This study investigated the effect of using different combinations of commer-cial starter culture and lactobacilli strains on the antioxidant properties offermented camel milk for 14 days. The bacterial strains included Lb. caseisubsp. casei B-1922, Lb. paracasei subsp. paracasei B-4560, Lb. rhamnosusB-442 and Lb. rhamnosus B-1445. The antioxidant activity of fermented milkwas estimated using DPPH radical scavenging activity, ferrous ion chelatingactivity (FCA) and ferric reducing power assays. The total phenolic content(TPC), titratable acidity, proteolysis degree and sensory acceptability of sam-ples were also evaluated. The results showed that all the studied parameterswere affected by both the type of starter culture and storage. Samples con-taining the commercial starter and Lb. rhamnosus B-1445 had the highestDPPH radical scavenging activity and TPC throughout storage. Fermentedmilks prepared using the commercial starter and Lb. rhamnosus B-442 or Lb.paracasei retained their high FCA and reducing power throughout storagecompared to the other samples. Fermented milk containing the commercialstarter and Lb. casei showed the lowest antioxidant activity. The DPPH sca-venging activity for all fermented milks decreased sharply during storage,while the change in FCA, reducing power and TPC differed among the sam-ples during storage. The highest acidity was observed in the samples contain-ing the commercial starter and Lb. paracasei, while fermented milk preparedusing commercial starter and Lb. rhamnosus B-1445 had the lowest acidity.Samples containing the commercial starter and Lb. casei had the greatestproteolysis during the first week of storage, while samples containing thecommercial starter and Lb. rhamnosus B-1445 had the highest proteolysis onday 14. Fermented milks with commercial starter and Lb. rhamnosus B-1445or Lb. paracasei were the most acceptable products, while samples containingthe commercial starter and Lb. casei were less acceptable.
展开▼
