title: Estimation of the antioxidant activity of the commercially available fermented milks.
abstract: BACKGROUND
  Free radicals are connected with the increased risk of certain diseases, especially cancers. There is some scientific evidence that antioxidant-rich diet may inhibit the negative impact of free radicals. The aim of the present study was to analyse the antioxidant capacity of the selected commercial natural and flavoured fermented milks offered in Poland, derived from different producers.
  
  
  METHODS
  The following commercially available natural fermented milks: 12 yoghurts, 12 kefirs, 2 butter milks, 2 cultured milks, Turkish yoghurt drink (ayran) and the following flavoured fermented milks: 22 yoghurts, 2 acidophillus milks, 2 kefirs, butter milk and vegetable flavoured fermented milk were analysed for their antioxidant potential. The antioxidant capacity was assessed, in two replicates and twice for each product, by means of ferric reducing antioxidant power (FRAP) and DPPH radical scavenging ability (expressed as ARP - anti radical power) methods.
  
  
  RESULTS
  Among all analysed plain products, yoghurts and kefirs were characterised by the highest antioxidant activity. The presence of probiotic Lactobacillus casei strains in the product positively affected both FRAP and ARP values. Antioxidant capacity of the flavoured fermented milks was primarily affected by the type and quality (e.g. fruit concentration) of the added flavouring preparation. The most valuable regarding the estimated parameters were chocolate, coffee, grapefruit with green tea extract as well as bilberry, forest fruits, strawberry and cherry with blackcurrant fillings.
  
  
  CONCLUSIONS
  Protein content, inclusion of probiotic microflora as well as type and quality of flavouring preparations are the main factors affecting antioxidant properties of fermented milks.
authors.affiliation: Department of Animal Product Technology, University of Agriculture in Krakow, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Najgebauer-Lejko
authors.affiliation: Department of Animal Product Technology, University of Agriculture in Krakow, Poland.
authors.forename: Marek
authors.initials: M
authors.lastname: Sady
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000032:analysis*; D000069956:Chocolate / Q000032:analysis; D003069:Coffee / Q000737:chemistry; D043302:Cultured Milk Products / Q000032:analysis* / Q000382:microbiology; D005285:Fermentation; D063427:Food Quality; D016166:Free Radical Scavengers / Q000032:analysis; D005638:Fruit / Q000737:chemistry; D000070716:Kefir / Q000032:analysis / Q000382:microbiology; D007780:Lacticaseibacillus casei / Q000302:isolation & purification; D008894:Milk Proteins / Q000032:analysis; D011044:Poland; D015014:Yogurt / Q000032:analysis / Q000382:microbiology
chemical_list: D000975:Antioxidants; D003069:Coffee; D016166:Free Radical Scavengers; D008894:Milk Proteins
keywords: antioxidant activity; butter milk; kefir; probiotics; yoghurt