Violet red bile agar

Representative duplicate 10 g portions were retrieved from each cheese sample during various time intervals and blended with 90 mL of sterilized 2% w/v tri-sodium citrate solution. The suspension was then submitted to 10 decimal serial dilutions with ¼ strength Ringer’s solution. Viable counts of total aerobic bacterial counts, Lactococci, Lactobacilli, yeasts and fungi, and coliforms were determined in triplicate by pour plating of appropriate dilutions (0.1 mL or 1 mL) on the selective media for each species according to instructions of the manufacturer [26 (link)]. Specifically, viable counts of total aerobic bacterial counts were enumerated on plate count agar (PCA) (Merck) by suspended 0.1 mL of the sample after incubation at 30 °C for 72 h. Lactococci were enumerated on M-17 agar (Merck) by suspended 1 mL of the sample after incubation 30 °C for 48–72 h. Lactobacilli were enumerated on MRS agar (Merck) by suspended 1 mL of the sample after incubation at 37 °C for 48 h. Yeasts and fungi were determined by suspended 0.1 mL of the sample after incubation on Potato Dextrose agar (PDA) (Merck) at 30 °C for 72 h. Finally, coliforms were enumerated on Violet Red Bile agar (LabM, Heywood, U.K.) by suspended 1 mL of the sample after anaerobic incubation at 30 °C for 24 h. All cell counts were expressed as log of mean colony forming units (CFU).

Aliquots of 10 mL were collected from each pomegranate juice (after homogenisation by shaking thoroughly) at various time intervals during fermentation and storage. The samples were blended with 90 mL of sterile 1/4 strength Ringer’s solution (Sigma-Aldrich) and mixed in a stomacher blender and subjected to serial decimal dilutions in 1/4 strength Ringer’s solution. Viable counts of lactobacilli, yeasts and fungi, and coliforms were determined in triplicate by plating appropriate dilutions on the selective media for each species [31 (link)]. Specifically, viable counts of Lactobacillus plantarum were enumerated on acidified MRS agar (Merck, Darmstadt, Germany) at 37 °C for 72 h, anaerobically (Anaerobic jar, Anerocult C, Merck, Darmstadt, Germany). Coliforms were enumerated on Violet Red Bile agar (Lab M, Lancashire, UK) after incubation at 30 °C for 24 h. Yeasts and fungi were determined by plating on Sabouraud Chloramphenicol Agar (Merck, Germany) after incubation at 30 °C for 72 h. All cell counts were expressed as log of mean colony forming units (cfu) per mL of pomegranate juice. All results are presented as means of three repetitions plus standard deviations.