Accelerated Shelf-Life Testing

In case there is a significant difference between the stressed and the nonstressed sample, off-flavours or strong sensorial deviations are monitored. As a next step, further analytical evaluations, e.g. GC-MS, are performed for the identification of relevant degradation products. 

The kinetics of degradation processes in foodstuffs are not simulated by the accelerated shelf-life testing method in the same way. Different parameters like Uw value, pH value, acidity levels, sulphur compounds, etc. affect flavour degradation in the foodstuff very individually therefore, a careful transfer of results is absolutely essential. The tested products have to be clustered depending on their ingredients and parameters for the accelerated testing have to be adapted (Fig. 21.10). 

Foodstuff Mai Hard Reaction Oxidation Enzymatic Degradation other Reactions 

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Calibration and maintenance programs [45], challenge tests [2], accelerated shelf life tests [53], auditing [2], sensory tests [46], microbial tests [47]... 

Shelf Life. Encapsulated orange oil samples were subjected to accelerated shelf life testing at 37 ad 50 C. Control samples were stored at 25 C. The samples were evaluated until degradation was sufficient to produce a level of 2 mg... 

We have used the polyamide fluorescence reaction in accelerated shelf life tests of fats and oils, either with the neat oils or with plates pre-dipped in cobalt chloride for acceleration. 

ASLT (accelerated shelf life testing) must also be run on the sensor and its individual components to define realistic shelf life, storage conditions, and usage conditions. This information is also critical to the overall quality control for the sensor and the instructions for its use. 

Accelerated shelf life tests take at least 48 hr or one week to provide results. More rapid predictions of beer stability are sometimes obtained using chemical precipitants such as ethanol [185] or formaldehyde [186]. Proteins can be precipitated with ammonium sulphate [187], magnesium sulphate, or gallic tannic acid [188]. 

Reich concludes, however, that the concept can be useful (as a rationale) for the accelerated aging of packages. Hemmerich concurs that this type of conservative relationship is appropriate for a wide range of medical polymers that have been previously characterized. Nevertheless, the simplified protocol for accelerated shelf-life testing is not a replacement for more complex and advanced accelerated aging (techniques). ... 

Ragnarsson, J.O. and Labuza, T.P. Accelerated shelf-life testing for oxidative rancidity in foods - a review. Food Chem. 2, 291-308 (1977). 

Expiration claims could be documented by real-time shelf life testing, however, the timelines for product development would be adversely affected. The developers of the ISO 11607 standard recognized this hindrance and therefore have allowed that accelerated aging tests may be undertaken in addition to real-time aging tests by storage under conditions of increased severity. This provision is beneficial however, no guidance is provided as to what conditions of adverse severity are permissible or technically reliable. It therefore has become crucial that guidance and standards be provided to help manufacturers establish product shelf life and expiration claims. 

Shelf life testing is a relatively expensive undertaking that for most practical purposes must be applied to specific food products. Results of such tests are sparse in the literature. Many complex factors affect the prediction of shelf life of foods. The effect of heating foods containing fats, proteins, carbohydrates and phospholipids is confounded by many factors that may either underpredict or overpredict their shelf life, because accelerated conditions may not reflect... 

The routine compositional and functional testing done on the adhesives includes gas chromatographic testing for purity, potentiometric titrations for acid stabilizer concentrations, accelerated thermal stabiUty tests for shelf life, fixture time cure speed tests, and assorted ASTM tests for tensile shear strengths, peel and impact strengths, and hot strengths. 

The plastic bottle and dispensing tip is made of low-density polyethylene (LDPE) resin, which provides the necessary flexibility and inertness. Because these components are in contact with the product during its shelf life, they must be carefully chosen and tested for their suitability for ophthalmic use. In addition to stability studies on the product in the container over a range of normal and accelerated temperatures, the plastic resins must pass the USP biological and chemical tests for... 

Marked variations in the stability of 21 tinctures and 13 related singleentity plant compounds were noted (26). Bilia et al. (27) investigated the stability of 40% and 60% v/v tinctures of artichoke, SJW, calendula flower, milk thistle fruit, and passionflower. The investigation showed a very low thermal stability of the constituents from accelerated and long-term testing as determined by HPLC iode array detector and MS analyses. Stability was related both to the class of flavonoids and water content of the investigated tinctures. Shelf life at 25° C of the most stable tincture (passionflower 60% v/v) was about six months, whereas that of the milk thistle tinctures was only about three months. The stability of artichoke and... 

If significant change occurs between 3 and 6 months testing at the accelerated storage condition, the proposed shelf life should be based on the real-time data available from the long-term storage condition. If significant... 

The stability of excipients is almost always taken for granted. Obviously, there is the potential for a phase change with certain lower melting excipients, e.g., semisolid materials, however, this is not a chemical phenomenon although it may enhance the potential for interaction by increasing the effective interface available at which the interaction can take place. However, some materials are not stable under conditions encountered in excipient compatibility screening or accelerated stability testing. A notable example is dibasic calcium phosphate dihydrate. At temperatures as low as 37°C, under certain conditions, the dihydrate can dehydrate to form the anhydrous material with the concomitant loss of water of crystallization (25), and at 25°C, it is a stable solid with a shelf life, when stored correctly, of more than two years. 

Swisher (1 ) conducted an accelerated spoilage test on the product (encapsulated orange peel oil) he obtained via this process and estimated shelf-life at about 1 year. 

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