PET Food Processing - March 2018 - 58


"The broad range of pet diets today
requires processors to expand their
methods to deliver a stable product that
pets will readily enjoy."
Eric Altom, Balchem
ditions of processing by being complexed to a polysaccharide compound," explains Jack Garrett, Ph.D., director research and technical support, QualiTech, Chaska,
Minnesota. "The polysaccharide compound protects the
trace mineral from negatively interacting with other nutrients until it goes through the stomach and arrives in
the intestines. The change in pH in the intestines triggers the release of the mineral for absorption."
"Depending on the vitamin molecule, vitamin manufacturers offer chemically stabilized vitamins and micronutrients or use encapsulation to physically protect
them," Alix says. "Across all formulations, the essential
nutrients vitamin A, vitamin D and carotenoids are
some of the most heat-labile and sensitive to oxygen.
For dry pet foods, excessive heat and oxygen are the
greatest challenges these nutrients face. In high moisture pet foods, the essential nutrient thiamine, vitamin
B1, represents an additional safety challenge due to its
sensitivity to high temperatures and pH."
Nutrient bioavailability must be considered when creating a complete-and-balanced diet for pets, but if a pet won't
eat the food, the product cannot deliver the proper nutrition. Aroma and taste drive product acceptance for pets.
External dietary fat application, moisture content, finished
diet preservation technologies and selected palatants are all
critical factors that determine aroma and taste. "Pet food
must be fresh and shelf stable without mold and rancidity and meet the on-package 'Best Used By Date' nutrient
guarantees. This is a critical area where beneficial acids and
natural preservative systems come into play," Altom says.
"The broad range of pet diets today requires processors to
expand their methods to deliver a stable product that pets
will readily enjoy and meet ingredient declarations that are
acceptable to the pet owner."

Formula opportunities, challenges
Increased use of fresh and frozen meats and novel grain
sources has led to the need for new solutions. "Historically,
many pet foods were composed of underutilized feed or
food-industry by-products, which delivered excellent nutrition at an attractive economic value," Mann explains.
"Over the past two decades, however, the pet food market has become extremely dynamic and diets have more



closely resembled human food. The trend of pet humanization is largely responsible for this and continues to
drive innovation into pet food stabilization options that
are more natural." Many of the novel ingredients can require innovative antioxidant solutions to maintain palatability and stability. "Cats and dogs are much more sensitive to oxidation compounds than humans. Changes in
ingredient composition and product format of pet food
and pet treats require new antioxidants," Mann adds.
"This is driving pet food manufacturers and consumers alike to look for cleaner, more natural alternatives to
synthetic antioxidants, such as BHA and BHT."
Product formulation is about balance. Any shift in ingredients will require a counterbalance solution. "The byproduct of grain-free formulas is more animal protein,
which results in a potential oversupply of protein and an
imbalance in amino acids in the formulation. Or if pea
protein is used as a source of starch in lieu of grains, it
is very unbalanced in key amino acids and needs to be
paired with something like egg to correct that imbalance
while still controlling ash," Middelbos says.
Altom points out, "With raw and dehydrated products some of the nutrients may be more stable and go
through a more gentle process, but the finished product
may be at greater risk of exposure to pathogenic bacteria
without effective processing controls."
Any time there is protein in a process that is susceptible
to bacteria, killing as much bacteria as possible on the protein as early as possible is the goal. "If you kill the bacteria
early you won't have to worry about continually measuring
pH on the protein as it goes through the process all the way
downstream," Monteleone says. "Enriching minerals and
pH organic acids don't go well together because a mineral
will just knock out a pH organic acid. So, the earlier you
start killing the bacteria, the more efficacy you can provide
before the addition of nutrients, especially enriching vitamins and minerals that would counter act the pH of acids.
These two steps should be separated in time and process."

A subtle approach is best
Consistently delivering nutritious food to pets is a
complex process in which every ingredient must play
well with others, and each step must be properly cal-

Table of Contents for the Digital Edition of PET Food Processing - March 2018