Microbiological Spoilage of Dairy Products
HOUSING BREEDING FEEDING
HYGIENE ENVIRONMENT MILKING RETAINING QUALITY CONTAMINATION
BASIC REQUIREMENTS FOR OPTIMUM PRODUCTIVITY
Microbes in raw milkThree basic sources From within the udder From exterior of teats and udder From milk handling and storage equipment
Factors Affecting Duration
of milk storagetime vary widely Udder-diseases-mastitis associated microorganisms
Initial micro flora Bio-security, udder diseases and bacterial content Pathogens for man in raw milk Environmental sources Micro flora of milking equipment Influence of storage and transport
Factors influencing microbiological quality of raw milk
Microbial Count Vary:106 /ml
Types of Microflora Heterogeneous
populationmesophilic, thermoduric, thermophilic, psychrotrophic and pathogenic organisms Presence/relative proportions vary with the conditions of milk production and handling.
Cultivation conditionsPsychrotrophs: incubation at 5-7C for 10 days Thermodurics: after pasteurizing milk sample Other groups: selective media coliforms, lactic acid bacteria, Gram-negative rods, pathogenic organisms, etc.
Mesophilic MicrofloraGrowth temp. >30C in 2-3 days (less than 5,000 cfu/ml) Micrococci & Staph. 30-90% Streptococci 0-50% Asporogenous Gram+ve rods