Meal Particle Size & Its Effect on Feline Palatability, Processing Parameters &...

Meal Particle Size & Its Effect on Feline

Palatability, Processing Parameters & Texture

Kristopher Figge

Sr. Scientist, TSM

AFB International

Introduction

General discussion about felines

Factors affecting feline palatability (PAL)

Hypotheses

Experimental design, measurements

Results

Conclusions

General Items about Felines

As obligate carnivores, will choose higher protein diets over lower protein diets.

Cats are 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 mayhelp salivation.

Surface texture plays a role in palatability.

Different breeds of cats pick up their food differently with their tongue (Royal Canin 2002).

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.

Factors Affecting Feline PAL

Raw Materials

(Fats, oils, meals, palatants, etc.)

Texture / Size /

Shape

Processing

(sME, etc.)

Pilot Study PAL Results

In an initial study conducted at the Lovejoy Resource Center, we saw a significant PAL improvement with the meal that was double ground.

Ration A Ration B IR-A FC-A CR PREF p-value

Double Grind Disc Control Grind Disc 0.65 0.68 1.8A 12A : 3B 0.002

However, this study only focused on PAL.

During the extrusion we found some very interesting changes in processing parameters with the double ground kibble.

Also, anecdotally, we noticed some texture differences

Hypotheses—New Study

Meal particle size will affect:

1) The processing parameters of a dry feline

diet.

2) The texture and physical profile of a dry

feline diet.

3) The PAL of a dry feline diet.

Experimental Design

Standard / fixed reference points:

Both diets were extruded as a disc, based on previous

research.

Same lot of meal used for both diets.

Meal: 34% protein / 13% fat; by-product meal & grain-based.

Both diets coated with the same components:

Fat: 5.0% poultry fat

Palatant: 1.5% dry cat palatant

Same moisture content

Actual: 7.2% (control) and 6.5% (double)

Same bulk density (lbs./ft3)

Actual: 21.5 (control) and 23.0 (double)

Experimental Design (cont’d)

Variable(s) in the study:

1) ―Control‖ ground meal

2) ―Double‖ ground meal

Hammer Mill (#3)• WHOLE

GRAINS

Mixer• VITAMINS

• MINERALS

• OTHER INGREDIENTS

Hammer Mill (#3)

Pre-Conditioner Batch Hopper

Pre-Conditioner

Extruder

Dry Feline Formula

INGREDIENT POUNDS %

CHICKEN BY-PRODUCT MEAL 1125 28.13%

CORN FLOUR 853 21.33%

CORN GLUTEN MEAL 630 15.75%

WHEAT FLOUR 405 10.13%

BREWER'S RICE 405 10.13%

SOYBEAN MEAL 225 5.63%

FISH MEAL, MENHADEN 135 3.38%

CELLULOSE 135 3.38%

CALCIUM, GRANULAR 22.5 0.56%

POTASSIUM CHLORIDE 22.5 0.56%

SODIUM CHLORIDE 11 0.28%

CHOLINE CHLORIDE 11 0.28%

TAURINE 6.5 0.16%

VITAMIN PRE-MIX 4.5 0.11%

MINERAL PRE-MIX 4.5 0.11%

D,L-METHIONINE 4.5 0.11%

TOTALS 4000 100.00%

Equipment

Measurements

1) Processing parameters during:a) Extrusion

b) Drying / Screening

2) Texture and physical profilea) TA.XT Plus Texture Analyzer

TA-17 Probe and TA-52 Probe

b) GC-MS and proximates

3) PAL due to meal particle sizea) 2 bowl, paired comparison test

b) 20 cats x 2 days

Meal particle size will affect the processing

parameters of a dry feline diet.

Particle Size Distribution

Measured via Laser Defraction

Particle diameter

◦ Double Grind – 50% of the particles were smaller than 250 m

◦ Control Grind – 50% of the particles were smaller than 271 m

Overall, there was a significant difference in the particle size of the two diets.

Control Grind Double Grind

Particle Size Distribution

Measured via Laser Defraction

Particle diameter

◦ Double Grind – 50% of the particles were smaller than 250 m

◦ Control Grind – 50% of the particles were smaller than 271 m

Double Grind

Extrusion Measurements / Settings

The double grind meal used 33% less steam in the pre-

conditioner to achieve the same gelatinization (96.1% vs. 95.4%).

The double grind meal also used 20% less water in the pre-

conditioner.

Pre-Con Steam(lbs/hr)

Pre-Con H2O(gal/hr)

Control Grind 174.13 100.00

Double Grind 116.10 80.00

Major extrusion settings were held constant:

Feed Rate(lbs/hr)

Extruder

AmpsMeal Temp

( F)

Extruder

Freq. (Hz)

Pre-Con

Freq. (Hz)

Barrel Temp.( F)

Control Grind 650.00 56.25 210.00 41.00 30.00 212.13

Double Grind 650.00 56.10 210.00 41.00 30.00 209.20

Dryer Measurements / Settings

The double grind extrudate had 11% less moisture going

into the dryer (21.6% vs. 19.2%)

The double grind kibble required less dryer heat and still

had a lower final moisture.

The double grind kibble produced 17% less fines than the

control grind kibble.

Moisture (Pre-Dryer)

Dryer Temp.(F)

Moisture(Final)

Final Bulk

Density (lbs/ft3)

Diameter / Thickness(mm)

Control Grind 21.60% 205 7.2% 21.5 7.4 / 4.1

Double Grind 19.20% 195 6.5% 23.0 7.4 / 4.1

Meal particle size will affect the texture

and physical profile of a dry feline diet.

Kibble Pictures

Which kibble is the ―control‖ grind and which kibble is the ―double‖ grind?

Control Double3.7mm

Kibble Pictures


Double Control

3.7mm

Kibble Pictures


Double Control

Texture Discussion

TA.XT Plus Texture Analyzer

◦ TA-17 probe

◦ TA-52 probe

20 samples of each diet were analyzed.

Mean Force (g) = average force needed to crush the kibble during the test.

Peak Force (g) = maximum amount of force needed to continue crushing the kibble.

Area (Work)(gsec) = indicates how much effort was required to crush the kibble.

Texture Results

Not a significant texture difference between the diets.

However, the control grind kibble split in half, whereas the double grind kibble broke into multiple, smaller pieces.

In the domesticated cat jaw, the canines apply ~23,000g of pressure and the carnassials ~28,000g (Buckland-Wright 1978).

Mean Force (g) Peak Force (g) Area (Work)(g•sec)

Control Grind 331.96 892.42 637.45

Double Grind 296.72 824.54 640.99

-10.60% -7.60% 0.55%

GC-MS Analysis

Analysis shows some significant differences between the

two uncoated diets.

Chemical Class

# Chemicals

IdentifiedSingle Grind

(Total ppb)

Double Grind(Total ppb)

% Difference

Acids 9 456.00 704.75 35.3%

Alcohols 16 674.08 920.94 26.8%

Aldehydes 18 1,342.51 2,364.14 43.2%

Antioxidants 2 49.42 47.87 -3.2%

Esters 2 17.28 15.15 -14.1%

Furans & Furan-containing 6 168.47 245.44 31.4%

Hydrocarbons 5 54.09 73.74 26.6%

Ketones 14 235.45 350.96 32.9%

Nitrogen-containing 9 121.77 188.79 35.5%

Sulfur & Sulfur-containing 2 64.07 111.21 42.4%

Meal particle size will affect the PAL of a

dry feline diet.

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 < 0.05 = 95% confidence level)

Confirmatory PAL Results

The data showed a significant PAL improvement with the meal that was double ground.

Results from the initial study:





Conclusions / Summary

Processing Parameters

Decreased pre-conditioner steam need for the double ground diet.

The double ground diet produced 17% less fines.

Texture Analysis

Not a significant difference in the texture profile of the two diets.

However, the double ground kibble ―fractures‖ differently than the control grind kibble.

Some differences observed in GC-MS analysis.

PAL

The double ground kibble showed a significant PAL improvement over the control grind.

Future Research

Would we see the same results with a diet that has ―fresh‖ meat added in the pre-conditioner?

Further understanding of how cats ―feel‖ and interpret kibble texture.

Would we see the same outcome with other shapes?

Would we see the same effect on other ingredients (i.e. grains, grain-free diets, etc.)?

Expanded research into the effect sME has on PAL and other factors.

References

Plattner, B. , 2007. Extruding for Palatability. www.petfoodindustry.com/printpage.aspx?id=4053.

Royal Canin Almond 11 / Persian Cat Study. www.royalcanin.us/adx/aspx/adxGetMedia.aspx?DocID=41,12,1,Docume

nts&MediaID=4159&Filename=persian_30_brochure.pdf

Buckland-Wright, J.C. 1978. Bone Structure and the Patterns of Force Transmission in the Cat Skull (Felis Catus). Journal of Morphology, 155:35-62.

Thank You

Other Contributors:• James Lindmeier

• Jennifer Radosevich, PhD

• Bola Oladipupo, DA

Kristopher Figge

Sr. Scientist, TSM

AFB International

Tel: (636) 634-4142

Email: [email protected]

Meal Particle Size & Its Effect on Feline Palatability, Processing Parameters &...

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