6533b86cfe1ef96bd12c88f2

RESEARCH PRODUCT

Cream fermentation by a mixed culture of lactococci entrapped in two-layer calcium alginate gel beads

Hervé PrévostCharles Diviès

subject

Calcium alginatebiologyLactococcus lactisfood and beveragesPasteurizationBioengineeringSouringGeneral Medicinebiology.organism_classificationApplied Microbiology and Biotechnologylaw.inventionLactic acidchemistry.chemical_compoundchemistryBiochemistrylawBioreactorFermentationFood scienceBacteriaBiotechnology

description

This investigation was directed towards the development of a process which produces a fermented cream of greatly reduced cell number.Lactococcus lactis subsp.Lactis andLactococcus lactis subsp.lactis biovardiacetylactis were entrapped separately in normal or two-layer Ca-alginate gel beads. Pasteurized cream (31% fat content) was inoculated with free-cells and with normal or two-layer beads. When 8% of the total volume was occupied by the gel, there was 300–800 times more inoculum in this system and the fermentation time was considerably reduced (5h against 18h). When pH 5.0 was reached, the residual free-cell count was 150 and 1800 times less than for a classical inoculation method with free-cells for normal and two-layer beads respectively. This result was reproducible for several consecutive runs. Also, the problems linked to storage acidification (souring, wheying-off) appeared later and living lactic acid bacteria were maintained in the product.

https://doi.org/10.1007/bf01023945