Co-extruded alginate as an alternative to collagen casings in the production of dry-fermented sausages: Impact of coating composition

The performance of co-extruded alginate coatings containing no extra additives (A), polyglycerol esters of fatty acids (EA), or pea protein (PA) was assessed as an alternative to collagen casings (C) for the manufacturing of dry-fermented sausages (fuet) with no inoculation of moulds and without a fermentation step (NMNF) and fuet inoculated with Penicillium candidum and fermented (MF). Stuffing into collagen casings resulted in slower sausage drying kinetics compared with alginate coating. No significant differences in a_w were observed among the studied casing types for NMNF and MF fuets and for the evolution of the technological and spoilage microorganisms. Fuets coated with A, EA, and PA showed lower pH values than fuets stuffed in collagen casings. No significant differences on sensory properties between casing types were observed. Therefore, alginate coatings would be a feasible alternative to collagen casing from a technological and safety point of view.

Biocontrol of Penicillium griseofulvum to reduce cyclopiazonic acid contamination in dry-fermented sausages

Dry-fermented sausages are very appreciated by consumers. The environmental conditions during its ripening favor colonization of their surface by toxigenic molds. These molds contribute to the development of sensory characteristics; however, some of them could produce mycotoxins such as cyclopiazonic acid (CPA). CPA is mainly produced by Penicillium commune and Penicillium griseofulvum which have been found in dry-cured meat products. Thus, strategies to prevent the CPA contamination in dry-fermented sausages are needed. The objective of this work was to evaluate the ability of P. griseofulvum to produce CPA in dry-fermented sausage during its ripening as well as to test different strategies to prevent CPA production. The ability of PgAFP antifungal protein-producing Penicillium chrysogenum, Debaryomyces hansenii and Pediococcus acidilactici for inhibiting CPA production by P. griseofulvum was tested on dry-fermented sausage-based medium. Only P. chrysogenum inhibited the CPA production, so this mold was co-inoculated with P. griseofulvum on sausages whose ripening was performed at low temperature. CPA reached around 800 ng/g in the control batch, being reduced to 20 ng/g by the presence of P. chrysogenum. This work demonstrates the risk posed by CPA on dry-fermented sausages, and provides a successful strategy to prevent this hazard.

Healthy Spanish salchichón enriched with encapsulated n-3 long chain fatty acids in konjac glucomannan matrix

Reduction of fat content and improving fatty acid composition were the strategies used to reformulate Spanish salchichón with better lipid content by partial substitution of pork backfat by microencapsulated fish oil in konjac glucomannan matrix. For the present study, four different batches were manufactured: control (CO) with 100% of pork backfat and ME25, ME50 and ME75 where the pork backfat was replaced with 25, 50 and 75% by microencapsulated fish oil, respectively. The fat replacement by microencapsulated fish oil was accompanied by a decrease (P<0.05) in lightness and redness. On the other hand, the incorporation of microencapsulated fish oil increased (P<0.001) hardness, gumminess and chewiness, but did not influence springiness and cohesiveness. The incorporation of microencapsulated fish oil in konjac gel significantly (P>0.001) decreased the fat content (30.4%) as compared with the CO group. The total amount of PUFA in the modified sausages increased by 2.3% compared to the control batches. Finally, the reformulation process showed a significant (P<0.05) increase in the lipid oxidation (TBARs values and aldehydes content) related to the greater susceptibility to lipid oxidation of unsaturated (particularly EPA and DHA) fatty acids. To conclude, it is technologically feasible to develop Spanish salchichón enriched with microencapsulated n-3 fatty acids from fish oil.

Effect of relevant environmental stresses on survival of enterohemorrhagic Escherichia coli in dry-fermented sausage

Dry-fermented sausages (DFSs) have been linked to several serious foodborne outbreaks of enterohemorrhagic Escherichia coli (EHEC). The ability of pathogens to utilize adaptive responses to different stressful conditions intended to control their growth in foods, food preparation and production processes may enhance their survival. In certain cases, induced tolerance to one type of stress may lead to enhanced resistance to the applied stress as well as to other stresses. We exposed two EHEC strains, MF3582 of serotype O157:H- and MF5554 of serogroup O145, to different stresses commonly encountered during a production process. The two EHEC strains, previously shown to have different abilities to survive DFS production process conditions, were subjected to low temperatures (4°C and 12°C), 5% NaCl or 1% lactic acid for 6days prior to being added to sausage batters. Survival of EHEC was recorded in salami of two recipes, fermented at two temperatures (20°C and 30°C). The results showed that recipe type had the largest impact on EHEC reductions where Moderate recipe (MR) salami batters containing increased levels of NaCl, glucose and NaNO2 provided enhanced EHEC reductions in salami (2.6 log10) compared to Standard recipe (SR) salami (1.7 log10). Effects of pre-exposure stresses were dependent both on strain and recipe. While acid adaptation of MF5554 provided enhanced log10 reductions from 2.0 to 3.0 in MR sausages, adaptation to a combination of acid and salt stress showed the opposite effect in SR sausages with reductions of only 1.1 log10 as compared to the average of 1.8 log10 for the other SR sausages. Otherwise, the salt and acid adaptation single stresses had relatively small effects on EHEC survival through the DFS production process and subsequent storage and freeze/thaw treatments. Growing cells and cells frozen in batter survived poorly in MR sausages with an average reduction of 3.4 and 3.2 log10, respectively. The reductions of EHEC after storage of DFS increased with higher temperature and storage time. Up to 3.7 log10 additional reduction was obtained when MF3582 was stored for 2months at 20°C. In conclusion, adaptation of EHEC to acid, salt and low temperatures prior to being introduced in a DFS production process has limited, but strain dependent effects on EHEC reductions. Producers should avoid conditions leading to acid and salt adapted cells that can contaminate the sausage batter. Recipe parameters had the largest impact on EHEC reductions while storage at 20°C is effective for enhanced reductions in finished products.