Περίληψη:
The market demands for quality, safety, low cost, longer shelf life in
foods and at the same time less use of “chemicals", have guided the scientific
research on alternative ways of preservation and packaging. Thus, the aim of
this study was to reflect the new trends and the commercial applications of
new technologies in the field of food packaging. Since cold cuts are among
the most popular packaged/ready to eat foods (RTF) and at the same time an
ideal microenvironment for the growth of microorganisms, a case study was
carried out in order to investigate the effect of sodium alginate edible films,
with and without the addition of nisin, in the microbial, physicochemical and
organoleptic profile of the product, under vacuum conditions and its
maintenance at 4°C and 10°C. Simultaneously a study was carried out with
regards to the cost, to investigate whether the application of edible films with
nisin, as antimicrobial agent, is an advantageous investment-option for
companies and consumers.
To investigate the efficacy of edible films in microbiological and
physicochemical level, ham slices, procured from large supermarket and cut
into uniform samples (5x5 cm) (under aseptic conditions), were packaged with
the membranes of sodium alginate (1.5%) and four cases resulted: ham
without edible films, ham with edible films without nisin, ham with edible films
and nisin 250 IU/ml, and ham with edible films and nisin 750 IU/mL. All the
samples were packed in vacuum and then stored at 4°C and 10°C. Then,
samples were taken at regular intervals to perform microbiological analyzes,
color analysis and the measurement of pH.
Both nisin concentrations (250 and 750 IU/mL) inhibit microbial growth,
at both temperatures, without altering the color of the product. This inhibition
appears to be greater when the concentration of nisin is higher and is
combined with an additional obstacle, like low temperature (4
C). The
dominant microorganisms were the lactic acid bacteria (LAB), which is
confirmed by the decrease in pH in all samples. Regarding costs, the
packaging of 200g with edible films is charged with 0.70 € more (compared to
packaging without edible films) and packaging of 400g is charged with 1.33 €
more. Prices are indicative and certainly if the product is produced by an
industry, on a large scale they will be reduced even further. It is a product with
many advantages, but due to the financial crisis, perhaps it is not the right
time for a company to make such an investment.
