Effect of Flaxseed Meals and Extracts on Lipid Stability in a Stored Meat Product

Flaxseeds have been recently in focus due to the antioxidant capacity of some of their compounds.  However, there is a lack of easily accessible information concerning their activity against lipid oxidation in food systems.  Therefore, the aim of the study was to determine the effect of defatted meals (DFM) and the aqueous extract (AFE) obtained from brown and golden flaxseeds on lipid oxidation in pork meatballs.  Fatty acid composition, peroxide value (PV), thiobarbituric acid reactive substances (TBARS) and cholesterol content were monitored during 6 months of freezer storage.  Cholesterol oxidation products were identified and quantified.  Both DFM and AFE limited fatty acid and cholesterol oxidation during meatball storage.  Their antioxidant effect depended on flax variety (brown or golden) and preparation type (DFM or AFE).  Lower level of PV and TBARS, compared with the ones with AFE were noted in meatballs with DFM.  Both DFM and AFE, from the brown seed variety, protect the lipids against oxidation to a higher extent.  During the storage, a cholesterol degradation was observed.  AFE (particularly from the brown variety) limited changes in cholesterol content.  Moreover, they stabilized fatty acid composition of stored meatballs.  However, DFM efficiently inhibited cholesterol oxidation. (Authors abstract)

Flaxseed contains phenolic compounds such as lignans, phenolic acids (p coumaric, ferulic, p hydroxybenzoic, caffeic, and sinapic acids) and their glucosides, as well as flavanoids (herbacetin and campherol diglucoside).  There are numerous examples of flaxseed or oil application in production of bakery goods and some their utilization in meat products.  The aim of the study was to determine the effect of defatted flaxseed meals and flaxseed aqueous extracts on lipid oxidation in pork meatballs during storage.  In order to analyze the impact of flaxseed composition on the effect, brown and golden varieties were selected as research materials.

Both defatted meals and aqueous extracts from flaxseeds show an antioxidant effect towards lipids during storage of meat products in a freezer.  Therefore, they can be utilized in the meat industry to design products fortified with bio active compounds of flax seed origin.  In addition, they can prolong the self life of the products by protecting them against oxidation processes and their negative impact on sensory and nutritional food quality.  However, the anti oxidant efficiency of the preparations obtained from flax seeds depends on material composition (flax variety) and preparation procedure that affect active compound concentration.  (Editors comments)