17: Diet Forms and Formulations

Question 1

What is the quality of food related to? Why?

Answer 1

Not related to its form but to its formulation

Ingredient composition drives nutrient composition

Question 2

Differences in ingredient selection process for formulation between dogs and cats

Answer 2

Dogs have more flexibility in ingredient selection and formulation. You can formulate an adequate diet without animal-based ingredients.

Cats are carnivorous and diet must contain a portion of animal-based ingredients. Significant amount of plant-based ingredients is possible, but vegetarian diets fed alone are not adequate.

Question 3

Why must cat diets contain a portion of animal-based ingredients? (3)

Answer 3

• Increase acceptability by cat
• specific nutrients: arachidonic acid, taurine
• improve palatability

Question 4

An ingredient has multiple characteristics related to…

Answer 4

• nutrient characteristics
• functional characteristics (affect on feces quality, skin/gut health)
• food processing characteristics
• taste
• colour (for person)

Question 5

Following extrusion, what characteristics can be added to the kibble?

Answer 5

Extruded particles can be coated:
- fat, flavour
- palatability enhancers

Question 6

When we talk about ‘extrusion quality,’ what might this mean?

Answer 6

Whether kibble stays together, is nutritionally sound after extrusion, looks good and tastes good

Question 7

What factors affect the quality control of extrusion?

Answer 7

1 is ingredient characteristics

then equipment variables, conditioning, pre-processing, cooling and drying

Question 8

Why are ingredient characteristics important in quality control of extrusion?

Answer 8

Ingredients must have binding capacity

Wheat has gluten = sticking capacity, corn has poorer

Question 9

Food properties, density and starch gelatinization are impacted by… (3)

Answer 9

• precondition and extrusion
• retention time, temperature, pressure and moisture
• degree of cook

Question 10

What is starch gelatinization and what does it do?

Answer 10

Extrusion process for starch
Opens the starch up and improves its digestibility and palatability

Question 11

Slide 8

Answer 11

Extruder operation*

Question 12

One problem associated with extrusion/starch gelatinization

Answer 12

Retrogradation
Creates a starch-lipid complex if you heat it up and cool it down too fast
Slows starch and lipid availability
Resistant starch cats can’t digest

e.g. amylose-lipid complex

Slide 9

Question 13

Pet food categories

Answer 13

Dry:
1. Dry-extruded (10-12% moisture)
2. Semi-moist (25-35% moisture) ‘treats’

Canned: 74-78% moisture

Question 14

Why do consumers prefer dry extruded?

Answer 14

Storage, option to buy in bulk

Question 15

Slides 11,12

Answer 15

Nutrient content as fed vs 100% DM basis in dry, semi-moist and canned foods

Question 16

Major, minor and other ingredients in dry extruded foods? They are marketed as…

Answer 16

Major (24-50%, with starch): cereal grains, grain by-products
Minor (5-25%, animal protein): animal by-products, etc

Marketed as: kibbles, meals, pellets, baked

Question 17

Advantages and disadvantages of dry extruded

Answer 17

Advantages:
- ease of storage and feeding
- lower cost (one-third to one-half of canned)
- free choice feeding option
- abrasive effects reduces tarter build up

Disadv:
- lower palatability
- change of reduced nutrient content w improper heating
- restricted amounts of fat and energy, lower digestibility
^^ can be overcome by proper formulation and processing

Question 18

How are baked pet foods produced?

Answer 18

Traditional means of dough formation, shape cutting, baking
Fats and oils rarely applied post-baking

Question 19

In semi-moist, which two ingredients are added with the purpose of preventing/reducing water activity in the food?

Answer 19

• Humectants (sugar, NaCl, sorbate): bind water and reduce water activity improving shelf stability, preventing mold and microbial growth
• Stabilizers: polyhydric (propylene glycol), food grade acids (citric acid)

Question 20

Why are water binders needed in semi-moist foods?

Answer 20

Reduce water activity by binding it
Without them, the treats would spoil (mold, microbial growth)

Question 21

How are semi-moist foods sold? Dried?

Answer 21

Sold in low-moisture diffusion packaging, sealed pouches (to prevent moisture loss and changes in water activity)

No drying after extrusion

Question 22

Advantages and disadvantages of semi-moist foods

Answer 22

Adv:
- can be sold in bags, do not require refrigeration
- can be fed free choice, can be sold in larger amounts
- can be fed as patties

Disadv:
- greater cost of manufacturing and shipping
- contain acidifiers to lower pH and prevent bacterial growth
- higher in sugar to improve taste

Question 23

How are snacks/treats for pets produced? What is a characteristic about them?

Answer 23

Historically produced using traditional means (dough, shape cutting, oven baking)

Recently, using extrusion

There is no requirement for them to bear feeding directions, as they are not ‘complete and balanced’

Question 24

Canned/wet food often contains more…. They have high…

Answer 24

More fresh or frozen meat, poultry, or fish and animal by-products; 25-75%

High energy densities

Question 25

Advantages and disadvantages of canned/wet food

Answer 25

Adv: increased palatability (higher in protein and fat; easier to eat)

Disadv:
- generally, too much protein and fat (limited self control = obesity)
- greater cost, complex processing
- increased attention to dental care (not abrasive enough)

Question 26

How is canned petfood processing complex? (explain the process)

Answer 26

Blending fat and meat ingredients + water + dry ingredients
Blended, ground to produce thick slurry
Heated to cook
Can, then sealed
Retorted (heat and pressure cooking and sterilization to destroy food-borne pathogens)
^ can lead to destructions of nutrients

Question 27

Advantages of processing? (7)

Answer 27

• increased palatability and acceptability
• increased nutrient availability
• removes toxins, inhibitors
• increases shelf life and storage time
• improves texture, taste or appearance
• increases or decreases nutrient density
• flexibility for consumer

Question 28

Disadvantages of processing

Answer 28

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

Question 29

Examples of new pet food categories? Their popularity has more to do with…

Answer 29

• fresh (refrigerated)
• raw
• dehydrated
• freeze-dried

Anthropomorphism

Question 30

Benefits and risks of raw pet food

Answer 30

Nutritional benefits:
- greater bioavailability of some nutrients (that would be heat damaged)

Infectious disease risks:
- greater risk of pathogenic bacteria (risk to pets and owners)
- heat can kill these bacteria