Liquid products preservation

Failure of preservative systems to protect liquid products,... 

Tray dryers, the simplest type of dryer, are commonly used for batch drying of biological materials, where the wet solids are placed on trays which are then transferred into a chamber. The chamber may have a heating jacket, heated tray supports, or a hot air supply. Vacuum may be applied to reduce the temperature at which the liquid evaporates, preserving heat labile products. These are well suited to low-volume products or flexible plants where a number of different products with different characteristics must be dried. They are relatively inefficient to operate, difficult to clean, and labor intensive to operate. The product is exposed when being loaded and unloaded, so the dryer may need to be located in a clean room or area for pharmaceutical products. 

Preservatives In addition to those processing controls mentioned above (Section 3.1.4.3), the sterility of a product may be maintained through the addition of antimicrobial preservatives. Preservation against microbial growth is an important aspect of multidose parenteral preparations as well as other formulations that require preservatives to minimize the risk of patient infection upon administration, such as infusion products [52], Aqueous liquid products are prone to microbial contamination because water in combination with excipients derived from natural sources (e.g., polypeptides, carbohydrates) and proteinaceous active ingredients may serve as excellent media for the growth [57], The major criteria for the selection of an appropriate preservative include efficiency against a wide spectrum of micro-... 

Liquid dosage forms. The liquid products are prepared by dissolving the ingredients in the appropriate solvent systems. Dyes, flavors, sweeteners, and antimicrobial preservatives are added to mask unpleasant taste or appearance, and to prevent mold and bacterial growth. The final products are stored in large tanks before final packaging. If the liquid is used for injection or ophthalmic use, the liquid must be sterilized. Solutions for external or oral use do not require sterilization but generally contain antimicrobial preservatives [16, 17]. 

Less esoteric but equally important stabilizers include preservatives in liquid products to prevent microbial growth and buffers to provide an environment conducive to good stability where degradation is pH-related. Chelating agents also are used as... 

As more restrictions on product preservatives have been set in the last 10 years, more instances of microbial contamination have appeared and liquid detergent process equipment and operations have approached those used in the food and pharmaceutical industries. Process equipment is being installed to a more sanitary level, which means easier to clean and disinfect. Predominantly the equipment is designed for cleaning in place (CIP) without the need to disassemble. This chiefly means that surfaces are polished, circulation dead spaces are avoided, and drainage is virtually perfect. Usually the equipment is washed with alkaline and acid solutions, and then with a disinfectant solution. Additional equipment to handle and recirculate disinfectant solutions becomes part of the system design. 

A sterile product incorporated a preservative system to cover withdrawal of a multidose liquid product. The product passed the USP XX microbial challenge test when first made and packed. After six months it was noticed that the level of ethylenediamine tetra acetate (EDTA) had significantly reduced, possibly by chelation with heavy metals + surface adsorption onto the plastic. A repeat microbial challenge test was not passed. It was theorised that this was due to slight preservative loss coupled to the loss of EDTA which tended to enhance the preservative efficacy, i.e. a chemical + physical change (preservative adsorption) had created a drop in preservative efficacy. Changing the EDTA/preservative levels was subsequently necessary in order to meet the microbial challenge test over the full shelf-life period. 

In recent years, there are several reports to deal with the effect of CDs on the antimicrobial properties of AITC in a liquid-state condition [12,13]. To clearly illustrate the effect of CDs on AITC in real food systems, a practical example has been drawn below to follow the preparation, releasing properties and use of CD-AITC inclusion complexes for the meat and baking products preservation. 

Preservatives, Protect from oxidation, Butylated hydroxytoluene Liquid products with... 

In material protection, silver based biocides are used mainly for the preservation of consumer products like household articles, textile products and pvc floors. The preservation of liquid products with silver-based ingredients is possible with systems which allow controlled release of silver ions. A controlled release systems is necessary, because, if the silver concentration in the liquid phase is to low, microorganisms will grow, but, if the silver concentration is to high, the product will get black. Therefore different releasing systems based on zeolithe or titanium dioxide carriers or on polymers have been developed. 

Secondly, the developed bacteria-catalyzed production of inexpensive calcium magnesium acetate (CMA) and potassium acetate (KA) from gasified municipal solid wastes (MSW) or from waste cheese whey is an important product area (see section O Development of Processes for Production of Calcium Magnesium Acetate in this chapter). The superiority of CMA and KA as deicers for roads and airport runways as well as the economic advantage of the bacteria-based production processes predicts an important area for profitable industrial development for the future. It has been estimated that if only 10 % of rock salt is replaced with CMA, the projected annual use of CMA deicer would be 2-2.8 x 10 Ibs/year. There are also a number of other important industrial uses for acetate salts listed in O Pig. 1.5, such as for heat transfer liquids, meat preservation, and fungicides. 

Foods can be grossly divided into vegetable- or animal-derived products. They are characterized by an intrinsic complexity and heterogeneity of the matrix that is reflected in the presence of several classes of metabolites with different chemical properties and wide concentration ranges, which must be preserved as much as possible during the analysis. In this respect, NMR-based metabolomics is more suitable for the application on liquid products (i.e. juices, beverages, etc.) where the samples are practically ready for the analysis requiring a dilution step at most. On the contrary, solid foodstuffs have to be extracted to obtain a liquid representative sample. 

Product COSAN 145 is a liquid organic preservative recommended for use in resin emulsions, latex paint, adhesives, dispersed colors, pigment slurries, and ready-mix joint cements. 

Liquid Dosage Forms. Simple aqueous solutions, symps, elixirs, and tinctures are prepared by dissolution of solutes in the appropriate solvent systems. Adjunct formulation ingredients include certified dyes, flavors, sweeteners, and antimicrobial preservatives. These solutions are filtered under pressure, often using selected filtering aid materials. The products are stored in large tanks, ready for filling into containers. QuaUty control analysis is then performed. 

Benzoic Acid. Ben2oic acid is manufactured from toluene by oxidation in the liquid phase using air and a cobalt catalyst. Typical conditions are 308—790 kPa (30—100 psi) and 130—160°C. The cmde product is purified by distillation, crystallization, or both. Yields are generally >90 mol%, and product purity is generally >99%. Kalama Chemical Company, the largest producer, converts about half of its production to phenol, but most producers consider the most economic process for phenol to be peroxidation of cumene. Other uses of benzoic acid are for the manufacture of benzoyl chloride, of plasticizers such as butyl benzoate, and of sodium benzoate for use in preservatives. In Italy, Snia Viscosa uses benzoic acid as raw material for the production of caprolactam, and subsequendy nylon-6, by the sequence shown below. 

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