Comparative Evaluation of Bulk Starter Substrates on Activity and Storage of Two Commercial Starter Strains

Two out of five commercial strains of Lactococcus laclis ssp.cremoris were selected for their sensitivity or insensitivity to acidity based on growth and storage in 10% reconstituted skim milk.It was shown that both the acid-sensitive and acid-insensitive strains were protected when grown and stored in skim milk media with solids content increased by UF or by added solids (20% or 24% reconstituted skim milk).Internal pH medium was used as a reference for protective growth and storage of lactic starter cultures.Maintenance of activity over 5 d of storage at 2"C in 24% reconstituted skim milk and UF milk retentate (concentrated 3x) was better than or equal to internal pH medium for both strains of L. laclis ssp.cremoris.