No abstract

Bioactive peptides are specific protein fragments that have a positive impact on body functions and conditions and may ultimately influence health. Most of the biological activities are encrypted within the primary sequence of the native protein and can be released by enzymatic hydrolysis and proteolysis or by food processing. Milk is a rich source of bioactive peptides which may contribute to regulate the nervous, gastrointestinal and cardiovascular systems as well as the immune system, confirming the added value of dairy products that, in certain cases, can be considered functional foods. The main biological activities of these peptides and their bioavailability in dairy products are reviewed. The natural concentration of these biomolecules is quite low and, to date one of the main goals has been to realize products enriched with bioactive peptides that have beneficial effects on human health and proven safety. Even though several health-enhancing products have already been launched and their integration in the diet could help in the prevention of chronic diseases such as hypertension, cancer and osteoporosis, more clinical trials are required in order to develop a deeper understanding of the activity of biopeptides on the human physiological mechanisms and also to assess the efficacy of their effects in a long term view. New scientific data are also needed to support their commercialisation in compliance with current regulations

Milk is a source of bioactive compounds essential for health and growth of newborns. Donkey milk, rich in lactose and whey proteins, has been proven to be a good breast milk substitute during infancy and adequate nourishment for patients with cow milk protein allergy. Beside, this milk is gaining a growing interest for human nutrition because of some other alleged health benefit. It shows antibacterial activity toward a wide range of Gram-positive and Gram-negative bacteria, stimulates immune system in convalescence, regulates gastrointestinal flora, and prevents inflammatory and autoimmune diseases. As regards its antimicrobial properties, although all the milk components might contribute to this activity, the whey protein fraction of donkey milk is generally believed to play the main role. The aim of this review is to highlight the antimicrobial properties of donkey milk with a special focus on the whey protein fraction. The effects of preservation and processing treatments on whey protein content and antimicrobial activity are also discussed.

In this review we summarize the current knowledge on the extensive goat casein polymorphism. Gene structure, and allelic and non-allelic protein variants, characterized by genomic and proteomic analysis, have been described. The effect of genetic casein polymorphism on technological and nutritional properties of goat's milk has been briefly reported. Goat casein genes show a range of different post-translational modifications and complex patterns of splicing, leading to a great heterogeneity of this fraction. In the light of some recent findings, a genomic and proteomic combined approach appears to be the tool of choice in order to gain an exhaustive characterization of these milk proteins. goat's milk / casein fraction / heterogeneity / genetics / proteomics

The genomic variability of local Italian chicken breeds, which were monitored under a conservation plan, was studied using single nucleotide polymorphisms (SNPs) to understand their genetic diversity and population structure. A total of 582 samples from 23 local breeds and four commercial stocks were genotyped using the Affymetrix 600 K Chicken SNP Array. In general, the levels of genetic diversity, investigated through different approaches, were lowest in the local chicken breeds compared to those in the commercial stocks. The level of genomic inbreeding, based on runs of homozygosity (FROH), was markedly different among the breeds and ranged from 0.121 (Valdarnese) to 0.607 (Siciliana). In all breeds, short runs of homozygosity (ROH) (<4 Mb in length) were more frequent than long segments. The patterns of genetic differentiation, model-based clustering, and neighbor networks showed that most breeds formed non-overlapping clusters and were clearly separate populations, which indicated the presence of gene flow, especially among breeds that originated from the same geographical area. Four genomic regions were identified as hotspots of autozygosity (islands) among the breeds, where the candidate genes are involved in morphological traits, such as body weight and feed conversion ratio. We conclude that the investigated breeds have conserved authentic genetic patterns, and these results can improve conservation strategies; moreover, the conservation of local breeds may play an important role in the local economy as a source of high-quality products for consumers.