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Flashcards in Food technology 3 Deck (100)
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Outline the importance of bees

- Honey production
- Pollination
- Medicinal products
- Cosmetics


Outline reasons for the declining be population in developing countries

- Change in agricultural practice
- Monocultures unattractive to bees, food is not available throughout year
- Addition of pesticides
- Introduction of diseases and parasites


What is the purpose of the National Bee Unit?

To achieve a sustainable and healthy population of honey bees for pollination and honey production in England and Wales, via strengthened partnership working between Government and other stakeholders


Outline the structure of honey bee colonies

- 60,000 workers, 2000 drones, 1 queen
- In winter, 10,000 workers, no drones 1 queen


Outline the honey bee lifecycle

- Each egg laid in hexagonal wax cell, hatch into larvae
- Not all eggs treated equally
- Workers "cap" cells when larvae are ready to pupate
- Adult emerges at different times depending on caste
- Queen: 16 days, workers 21 days, drones 24 days


Outline honey bee feeding

- Nectar, is mainly sucrose. Converted to glucose and fructose by invertase
- Nectar regurgitates into storage cells
- Pollen mixed with nectar, collected in baskets, packed into cells by worker "house" bees
- Workers forage for food towards end of life


Outline the structure of honey bee hives

- British National Hive used
- Series of stacked boxes
- Used for brooding and honey production
- Entrance at bottom into brood box, then queen excluder, then honey supers then wooden crown board and waterproof roof


What is the function of the brood box in a bee hive?

Is the heart of the colony where the queen lays her eggs


What is the function of the queen excluder in a bee hive?

Prevents access of the queen to the levels above but workers are able to access. Allows storage of excess honey in honey supers


Describe honey production in the hive

- Nectar brought in, stored in honey supers
- Dilute sugar solution
- Thermoregulation and ventilation by bees to evaporate water from solution
- Once approx 17% water, capped with wax to seal
- Good hive produces 60lbs in a season, average is 25lbs


Outline the harvesting of honey

- July and August
- Honey released by sliding long knife over surface of cells
- Remove wax cap and frames placed in centrifuge to spin out honey
- Must not remove too much as large colonies will starve
- Honey filtered and pasteurised before sale


Describe the UK honey market

- 80% reliant on foreign imports
- Main EU suppliers: Germany, Hungary, Spain and France
- Main Third Country suppliers: Argentina, New Zealand, China, Mexico, India
- Most honey is blended


Describe migratory bee keeping

- Type of flower foraged impacts flavour and texture of product
- Heather highly valued
- May move to these areas (Yorkshire Moors)
- Can be successful if manage well, good bees, good livestock management and good weather conditions


What are the main microbiological and pharmacological residue issues associated with honey production?

Clostridium botulinum and veterinary residues such as streptomycin


Describe the issues associated with Clostridium botulinum in honey

- Viable spores found in honey
- Infant botulism is a risk (paralysis and death)
- Immature gut flora cannot compete
- Do not feed to children <12 months old


Describe the issues associated with pharmacological residues in honey

- No MRLs for antimicrobials in honey sold in the EU as are not permitted to use antimicrobials
- In some cases APHA permits use of oxytetracycling BUT cannot be sold for 6 months
- Few products are authorised for apiculture
- Chloramphenicol, streptomycin, tetracyclines and sulphonamides are tested for, has led to some import bans where found
- Risk of pesticides also being present (organophosphates, organochlorines, metals e.g. cadmium and lead)


Who has responsibility for residue testing of honey in the UK?

VMD via the NBU


What factors may affect bee colony productivity?

- Management (host genetics, pesticides, husbandry, nutrition)
- Environment (pesticides, climate, nutrition)
- Pests and diseases (varroa, nosema, viruses)
- Are all inter linked


What is the role of vets in bee colony management?

- Bees are vital to economy and food security
- Control of diseases and pests therefore important
- Use of licensed therapeutic products
- Drug resistance and residues potential


What legislation covers the control of bee disease?

Bees Act 1980
- Orders from ministers and sec of state to control diseases and pests affecting honey bees
- Provides powers of entry for authorised persons
-Statutory orders list diseases against which statutory action must be taken


List the important diseases of bees and state whether they are notifiable or not

- European Foul Brood (notifiable)
- American Foul Brood (notifiable)
- Tropilaelaps mites (notifiable)
- Small hive beetle (notifiable)
- Varroa destructor
- Nosema
- Asian hornet


Outline European Foul Brood

- Melisossocus plutonius bacteria most important cause (are others)
- Internation
- Affects brood before capped and develops into adults
- Brood exhibits shotgun pattern
- Shook-swarm technique can be used in mild cases
- Destroy colony in severe cases
- Occasionally AHVHA has allowed use of oxytetracycline to treat EFB, but is not first choice


Describe the appearance of larvae affected by European Foul Brood

- Dead larvae
- Brown or tan colour
- Melted appearance


What is the shook-swarm technique?

Transfer of adults to new hive and destruction of old comb and hive


Outline American Foul Brood

- Paenibacillus larvae, Gram +ve spore forming bacteria
- More severe than EFB
- Brood die after being capped
- Does not affect adult bees
- Larvae infected by consumption of contaminated feed, multiplies in gut until larvae die
- Spores can be viable for >40 years, easily transferred to other hives by fomites or bees


Outline the control of AFB

- Destroy colony, burn equipment under supervision of inspector
- Good biosecurity, acquitision of bees from reputable sources
- Not sharing equipment with other bee keepers
- Antimicrobials not used


How is AFB diagnosed?

- Ropiness test
- Stir contents of cell with small probe, as probe is pulled out "rope" 1-3cm long will form if AFB present


Outline Tropilaelaps

- Parasitic mites affecting developing brood and adults
- Mites feed on haemolymph of developing larvae, leads to brood patterns, stunted adults and potential colony collapse
- Abnormal brood development (deformed wing virus in developing larvae)


What are the consequences of Tropilaelaps infection?

- Abnormal development of brood
- Deformed wings
- Cannot forage for food
- Colonyy starves
- Is notifiable


Outline the control of Tropilaelaps

- Exact geographical range unknown but currently not found in UK
- Mainly SE Asia
- Import control is main defence


Outline the Small Hive Beetle

- Aethina tumida
- Widespread in many areas but not in UK
- larvae eat wax, pollen, honey, bee brood and eggs
- Contaminate honey with faeces causing it to ferment


Outline the control of the Small Hive Beetle

- Good husbandry is effective defence
- Unlikely that small hive beetle could be eradicated once present in the UK


Outline Varroa destructor

- Parasitie mite
- Reproduces in sealed brood cells, feeds on haemolymph
- Present in all inhabited continents except Australia
- Vector for pathogen such as deformed wing virus
- Most colonies die if let untreated


Outline the control of Varroa destructor

- Integrated pest management
- Chemical treatments e.g thymol, flumethrin tau fluvalinate, formic acid
- Oxalic acid effective but unlicensed
- Dusting with icing sugar, trap combs also effective


Outline Nosema appis

- Microsporidian (fungal) parasite, invades midgut of bees, causes dysentery
- Infects gut of adult bees
- If queen infected, ovaries degenerate, egg production drops
- Can reduce honey yields significantly


Outline the diagnosis and control of Nosema apis

- Yellow stripes of faecal matter seen in infected colonies and on hive
- Diagnosis by light microscopy or PCR
- No licensed treatments available


Outline Asian hornets as a disease of bees

- Vespa velutina nigrithorax
- Highly motile, very few required to destroy entire colony
- Attempts to control in France highly unsuccessful
- Risk of spread to Uk


List the common steps in the flow diagram of fish processing

- Gutting and deheading
- Desliming
- Weighing
- Filleting
- Trimming
- Pinbone removal
- Skinning
- Fillet washing
- Grading


Outline "desliming" in fish processing

- Removal of fish slime
- Improves presentation
- Reduces bacterial contamination
- Can use high water pressure in highly mechanised plants


Outline filleting in fish processing

- Cutting fish into fillets
- Can be manual or mechanical
- Efficiency essential to not affect yield


Outline "trimming" in fish processing

- Trimming methods vary
- Depends on throughput, labour costs, traceability requirements
- Can be highly advanced automatic or basic manual


Outline manual trimming in fish processing

- Most designed as active lines
- Trimming conducted on conveyor belt while it is running
- Throughput depends on fish size and trim level


Outline fillet washing in fish processing

- Prior to packing, freezing, further handling washing unit used
- rinse off slime, blood, remains from filleting, trimming, pinboning
- Can reduce bacterial count


What is the main cause of food-borne illness from fish?

- Fish usually only lightly cooked, raw or pickled
- Increases chance of pathogen survival


What are the main human health hazards from fish?

- Food-borne pathogens
- Zoonoses
- Allergens
- Toxins
- Contaminants
- Antimicrobial resistance risks


What are the main zoonoses of fish?

- Chlonorchis sinensis
- Diphyllobothrium latum
- Anisakis spp
- Mycobacterium marinum


What is Chlonorchis sinensis?



Describe the infective stage of Chlonorchis sinensis

- Metacercaria
- Found in musculature, subcut tissue, scales, fins and gills of cyprinids, clupeids


Outline the zoonotic effects of Chlonorchis sinensis

- Also found in rats, cats, dogs, pigs and humans
- In humans can be foung in bile ducts
- Can be fatal as infection may cause pancreatitis and lead to liver carcinoma


Describe Diphyllobothrium latum

- Cestode
- Procercoid found in musculature and viscera of marine and freshwater fish species
- Also found in birds, bears, seals, walruses, dogs


Describe human infection with Diphyllobothrium latum

- Humans are not end host
- Found in mucosa of ileum and jejunum of humans
- Infection usually asymptomatic, can cause malabsorption, anaemia and weight loss
- Praziquantel used


Describe Anisakis spp.

- Nematode
- life cycle involves marine crustaceans, fish, squid and mammals
- Larvae found in viscera and muscle many fish spp
- Definitive hosts are marine mammals


Describe human infection with Anisakis spp.

- Adult nematide in intestine of humans
- Infection by consumption of raw/pickled fish
- Invasive and non-invasive form
- Non-invasive asymtpmatic
- Invasive = severe reaction, bloody stools, nausea, ulcers
- Can result in hypersensitivity
- Treatment is surgery


Describe Mycobacterium marinum

- Ubiquitous resistant bacteria, cause disease in ornamental fish
- Aka aquarist's finger
- Cutaneous nodular lesions in humans associated with wounds
- Slow response to antibiotic treatment


List some biological hazards associated with bivalve consumption

- Bacteria
- Viruses (most common aetiological agent)
- Chemical
- Organics
- Biotocins


List the bacteria associated with bivalve consumption

- Salmonella spp.
- Shigella spp.
- Vibrio parahaemolyticus, vulnificus, cholerae
- Campylobacter spp
- Listeria monocytogenes


List the viruses associated with bivalve consumption

- Norovirus
- Hepatitis A virus


List the organics associated with bivalve consumption

- Dioxins
- Polychlorinated biphenyls (PCBs)
- Polycyclci Aromatic Hydrocarbons (PAHs)
- Pesticides


List the chemicals associated with bivalve consumption

- Heavy metals including mercury
- cadmium
- Lead


List the biotoxin diseases associated with bivalve consumption

- Paralytic shellfish poisoning (PSP)
- Diarrhoeic shellfish poisoning (DSP)
- Amnesic shellfish poisoning (ASP)
- Neurotoxic shellfish poisoning (NSP)


Explain why shellfish can cause health problems in humans

- Many shellfish areas impacted by sewage
- Filter large amounts of water per hour
- Filtration results in accumulation of toxins, bacteria, viruses etc within the shellfish
- Shellfish are often eaten raw or lightly cooked


Describe Vibrio vulnificus

- Warm sea water (>13dC)
- Not associated with sewage
- Contaminated seafood or open infections
- Causes VD, abdominal pain, septicaemia and death
- Blistering skin esions
- oysters are frequent source
- Global warming may increase presence in Europe


Describe Vibrio parahaemolyticus

- Gastroenteritis
- Readily detected in ~30% of shellfish samples


Describe Norovirus

Intestinal disease
- Major problem in contained populations
- Incubation period 1-4 days
- Clinical signs ~2days long, usually complete recovery
- Susceptible to reinfection 5-12 months after previous episode


Describe Hepatitis A virus

- Endemic infection in developing countries
- In developed countries, large proportion susceptible
- Stable, long incubation period (2-6 weeks)
- Serious debilitating disease
- Self-limiting, rarely causes death
- Patient incapacitated for several months


Describe the clinical signs of Hepatitis A infection in humans

- Overt hepatitis mainly in adults, in children only mild illness
- Signs: fever, headache, nausea, vomiting, diarrhoea, abdominal pain, jaundice
- Recovery is complete, long term immunity


Describe algal toxins

- Phytoplankton species produce biotoxins
- Filter feeding shellfish accumulate these in flesh
- DSP persistent problem in some Uk coastal areas, PSP very rare, ASP very rare and fatal
- Cooking shellfish will not destroy toxins
- Resistant to freezing


How is the risk from algal toxins reduced?

- Weekly sampling
- Reduced to monthly if supported by risk assessment


What control measures are used to control/reduce the human health risks from fish?

- Freezing
- Cooking
- Water depuration
- Cleaning/disinfection of equipment in food processing plants
- Monitoring


Outline some of the tasks performed under EC 854/2004 with regards to fish production

- Information and guidance on relevant analytical methods
- Working with national reference labs on application of methods
- Coordinating research into new methods
- Organising trainign courses and workshops
- Collaborating with third country labs
- Providing scientific and technical assistance to the European Commission
- Helping reference labs implement quality assurance systems, e.g. accreditation


Who carries out the monitoring of bacteriological and viral contamination of bivalve molluscs?

Centre for Environment, Fisheries and Aquaculture Science (CEFAS) from the UK, which is the European Union Reference Laboratory (EURL)


Outline the requirements regarding the freezing of fishery products

- All products destined to be eaten raw must be frozen before use
- Includes products that will be marinated and salted
- Also where smoking does not lead to core temperature of 60degrees for at least 1 min
- Must be frozen at -20degrees for 24 hours OR -35degrees for 15hours
- 4 exceptional conditions


Why is freezing used as a control measure in fisheries?

Protects consumer against parasites (does not kill the parasite) e.g. Anisakis


Outline the exception for the freezing of fishery products

1: Where products have been or will be heat treated at a level that will kill viable parasites (60degrees for 1 min except trematodes)
2: Fish preserved as frozen for long enough to kill viable parasites (-18degrees for 4 days for storage, transport and distribution)
3: Wild catches authorised by FSA where evidence shows no health hazard at fishing grounds (none of these in UK)
4: Farmed fish where are cultured from embryos and fed on diet that cannot contain viable parasites, environment free from parasites, evidence that fishery products have no parasites


Why is cooking used as a control measure in fishery products?

Kills parasites, viruses and bacteria, however does not inactivate biotoxins


Why is cleaning and disinfection effective in controlling health hazards from fishery products?

- Organic residues are good source of nutrients for microorganisms that can develop and establish on surfaces
- Biofilms can then contaminate the food processed on these
- Key target is Listeria monocytogenes


Why is water depuration used in the control of health hazards from fishery products?

- Effective against bacteria normally faecal contaminants, excreted and present in water)
- Poorly effective against viruses as these are within the flesh of the animal
- Not consistently effective at reducing contamination with biotoxins
- Relies on harvesters compliance


What is water depuration?

Seawater from tanks (particularly for shellfish) continuously pumped through an ultraviolet chamber


Outline the method classification of shellfish harvesting areas

- Inshore waters monitored closely for contamination
- At height of season tested weekly
- Content of faecal coliforms measured, used as indication of general bacterial and viral contamination
- Grading from A to D where A is safest and D is poorest


Describe the criteria and treatment for a category A shellfish harvesting area

- Criteria: molluscs contain less than 230 E. coli per 100g of flesh
- Treatment: can be harvested for direct human consumption


Describe the criteria and treatment for a category B shellfish harvesting area

- 90% of samples molluscs <4,600 E. coli for 100g of flesh
- 10% of samples <46, 000 E. coli per 100g of flesh
- Treatment: human consumption after depuration or re-laying in an approved class A area or after approved heat treatment process


Describe the criteria and treatment for a category C shellfish harvesting areas

- Criteria: <46,000 E coli per 100g of flesh
- Treatment: human consumption after relaying for at least 2 months in approved relaying area and treatment in a depuration centre or after approved heat treatment process


Describe the criteria and treatment for category D shellfish harvesting areas

- Criteria: >46,000 E. coli per 100g of flesh
- Treatment: must not be harvested or offered for human consumption


List the farmed marine finfish

- Atlantic salmon
- Cod
- Halibut
- Turbot


List the farmed freshwater finfish

- Rainbow trout
- Brown trout
- Carp
- Barramundi
- Tilapia
- Pangasius


Outline the reasons for farming fish

- Food production
- Stocking recreational fisheries
- Diversity of species
- Pet trade


What are the different methods of mussel farming?

- Wild harvest
- Seabed culture
- Suspended culture


What is mussel growth dependent on?

- Natural plankton must be present (no additional food is added to water)
- Stable natural habitat to settle and grow into adult stock


Outline wild harvest mussel farming

- Mussels grow naturally in large beds subtidally or between tides
- Occurs in many areas by towed dredge or hand-raking at low tide
- All operations must meet water quality and food safety regulations


Outline seabed and suspended culture mussel farming

- Locating and fishing seed mussel ~10mm length from offshore beds, relay in more productive/protected location (lay)
- In suspended culture, grow on ropes/floats until harvested 18-24 months later


What other activities may take place in areas of mussel cultivation?

- Other fish farms
- Leisure
- Shipping


What are the EU's End Product Standards regarding mussels?

- Must be alive
- Fresh and in good condition
- Contain inter-valvular fluid
- Respond to sharp tap
- Meet specific bacterial and toxin standards


What are the licensing and location regulations for fish farming in Scotland?

- No formal license, instead permission from 3 institutions
- Planning permission from local council, Marine licence from marine Scotland, discharge licence from Scottish Environment Protection Agency
- MAB depends on location


What is MAB in fish farming?

- Maximum Allowed Biomass
- Determines for each area based on environmental concerns e.g. capacity of local marine environment to accommodate fish farm


Describe the fish farming licence distribution in Scotland

- Legal to trade licenses, no restrictions on number, but is limit on production quantity ascribed to any one company
- Limit determined by Competition Commission authorities
- Currently in transitory state: new applications must request planning permission, existing leases without planning permission are undergoing review, if have planning permission are not required to undergo review


Describe salmon farming in the UK

- 320 marine sites
- Mostly West coast of Scotland and Shetland Isles
- Large multinational companies mianly in Scotland
- Juveniles (smolts) produced at specialised freshwater hatcheries, 6 months old introduced to seawater cages, harvest 2+yo (2-3kg)


Describe trout farming in the UK

- Most freshwater, river or spring sources of water
- Can also grow in seawater (larger fish)
- Hatcheries:specialised in producing juveniles to be sold to ongrowing farms. Number reduced
- Ongrowing farms: produce final product, more than 300 in UK, variable size and practice


Describe the rainbow trout broodstock

- All rainbow trout stock in UK is female
- Grow to desired weight (300-400g) without reaching sexual maturity
- At sexual maturity growth rate slows and condition loss at spawning time
- Males reach maturity before 300g


What is triploidy?

Sterile, no sexual maturity


How and why are rainbow trout triploids?

- Eggs subjected to temperature shock in order to induce triploidy
- Where heavier trout are required as do not want sexual maturity preventing growth past 300-400g