Modification of the milk protein casein by enzymes could offer formulators a natural antioxidant for beef and poultry products, according to new research from Brazil.
Karina Rossini and co-workers from the Universidade Federal do Rio Grande do Sul in Brazil report that enzymatic hydrolysis of casein produced smaller peptides, which could prevent the spoilage of meat products.
“Casein peptides may be useful in meat processing as another naturally occurring antioxidant, helping to prevent off-flavour formation of meat and its products and increasing shelf life,” wrote the authors in the journal LWT - Food Science and Technology.
Typically, the oxidative deterioration of meat and meat products is caused by the degradation reactions of fats and pigments. Oxidation processes in food can lead to organoleptic deterioration in taste, colour and texture
“At present, consumer demand for natural functional foods has been increasing, and therefore casein peptides can be used as a functional food ingredient in pharmaceutical and food industries,” added the researchers.
The research does indeed tap into growing interest in natural food additives as replacements to synthetic antioxidants like butylhydroxyanisole (BHA) and butylated hydroxytoluene (BHT) to slow down the oxidative deterioration of food.
According to a 2003 report by Frost and Sullivan, the synthetic antioxidant market is in decline, while natural antioxidants, such as herb extracts, tocopherols (vitamin E) and ascorbates (vitamin C) are growing, pushed by consumer desire acceptance and easier market access.
The researchers used the commercial enzymes Flavourzyme and Alcalase (Novozymes) to hydrolyse casein. The resulting peptides from Flavourzyme were found to contain more soluble protein and free amino acids than Alcalase.
Measures of the peptides’ antioxidant activity revealed that those produced by Flavourzyme had higher values, compared to those obtained with Alcalase.
When formulated into ground beef homogenates and mechanically de-boned poultry meat, the researchers found that the casein peptides “effectively inhibited lipid peroxidation” in the beef (100 per cent inhibition), and by 21 per cent for the poultry product, and thereby produced an extension of the products’ shelf-lives.
While the study is not the first of its kind to investigate the effects of casein peptides in meat formulations, it does support the potential of these ingredients at a time when food manufacturers continue to look for ‘natural’ additives to their products.
“These results suggest that bioactive peptides from casein hydrolysis may be used as natural antioxidants in meat systems,” concluded Rossini and her co-workers.
Source: LWT - Food Science and TechnologyVolume 42, Issue 4, Pages 862-867“Casein peptides with inhibitory activity on lipid oxidation in beef homogenates and mechanically deboned poultry meat”Authors: K. Rossini, C.P.Z. Norena, F. Cladera-Olivera, A. Brandelli