Kibble Shape and its Effect on Feline Palatability

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Kibble Shape and its Effect on Feline Palatability

• Kristopher Figge
• Senior Scientist, Technical Services Mgr.
• AFB International

2
Presentation Layout

• Introduction
• Experimental design
• Definitions Results
• Other related topics
• Comments / discussion

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General Items about Cats

• As obligate carnivores, will choose higher
  protein diets over lower protein diets.
• More likely than dogs to avoid spoilage aromas.
• Lack lateral jaw movement hence, texture and
  size are very important.
• Lack molars, and cannot grind their food.
  Acidification helps salivation.
• Surface texture plays a role in palatability.
• Different breeds of cats pick up their food
  differently with their tongue.
• In PAL testing, cats tend to consume food from
  both bowls. First choice is not necessarily
  linked to total consumption. Feeding time is
  generally 15 hours.

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Factors Affecting Feline PAL
Raw Materials (Fats, oils, meals, palatants, etc.)
Texture / Size / Shape
Processing
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Hypothesis

• Kibble shape affects the PAL of dry cat food(s).

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Experimental Design

• Standard / fixed reference points
• A finely ground (3) 34/13, grain-based meal
• Same lot of meal used for all shapes
• All variables coated with the same components
• Fat 5.0 poultry fat
• Palatant 1.5 dry cat palatant
• Same moisture specification 6.5 - 9.5
• Same density specification 19 - 24 lbs./ft3

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Experimental Design (contd)

• Variable(s) in the study
• Kibble shapes
• X Cross / Star
• ? Triangle
• O Flat Disc
• Cylinder
• Triangle w/ center hole

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Experimental Design (contd)

• What was measured
• Texture
• Max. Load c) Energy to Break Pt.
• Energy to Yield Pt. d) Toughness
• PAL due to kibble shape
• 2 bowl, paired comparison test
• 25 cats x 2 days
• Same panel of cats was used
• All possible paired tests were done (10)

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Equipment
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Results

• In-process data
• Kibble shape pictures
• Texture terms results
• PAL data terms results

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In-Process Data
Shape Moisture () Density (lbs./ft3) Diameter (cm) Thickness (cm)
O Disc 7.40 21.13 0.36 0.19
X Cross 8.59 22.25 0.54 0.18
? Triangle 8.59 23.25 0.45 0.18
Triangle w/ hole 6.96 20.00 0.41 0.20
Cylinder 8.58 21.37 0.32 0.39

• Moisture 6.5 - 9.5
• Bulk Density 19 24 lbs. / ft3
• Based on In-Process data, all variables were
  within target specifications.

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Kibble Shape Pictures

• Uncoated kibble is shown on the top row
  comparable commercial products are on the bottom.

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Texture Analysis Terms

• Maximum Load maximum amt. of force necessary to
  fracture a kibble (measured in kgs of force).
• Energy to Yield Point energy required to reach
  a point where kibble begins to fracture (measured
  in graminch).
• Energy to Break Point energy required to reach
  a point where kibble finally gives way and
  fractures completely (measured in graminch)
• Toughness energy to break point divided by
  gauge length kibble width kibble thickness
  (measured in g/inch2)

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Texture Analysis
Shape Max. Load (kg-Force) Energy to Yield Pt. (gram-inch) Energy to Break Pt. (gram-inch) Toughness (g/inch2)
O Disc 5.39 41.46 56.85 227.39
X Cross 8.08 51.39 69.06 276.23
? Triangle 7.06 63.79 100.10 400.41
Triangle w/ hole 2.48 14.07 20.54 82.15
Cylinder 4.23 61.99 145.45 626.90

• Measurements done with an Instron Texture
  Analyzer 3342 and Cherry Pitter Needle probe

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Maximum Load
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Energy to Yield Point
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Energy to Break Point
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Toughness
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Texture Summary

• The Triangle w/ hole had the lowest texture
  numbers.
• The Cylinder had the highest scores in all
  categories except maximum load.
• The O Disc had the second lowest texture
  numbers.
• The X Cross scored in the middle except for
  max. load where it had the highest number.
• The ? Triangle had the second highest scores.

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PAL Data Interpretation

• Consumption Ratio (CR) Consumed A / Consumed B
• Intake Ratio (IR-A) Consumed A
• 
  (Consumed A Consumed B)
  
  
• First Choice (FC-A) Animals eating out of
  Bowl A first
• Preference Outside the range of 0.45-0.55 IR
• p-Value (p) Probability that A is significantly
  different from B (want lt 0.05 95
  confidence level)

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O Discs
Ration A Ration B IR-A CR FC-A PREF p-Value
X Cross / Star 0.57 1.3A 0.57 10A 3B 0.013
? Triangle 0.47 1.0B 0.55 7A 9B 0.222
Cylinder 0.64 1.9A 0.39 12A 2B 0.002
Triangle w/ hole 0.66 2.0A 0.56 12A 1B 0.000

• O gt X, Cylinder Triangle-hole
• O ?

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X Cross / Star
Ration A Ration B IR-A CR FC-A PREF p-Value
? Triangle 0.61 1.5A 0.55 14A 5B 0.007
O Disc 0.43 1.3B 0.43 3A 10B 0.013
Cylinder 0.63 1.7A 0.52 17A 5B 0.000
Triangle w/ hole 0.56 1.3A 0.50 12A 6B 0.078

• X gt Cylinder, Triangle Triangle-hole
• X lt Disc

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? Triangle
Ration A Ration B IR-A CR FC-A PREF p-Value
X Cross / Star 0.39 1.5B 0.45 5A 14B 0.007
O Disc 0.53 1.0A 0.45 9A 7B 0.222
Cylinder 0.71 1.5A 0.41 12A 3B 0.086
Triangle w/ hole 0.51 1.0B 0.57 10A 9B 0.408

• ? gt Cylinder
• ? Disc Triangle-hole
• ? lt X

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Triangle w/ Hole
Ration A Ration B IR-A CR FC-A PREF p-Value
X Cross / Star 0.44 1.3B 0.50 6A 12B 0.078
? Triangle 0.49 1.0A 0.43 9A 10B 0.408
O Disc 0.34 2.0B 0.44 1A 12B 0.000
Cylinder 0.61 1.6A 0.61 11A 5B 0.028

• Triangle-hole lt O
• Triangle-hole gt Cylinder
• Triangle-hole ? X

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Cylinder
Ration A Ration B IR-A CR FC-A PREF p-Value
X Cross / Star 0.37 1.7B 0.48 5A 17B 0.000
? Triangle 0.29 1.5B 0.59 3A 12B 0.086
O Disc 0.36 1.9B 0.61 2A 12B 0.002
Triangle w/ hole 0.39 1.6B 0.39 5A 11B 0.028

• Cylinder lost to the other (4) shapes

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Conclusions

• Kibble shape was the primary driver for PAL -
  texture across a given range did not drive PAL.
• Triangle-hole had the lowest texture scores, but
  few cats preferred this shape.
• The O Disc had mid-range texture scores and
  was the most preferred shape.
• The Cylinder was outside the range and was least
  preferred.
• The X Cross had slightly more favorable
  texture scores than the cylinder however, its
  PAL was closer to the O Disc
• The ? Triangle had higher texture scores than
  the O Disc but similar PAL

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Product Considerations

• The O and the X had the best overall PAL
• Head-to-head, the O was better.

• Operations Implications
• The O is easier to extrude
• Less potential for die blockage
• ? drag ? throughput
• The O has lower tooling costs

• Product Implications
• The O is more durable
• The O had less fines
• The O has more surface area

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References

• Royal Canin Almond 11 / Persian cat study

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Thank You!

• Kristopher Figge
• AFB International
• Sr. Scientist Tech. Service Mgr.
• Tel [phone]
• Fax [phone]
• Email kfigge_at_afbinternational.com

Other Contributors Pat Moeller, PhD Amy
McCarthy, PhD Cheryl Murphy Bola Oladipupo, DA