.2. Thinking about fish
1.2.1. Naming the unknown
In the order of the living, fish has always occupied a singular place that should be placed in relation to the representations of its habitat as well as of its own characteristics such as they have been conveyed both by academic discourse and through religious or popular beliefs. For a very long time, fish and other aquatic creatures remained poorly known because, not immediately visible to “earthlings”, they escaped any sensitive experience. Then, the rare occasions to observe them and to understand their habits, their ways of life and reproduction did not facilitate the work of species classification.
In antiquity, fish, their anatomy, their behaviors (olfaction, reproduction, sight, mobility, etc.) were thought of by analogy with terrestrial animals and by anthropomorphic projection and thus many errors of interpretation have been highlighted (Byl and Schouls 1990). Well before scientific nomenclatures, in his History of Animals (Barthélémy-Saint Hilaire 1883), Aristotle used vernacular names or names borrowed from terrestrial animals, such as mule, wolf or “sea toad”, to designate fish, to which certain characteristics of very distant animals, terrestrial mammals, birds or batrachians were attributed (Louis 1971). At the end of the Middle Ages, only a dozen fishes were known.
The underwater imaginings deployed in Jules Verne’s 1870 work, Twenty Thousand Leagues Under the Sea, then fed into collective representations of the sea and aquatic creatures, which have endured long despite the beginning of oceanography as a science in the 19th century. As Elkays (2018, p. 14) puts it, “from an epistemological perspective, the marine environment is only accessible through technological artifacts”. And it is perhaps this that explains why, despite the advent of modern science, the sea remains a relatively alien world to terrestrial humans, still charged with imaginaries and beliefs that give aquatic foods a special place in the food order.
1.2.2. The imaginary of the marine world: permanence and metamorphosis
The marine world nourishes ambivalent representations, fascinating and repulsive at the same time (Geistdoerfer 1998). For a long time, it has been thought of as the domain of monsters (Le Bras-Chopard 2000), of the damned, of the dead, and the fears embodied by necrophagous fish are still alive.
Corbin (2005) explains how relations with the sea have been shaped over time, a world that was at first unknown, then a medium for anxieties and imaginations linked to the abyss and perils of the sea, the scene of the flood for fishermen and sailors exposed to the risks of Hell. The marine world does not belong to the divine but is part of a vision opposed to that of the earthly paradise, of Eden. These representations were progressively transformed, more positive from the 18th century with the increase of the frequentation of the seaside for its beneficial and therapeutic effects. While the image of a “tamed” sea was taking shape and the “desire for the shore” was awakening among land lovers in search of visual and sensory emotions, the coastal fringes became a place of vacation and relaxation where fishing and boating were practiced (Corbin 1990). In the Dutch and Italian paintings of the end of the 18th century, this slow metamorphosis is felt and the figures of the agitated sea made people want to “see the sea” and to “eat fish”. It was henceforth a sea which made a spectacle of itself and which marked at the same time, under the influence of the Christian church, the separation between Mankind and the cosmos with the favor of a “natural theology” (Corbin 1997).
The inversion of these representations was also illustrated by the promotion of “sea bathing”, especially on the British coasts, whose “cold, salty and choppy” water was reputed to be a remedy for the ills of the soul and the body, or even female sterility; the analogy between the composition of sea water and that of blood serum was also supposed to explain, among the inhabitants of the coast, the fertility of fishermen. At the dawn of the 19th century, the virtues of warm water and sunbathing were proclaimed, inspired by Mediterranean habits, and in less than a century a new relationship with the sea and with bathing was established, as illustrated by the effervescence of seaside resorts during the summer (Geistdoerfer 2003). As Corbin (1997) points out, this is not a question of a clean break, because all these representations continue to exist and are still intermingled in the minds of contemporaries. At the time of the awareness of global warming, of the pollution of the seas and oceans, it is the figures of the deluge and the threats on the fringes of the continents which are reactivated. We are worried about the irreversible stigma left by a sea “coveted” for its living or energy resources.
These representations are particularly intertwined in the minds of the French, who, although they have access to a long coastline, are above all “land lovers”, contrary to the countries of northern Europe or in particular, Portugal (Geistdorfer 2007). The French are attracted to the sea especially during vacation periods to see the last wilderness or an “ecologized” shoreline staged by tourism agents. Sincere attraction to the people and jobs of the sea is less common, even where we might expect it, such as in local fish distribution channels (Lazuech and Debucquet 2017).
1.2.3. The representations associated with marine foods: the historical legacy
By going back to the origins of the opposition between “flesh (associated with meat)” and “fish”, Vialles (1998) shows that this distinction is not based on the objective or anatomical characteristics of the products but on their origin and, therefore, on the systems of representations associated with the sources of these foods. Thus, it is necessary to resituate this opposition in the binary prescriptions of Roman Christianity distinguishing “lean foods” for the days of Lent from “meat” or “fatty foods” for the days of carnage. During Lent, fish is one of the few animal foods tolerated. To abstain from meat during Lent means to deprive ourselves of fat and blood as well as to abstain from all food pleasures (Rousseau 2005). It is because of its lesser symbolic proximity to human and human flesh that fish food is tolerated; unlike the meat of land animals, it is less able to regenerate bodies and “make blood” (Rousseau 2005). In Aristotelian representations, partly taken up in Christian beliefs, fish are indeed “cold beings”, “devoid of blood”, their vital force being supposed to come from the water itself (Vialles 1998; Rousseau 2005)1. It is interesting to note the survival of these representations among contemporary eaters; the presence of blood is spontaneously evoked only in fish such as salmon or tuna, whose meat is red2.
Thus, the appropriation of fish by land lovers and the shaping of its status in the food space were largely determined according to a mechanism of symbolic devaluation in relation to the meat of land animals. Fish is the default food for “lean days” and is thus considered less nourishing than meat. However, the dietetic discourse which has prevailed since the end of the 20th century has made it possible to raise the value given to this food and to charge it with new meanings.
1.3. Eating fish
1.3.1. Dealing with animality
According to EUFOMA data (2017 (2015 data)), the average consumption in Europe is 25.1 kg of fish and seafood per capita per year but with great disparities. Portugal leads with 55.9 kg, Spain is second with 45.2 kg and finally France is third with 33.9 kg. The average French consumption actually hides important contrasts observed since time immemorial between the coastal fringe and inland (Salembien 1958; INCA 3 2017), with coastal inhabitants consuming more and more regularly than the latter, for reasons of access to the resource and familiarity with fish. According to the INCA 3 survey, the fish consumption rate is 40.2% among 18–44 year olds, 41.8% among 45–64 year olds and 50% among the over 65 year olds compared to 62.5%, 73.4% and 72.9%, respectively, for meat. Finally, the fish consumption rate is lower among those with a lower rate of education: it is around 40% (compared to 70% for meat) among those with at most a bachelor’s degree and 46% (compared to 63% for meat) among those with at least a bachelor’s degree or higher. Since the price factor is not sufficient to explain the differences, we observe that the “fish” is more valued among the older and higher classes because it is considered to be low-fat. As Boltanski (1971) has shown, fatty foods are subject to contrasting interpretations between the working classes and the upper classes, the former consuming them for their satiating, fortifying and energetic qualities, while the latter deplore their “heaviness” and their propensity to induce “nausea” and “indigestion”. Moreover, the concern for the body among the upper classes, coupled with a greater awareness of the role of food in health, has increased in recent decades, and the rate of fish consumption is a significant marker of this.
In 2020, the French consumer’s seafood basket was composed, in volume, of 31.2% of fresh products (of which 56.5% fish and 43.5% seafood), 30.5% of chilled delicatessen products, 19.1% frozen and finally 19.2% canned (FranceAgriMer 2020). Of the volume of fresh fish, the share of whole and cut fish is, respectively, 27.9% and 69.8%. Over the last decades, the share of canned fish has decreased significantly and that of chilled delicatessen products has increased significantly, while the share of fresh fish has increased slightly since 2017 after a downward trend since the 1960s (Guillotreau et al. 2008).
Changes in lifestyles help explain the increase in the share of “ready-to-eat” fish and prepared fish dishes (INCA 3 2017), but the very low share of whole fish (about 5% of total purchases) still reveals a certain number of specific characteristics of fish consumption. Indeed, consumers very frequently mention the difficulties in preparing fish (scaling, skinning, gutting, filleting, etc.), the lack of expertise and knowledge of species (Lazuech and Debucquet 2017). Even today, those who eat fish have difficulty spontaneously naming more than three species, which poses a real challenge when it comes to incorporating unknown species, such as those from the great depths that fishmongers strive to make “good to eat” to offset the scarcity of more common species such as pollock, cod or hake (Geistdoerfer 2007). In addition, apart from the price factor (Guillotreau et al. 2008), obstacles to the purchasing of fresh whole fish are often linked to fears, whether conscious or not, of not knowing how to deal with a form of marine animality, the treatment of which, in the minds of land lovers, is the responsibility of the men of the sea for “white-flesh” fish and above all for red-flesh fish3. The success of “fish fillets” can thus be explained, beyond its practical side, by the symbolic distance that most French eaters want to keep with marine foods.
1.3.2. Fish today, between pleasure and nutrition
The negative background described above has been partially eclipsed by the health-dietary discourse promoted in the last two decades and highlighted the nutritional qualities of fish compared to meat. Fish is indeed an important source of long polyunsaturated fatty acids for the human diet (Médale 2009) – representing 58% of EPA and 67% of DHA (INCA 3 2017), and its consumption is recommended for the proper functioning of the nervous system and the prevention of cardiovascular diseases. The French National Agency for Food, Environmental and Occupational Health Safety (Agence nationale de sécurité sanitaire de l’alimentation, de l’environnement et du travail, Anses) recommends eating fish twice a week by combining a fatty fish with a high omega-3 content (salmon, sardines, mackerel, herring, trout) and a lean fish, while specifying certain risks related to certain chemical contaminants (methyl-mercury, PCBs in particular) for sensitive populations (pregnant and breastfeeding women, children under three years of age)4.
The more positive view of fish is reflected in the spontaneous evocations collected from consumers, since fish consumption is associated with the idea of health and freshness, as well as with pleasure, gustatory pleasure and festive consumption (Gouin et al. 2009). The symbolism of the sea, invigorating and purifying, contributes to the construction of representations of fish, a food that is strongly revalued today for its healthy and balanced character, and perceived as “lighter” than the meat of land animals (Paquotte 2004). The image of fish is thus in a way ennobled, even if the more negative images of polluted seas, the effects of global warming or intensive aquaculture somewhat tarnish the representations (Paquotte 2004; Michel-Guillou 2014). Moreover, studies show, still today, the lack of knowledge of the population on the species and their intrinsic qualities. Certain paradoxes can be noted, such as the declared attraction for “wild” and “lean” fish, while salmon, a fatty fish that is mostly farmed, remains the leading fish consumed (26% of the volume of fresh fish), followed by cod (14%) and pollock (8%). It is interesting to note that these three species are largely the most consumed, while all the others (trout, sea bream, monkfish, mackerel, whiting, sardines, hake, sea bass, blue ling, etc.), among which excellent “fatty” fish for their omega 3 content, share the remaining volumes (FranceAgriMer 2020). This paradox is explained by the difficulty of making sense, for most French people, with this lean/fat opposition when it concerns fish, fat being more associated with land animal meat and food eaten outside of Lent. Finally, the lack of knowledge of polyunsaturated fatty acids is not surprising, as a detailed understanding of these nutritional issues is not within reach of all eaters despite the multiplication of claims on food packaging over the past two decades (Masson et al. 2016). In doing so, the lesser knowledge of fish species and the nutritionalization of fish contribute to confirm the intuition of Geistdoerfer et al. (2003): many contemporary citizens eat fish, i.e. a material for its nutritional qualities and not an animal. Recent developments in consumption and supply patterns seem to be slightly changing this relationship with fish.
1.4. Reconnecting with the fish animal?
1.4.1. A culinary exoticism: raw fish
As Lévi-Strauss (1964) has shown, cooking occupies a central place in culinary practices in that it facilitates the passage from nature to culture. Williot (2015) shows that the opposition between raw meat eaters and cooked meat eaters is nowadays expressed in multiple ways, revealing personal (taste preferences), religious, culinary habits or precautions linked to intuitive or hygienic knowledge. While the consumption of raw meat tartar is historically common in France, the very rapid progression of raw fish consumption raises questions.
According to the INCA 3 survey (periods 2014–2015), the consumption of raw foods has increased significantly and more strongly for fish. Indeed, the rate of consumption of raw fish, consumed in the form of sushi or ceviche, has doubled since the last INCA 2 survey (periods 2006 and 2007), rising from 15% to 31% of the population concerned. It is more common among adults aged 18–45 years, men, those with a higher education and those in higher professions and socio-professional categories (SPCs). Historically an uncommon practice in France, it now occupies an important place among French eaters, fond of a certain food exoticism (Régnier 2015). These ways of consuming fish, which originated in Asia, Oceania and South America, are associated with festive and convivial moments and contribute to a reconnection with the sea and its symbols, naturalness, freshness and health. This consumption is a source of hedonism and curiosity for those who wish to reconnect with the foods of the sea. Is eating it raw a way to change the status of fish or to make it become “flesh” symbolically? As mentioned earlier, most contemporary eaters still share the image of fish as a bloodless being, which excludes it from the category of meat. The possible presence of parasites is often counter-intuitive for raw fish eaters, because it confronts them with a form of animality somewhat buried in the collective unconscious (Debucquet 2011). Still, in contrast to the success of prepared fish dishes (FranceAgriMer 2020), the growing consumption of raw fish seems to allow the eater to appreciate and rediscover the textures and unique tastes of different species of fish, such as salmon, tuna, sea bass, sea bream, mackerel, etc.
1.4.2. The local distribution channels of fish
The SARS-CoV-2 pandemic and subsequent lockdowns have revitalized home-made and local and/or direct sourcing. The purchase of aquatic products increased by 6% in volume between 2019 and 2020, and by 3% for fresh fish in the seafood department in particular (+ 2% for whole fish) (FranceAgriMer 2020). Even if these increases are moderate, they are part, beyond the contingencies of the pandemic, of a context of food anxiety and the desire to reclaim food via raw products. This is illustrated by the return of local or short-distance supply chains. According to the INCA 3 survey (2017), fish purchases are made primarily in supermarkets (58.9% of households), in convenience stores and fishmongers (19.6%) and finally in markets/direct sales (9.6%), the last two channels more particularly among the most educated. However, the last decade has seen the emergence of various short direct supply chains, such as the Poiscaille5, Ô’Poisson6 or the AMAP-Poisson de Yeu-Nantes websites, which promote fresh, local, “wild” fish from French coasts, “line-caught” fish and also “noble and forgotten” species7. These two modes of supply are very successful, especially in the western regions, especially in the hinterland, where street fish sales almost disappeared at the end of the last century. Recent surveys show that the motivations are plural, economic, social and culinary (Salladarré et al. 2018). The case of the AMAP Yeu-Nantes is interesting in this respect because the members ultimately show little interest in the men and trades of the sea, the techniques and fishing areas. They are more interested in acquiring knowledge about fish in order to be able to better differentiate them, name them and above all gain know-how to prepare and cook them (Lazuech and Debucquet 2017). Among the exclusive buyers of these channels, the main motivation is relational for exchanges and reciprocity with other citizens who wish to support locally regarding fish recipes. These forms of supply help to overcome the obstacles related to the lack of knowledge, expertise and self-confidence to reappropriate the foods of the sea8. Communities of “fish eaters” are thus being consolidated for the horizontal transmission of knowledge about the fish animal and the fish food (Debucquet et al. 2020).
1.5. Conclusion
This chapter has highlighted the duality of the relationship with fish through the lens of the imaginary of the sea and sea creatures, contemporary dietary injunctions and finally social and commercial innovations to restore a certain proximity with marine foods. Eating fish has some peculiarities since the status of fish and its animality remains endowed with a strong symbolic valence; historically associated with a time of penitence throwing out the criteria of exclusion from the category of meat, fish has then become one of the emblems of food hygiene in Western societies. The food pleasure has not been rested for pescatarians as for certain occasional eaters ready to pay an additional cost to obtain fish whose animality is preserved until plate serving (the setting in scene of whole fish, fresh, “line caught”, etc.). For the rest of the contemporary eaters, industrial preparations of fish-based dishes allow them to manage the symbolic distance with the sea and its living resources or to reify the fish animal.
In the light of the dietary transition requiring a reduction in the consumption of animal proteins and the awareness of the pollution of the seas and the consequences of overfishing, we can ask ourselves what will happen to the relationship between Western eaters and fish. Will we eat less “fish” and/or rediscover the diversity of “fishes”, while gaining knowledge and know-how to better appreciate their taste and health qualities? The degree of change in eating habits will tell us.
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Notes
1.
Another illustration of the system of symbolic thought that relates sea water and blood is seen in the representations associated with sailors: “The ‘land lovers’ do not understand the particularities of the practices and thoughts of sailors [...] [t]he ‘land lovers’ represent these ‘beings’ who have ‘sea water in their veins instead of blood’. It cannot be otherwise, in the opinion of several authors, because to be able to live at sea, with the sea […] one must come from it, be a ‘sailor’, etymologically ‘of the sea’” (Geistdoerfer 1998, p. 32; 2007).
2.
In a research program devoted to fish parasites, particularly those of the family
Anisakidae
, consumers interviewed associated the presence of parasites with the presence of blood, parasites being, for them, an incarnation of
spontaneous generation.
The presence of parasites in white fish came as a great surprise to the subjects and was counterintuitive to most of them since white fish were perceived to be bloodless (Debucquet 2011).
3.
This animality in the representations of the marine world remains, for the reasons mentioned above, ambiguous. Vialles (1998) explains how tuna fishermen align, through their practices, “the real with the ideal” (p. 5), by eliminating the apparent blood of tunas that are actually “fishes”. The treatment of the blood deemed inappropriate and the absence of “real” bleeding contribute to the exclusion of tuna from the “meat” category and make it conform with the representations of fish. As Vialles (1998) puts it, it is a matter of “fishifying” it (p. 5).
4.
According to the latest INCA 3 survey (2017), 36% of respondents report being familiar with the PNNS fish benchmark (“recommended consumption two times a week”), 40% among women versus 33% among men, 41% among 18–44 year olds versus 32% among 45–64 year olds. This benchmark is also better known among those with a higher education.
5.
See:
https://poiscaille.fr/
.
6.
See:
https://www.o-poisson.fr/bar-de-ligne.html
.
7.
See the home page of the Poiscaille website op. cit.
8.
More than one in two adults (57%) consider that they do not eat enough fish, because of the high price (for 43% of them), because they do not know how to prepare it (22%), because they do not like fish (20%) and finally because of the odors released during cooking (20%) (INCA 3 2017).
2Fish Quality and Freshness
Grethe HYLDIG
Technical University of Denmark, Lyngby, Denmark
2.1. Introduction
Freshness and quality is a very complex concept and needs to be defined, as the definition changes with the context where it is applied. The concept is frequently described using terms related to nutritional, microbiological and physiochemical characteristics alone, but none of these terms serve as adequate indices of quality – sensory perception and consumer acceptability must be included (Nielsen et al. 2001). Sensory quality is important in each chain link, all the way from catch to consumer. Analysis of sensory quality attributes describing product characteristics is important, and objective sensory analysis can give a full description including appearance, taste, smell and texture in one analysis. In the food industry, sensory knowledge and training is essential and can be used not only for sensory evaluation, but also when managing raw material. Therefore, it can be used in all of the different steps in the production chain.
This chapter will look into what affects the sensory quality and freshness of fish, and describe some of the sensory methods that can be used for fish as objective markers of quality in the chain, from catch to consumer.
2.2. Factors that affect the sensory quality
Compared with other food commodities, fish are very different in terms of their methods of harvesting, fragility of the product during transport to processing sites, and further down the chain, temperature dependency and variety of species. Therefore, it is necessary to monitor sensory quality in the whole chain. Sensory assessment of fish and fish products has therefore played a natural part of the seafood chain for years. Factors affecting sensory quality are shown in Figure 2.1.
Figure 2.1.Factors affecting the sensory quality
2.2.1. Genetic
2.2.1.1. Fish (vertebrates)
Fish are generally defined as aquatic vertebrates that use gills to obtain oxygen from water, with fins consisting of a variable number of skeletal elements called fin rays. Fish are the most numerous of the vertebrates, with at least 20,000 known species, with more than half of the species found in the marine environment (Thurman and Webber 1984). Each species is identified by a scientific name which has two parts – the genus and the specific epithet (binominal nomenclature). For example, the scientific (species) name of the common cod is Gadus morhua.
2.2.1.2. Fish anatomy
The backbone of the fish runs from the head to the tail and consists of segments (vertebrae). The vertebrates are extended dorsally to form neural spines, and in the trunk region they have lateral processes that bear ribs. The ribs are cartilaginous or bony structures in the connective tissue between the muscle segments. Many species also have a corresponding number of false ribs or “pin bones” extending more or less horizontally into the muscle tissue. These bones have to be removed if a bone free fillet is the goal. Fish has muscle (see Figure 2.2) cells running in parallel and connected to sheaths of connective tissue (myocommata) anchored to the skeleton and the skin. The bundles of parallel muscle cells are called myotomes.
Figure 2.2.Fish muscle
The muscle can be white or have a light color (white muscle), but the muscle also has a certain amount of dark tissue that is a brown or reddish color (dark muscle). The dark muscle has a higher level of lipids and myoglobin. The location of the dark muscle is just under the skin along the side of the body. The proportion of dark muscle varies with the activity of the fish. The more active the fish, the larger the dark muscle. In some products, the high lipid content of dark muscle is important and can give high intensities of desirable sensory attributes, but the high lipid content can also give a shorter shelf life due to lipid oxidation, resulting in rancid and sour attributes, among others. A typical pelagic fish such as herring will contain approximately 25% of the dark muscle required for prolonged aerobic muscle activity. The proportion of dark muscle varies with the activity, the more active the fish, the larger the dark muscle. Demersal species such as cod have a white flaky and tender muscle; textural changes such as toughness and chewiness are the most notable problem during storage. Fish can contain natural antioxidants such as tocopherol and astaxanthin; these can also give the fish muscle a red color.
2.2.1.3. Species
There can be large variation between the different fish species, but there can also be considerable variation between individuals. Within the same species, there can also be variation due to their living conditions. The lipid in the fish differs from lipid in mammals by a high content of long-chain polyunsaturated fatty acids, including ω-3 fatty acids. The unsaturated fatty acids are easily oxidized and become rancid. Marine fish and some freshwater fish species contain trimethylaminoxid (TMAO). Bacteria decompose TMAO to trimethylamine (TMA) and by enzymes, in some species, to dimethylamine DMA. Both TMA and DMA smell and taste like rotten fish.
Fish species are often divided according to the lipid content; lean, semi-fat and fat. Some example of lean fish species with 0–2g lipid/100g fish are cod (Gadus morhua), hake (Merluccius merluccius) and place (Pleuronectes platessa). Some example of semi-fat fish species with 2–8g lipid/100g fish are trout (Oncorhynchus mykiss), Nile perch (Lates niloticus) and halibut (Hippoglossus hippoglossus). Some example of fat fish species with 8–35g lipid/100g fish are herring (Clupea harengus), mackerel (Scomber scombrus) and salmon (Salmo salar). The lipid content will have an influence on the sensory and technological quality, shelf life and commercial value.
In a study with farmed rainbow trout (Oncorhynchus mykiss), fed and handled in the same way, groups of fish were sampled three different times during a production day. The rainbow trout were analyzed by the objective sensory profiling of minced fillets that were heat-treated. The results showed significant differences in the sensory profiles of individual fish within all three groups as well as significant differences between the groups. The results showed a significant negative correlation between the lipid content and firm texture, but in general, the chemical and physical measurements could not explain the differences in sensory profiling or mechanical texture measurements (Green-Petersen and Hyldig 2010). For wild caught fish such as herring (Clupea harengus), there can also be a wide variation in lipid content. A single catch can contain herring with a lipid content ranging from 1 to 25%. This variation is due to heterogeneity caused by mixing between stocks (Nielsen et al. 2005a).
2.2.2. Age
During growth, the sizes of each muscle cell increase, not the number of muscle cells. Also, the proportion of connective tissue increases with age. Fish become sexually mature when they reach the characteristic size for the species and the growth rate decreases after the fish has reached maturity. Mature fish use energy to build up gonads (roe and milk).
2.2.3. Time of year
Fish will have a natural period of starvation when they are migrating or spawning, as well as due to a shortage of feed. Such a starvation will give a variation in the sensory quality of the fish. The length of the spawning season varies greatly between species.
In herring, the lipid content will reflect the season and become low during the spawning period; this was shown in studies by Nielsen et al. (2005a) and Hyldig et al. (2012). In the study by Hyldig et al. (2012), they also concluded that both catching location and season had an effect on the development of the sensory quality of herring.
2.2.4. Environment and aquaculture
Some off-flavors can come from feeding on different contaminants or organisms. Two of the most known off-flavors in freshwater fish are geosmin (trans-1, 10-dimethyl-trans-9-decalol) and 2-methylisoborneol (exo-1,2,7,7-tetramethylF2.2.1]-heptan-2-ol, MIB), which are produced by different microorganisms. The off-flavor from MIB gives a moldy and musty smell and taste, and geosmin gives a muddy smell and taste that it is difficult to remove from the mouth (Petersen et al. 2011).
Theoretically, there are no differences in the content, quality and shelf life of aquaculture fish and wild fish of the same species, given that they have the same feed and physical activity. To a certain extent, the fish farmer is able to design the fish by selecting the farming conditions. It has been reported that factors such as feed composition, environment, fish size and genetic traits all have an impact on the composition and quality (Green-Petersen et al. 2014).
2.2.5. Feed
Variation in the composition of the fish is affected by the feed intake, migration and spawn period. It is natural for fish to fast due to spawning and migration, as well as if there is a scarcity of feed. In this period, the fish will use their lipid store; they can also use protein if it is a long migration.
In a diet study (Baron et al. 2009) with rainbow trout (Oncorhynchus mykiss) feed, a total of six different diets were studied, containing either fish oil or rapeseed oil, with or without 200 mg/kg of carotenoid (either astaxanthin or canthaxanthin). The farming conditions were the same for all of the six different groups. The fish were slaughtered and stored as butterfly fillets in individual polyethylene bags for 22 months at -20°C. The fish fed fish oil had a grainier, more fibrous and firmer texture compared to the fish fed vegetable oil. In contrast, the “fish fed” vegetable oil was juicier. In general, they also had a less rancid odor and flavor compared to the fish fed fish oil. Fish fed vegetable oil had cooked potato, sweet and mushroom flavors, whereas fish-fed fish oil had more sour flavors. For the fish fed fish oil, the highest rancid odor and flavor were observed when astaxanthin was present in the feed. In contrast, the lower score for rancidity was observed when canthaxanthin was present in the feed. The picture was more complex and difficult to describe for fish-fed vegetable oil, but fish receiving the no-pigment feed had a lower score for both rancid odor and flavor than both samples that were fed carotenoids.
In a feed experiment by Green-Petersen et al. (2014) with organic rainbow trout (Oncorhynchus mykiss), they used six different organic diets. The control feed contained mainly fish meal as the protein source and fish oil as the lipid source. In the other five tested diets, 47% of the fish meal protein was replaced by a matrix of organic vegetable protein concentrates containing peas, horse beans and rapeseed (in the ratio 1.07:1.0:0.66). In four of these diets, fish oil was replaced by organic linseed, sunflower, rapeseed or grape seed vegetable oils, while one of the diets had fish oil as the lipid source. All feed types had an analyzed protein content of 45–46% w.w. and a lipid content of 28% w.w. The sensory quality was measured with objective sensory profiling conducted with a tested and trained sensory panel. Their results showed that the dietary lipid sources influenced the sensory characteristics of the trout in different ways during storage in ice. They found differences in texture after three days of ice storage, but after five days of ice storage, the fish showed more similarity in the sensory profile. However, after seven days in ice, some differences appeared. The trout which had rapeseed oil and grape seed oil generally had a more neutral flavor and odor profile with a lower intensity of mushroom odor, boiled potato odor, fresh fish oil and sweet flavor. Furthermore, the texture was less flaky, firm, juicy, stringy and oily compared to the other samples. The ice storage of trout fed with rapeseed or grape seed oil resulted in a more neutral odor and flavor, and a reduced texture quality compared to fish fed with fish oil, linseed oil, or sunflower oil.
2.2.6. Catch handling and slaughter
The balance in lipids and pro- and antioxidants changes when a fish dies and the initiation of lipases and proteases begins. This means that the oxidation and breakdown of lipids and protein structure take place, and these processes can results in a low sensory quality due to the formation of off-flavors and a soft texture. It must therefore be pointed out that it is important to have a fast and effective handling procedure resulting in the rapid chilling of the catch. A whole gutted fish has a longer shelf life than a fish fillet because the fish skin protects the muscle. The size and fat content will also affect shelf life.
In some fisheries, a uniform white fillet is desirable and therefore bleeding of the fish is very important. Bleeding is most affected by time on-board prior to bleeding/gutting, and the best bleeding is obtained if the fish is cut before it enters rigor mortis, since it is the muscle contractions that force the blood out of the tissues.
Physical rough handling in the net (long trawling time, very large catches) or on the deck (fishermen stepping on the fish or throwing boxes, containers and other items on top of the fish) may cause bruises, rupture of blood vessels and blood oozing into the muscle tissue (hematoma).
2.2.6.1. Rigor
Rigor mortis begins immediately or shortly after death depending on species, size, physical condition, catch method and catch handling. It also depends on whether the fish is starved, which results in depleted glycogen reserves, or if the fish is stressed. The method used for stunning and killing the fish also influences the onset of rigor. The technological significance of rigor mortis and whether the fish has been filleted before or in rigor are also of importance (Cappeln and Jessen 2002). In rigor, the fish body will be completely stiff; the filleting yield will drop significantly, and rough handling can cause gaping in the fillets. If the fillets are removed from the bone pre-rigor, the muscle can contract freely and the fillets will shorten following the onset of rigor.
