Editorial [Hot Topic:Food-Derived Bioactive Proteins and Peptides as Potential Components of Nutraceuticals (Executive Editor: H. Meisel)]

In the last two decades fundamental studies have opened a new field of research related to bioactive food components that not only help ensure adequate nutrition, but may provide specific health benefits [for review: 1]. Bioactive components of food origin can be defined as substances, both nutrient and non-nutrient, which may exert regulative activities in the human organism beyond basic nutrition. In particular, food-derived bioactive proteins and peptides are claimed to be health-enhancing components used to reduce the risk of disease or to enhance a certain physiological function. This issue as well as the next Volume 13, Number 9, 2007, focuses on the advances being achieved in the research on the biochemical properties, physiological effects, production, safety and applications of different bioactive components derived from food. Bovine milk and avian eggs contain an array of bioactivities due to proteins and peptides present in active form, such as lactoferrin, immunoglobulins, growth factors and hormones. In addition to these fully active components, many bioactivities are latent in that they are inactive within the protein sequence, requiring enzymatic proteolysis for release of bioactive peptides from protein precursors. Bovine milk is currently the main source of a range of bioactive peptides encrypted in major milk proteins [for review: 2]. Activated peptides may exert quite different bioactivities, such as opioid, ACEinhibitory, immunomodulatory, antimicrobial, mineral binding, antimutagenic and cytomodulatory effects. In the first article, Murray and FitzGerald [3] underline that the biofunctional peptide activity currently most studied in food proteins appears to be those that inhibit Angiotensin-converting-enzyme (ACE) which plays a central role in the regulation of blood pressure. Numerous ACE inhibitory peptides have been isolated from milk proteins. However, a greater understanding of the biological mechanisms surrounding control of the cardiovascular system within the body is necessary in order to effectively design and produce new food derived antihypertensive agents. The article of Cross and Coworkers [4] demonstrates the potential anticariogenicity of casein phosphopeptides (CPP) derived from the bovine milk protein casein. The anticaries efficacy of casein phosphopeptide-amorphous calcium phosphate (CPPACP), which is able to remineralize carious lesions in dental enamel, has been demonstrated in various caries models and clinical trials. It is concluded that the CPP are a safe and novel carrier for calcium, phosphate and hydroxide (fluoride) ions to promote enamel remineralization. The paper of Weinberg [5] gives a complete overview of the numerous biological activities of the mammalian natural defense glycoprotein lactoferrin (LF) and its peptide derivates. Besides its powerful iron scavenging ability, Lf might have additional useful medicinal attributes, for example antibacterial, antifungal, antiprotozoan, antiviral, immunmodulatory, antineoplastic and bone remodelling activity. The article of Parodi [6] focuses its attention on the influence of certain dietary proteins and peptides on carcinogenesis. There is now ample evidence that whey proteins from bovine milk and their peptides have the potential to inhibit cancer development at some sites, particularly the colon and breast. It is suggested that the anticancer action of whey protein is to a large degree due to its content of cystine/cysteine and γ-glutamylcystine dipeptides. Nevertheless, much can still be learnt about mechanisms of anticancer effects. The paper of Korhonen [7] highlights existing modern technologies applicable for the isolation of bioactive native proteins and peptides derived from bovine colostrum, milk and cheese whey, and discusses aspects of potential applications for promotion of human health. Industrial-scale methods have developed for native whey proteins such as immunoglobulins, lactoferrin, lactoperoxidase, α-lactalbumin and β-lactoglobulin. At present, the industrial-scale production of bioactive peptides liberated from precursor milk proteins by proteolysis is limited by a lack of suitable technologies. On the other hand, a number of bioactive peptides have been identified in fermented dairy products......