Economic replacement of synthetic antioxidants in pet foods By Catharina Nieuwenhuizen, Barentz Animal Nutrition The addition of antioxidants in feed can prevent, or delay, lipid oxidation
given to synergy between naturals and “more acceptable” synthetics used
thus prolonging shelf life, improving palatability and assuring nutritional
successfully in food systems with proven long-standing safety, such as
composition. However, the acceptance of certain synthetic antioxidants,
infant nutrition. Ascorbates (Vitamin C and its derivatives), gallates and
currently widely used in pet foods, is becoming more restricted due to
chelates work well with natural antioxidants and, with a lower cost base,
potential health effects. The good news is, natural antioxidants can
are cost-effective. The drivers are how these compounds are used, work
provide cost effective options.
together and where in the pet food process they are used.
Cost-effective options in fats Antioxidants used in pet foods, such as BHA and BHT, are typically fatsoluble. Non-oil-soluble polar antioxidants work efficiently in fat systems as coating fats for kibbles, due to the ‘polar-paradox’.
Cost-effective options in meal Studies based on factory produced turkey meal, high in polyunsaturated fats, show the efficacy of such an approach whilst still avoiding the use of both BHA and BHT. The turkey meal was produced using proprietary antioxidants containing BHA and BHT, naturals and the Vitablend product PET-safe (excluding BHA and BHT). Antioxidant capacity was measured by the induction point (hrs) to oxidation under accelerated conditions
Forces of change A concern for naturalness in human foods has extended to a greater
using the Mikrolab Oxipres. Relative performance is shown compared to the standard control of no antioxidant.
by a slow, but ever increasing rate at which synthetic antioxidants are being re-evaluated for safety in feed. This re-evaluation has extended to the antioxidants BHA (Butylated hydroxyanisole) and BHT (Butylated hydroxytoluene). Most current concerns are expressed over BHA and, in particular, its re-authorisation for use in cat foods. In changing from synthetics such as BHA and BHT to only naturals we might see that naturalness comes at a price, both in cost and the stability of the pet food.
awareness about additives in pet foods. This has been accompanied
Natural options Natural mixed tocopherols (mixed Homologues of Vitamin E) and Vitamin
Figure 1: Turkey meal oxidative stability with antioxidant additives
E itself, are the only class listed as natural antioxidants for feed. The
compared to control.
definition of naturalness in feed has no clear definition and remains subject to interpretation. As such compounds for feed i.e. flavours and
The study showed that PET-safe, without BHA and BHT, extends
botanical extracts offering antioxidant capacity are utilised, for example
the shelf life of the turkey meal by a factor of 25 compared to a control
Rosemary extracts.
with no antioxidant addition. Matching the performance of standard combinations of BHA and BHT is achieved and without the on-cost often
Understanding options
seen using natural antioxidants.
An alternative to the use of synthetic antioxidants
Vitablend, part of Barentz, places emphasis on formulation and
may be considering only natural options with
application work to help manufacturers decide on the most appropriate
additional cost and a less effective response. This
antioxidant for protection to substantiate any change. Our advice for
need not be so. Closer consideration should be
selecting the right antioxidant would be to consider where in the process it is to be employed and whether to use natural or semi-natural options in replacing synthetic antioxidants.
Extracts offering antioxidant capacity, from plants such as Rosemary, may utilised in pet food
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Pet Food Supplement 2020
Further information: www.barentz.com/animal-nutrition
