No matter how well formulated and produced a petfood may be,
all that nutrition and quality won't do any good if the animal
won't eat it. Thus, suppliers are continually conducting
research and offering innovations to help manufacturers make
their products more palatable. From collaboration with clients
to natural ingredients to processing techniques and equipment,
examples of new ways to improve palatability abound.
AFB International, a petfood palatability enhancement
company, takes a partnership approach with its customers and
aims to contribute to all aspects of petfood development and
manufacturing, according to Cheryl Murphy, product manager. For
these reasons, the company has established a new research
facility, the Lovejoy Resource Center.
Opened in fall 2006 as part of the new AFB headquarters, the
resource center gives petfood manufacturers access to a
state-of-the-art facility for product development and flavor
enhancement, Murphy says. The center is located on six acres in
St. Charles, Missouri, USA, just west of St. Louis. It includes
16,000 square feet of laboratory space adjacent to a
comprehensive process research lab.
"The Lovejoy Resource Center allows AFB's customers to
improve current products and more efficiently and effectively
develop the next generation of petfoods," says Murphy.
At the center, AFB's staff of flavor chemists, biochemists,
food technologists, process engineers, animal scientists and
process technicians can partner with customers in an
environment that provides access to equipment and processes
applicable to the marketplace. Testing can be conducted on the
application of palatant systems and alternative kibble
Extruded products can be measured for texture and shape
acceptance. Canned, semi-moist and dry petfood products can be
evaluated in terms of palatability.
"AFB's scientific staff leads the industry in their
understanding of petfood manufacture, flavor creation, sensory
analysis, animal nutrition and analytical and protein
chemistry," Murphy adds.
The scientists team up with AFB's process engineers who are
experienced in all areas of flavor development. This allows AFB
to produce a steady stream of new flavor products and
innovations for their customers.
Immediate acceptance of offered food is often the pet
owner's criterion for nutritional desirability, says Slobodan
Baskot, R&D assistant with BHJ Pet Food in Graasten,
Denmark. Research with flavor enhancers has proliferated, and
many different enhancers, both liquid and dry, are available,
ranging from ones added in minute quantities to
Baskot conducted an experiment to evaluate the effect of two
palatability enhancers of dry extruded dog food: freeze-dried
rumen of cattle and freeze-dried swine liver. The purpose was
to show the importance of including natural palatability
enhancers in petfood manufacturing, Baskot says.
The feed was processed in a twin screw extruder using the
same conditions and equal conditioner temperature of 82Â°C
(180Â°F) but carried out three times to produce three types of
dry extruded dog food: feed 1 (control diet-Labb Active), feed
2 (Labb Active with 2% freeze dried cattle rumen) and feed 3
(Labb Active with 2% freeze-dried swine liver). Tests such as
dry weight measurement, bulk density, Holmen durability and
strength at rupture showed adding the freeze-dried rumen or
liver to the control diet during and after extrusion caused
only minor changes in the chemical composition of the feed,
For the preference tests, 40 dogs were divided into two
groups. Food preference was determined entirely by the owners'
interpretation of the dogs' response, Baskot says. Owners
recorded daily the different kinds of dog food used and
commented on the dogs' response. Each dog owner received the
control feed (1) and one of the two flavor-enhanced feeds (feed
2 or feed 3). Each dog was offered equal amounts of both feeds
simultaneously at feeding time, once or twice per day; no dogs
had continuous access to feed.
The results (see Figures 1 and 2) showed feed 3, with
freeze-dried swine liver as a pure natural palatant, was
consumed by the dogs more than the other two types. Feed 2,
with freeze-dried rumen added, did not induce a preference over
the other feeds. When a dog showed no preference, it chose a
random feed from the two offered and chose not to consume the
alternative feed more than 75% of the time. None of the dogs
preferred feed 1 (the control) more than 75% of feeding times.
Most dogs (93%) also ate the other feed type after eating the
preferred feed first. This indicated the dogs involved had good
appetite and that feed 1 also had satisfactory taste, Baskot
"These results point out the need for further research on
dog feeding behavior and awareness of the importance of natural
palatability enhancers for commercial petfood," he
SPF, a palatability company, and Clextral, a twin screw
extruder manufacturer, have partnered during the last few years
to quantify the effect of extrusion on palatability, according
to Laurent Garcia of Clextral. The companies have also
investigated new ways, such as encapsulation, to enhance the
palatability of extruded petfoods.
In one example of this partnership, the petfood sample was
manufactured at the Clextral research center in Firminy,
France, using an Evolum53 twin screw extruder and the Rotante
(rotary) dryer, Garcia says. "The kibbles were coated in the
SPF laboratory in Elven, France. Finished products were then
tested with cat and dog panels at Panelis. Each palatability
test was conducted with 40 cats or dogs," he adds.
To quantify the effects of density on palatability, the
first trials included extruding and drying two different
standard and premium formulations of cat kibbles to produce
three densities: 330 g/l, 380 g/l and 440 g/l. Palatability
tests were conducted using two different fat and palatability
enhancer applications. The final moisture content was the same
for all the trials, Garcia says, and the results showed cats
significantly preferred the lowest kibble densities.
A second program, aimed at leveraging the capabilities of
twin screw extrusion to incorporate encapsulated palatability
enhancers in a matrix, involved injecting palatants directly
into the extruder or premixer. "The extrusion parameters were
set to properly control the mixing and shear rate in the
extruder and preserve the ingredients, while producing a
satisfactory kibble," Garcia explains. Several levels of
palatants were incorporated into the product and tested against
product with no encapsulated enhancers.
Trials used four different kibbles for cats and two types of
kibbles for dogs. Overall, the cats and dogs showed a
significant preference for several types of kibbles with
encapsulated enhancers, even if the products were coated with
fat and liquid palatability enhancers. "These promising results
have encouraged SPF and Clextral to pursue their cooperation
for the benefit of petfood manufacturers," Garcia says.
According to Dinnissen Process Technology, a paddle mixer
makes it possible to significantly improve the taste of cat
kibbles. "The secret is quite simple: It allows you to add
liquid as well as dry palatability enhancers, precisely and
evenly, to each individual kibble," says Peter Raeven, project
manager, of Dinnissen Process Technology. "This is very
important for cat food in particular, as cats have the habit of
inspecting their meal, kibble for kibble, before eating."
Besides selecting appropriate, high-quality palatants,
ensuring they are added to the food the right way is important.
A tool such as the Pegasus Paddle Mixer from Dinnissen offers
such a way, Raeven says. A fixed and precisely weighed quantity
of food is introduced into the sealed batch coater, wherein
contrast to continuous operation systemsthe entire process of
adding liquid and dry palatability enhancers to the kibbles
takes place. "For each batch of food, the exact quantity of
fat, liquid and dry palatability enhancers needed can be
weighed out and added. The process conditions, including
temperature, kibble rotation speed, residence time of the food
in the mixer and total processing time, can also be precisely
controlled," Raeven adds.
The result is a precise and even distribution of the
palatability enhancers over the product, according to
Dinnissen. In addition, the strength of the bond between the
palatability enhancer and the kibble can be optimized, and each
individual kibble can be coated with a tough protective layer
to ensure the palatability enhancers remain intact during
transport, Raeven says.
Cheryl Murphy, product manager
St. Charles, Missouri, USA
Slobodan Baskot, R&D assistant
BHJ Pet Food
Laurent Garcia, sales manager
Peter Raeven, project manager
Dinnissen Process Technology