Flashcards in 10d Diet Forms and Formulations Deck (31):
The quality of food is not related to its ____ but to its ______
not related to its form, but its formulation
- however pets are individualistic in feeding behaviour and food preferences
What are some steps that need to be taken when formulating a diet?
- consider nutrient requirements
- select ingredient and determine ingredient bioavailability
- consider food intake and adjust nutrient density
- consider expected or legal minima or mama in nutrients or ingredients
- feeding management ( ad libitum or single meal)
How can one use excel when formulating diets?
- can calculate costs/ limits/ compositions
- select least cost formulation
How does formulating diets for dogs and cats differ?
- dogs: more latitude in ingredient selection and formulation, feasible to formulate without animal ingredients; can adapt
- cats: commercial diets have significant amount of plant based and animal based ingredients; veg diets alone are not nutritionally adequate
How does ingredient selection play a critical role in feed processing?
- starch helps binding during extrusion
What are the 2 main types of food?
- dry and canned
What are the 3 types of dry food?
1. dry expanded
2. semi moist
3. soft expanded
- major ingredients: cereal grains, grain by products
- minor: animal by products
- other: 10-30% vegetable protein, fat, supplements
- marketed as: kibble, meal, pellets, baked
- suited for incising rather than grinding
What are some advantages of dry expanded?
- ease of storage and feeding
- lower cost
- free choice feeding option
- abrasive effects
What are some disadvantages of dry expanded?
- lower palatability
- change of reduced nutrient content with improper heating
- restricted amounts of fat and energy, lower digestibility
- can all be overcome by proper formulation and processing
baked pet foods
- not common
- some owners of dogs prefer
- shape of bones to attract buyers
- produced using traditional means of dough formation, shape cutting, baking
- high levels of cereal flours (>50%)
- fats and oils seldom applied post baking
- usually contains meat or meat by product slurries prior to or during extrusion
- incorporate humectantL sugar, NaCl, sorbate to reduce water activity (shelf stability, prevent old, microbial growth)
- stabilizers: propylene glycol, food grade acids (citric acid), antimycotic agent
- must be packed in low moisture diffusion packaging to prevent moisture loss and changes in water activity
- no drying process after extrusion
- softer in texture, not wet to touch, chewy but not sloppy
Advantages of semi moist
- can be sold in bags, does not require refrigeration
- can be fed free choice, can be sold in larger amounts
- can be fed as patties
disadvantages of semi moist
- greater cost of manufacturing and shipping
- contain acidifiers to lower pH and retard bacterial growth
- higher in sugar to improve taste (consumer concern, maybe for problem animals)
Soft expanded (soft dry)
- similar to semi moist pet food but differ in expanded appearance after extrusion
- extrusion parameters are similar to dry expanded food processing but ingredients include humectants to control water activity
- relatively higher level of meat byproducts
- often have higher levels of fats and oils than dry expanded foods
- expansion of semi moist pet food is difficult due to high moisture and predominance of non expandable materials
Describe what kind of pet treats there are.
- historically, dough forming, shape cutting and oven baking
- recently use extrusion
- no requirement for feeding directions if not being complete and balanced
- often contain higher levels of fresh or frozen meat, poultry or fish products and animal by products
- may contain significant level of texturized protein, meat analogue, mimics appearance (soy or wheat gluten based, reduce formula cost, improve nutrient profiles)
- high energy density DM basis (dictate high concentration of amino acids, vitamins, minerals)
- commonly used as supplements to improve the acceptability of dry pet foods
advantages of canned
- increased palatability (higher in protein and fat, easier to eat)
disadvantages of canned
- generally too much protein and fat
- greater cost, processing is a complex endeavour
- increased attention to dental care, not abrasive enough
How is canned pet food processed?
- complex endeavour
- blend fat, meat, water, dry ingredients
- heated to cook or directly through filling device can, sealed
- retorted (heat and pressure cooking and sterilization, destroy food borne pathogens)
- destruction of nutrients due to heat and pressure
- 74% loss thiamin
Advantages of processing
- increases salability and acceptability
- increases nutrient availability
- removes toxins, inhibitors, unwanted fractions
- increases shelf life and storage time
- improves handling characteristics
- improves texture, taste or appearance
- increases or decreases nutrient density
- adds flexibility in consumers choice
problems with processing
- decreases palatability and acceptability
- can decrease digestibility
- can accidentally introduce contaminants
- may reduce texture, taste and appearane
What is extrusion
- developed 1954
- uses raw materials
- needs no chemicals/solvents
- generates insignificant waste
- cook using high heat, moisture, high pressure, forced through a die
What are the 5 steps of an extruder operation?
1. mixes inside
2. w/ liquids or heated with steam
3. 1 or 2 screws (1 for cat food)
4. rotate contents toward barrel end
5. expands into desired shape.size
Why is extrusion an important process?
- food properties, density and starch gelatinization impacted by precondition and extrusion, retention time, temperature, pressure and moisture, degree of cook
- starch gelatinization improves digestibility and palatability
How does the distance from the die affect gelatinization?
- further from die = gelatinization smaller
- closer to die, gelatinization increases
what is the relationship between temperature and starch gelatinization?
- as temp increases, gelatinization increases
- eventually gelatinization plateaus
How does starch gelatinization and retrogradation work?
- as temp increases starch granule forms gel
- gelatinized starch cools down, forms rigid structure
- retrograded starch may be very difficult to digest like resistant starch
What is an extrusion problem with fat?
- creates starch lipid complex
- may not significantly affect starch and lipid availability, but slower
- can interfere with assay for determining ether extract, but can use acid hydrolysis to determine fat content
How does fat content affect starch gelatinization?
- as fat content increases, leads to decreased degree of starch gelatinization
- depends on type of fat