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A study examines the quality of bread when fermented yeast extracts are added to dough while making bread. It is revealed that gas is produced during this process.

Lactic acid fermentations were undertaken on yeast extracts (YE) to determine the effects of high concentrations of YE on growth, diacetyl production and acidification by lactic cultures. Little acidification occurred at 100 g/L. Results indicated that a scale-up of fermentation for diacetyl production requires further research.

The potential application of maple syrup in fermented meat product manufacture was analyzed by substituting maple syrup for the glucose-sucrose component of a standard dry sausage fermentation. A mixed starter culture consisting of Lactobacillus plantarum, Pediococcus acidilactici and Micrococcus varians was used to inoculate sausage batters with either carbohydrate. The manufacture of novel fermented meat products has potential for the use of maple syrup.

An analysis to determine the influence of small changes in temperature and oxygen levels on the capability of L. rhamnosus R0011 in a combination of apple, pear, and strawberry juices in opened 1-L bottles of polyethylene terephthalate (PETE) is discussed. It is suggested that the a good feasibility of L. rhamnosus R0011 is expected over a few weeks of storage in a refrigerator, inspite of the bottles being opened and cells exposed to oxygen.

A study was undertaken to investigate the effect of whey protein isolate (WPI) gel on the viability of Lactobacillus rhamnosus R011. It is concluded that the entrapment process in WPI can protect the freeze-drying cells against subsequent acidic and alkaline conditions and the heating and freezing of food products.

A comparison of the protective effect against heat treatment of cell immobilization procedure in de Man-Rogosa-Sharp broth and in an acidified chicken meat model is presented.

d. bergmaier, c.p. champagne and c. lacroix. 2004.Aims: Biomass and exopolysaccharide (EPS) production were studied during chemostat cultures in whey permeate medium withLactobacillus rhamnosusRW-9595M-free cells and cells immobilized on solid porous supports (ImmobaSil®).A continuous culture with free cells was conducted for 9 days at dilution rates (D) between 0·3 and 0·8 h−1 in yeast extract (YE)/mineral supplemented whey permeate. Maximum EPS production (1808 mg l−1) and volumetric productivity (542·6 mg l−1 h−1) were obtained for a lowDof 0·3 h−1. A continuous fermentation in a two-stage bioreactor system, composed of a first stage with immobilized cells and a second stage inoculated with free cells produced in the first reactor, was carried out for 32 days. The influence of YE concentration, temperature and dilution rate, and their interactions on biomass, EPS and lactic acid production was investigated. A statistically significant model was found only for lactic acid production. Marked cell morphological and physiological changes led to the formation of very large cell-containing aggregates and a low mean soluble EPS production (138 mg l−1). Aggregate volumetric productivity of the two-stage system varied between 5·7 and 49·5 g l−1 h−1 for different fermentation conditions and times. Aggregates contained a very high biomass concentration, estimated at 74% of aggregate dry weight by nitrogen analysis and 4·3 × 1012 CFU g−1 by a DNA extraction method and a high nonsoluble polysaccharide content (14·2%). At age 24 days, insoluble EPS concentration and volumetric productivity were 1250 mg l−1 and 2240 mg l−1 h−1 respectively. The physiological changes were shown to be reversible when cells were incubated during three successive batch cultures.EPS production and volumetric productivity during continuous free-cell chemostat cultures withL. rhamnosusRW-9595M are among the highest values reported for lactobacilli in literature. Immobilization and continuous culture resulted in low soluble EPS production and large morphological and physiological changes ofL. rhamnosusRW-9595M, with formation of macroscopical aggregates mainly composed of biomass and nonsoluble EPS.This is the first study on continuous EPS production by immobilized LAB. Immobilization and culture time-induced cell aggregation and could be used to produce new synbioticproducts with very high viable cell and EPS concentrations. [ABSTRACT FROM AUTHOR]

Studies the impact of process parameters on the production and drying of Leuconostoc mesenteroides cultures. Key issues of interest; Analysis of pertinent topics and relevant issues; Implications on industrial microbiology and biotechnology.

BSTRACT Strains of Pediococcus cerevisiae, Pediococcus acidilactici, Lactobacillus plantarum, Lactobacillus casei and Micrococcus varians were studied with the aim of preparing mixed cultures of compatible strains for meat fermentations. Addition of 0.18% nitrite was slightly inhibitory while addition of 7% of a spice mix proved stimulatory. Antibiosis was observed between lactobacilli and pediococci. Micrococcus varians did not produce inhibitory substances toward other cultures and was insensitive to bacteriocins produced by the lactobacilli or the pediococci. Antibioses observed using disk assays were confirmed in mixed acidification trials, and mixes of some fast-acidifying strains were unsuccessful. [ABSTRACT FROM AUTHOR]