Product quality chapter

Tailoring of the particle size of the crystals from industrial crystallizers is of significant importance for both product quality and downstream processing performance. The scientific design and operation of industrial crystallizers depends on a combination of thermodynamics - which determines whether crystals will form, particle formation kinetics - which determines how fast particle size distributions develop, and residence time distribution, which determines the capacity of the equipment used. Each of these aspects has been presented in Chapters 2, 3, 5 and 6. This chapter will show how they can be combined for application to the design and performance prediction of both batch and continuous crystallization. 

Part II provides detailed information on the main quality and safety issues related to the production of organic livestock foods. This includes three chapters (Chapters 7 to 9) which review the effect of livestock husbandry on nutritional and sensory quality of livestock foods including milk and dairy products (Chapter 7), poultry (Chapter 8) and pork (Chapter 9). It also includes four chapters (Chapters 10 to 13) which review the strategies used to minimise microbiological risks and antibiotic and veterinary medicine use in livestock production systems including safety of ruminants (Chapter 10), mastitis treatment in organic dairy production systems (Chapter 11), internal parasites (Chapter 12) and pigs and poultry (Chapter 13). 

Attrition of particulate materials occurs wherever solids are handled and processed. In contrast to the term comminution, which describes the intentional particle degradation, the term attrition condenses all phenomena of unwanted particle degradation which may lead to a lot of different problems. The present chapter focuses on two particular process types where attrition is of special relevance, namely fluidized beds and pneumatic conveying lines. The problems caused by attrition can be divided into two broad categories. On the one hand, there is the generation of fines. In the case of fluidized bed catalytic reactors, this will lead to a loss of valuable catalyst material. Moreover, attrition may cause dust problems like explosion hazards or additional burden on the filtration systems. On the other hand, attrition causes changes in physical properties of the material such as particle size distribution or surface area. This can result in a reduction of product quality or in difficulties with operation of the plant. 

Plant metabolism can be separated into primary pathways that are found in all cells and deal with manipulating a uniform group of basic compounds, and secondary pathways that occur in specialized cells and produce a wide variety of unique compounds. The primary pathways deal with the metabolism of carbohydrates, lipids, proteins, and nucleic acids and act through the many-step reactions of glycolysis, the tricarboxylic acid cycle, the pentose phosphate shunt, and lipid, protein, and nucleic acid biosynthesis. In contrast, the secondary metabolites (e.g., terpenes, alkaloids, phenylpropanoids, lignin, flavonoids, coumarins, and related compounds) are produced by the shikimic, malonic, and mevalonic acid pathways, and the methylerythritol phosphate pathway (Fig. 3.1). This chapter concentrates on the synthesis and metabolism of phenolic compounds and on how the activities of these pathways and the compounds produced affect product quality. 

This chapter has focused on the synthesis and metabolism of phenolic compounds that constitute the most important induced secondary products affecting product quality. 

An adequate and balanced supply of nutrients in the soil is essential for several reasons. Nutrient surpluses might result in nutrient losses which subsequently could lead to water and air contamination (see chapter 3.2.2 and 3.2.3) and eutrophication. However, nutrient deficiency is synonymous with the overexploitation of soil nutrients in the long run and leads to a decrease in yield and product quality. 

Food and feed additives, also known as dietary supplements, are minor ingredients added to improve the product quality. Most commonly, the effects desired relate to color, flavor, nutritive value, taste, or stability in storage. The market sizes are estimated to be 20 billion each for food and for feed additives, respectively. The major customers for the food additives are the big food companies Ajinomoto, Danone, Kraft, and Nestle, mentioned at the beginning of the chapter. With the exception of Ajinomoto, these companies are rarely backward-integrated. As they prefer to use natural ingredients rather than synthetic ones, they are not very important customers of the fine-chemical industry. Premixers, that is, enterprises that prepare ready-to-use mixtures of nutrients for the farmers who raise cattle, pigs, and chicken, are the main users of feed additives. 

Petroleum product physical and chemical properties such as viscosity, aromatic content and distillation profile can provide a wealth of information about product quality and performance. The information provided in this chapter can be used to help identify how specific physical and chemical property measurements can be used to identify and solve fuel problems. 

For more detailed discussion of potato product quality assessment and assurance, the book Total Quality Assurance for the Food Industries (Gould, 2001) is essential reading, and for frozen French fried potatoes we especially recommend Hui s chapter of the Handbook of Vegetable Preservation and Processing (Hui, 2004). 

Such strategies attempt to combine prior experiential knowledge and available processing models to predict product quality so that any deviations from the quality specifications can be detected and corrected before the processing is completed. This chapter examines the evolution of these intelligent processing strategies and the current research in this field. 

Whereas intelligent control comprises the aforementioned computer technology, control methods, and sensors, the control methods and advances in them are the focus of this chapter. Sensors parallel control methods in their importance to intelligent control of product quality, but a discussion of them is left to other works [1-8]. The control methods discussed in this chapter are on-line supervisory control methods, as opposed to regulatory control methods. The latter are commonly used, for example, to keep the operation of an autoclave in control When a ramp in temperature is called for, regulatory control methods govern the autoclave in achieving that ramp however, the supervisory control determines the ramp rate in order to influence product quality. 

VVTinery quality control has not been formalized in the United States to the point where standard methods, practices, or performance criteria are established. The literature devotes little attention to the subject of wine production quality control, per se. The first survey of quality control in the California wine industry appeared as late as 1972 (I), and it is limited to sanitation aspects. One does not find chapters on quality control of winemaking in any of the major wine technology texts. 

It is always difficult to compare different processes. The reaction-rate and the product-quality have to be compared to the overall economy of the whole process. In this chapter we will use the reactor productivity as a simplified way to find the major differences between different reactors. We will express the productivity as kgpr0duct/m3reactorh. 

Again regardless of in-house or outsource development, document a list of features and prioritize them. Break the project down into short, timeboxed iterations, each focusing on one or two of these features (Chapter 5). Do not let the iteration deadline slip. Reduce the scope of the iteration if necessary. Implement features with high business values and high business and technical risks in early iterations. Make sure each iteration delivers a production quality partial system to solicit feedback and let the system grow incrementally. The project plan should be adjusted based on the feedback. It is OK if the initial project plan is not accurate. However, it should become more and more accurate as more iterations are completed. Test and integrate early and frequently. 

Historically, and even today, emphasis on the validation of sterile products is placed mainly on the sterilization processes. No manufacturing operation can be considered under complete control without qualification of every system that can potentially affect product quality, however. The following discussion will touch upon other systems and processes involved in sterile product manufacturing expected to be validated. Much of this section relies on the following literature sources [Refs. 43,73-80], Also refer to other chapters in this book that discuss certain topics in much greater detail. 

For emissions testing to be accepted as a meaningful and necessary part of product quality assessment, relevant test methods must ensure acceptable uncertainty. Any associated products standards, incorporating pass/fail criteria, must also take into account the actual uncertainty of the standard methods specified. A relatively detailed summary of some of the major potential causes of error in the multistep materials emissions testing process is presented later in this chapter (see Section 6.6.2). For an emissions test standard/protocol to be robust and useful, it must take into account all of these issues and include sufficient guidance to ensure that a competent laboratory can achieve results within the expected uncertainty limits. 

Since the goal of this chapter is to examine the impact of total quality performance of forward quality on compliance, an interesting and relatively unexplored prospect is a formal recall prevention program. In order to begin considering the value of such a program, one must first determine which if any quality indicators can be used to effectively monitor fluctuations in product quality and justify withholding product from commerce in avoidance of a potential recall. 

In polymer processing practice, we need to ensure that the particulate gravitational mass flow rate of the hopper exceeds, over the complete operating range, the extruder open discharge rate (i.e., the rate without any die restriction). That is, hoppers must not be the production-rate limiting factor. Second, and more importantly, it is necessary for stable extrusion operations and extruded product quality that the flow be steady and free of instabilities of the particulate flow emerging from the hoppers. Finally, as we will see in Chapter 9, we need to know the pressure under the hopper in order to determine the pressure profile in a SSE. 

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