Improving the Antioxidant Properties of Fermented Camel Milk Using Some Strains of Lactobacillus

Abstract

This study aimed at improving the antioxidant capacity of fermented camel milk using some single strains of Lactobacillus (Lb. helveticus B-734, Lb. casei subsp. casei B-1922, Lb. paracasei subsp. paracasei B-4560, Lb. rhamnosus B-1445 or Lb. rhamnosus B-442), as well as evaluating the acceptability of the final products. The acidity, proteolysis degree, antioxidant activity, viscosity and organoleptic properties of fermented milk were assessed during 14 days of storage at 4°C. Total phenolic content (TPC), DPPH radical scavenging activity, Ferrous ion chelating ability (FCA) and Ferric reducing antioxidant power (FRAP) assays were used to determine the antioxidant activity of fermented milks. The results indicated that fermented milks differed significantly (P Lb. helveticus had the highest proteolysis degree, while samples with commercial starter culture (control) showed the lowest degree of proteolysis. Fermented milks containing Lactobacillus strains showed higher DPPH radical scavenging activity compared to those samples containing commercial starter culture. By the end of storage, there was a significant improvement (P Lb. paracasei, Lb. rhamnosus B-442 or commercial starter culture had the highest FCA values, while Lb. rhamnosus B-1445 samples recorded the highest value at the end of storage. Lb. helveticus samples had the highest TPC and FRAP values (P 0.0001) between the proteolysis degree and the values of FRAP and TPC. Samples containing Lb. rhamnosus B-442, Lb. rhamnosus B-1445 or commercial starter culture received the highest taste and overall acceptability scores while Lb. helveticus samples were the lowest. It is recommended to use Lb. rhamnosus B-442 and Lb. rhamnosus B-1445 for producing fermented camel milk with high antioxidant activity and acceptability.