This method describes the procedure for conducting a stress test on non-alcoholic beverages.
Non-alcoholic beverages (soft drinks, beverages containing fruit juice)
The time required to develop a product – from conception to launch on the market – is steadily shrinking. Since recipes are also becoming ever more complex and a wide range of different types of packaging are now employed, forced stability tests have become absolutely essential, in order to establish a realistic indication of a product’s shelf-life.
Inferences about the shelf life of a product can only be made if the entire beverage concept is taken into consideration, such as the recipe, filling technology, packaging and distribution.
The most important stress factors in the aging process are heat, light and oxygen.
PET bottles have become a popular form of packaging for non-alcoholic beverages, and their permeability to gas, most especially oxygen, is therefore a critical parameter in the aging process
The testing process described below operates, of course, on the assumption that the chemical reactions in the aging process are subject to the same mechanisms, whether they occur at temperatures typical for beverage storage or at somewhat elevated temperatures, and that they follow a linear relationship dependent on temperature. The same applies to forced photochemical reactions and to reactions brought about by an increase in the partial pressure of oxygen on the beverage. To verify results from forced testing, they can be compared and correlated to results from real-time tests on the same product.
Boiler water for use in the production of beer and other foods
Hydrazine and p-dimethylaminobenzaldehyde in an aqueous solution containing alcohol form a compound which is yellowish red in color.
The method describes how to determine the oxygen content in water using a WTW measuring device.
If an electrode system, usually consisting of a gold cathode and a silver anode, is polarized under suitable conditions, any oxygen present in solution is reduced. The change in the polarization voltage that takes place as this occurs is directly proportional to the partial pressure of the oxygen (according to CLARK). The partial pressure and the volume of the gas are also proportional.
The method describes how to calculate the total exposure of individuals to radionuclides in drinking water.
Drinking water intended for use as an ingredient in the production of beer (brewing liquor) or other foods
Boiler feed water for use in the production of beer and other foods
Refer to W-000.40.115 Oxygen in Water, Titration Method According to WINKLER
Given the very low levels of oxygen present in boiler water, a method employing iodine comparison is recommended. In this analysis, the blank value of the reagent is measured by titrating a water sample free of Mn2+ (“red”).
Determination of the amount of cold break material in the pitching wort
Cast-out wort, wort from the midpoint of chilling/pitching wort (without yeast)
The hot break material (trub) and any hop particles which may be present in the wort, must first be removed. After the wort has been cooled to 2 °C, it is filtered through a glass fiber filter. The residue remaining on the filter is dried and then weighed.
Cold break material or cold trub refers to all material that settles out in the process of chilling wort after separation of the hot trub or hot break material. Cold trub can be filtered out of the wort and primarily consists of proteins (48–57 %), tannins (11–26 %) and carbohydrates (20–36 %). The amount of cold break material in wort depends on the quality and composition of the raw materials, brewhouse equipment and wort handling. In academic and professional circles, opinions regarding the significance of cold break material for downstream processes and for the quality of the finished beer are strongly divided [1, 2, 5]. Under certain circumstances, the quantity of cold break material in wort may exceed 250 mg/l, especially where accelerated fermentation is practiced. Ultimately, this can detract from the flavor of the finished beer [3]. Breweries, where removal of the cold break material has been practiced successfully, determine the quantity of cold break in their pitching wort at regular intervals, in order to evaluate the efficacy of their separation equipment.