Quality Of Dry Fermented Sausages Research Articles

Microbiological and sensory quality of dry fermented sausages containing alginate-microencapsulated Lactobacillus reuteri

The probiotic bacterium Lactobacillus reuteri was added to dry sausage batter, without or after being microencapsulated in alginate using either extrusion or emulsion technology. Pediococcus pentosaceus and Staphylococcus carnosus were added at 7 log cfu/g as starter cultures for fermentation. The sausage batter was stuffed in 55 mm fibrous casings and fermented, with smoking, at ≤ 26 °C and 88% relative humidity (RH) for 72 h. During fermentation as well as drying at 75% RH and 13 °C for 25 days, the pH and water activity ( a w) of the sausages were measured. The numbers of the three organisms in sausages during processing were determined. A consumer taste panel study was conducted to determine if addition of L. reuteri as unencapsulated cells or in microcapsules added at 1% (w/w) affected the sensory quality of the dry fermented sausages. Changes in sausage pH from 5.8 to 4.8, and a w from 0.97 to 0.89, were the same for both control and microcapsule-containing sausages. The numbers of unencapsulated L. reuteri cells dropped by 2.6 log units, whereas microencapsulated L. reuteri were reduced by only ≤ 0.5 log unit after drying. No significant difference in sensory quality was found between control and sausages containing either unencapsulated or microencapsulated L. reuteri. Thus, microencapsulation of probiotics like L. reuteri may be an option for formulation of fermented meat products with viable heath-promoting bacteria.

Use of Lactococcus lactis subsp. cremoris NCDO 763 and α-ketoglutarate to improve the sensory quality of dry fermented sausages

The aim of the present work was to enhance the degradation of free amino acids in dry fermented sausages as precursors of volatile compounds responsible for the ripened flavour. For this purpose, Lactococcus lactis subsp. cremoris NCDO 763, its intracellular cell free extract (ICFE) and α-ketoglutarate were added to sausages. Papain was also used to increase the amount of free amino acids. When L. lactis was inoculated in sausages, an increase in the proteolytic phenomena was observed. The addition of α-ketoglutarate increased transamination phenomena in batches where it was added. The enhancement of these phenomena determined a noticeable rise in the content of glutamic acid (the main final product in transamination reactions) and a decrease, among other amino acids, of valine and leucine, with the formation of high amounts of their derivatives 2-methylpropanal and 3-methylbutanal. These aldehydes are responsible for the ripened flavour of dry fermented sausages. Sensory analysis showed an improvement of odour and flavour when L. lactis and α-ketoglutarate were combined. On the other hand, the intracellular cell free extract of L. lactis did not show any important activity in relation to amino acid breakdown even when used together with α-ketoglutarate and/or papain.

The contribution of Penicillium aurantiogriseum to the volatile composition and sensory quality of dry fermented sausages

An atoxygenic, proteolytic and lipolytic strain of Penicillium aurantiogriseum was tested for its ability to accelerate the production of volatile compounds and to improve the sensory properties of dry fermented sausages. The following batches of sausages were prepared: control; superficially inoculated with a spore suspension; added with an intracellular cell free extract; and superficially inoculated and added with the intracellular cell free extract. Higher levels of lipid oxidation products were found in the aroma extracts of sausages without a mould cover. In contrast, branched aldehydes and alcohols presented higher concentrations in superficially inoculated and extract added sausages, while esters only showed higher concentration in the first ones. The sensory analysis showed that sausages prepared with both treatments received the highest scores in all the properties evaluated, which demonstrated both the potential of this mould as producer of volatile compounds and the effectiveness of combining both treatments.