Production of ingredient-type cheddar cheese with accelerated flavor development by addition of enzyme-modified cheese powder.

Fast-ripened Cheddar cheeses for ingredient purposes were produced by addition of a dried enzyme-modified cheese (EMC; 0.25 and 1 g/100 g of milled curd) at the salting stage during a standard Cheddar cheese-making procedure. Populations of starter and nonstarter lactic acid bacteria (NSLAB), levels of proteolysis and lipolysis, volatile analysis, and flavor development (by quantitative descriptive sensory analysis) were monitored over a 6-mo ripening period.

Sources of the adventitious microflora of a smear-ripened cheese.

Aims: To determine the relationships between the major organisms from the cheese-making personnel and environment and the surface of a smear cheese.

Methods And Results: 360 yeast and 593 bacteria from the cheese surface, the dairy environment and the hands and arms of personnel were collected. Pulsed-field gel electrophoresis, repetitive sequence-based polymerase chain reaction and 16S rDNA sequencing were used for typing and identifying the bacteria, and mitochondrial DNA restriction fragment length polymorphism and Fourier-transform infrared spectroscopy for typing and identifying the yeast.

Control of heat-induced aggregation of whey proteins using casein.

The ability of alphas1/beta-casein and micellar casein to protect whey proteins from heat-induced aggregation/precipitation reactions and therefore control their functional behavior was examined. Complete suppression (>99%) of heat-induced aggregation of 0.5% (w/w) whey protein isolate (pH 6.

The newly isolated lytic bacteriophages st104a and st104b are highly virulent against Salmonella enterica.

Aims: To screen Irish faecal samples from a variety of sources with a view to isolating novel anti-Salmonella phages and to subsequently evaluate their lytic capability.

Methods And Results: Two novel anti-Salmonella phages st104a and st104b were isolated from a screening programme based on their lytic capability. The phages produced significantly larger plaques (2 mm) on the chosen indicator Salmonella enterica strain, DPC6046, when compared with the well-known control phage, Felix 01 (0.

Enhanced survival of GroESL-overproducing Lactobacillus paracasei NFBC 338 under stressful conditions induced by drying.

GroESL-overproducing Lactobacillus paracasei NFBC 338 was dried, and its viability was compared with that of controls. Spray- and freeze-dried cultures overproducing GroESL exhibited approximately 10-fold and 2-fold better survival, respectively, demonstrating the importance of GroESL in stress tolerance, which can be exploited to enhance the technological performance of sensitive probiotic cultures.

A lacticin 3147 enriched food ingredient reduces Streptococcus mutans isolated from the human oral cavity in saliva.

Aims: To isolate and characterise Streptococcus mutans from Irish saliva samples and to assess their sensitivity to a food-grade preparation of the lantibiotic, lacticin 3147, produced by Lactococcus lactis DPC3147.

Methods And Results: Saliva samples collected from children with varying oral health status were screened on Mitis Salivarius agar for the presence of pathogenic streptococci. Following selective plating, 16S rDNA sequencing and Pulsed Field Gel Electrophoresis (PFGE), 15 distinct strains of Strep.

Polymorphisms within the lactoferrin gene promoter in various cattle breeds.

Lactoferrin (Lf) is an iron-binding protein and belongs to the serum transferrin family. It has broad spectrum antimicrobial action, and it is found in exocrine secretions including milk. The sequence of the bovine lactoferrin gene promoter was analyzed in five different cattle breeds (Holstein Friesian, New Zealand Holstein, Montebéliard, Normande, and Norwegian Red) to determine the extent of polymorphic variation, which exists in this region both within and across cattle breeds.

Environmental survival mechanisms of the foodborne pathogen Campylobacter jejuni.

Campylobacter spp. continue to be the greatest cause of bacterial gastrointestinal infections in humans worldwide. They encounter many stresses in the host intestinal tract, on foods and in the environment.

Sensitive detection of Escherichia coli O157:H7 by conventional plating techniques.

The direct detection and estimation of concentration of Escherichia coli O157:H7 down to 1 CFU/g of cheese was achieved by conventional plating techniques. Cheese was manufactured with unpasteurized milk inoculated with E. coli O157: H7 at 34 +/- 3 CFU/ml.

Casein-derived antimicrobial peptides generated by Lactobacillus acidophilus DPC6026.

Three peptides produced by a Lactobacillus acidophilus DPC6026 fermentation of sodium caseinate and showing antibacterial activity against pathogenic strains Enterobacter sakazakii ATCC 12868 and Escherichia coli DPC5063 were characterized. These peptides were all generated from bovine alpha(s1)-casein and identified as IKHQGLPQE, VLNENLLR, and SDIPNPIGSENSEK. These peptides may have bioprotective applicability and potential use in milk-based formula, which has been linked to E.

Effect of milk protein standardization using different methods on the composition and yields of Cheddar cheese.

Two sets of Cheddar cheese were made in which the milk protein level (%, wt/wt) was increased from 3.3 (Control A, CA) to 3.6 (set A) or from 3.