Finals Flashcards
Characteristics of fresh produce
- Perishable
- Grown seasonal (strawberries?)
- Move fast–> quick but gentle handling
- Long lead times
- Quality variations between producers and plots: variability
- Special storage conditions
- Fast handling
- Short delivery times to preserve freshness
Quality
- Suitability of a product for a specified purpose- judged against defined criteria
- Needs to be defined for each product
Shelf life
- Length of time food is able to be consumed before spoilage
Spoilage
- Deterioration of food by microbiological, physiological, physical means- no longer fit for purpose/ edible
Food safety
- Absence from harmful chemicals, physical or biological contaminants
Functionality
- Properties that contribute usefulness
How is quality measured
- Quantity
- Objective
- Subjective: Sensory
○ Acceptability is not easy to test
Components of flavour
- Sweet, sour, umami, bitter and sour
Types of sensory analysis
- Discrimination testing
- Preference, acceptability, hedonic testing
- Descriptive analysis
Optimum nutrition
- Adequate, balanced & prudent diets
- Food secure
- Normal development & healthy
Undernutrition: hunger
- Food insecurity, poverty, political unstable environments
Decreased physical and mental development, compromised immune systems. Viscous cycle
Overnutrition
- Overconsumption of food especially macronutrients (under consumption of micro)
- Obesity, metabolic syndrome, type 2 diabetes
Malnutrition
- Nutrition transition: previously food insecure
- Abundance of palatable food, some undernourished
- Double burden of infectious disease and often characterised by too many macro and too few micronutrients
Major macronutrient and its breakdown
- Carbohydrates
- 1/3 cellulose
- 1/3 pectin
- 1/3 hemicellulose
What affects respiration
- Part and age of plant
- Temperature
- Hormones
- Packaging
- Bruising and mechanical damage
Factors in post harvest disease of F&V
- Genetic susceptibility
- Moisture and temp
- Handling
- Storage
- Maturity & ripeness
Infection may originate (postharvest pathogens F&V)
- As endophytes
- From inoculm in field
- During harvest, transport, storage, display or in home
Fungus type and fruit and potential contamination spot
- Botrytis Sp.
- Strawberries & grapes
- inoculm in field
Egg anti-spoilage mechanisms
- Physical: hydrophobic & porous shell, membranes separating egg shell from albumen (3 layers)
- Chemical: sterile contents, inhibitory contents in egg white, high pH (difficult for gram positive bacteria)
Milk components
- Fat
- Proteins: caesin, amino acids, albumen and globulins
- Lactose: glucose and galactose
- Minerals and vitamins
- 87% water & 13% solids (3-4% proteins, lipids 3-4%)
5 milk quality parameters
- Compositionally complete
- free from off odours and flavours
- free from detectable drug residues, added water or adulterants
- Low total bacterial count (or TCP)
- Low SCC
what are muscle fibres made up of
sarcomeres
Muscle fibre of fish and impact
- darker= more oxygen and haemoglobin = swims long distances
- white fish swim in short bursts
Meat spoilage
- Break down of proteins= putrefaction and slime
- Production of lactic acid= sourness and discolouration
- Break down of fats= rancidity
Food/ mat poisoning
- infection and intoxication
Reduce spoilage of meat
- Minimise contact with product
- Hygiene condition
- Temperature control
- Storage
- Lighting during display
- Prevent dark cutting and gaping at the processing level
Post harvest approaches to increase shelf life
- sanitiser, preservation and non-chemical antimicrobial treatments
What causes food to be unsafe?
- Microbes
- Chemical
- Intrinsic and extrinsic
Physical (e.g. needles in strawberries)
Common food allergens
- milk
- eggs
- Wheat
- soy
- peanuts
- tree-nuts
- Fish
- crustacean shellfish
7 HACCP principles
- Conduct a hazard analysis
- Identify critical control points
- Establish critical limits for each critical control point
- Establish critical control point monitoring requirements
- Establish corrective actions
- Establish procedures for verifying the HACCP system is working as intended (validation & verification)
- Establish record keeping procedures
What is the second biggest industry?
Meat
Largest milk production country
India 21%
Main sugars in F&V (carbs)
fructose, sucrose and glucose
Nutritional composition of horticulture produce
- Water
- Carbohydrates
- Organic acids
- Low protein
- Vitamins and minerals
- Volatiles
- Bioactive compounds
Use of antioxidants in your diet
- ‘Mop’ up the free radicals released in metabolism
- Used for protection against many clinical conditions
Reasons F&V aren’t eaten in the right amount
- Seasons
- Convenience
- Access
- Consumer trends
U.S do ready to eat meals
Differentiation between red and white meat
- Red: high myoglobin- slow twitch muscle
- White: low myoglobin- fast twitch muscle fibre
Reasons for high consumption of Chicken
- Low fat protein source
- Niacin, vitamin A&E and magnesium
- Versatile use
- Efficient production
- Fast production cycle and can change rapidly to suit demand
Fishery meaning
- activities involved in catching a species of fish/ shellfish, or a group of species that share the same habitat
Different types of fisheries
- Commercial, subsistence and recreational fisheries
Fisheries type harvested
- Marine, freshwater and brackish water
- Fish: pelagic (mid depth), demersal (bottom) reef
- Shellfish: crustaceans, molluscs (oyster, octopus), and echinoderms (sea urchin)
- Plants: Macro-algae- rhodphyta (red), phaeophyta (brown), chlorophyta (green)
Importance of quality
- Consumer acceptability
- Product consistency for both fresh consumption and processing
- Nutritional value
- Reducing processing wastage, spoilage
- Trade (price and market share)
Factors affecting quality
- Genetics (variety)
- Environmental factors
○ Soil, nutrients, solar irradiation, rainfall, temperature
○ Time to anthesis - Processing technology
- Testing methods
- Deep soils, nutrients and plenty of water results in high vegetative growth and yield in grapes
- Influence of environment difficult to predict
How is quality measured
- Quantitative and qualitative aspects
- Parameters include appearances, texture and flavour
- Both sensory and instrumental analyses
Visual quality attributes
- Morphology (size, shape), appearance (colour, gloss, clarity, consistency)
- Physical defects
- Blemishes
Halo effect
Appearance modifies subsequent perception of flavour and overall acceptability
Instrumental assessment of texture
- Compression tests
- Shear tests
- Cut/ break tests
- Tensile strength tests
- Rheological (viscosity and shear) tests in fluid or semi-solid food
physicochemical analyses
- Particles and bulk density, porosity, surface areas
- Morphology using various forms of microscopy- light, electron, confocal
- Thermodynamic properties- temperature transitions
- Chemical composition
Tastants
are released during mastication and delivered to taste receptors, on the tongue and mouth surfaces
Odorants
are sensed through the nose but also released from the food matrix to the oral cavity headspace and saliva
Typical analyses of food (nutritional info)
- Energy value
- Protein
Fats - Carbs
- Sugar
- Salt: sodium
- may be added: moisture, ash and dietary fibre
Analytical methods
- physical and chemical analysis
- Function tests
Hazard Analysis and Critical Points (HCCP)
- Systematic approach to identify hazards and manage risks
- Preventative protocols for safety in food production
International Standards Organisation (ISO)
- Provides assurance about an organisation’s quality management systems
ISO9000
protocols for food management
ISO22000
protocols for food safety management
Food production and handling processes must consider?
- quality, functionality, shelf-life and safety to meet consumer or user demands
Main quality attributes of fresh produce
- Visual
- Textural
- Nutritional
- Microbiological
Fruit
swollen ovaries of a fertilised flower that has seeds, is the reproductive part of the plant. It is designed to disperse those seeds so that the plant can keep going.
Vegetable
can eat the whole plant, more savoury.
Factors affecting F&V quality
- Preharvest- genetic, agronomic and environmental
- Harvest- maturity, physical damage
- Immediate postharvest- temperature, handling
- Postharvest storage- temperature, atmosphere
- Transportation- packaging, temperature
- Non-technical- skilled personnel, extension
respiration and temperature
- Respiration rate increases just above freezing and ceases at thermal death point
- Within certain temperature limits (usually 0-20 degrees), respiration rate approximately doubles for every 10 degree rise in temperature
- Cold chain is one of the simplest and most effective ways to maximise shelf-life of perishable produce
O2 and CO2 (respiration)
○ Low O2 retards respiration rate
○ But too low O2 –> anaerobic glycolysis and off flavours
○ High CO2 retards respiration
High CO2 also controls pathogen growth
Climacteric
Ethylene is also produced during fruit ripening, causing a characteristic rise in respiration rate (and CO2)
- fruit are characterised as climacteric or climacteric based on their response to ethylene
Ideal time to harvest
- Ideal to harvest climacteric fruits early so they are still hard when transported, less likely to bruise it.
- Non-climacteric fruit are the best when they are first harvested, will only deteriorate from there
- The higher the respiration rate in a harvested plant, the faster the deterioration
Preharvest factors affecting quality
- Genetics
- Climate
- Crop nutrition
- Agronomy
- Pollination especially on fruit shape
- Pest and disease
Post harvest temp management
- The fist step is removal of field heat immediately after harvest
- Main methods are hydro-cooling, vacuum cooling and forced-air cooling
Chilling injury in F&V
If tonoplast (vacuole membrane) is damaged during storage by chilling or mechanical injury, leakage of acids damages the cell
Factors affecting visual quality continue
- Visual quality- bruising
- Vibration damage
- Pressure or compression damage
Shelf life prolonging
- Shelf life is prolonged by reducing respiration rate- immediately postharvest and during transport and storage
Respiration is regulated by?
plant part, temperature, O2/ CO2- tolerance to different conditions varies with produce
Anatomical structure of muscle
- Fibres arranged in longitude bundles
- Bundles arranged into primary, secondary and tertiary groups and encased in connective tissue
- Thick (myosin) and thin (actin) filaments make up a sarcomere
Rigamortis
- Final resting stage of the muscle—> no more ATP left, in a contracting or a relaxed state.
Pre processing factors influence meat quality traits
- Production system
- Genetics
- Nutrition
- Animal handling
- Transportation
Effect of carcase chilling on muscle shortening
- Increased moisture loss
- Tougher product
- Reduced EQ juiciness value
Forms of shortening
- Hort shortening
- Cold shortening
- Thaw shortening
Processing techniques to reduce shortening
- Stimulation of carcasses
- Tender stretching carcases
4 main types of fat
- external
- internal
- seam (between muscles)
- intramuscular (marbling)
The importance of fat
- When heated fats reach their melting point
- Solid state–> liquid state
- Release oils and aromas
- IMF melts
- Aids in flavour
- Enhancement
- Improvement mouthfeel
At risk of oxidation
Maillard reaction
- The chemical reaction that occurs when food is heated and results in enhanced and aromatic
- Why food browns and develops caramelised flavours
- The reaction begins at 140 degrees and ends at 180 degrees
Different types of fish categories
- White: <5% fat, delicate and lean
- Oily fish: 10-25% fat, dark and good source of Omega 3
- Shellfish: crustacean and molluscs
Nutritional benefits of seafood
- All essential amino acids
- Omega 3’s
- B group vitamins
- A+D vitamins (oily fish only)
- Minerals
Different cuts of fish
- Drawn
- Dressed
- Steaks
- Fillets
- Transition occurs in 3 main stages (seafood)
- Rigour mortis
- Oxidative deterioration
- Bacterial spoilage
Rigour changes occurring in fish before it is frozen can affect quality through? (3)
- Toughness and high drip loss in frozen whole fish or fillets
- Gaping in fillets taken from frozen whole fish
- Shrinkage of frozen fillets
Can reduced the impact of rigour on fish by: (3)
- Keeping fish cool (especially prior to rigour)
- Handling it carefully in rigour
- Freezing fillets taken from pre-rigour fish as soon as they are cut
3 main causes of spoilage in meat and seafood
- Moisture loss
- Enzyme action
- Microbial contaminationH
Shelf life influencing factors (meat)
- Storage environment
- Muscle tissue factor
- Microorganism type and level
Cause of spoilage: enzymes
- Breakdown structure and aid in increased fluid leaking during ageing
- Protein rich fluid provides an enviro for bacteria to proliferate
Current challenges to egg industry and food security
- Disease
- Health scares
- Competition for feed ingredients
- Animal welfare legislation
- Pollution
Current challenges for egg production and supply chain
- Disease risk
- Feed source
- Welfare
- Pollution
Macronutrients
- Carbohydrates (44%)
- Proteins (15-25%)
- Fats and oils (lipids) (33%)
Micronutrients
- Minerals
- Vitamins
- Water
We cant make and need to get form our diet
- Vitamins, minerals, phytonutrients, and fibres
Phytochemicals
- Chemicals naturally found in F&V that protect the plant from disease and insects, also help protect health of humans.
- Responsible for colour and smell of vegetables
Water soluble vitamins
B1-3, B5-7, B9 & B12
- C
Fat-soluble vitamins
A, D, E, K
4 principles of disease prevention
- Begin with healthy non-stressed produce
- Provide an environment that will maintain the freshness e.g. low temperature
- Prevent any mechanical damage during harvesting, grading and packaging and transport
- Use postharvest applications of fungicides/ pesticides/ heat if produce is destined for long term transport or storage. Follow instructions strictly.
Post harvest disease management
- Field hygiene and sanitation
- Hot water dips
- Fungicides and inhibitors
- Refrigeration
- Drying
- y-irradtaition
- Filtration
- Modified atmosphere
Post harvested washing of fruit and vegetables
○ Removal of dirt and dust (visual appeal)
○ Reduction of microbes causing post-harvest disease (food spoilage- increased self life)
- Reduction in human pathogens (food safety)
Chlorine based sanitiser
- used during washing or hydrocooling
- attacks pathogen cell wall
- Cl gas dissipates into environment upon agitation–> OH&S issues
generally accepted methods for preserving food for microorganism control
- Sterilisation by heat or radiation
- Refrigeration/ freezing
- Drying
- Chemical preservatives
Acute allergic reactions
- Anaphylaxis
- Welts
- Rash
Severe allergic reactions
- Multisystem
- Rapidly progressive
- Potentially fatal
- Anaphylaxis shock
Food allergy
Immunological
Food intolerance
Non-immunological
CODEX Alimentarius
- 1963
- Harmonise international food standards
- International food standards and guidelines
FSANZ
- Independent statutory agency established by the Food Standards Australia New Zealand Act in 1991
- Part of the Australian Government’s health portfolio
- regulates the use of ingredients, processing aids, colourings, additives etc.
- Responsible for labelling
the 4 chapters
- Standards that apply to all foods
- Food standards
- Food safety standards
- ## Primary production standards
Characteristics of potentially hazardous food
- Moist
- Nutrient rich
- Neutral pH
