208 Meat refrigeration recommendations(1986) define frozen storage life as being" the physical and biochemical reactions which take place in frozen food products leading to a gradual, cumulative and irreversible reduction in product quality such that after a period of time the product is no longer suitable for consump- tion or the intended process'. This definition tends to indicate that a frozen product may deteriorate until it is in a very poor condition before storage life ends, and so rather contradicts the ec definition. IIR(1986)recommendations also include the term of practical storage life(PSL). PSL is defined as 'the period of frozen storage after freezing during which the product retains its characteristic properties and remains table for consumption or the intended process. Bogh-Sprensen(1984) describes PSl as the time the product can be stored and still be acceptable to the consumer. Both of these definitions of PsL depend on the use of sensory panels, leading to the difficulty of defining acceptability and select ing a panel that represents consumers Another term referred to is high quality life(HQL). This concept wa developed in the 'Albany'experiments started in 1948. HQL is'the time elapsed between freezing of an initially high quality product and the moment when, by sensory assessment, a statistically significant difference P<0.01) from the initial high quality (immediately after freezing)can be established(IIR, 1986). The control is stored at"C or colder to mini- mise quality changes. Although well suited to research work, some draw backs have been noted The actual definition of storage life and the way it is measured has the ere fore been widely left to the assessment of individual authors. In some cases sensory assessment has been coupled with chemical or instrumental tests, which although probably more repeatable than human judgements, are again used at the author's discretion. Food technologists have no standard way of estimating shelf-life. Researchers have used many different methods of assessing samples, often with little thought of the initial quality, pre- freezing treatment or size of their samples. This deficiency has led to poor recommendations that can be misleading to users of the data The IIr(2000)definition of chilled storage is very similar to that of frozen storage life. Expected or practical storage life is'the greatest length of time for which the bulk of the produce may be stored either with imum commercially acceptable loss of quality and nutritive value or with maximum acceptable wastage by spoilage 10.2 Chilled storage Extensive data are available on the attainable chilled storage lives for many products (Table 10. 1). In most cases the limiting factors that control the chilled storage life of meat are based on bacterial growth. Off odours and slime caused by microorganisms are detected when populations reach carecommendations (1986) define frozen storage life as being ‘the physical and biochemical reactions which take place in frozen food products leading to a gradual, cumulative and irreversible reduction in product quality such that after a period of time the product is no longer suitable for consump￾tion or the intended process’. This definition tends to indicate that a frozen product may deteriorate until it is in a very poor condition before storage life ends, and so rather contradicts the EC definition. IIR (1986) recommendations also include the term of practical storage life (PSL). PSL is defined as ‘the period of frozen storage after freezing during which the product retains its characteristic properties and remains suitable for consumption or the intended process’. Bøgh-Sørensen (1984) describes PSL as ‘the time the product can be stored and still be acceptable to the consumer’. Both of these definitions of PSL depend on the use of sensory panels, leading to the difficulty of defining acceptability and select￾ing a panel that represents consumers. Another term referred to is high quality life (HQL). This concept was developed in the ‘Albany’ experiments started in 1948. HQL is ‘the time elapsed between freezing of an initially high quality product and the moment when, by sensory assessment, a statistically significant difference (P < 0.01) from the initial high quality (immediately after freezing) can be established’ (IIR, 1986). The control is stored at -40 °C or colder to mini￾mise quality changes. Although well suited to research work, some draw￾backs have been noted. The actual definition of storage life and the way it is measured has there￾fore been widely left to the assessment of individual authors. In some cases sensory assessment has been coupled with chemical or instrumental tests, which although probably more repeatable than human judgements, are again used at the author’s discretion. Food technologists have no standard way of estimating shelf-life. Researchers have used many different methods of assessing samples, often with little thought of the initial quality, pre￾freezing treatment or size of their samples. This deficiency has led to poor conclusions and recommendations that can be misleading to users of the data. The IIR (2000) definition of chilled storage is very similar to that of frozen storage life. Expected or practical storage life is ‘the greatest length of time for which the bulk of the produce may be stored either with maximum commercially acceptable loss of quality and nutritive value or with maximum acceptable wastage by spoilage’. 10.2 Chilled storage Extensive data are available on the attainable chilled storage lives for many products (Table 10.1). In most cases the limiting factors that control the chilled storage life of meat are based on bacterial growth. ‘Off’ odours and slime caused by microorganisms are detected when populations reach ca. 208 Meat refrigeration