Rapid and quantitative detection of the microbial spoilage of muscle foods: current status and future trends

The requirement for real-time monitoring in the modern and highly automated food processing environment has stimulated research into rapid microbiological testing. This review will concentrate on the search for a rapid detection system for the microbial spoilage of meats that has been ongoing since at least the 1970s. The metabolic processes and bacteria involved within the microbial spoilage of muscle foods will be outlined prior to a detailed overview of the current methods employed in the industry to quantify levels of spoilage organisms. Despite these detailed microbiological studies there is still a requirement within the food industry for new techniques which would ideally be accurate, non-destructive and give answers in real-time and a range of novel analytical technologies which are currently being developed for the rapid assessment of microbial spoilage in muscle foods will be examined. # 2002 Elsevier Science Ltd. All rights reserved. Introduction Muscle foods, which include both meat and poultry, are an integral part of the human diet and have been so for several thousand years. However, within the past two decades public concern, as well as awareness, has been raised due to high profile food safety issues such as the BSE and foot and mouth epidemics centred in the UK (Fox, 2001; Pickrell & Enserink, 2001). These outbreaks, along with concerns over specific pathogenic bacteria within meats (and eggs), namely Salmonella spp. (Schlundt, 2001; Stock & Stolle, 2001; White et al., 2001; Zhang-Barber, Turner, & Barrow, 1999), E. coli O157:H7 (Cassin, Lammerding, Todd, Ross, & McColl, 1998; Mariani-Kurkdjian & Bingen, 1999; Tarr, Besser, Hancock, Keene, & Goldoft, 1997; Tuttle et al., 1999) and Campylobacter spp. (Altekruse, 1998; Altekruse, Stern, Fields, & Swerdlow, 1999; Frost, 2001; Harris, Weiss, & Nolan, 1986; Hopkins & Scott, 1983), have illustrated the requirement for a rapid and accurate detection system for microbial spoilage of meats within what is a large-scale production industry whose turnover is billions of E and $ per annum. At present no such detection system exists within this industry. Whilst parts of the meat and meat products industry may have suffered some losses due to recent events, such as those dealing in beef and lamb, the converse can be said for the poultry industry. This may be in part concomitant with the issues already mentioned but is far more likely to be related to a more health conscious diet and perversely the huge increase in consumption of convenience foods to which poultry, a relatively inexpensive protein source, is ideally suited. This relatively recent change in eating habits has emphasised the requirement for advances in detection systems whereby those used at present are replaced by methods that are truly rapid and accelerate and enhance the detection of microbial spoilage in muscle foods.