New peptide based soft drink
Casein is a family of proteins found in mammalian milk and is generally classified into four types, αS1, αS2, β, κ. The amino acid sequence that makes up for it, largely contain groups of different peptides that are inactive. However, research in the area of finding bioactive peptides in Casein in the last decade has given numerous results. Several βcasein peptides, for instance, are now used as ingredients in protein shakes, energy drinks and other processed foods for their qualities like slow digestion (giving a continuous supply of amino acids and thus nitrogen to the body) and reduction of hypertension, etc.
Assuming that we have found a new βcasein peptide, the compound can be used as an ingredient in a milk flavoured soft drink like Calpis. Calpis is a concentrate to be mixed in water, giving it a slightly acidic, milky flavour. For the extraction of such a peptide, the process of proteolysis should be conducted on casein molecule. Proteolysis is the hydrolysis of proteins into amino acids and peptide chains. Diary fermentation is one way to conduct proteolysis. The resulting peptides would be pro-peptides which are not bioactive. They could be activated through enzymatic hydrolysis. Porcine and Bovine are a couple of such digestive enzymes derived from animal tissue. In production facilities, these processes are carried out in membrane reactors which have the capability of combining, in a single operation, enzymatic hydrolysis with product separation followed by catalyst recovery. A soft drink like Calpis contains water, non-fat dry milk and lactic acid as its ingredients. Considering we replace or mix lactic acid with our now bioactive peptide, the reactions will be minimal, the only problem being the water solubility of these peptides. Making the drink milk based instead of water based could help solve the issue, that is a concentrate mixed in milk instead of water. To acquire emulsifying states using the peptides, ultrafiltration methods are used to separate protein from enzyme and then the peptides could be fractionated. Different kinds of fractionation methods yield different results and accordingly ingredient interaction needs to be researched. The stability of peptides released should also be taken into consideration while developing novel purification and separation methods in order to make a successful food product with anti-hypertensive and energy infusing properties.
Fig 1: Generic downstream processing of a bioproduct
The limitations of using Casein bioactive peptides in food products are due to their cytotoxic nature as well as the possibility of being allergic. These can be overcome by performing cytotoxicity and allerginicity tests on the peptides (Jauregi, 2009).
Reference
Jauregi, P. (2009). Bioactive peptides from food proteins: new opportunities and challenges. Food Science and Technology Bulletin: Functional Foods, 5. 11-26.
