10d Diet Forms and Formulations

Question 1

The quality of food is not related to its ____ but to its ______

Answer 1

not related to its form, but its formulation

- however pets are individualistic in feeding behaviour and food preferences

Question 2

What are some steps that need to be taken when formulating a diet?

Answer 2

• 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)

Question 3

How can one use excel when formulating diets?

Answer 3

• can calculate costs/ limits/ compositions

- select least cost formulation

Question 4

How does formulating diets for dogs and cats differ?

Answer 4

• 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

Question 5

How does ingredient selection play a critical role in feed processing?

Answer 5

• starch helps binding during extrusion

Question 6

What are the 2 main types of food?

Answer 6

• dry and canned

Question 7

What are the 3 types of dry food?

Answer 7

1. dry expanded
2. semi moist
3. soft expanded

Question 8

dry expanded

Answer 8

• 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

Question 9

What are some advantages of dry expanded?

Answer 9

• ease of storage and feeding
• lower cost
• free choice feeding option
• abrasive effects

Question 10

What are some disadvantages of dry expanded?

Answer 10

• 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

Question 11

baked pet foods

Answer 11

• 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

Question 12

semi moist

Answer 12

• 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

Question 13

Advantages of semi moist

Answer 13

• 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

Question 14

disadvantages of semi moist

Answer 14

• 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)

Question 15

Soft expanded (soft dry)

Answer 15

• 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

Question 16

Describe what kind of pet treats there are.

Answer 16

• historically, dough forming, shape cutting and oven baking
• recently use extrusion
• no requirement for feeding directions if not being complete and balanced

Question 17

canned food

Answer 17

• 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

Question 18

advantages of canned

Answer 18

• increased palatability (higher in protein and fat, easier to eat)

Question 19

disadvantages of canned

Answer 19

• generally too much protein and fat
• greater cost, processing is a complex endeavour
• increased attention to dental care, not abrasive enough

Question 20

How is canned pet food processed?

Answer 20

• 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

Question 21

Advantages of processing

Answer 21

• 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

Question 22

problems with processing

Answer 22

• decreases palatability and acceptability
• can decrease digestibility
• can accidentally introduce contaminants
• may reduce texture, taste and appearane

Question 23

What is extrusion

Answer 23

• developed 1954
• uses raw materials
• needs no chemicals/solvents
• generates insignificant waste
• cook using high heat, moisture, high pressure, forced through a die

Question 24

What are the 5 steps of an extruder operation?

Answer 24

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

Question 25

Why is extrusion an important process?

Answer 25

• 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

Question 26

How does the distance from the die affect gelatinization?

Answer 26

• further from die = gelatinization smaller

- closer to die, gelatinization increases

Question 27

what is the relationship between temperature and starch gelatinization?

Answer 27

• as temp increases, gelatinization increases

- eventually gelatinization plateaus

Question 28

How does starch gelatinization and retrogradation work?

Answer 28

• 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
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Question 29

What is an extrusion problem with fat?

Answer 29

• 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

Question 30

How does fat content affect starch gelatinization?

Answer 30

• as fat content increases, leads to decreased degree of starch gelatinization
• depends on type of fat

Question 31

What are some important factors when extruding food for cats?

Answer 31

• grind to 1mm especially for cats
• sharp angles can hurt cats mouth so ensure die plate and knives in good condition
• for cat, diameter of kibble <1cm as cats have to move kibble in mouth before cracking