Petfood Forum Guide - 2018 - 14
See the separate Schedule of Events and Floor Plan brochure for times for the student paper oral presentations.
Impact of ancient grains and grain-free starches on processing
parameters and palatability in dogs
Julia Guazzelli Pezzali*, Greg Aldrich, Will Henry; Kansas State University;
Ancient grains are promising pet food ingredients due to their health and nutritional benefits and may represent an alternative to "grain-free" diets. However,
there is little information about their impact on processing conditions and on the
animal's acceptance of the food. Thus, the aim of this study was to evaluate
the effect of starches derived from ancient grains and grain-free ingredients on
extrusion processing parameters and palatability in dogs.
Two diets containing the same proportion of carbohydrates sources were formulated to meet the dog's maintenance requirement: ancient grain (AG), containing
sorghum, millet and spelt, and grain free (GF), produced with potato, pea and
tapioca starch. Diets were processed using a pilot scale single screw extruder in
five altering replicates to achieve similar bulk density out of the extruder. Twenty
kibbles from each replicate were evaluated for physical properties such as hardness. Palatability was assessed by a split-plate test (n = 20 dogs), where intake
ratio and first choice between diets were recorded. Comparison of the means
were performed using Student's t test. The similar bulk density out of the extruder
target was achieved (418.3 vs 426.2 g/L; P>0.10) through adjustment of the
following parameters: preconditioner feed rate (166 vs 82 kg/h) and steam
(14.5 vs 5.5 kg/h) were increased, and extruder screw speed (441.6 vs 636.6
RPM) was decreased for the AG compared to GF, respectively. The in-barrel
moisture (30.3 vs 38.2 percent) and the calculated specific mechanical energy
(114.8 vs 140.7 kJ/kg) were lower (P<0.05) for AG than GF, respectively. The
bulk density of AG was greater (P< 0.05) than GF (387.4 vs 367.8 g/L, respectively) after drying. Expansion ratio was higher (P<0.05; 3.08 vs 3.50 kgnm),
but hardness was lower (P<0.05; 3.12 vs 6.36 kg) for AG vs GF, respectively. In
the palatability assessment, dogs showed a high preference (P<0.05) for GF over
AG (IR = 0.835), which was also approached first (37 vs. 3).
In conclusion, ancient grains and grain-free starches behave differently during
extrusion and have a significant impact on the final product characteristics and
Julia Guazzelli Pezzali is originally from Xanxere, Brazil, where she earned her
DVM from Federal University of Rio Grande do Sul (UFRGS) with a focus on
animal nutrition. During college, Guazzelli Pezzali was awarded a scholarship that
allowed her to study at the University of Maryland for a year. She is currently
pursuing her Master of Science degree at Kansas State University under the
supervision of Dr. Greg Aldrich with a focus on pet food processing. She plans to
pursue a career in the pet food industry, developing new products that optimize
processing conditions and nutrition.
White space identification in canned cat food product category
Siim Koppel*, Kadri Koppel; Center for Sensory Analysis and Consumer
Behavior, Kansas State University; email@example.com
Aroma is one of the most important characteristics of wet cat food that pet owners base their purchase or re-purchase decisions on. The market is full of different
types of canned foods that claim different characteristics of the food, such as
grain-free, natural or organic, and are prepared with specific protein sources or
2018 Petfood Forum
other ingredients. The objectives of this research were to understand the aroma
profiles of canned cat foods and identify the product opportunities in the canned
cat food category.
A total of 40 commercial canned cat foods were evaluated by a highly trained
sensory panel for aroma characteristics and intensities. The results indicated that
most canned cat foods were pronounced in attributes that are driven mainly by
the protein and fat composition of the product, such as poultry, beef or fish. Several white spaces where products might potentially be developed were determined,
for example foods that had higher poultry aroma with low oily aroma.
These results help understand the canned cat food category better and provide
information to product developers about new product opportunities.
Siim Koppel is a research associate at the Center for Sensory Analysis and
Consumer Behavior, Kansas State University, and a PhD student in industrial
engineering, working with data analytics and Big Data applications.
Evaluation of carriers for use in supplemental nutrient premixes
in pet food and animal feeds
Briana Pontious*, Greg Aldrich, Spencer Smith; Kansas State University;
Rice hulls are the standard carrier for premixes in animal feed and pet food, but
do not comply with the new "grain-free" trend. There are alternative carriers to
rice hulls being used, but no data available regarding their performance for this
purpose. Therefore, our objectives were to evaluate alternative carriers relative to
rice hulls for their utility to this purpose.
Samples of rice hulls, soybean hulls, pea fiber, miscanthus grass and corn cob
meal were evaluated for particle size by rotational sieve analysis (Ro-Tap II RX-94;
Hogentogler & Company Inc.; Columbia, MD) to determine uniformity, for flow
ability by flodex (Flodex model no. 21-100-004; Hanson Research; Chatsworth,
CA), the angle of repose and by microscopic images at 0.75-5 X magnification.
Results for particle size (mean diameter) were 366 1.71, 320 2.00, 352 2.35,
134 1.91, and 332 1.37 microns, for flodex 26, 14, 22, >34, and 5 mm,
and for angle of repose 41.3 1.2o, 37.0 1.1o, 38.1 0.6o, 47.8 1.6o, and
38.1 0o, for rice hulls, soy hulls, pea fiber, miscanthus grass, and corn cob meal,
While there was no evidence that rice hulls were superior, these tests demonstrated that there are competitive alternative carriers. Further testing is needed; e.g.,
scanning electron microscopy (SEM), motion testing, bulk density evaluation,
hygroscopicity and mixer efficiency, to determine the full range of characteristics
for each alternative carrier.
Briana Nicole Pontious attended Johnson County Community College as a collegiate athlete (volleyball) for two years, followed by the University of Nebraska
at Kearney. After her career on the court was cut short by injury, she enrolled
at Kansas State University and is currently a fifth-year senior working towards a
Bachelor of Science degree in feed science and management with an emphasis in
pet food production. Pontious works as an undergraduate research assistant in the
pet food processing lab under Dr. Greg Aldrich. She also works in the food service
part-time to support her education. Pontious plans to graduate in December 2018
and pursue a career in the pet food industry.