ABSTRACT
Milk Products ........................................................................................... 252 8.7 Defects of Yogurt and Other Fermented Milks ........................................ 254
8.7.1 Aroma/Flavor Defects .................................................................. 254 8.7.2 Appearance Defects ...................................................................... 255 8.7.3 Body/Texture Defects ................................................................... 259
References .......................................................................................................... 259
The increasing awareness and demand of consumers for safe and high-quality food have led many dairy companies to undertake a comprehensive evaluation and reorganization of their food control systems in order to improve ef ciency, rationalization of human resources, and to harmonize approaches. This evaluation in food control systems has resulted in the necessity to shift from the traditional approach that relied heavily on end product sampling and inspection and to move toward the implementation of a preventive safety and quality approach, based on risk analysis and on the principles of the hazard analysis critical control point (HACCP) system [1]. The HACCP technique for the identi cation, evaluation, and control of food safety hazards was developed in the mid-1960s and publicly presented in the early 1970s. Since then it has been progressively adopted by the food industry and enforced by regulators [2]. Owing to its nature, fermented milks are regarded as perishable
products. Therefore, implementation of the HACCP system is of critical importance in ensuring a high-quality and safe end-product. HACCP has seven principles [3]:
1. Hazard analysis 2. Identify critical control points (CCPs) 3. Establish critical limits 4. Monitor the CCPs 5. Establish corrective actions 6. Record keeping 7. Veri cation
For a safe production of fermented milks, hazards that may present risk for the consumers must be carefully analyzed and effective measures must be taken to eliminate these sources of risks completely or to reduce the total assessed risk of that hazard to an acceptable level. For the ef ciency of the HACCP system, some prerequisites must be met. These prerequisites have been indicated in European Council Directive 92/46/EEC [4]. According to the directive, the possible microbial contamination sources in dairy plants are as follows:
i. External (raw material and additives, water, packaging, and small insects) ii. Internal (wet our, equipment, construction, and vehicles) iii. Air iv. Staff
For the success of the HACCP program, all these points must be controlled strictly [5]. There are three potential hazard sources of a fermented milk processing plant: (i) microbial, (ii) chemical, and (iii) physical hazards. Microbiological sources of hazard can be divided into three subgroups: severe, medium-severe with high risk of epidemics, and medium-severe with limited risk of epidemics (Table 8.1).
