In this work, a novel nanostructure of gold nanosheets (NSs)-decorated TiO.sub.2 nanocolumns (NCs) coated on carbon fiber (Au NSs-TiO.sub.2 NCs/CF) is designed and fabricated. The structure and ...morphology can be adjusted from Tanghulu-like to sausage-shaped with the final concentration of chloroauric ions in the reaction solution. Au NSs-TiO.sub.2 NCs/CF have been proven to be an excellent SERS substrate with a high analytical enhancement factor, good uniformity, and great stability. Most importantly, SERS experiments can be carried out on one strand of Au NSs-TiO.sub.2 NCs/CF with the aid of a Raman confocal microscope. These Tanghulu-like and sausage-shaped Au NSs-TiO.sub.2 NCs/CF have great potential in SERS analysis of trace samples.
Penicillium nordicum is the main ochratoxin A (OTA)-producing species on the surface of dry-fermented sausages, such as the “chorizo”. New antifungal strategies are being developed using biocontrol ...agents (BCAs), such as plant extracts and native microorganisms. This work aimed to evaluate the antiochratoxigenic capacity and the causative modes of action of BCAs (rosemary essential oil (REO), acorn shell extract and the yeast Debaryomyces hansenii (Dh)) in a “chorizo”-based medium (Ch-DS). BCAs were inoculated on Ch-DS together with P. nordicum and incubated at 12 °C for 15 days to collect mycelia for OTA analyses and comparative proteomics. Both REO and Dh alone decreased OTA accumulation up to 99% and affected the abundance of P. nordicum proteins linked to cell wall organisation, synthesis of OTA-related metabolites and ergosterol synthesis. It is worth highlighting the increased abundance of an amidase by REO, matching with the decrease in OTA. The use of REO and Dh as BCAs could be an effective strategy to reduce the OTA hazard in the meat industry. Based on their not fully coincident modes of action, their combined application could be of interest in “chorizo” to maximise their potential against ochratoxigenic strains.
•REO is a valuable strategy for reducing OTA by P. nordicum in “chorizo”.•Dh is an effective biocontrol agent for reducing OTA by P. nordicum in “chorizo”.•The combination of Dh and REO is also successful in reducing OTA.•AE does not affect OTA production in “chorizo”.•REO and Dh affect ergosterol-, secondary metabolites- and CWI-related proteins.
The aim of the present study was to assess raw pork sausages collected on the Dutch market for the presence of hepatitis E virus (HEV) RNA. 46 of 316 (14.6%) products sampled from Dutch retail stores ...in 2017–2019 were positive for HEV RNA. HEV RNA was detected in 10.8% of “cervelaat” (n = 74), 18.5% of salami (n = 92), 26.1% of “metworst” (n = 46), 16.3% of “snijworst” (n = 43) samples. This was significantly more often than in other raw pork sausages like dried sausages, fuet or chorizo (3.3%, n = 61). The percentage of HEV RNA positive products was not significantly different for products sold as either sliced or unsliced deli meat. The average viral load in positive tested products was 2.76 log10 genome copies per 5 g, incidentally reaching up to 4.5 log10 genome copies per 5 g. The average HEV RNA level was significantly higher in samples collected in 2017 than those in samples collected in 2018, and most of the samples in 2019. Typing by sequence analysis was successful for 33 samples, all revealing genotype 3c. The results support recent epidemiological studies that identified specific raw pork sausages as risk factor for hepatitis E virus infection in the Netherlands. Persons at risk, including Dutch transplant recipients, have been advised to avoid the consumption of raw pork sausages. The study warrants a continuation of monitoring to follow the HEV RNA levels in pork products for use in risk assessments and risk management.
•HEV RNA was detected in 46/316 raw pork sausages (14.6%) on the Dutch market.•Cervelaat, salami, metworst and snijworst more often positive than other sausages.•The HEV strains sequenced were typed as genotype 3c.•The average level in contaminated sausages was 2.76 log10 HEV gc per 5 g.•Quantitative data revealed change in HEV contamination over time.
Meat analogue research and development focuses on the production of sustainable products that recreate conventional meat in its physical sensations (texture, appearance, taste, etc.) and nutritional ...aspects. Minced products, like burger patties and nuggets, muscle-type products, like chicken or steak-like cuts, and emulsion products, like Frankfurter and Mortadella type sausages, are the major categories of meat analogues. In this review, we discuss key ingredients for the production of these novel products, with special focus on protein sources, and underline the importance of ingredient functionality. Our observation is that structuring processes are optimized based on ingredients that were not originally designed for meat analogues applications. Therefore, mixing and blending different plant materials to obtain superior functionality is for now the common practice. We observed though that an alternative approach towards the use of ingredients such as flours, is gaining more interest. The emphasis, in this case, is on functionality towards use in meat analogues, rather than classical functionality such as purity and solubility. Another trend is the exploration of novel protein sources such as seaweed, algae and proteins produced via fermentation (cellular agriculture).
Alheira is a naturally fermented meat sausage traditionally made in the Portuguese region of Trás-os-Montes. Lactic acid bacteria (LAB) are the dominant microorganisms in alheira and can endow it ...with various technological properties. This study aimed (1) to characterize technological features and in vitro antimicrobial activity of LAB isolated from alheira, and (2) to reveal associations between such phenotypic characteristics and the isolates species identified through amplification and sequencing of the 16S ribosomal gene. Sixty-two LAB isolates were identified and Enterococcus (E.) faecium corresponded to 32.3% of isolates, followed by Leuconostoc (L.) mesenteroides (19.4%) and Latilactobacillus (Lb.) sakei (17.7%), aligning with previous research on traditional Portuguese fermented meat sausages. The phenotypic analysis of LAB isolates indicated diverse acidification capacities, proteolytic activities, and inhibitory effects against foodborne pathogens Listeria (L.) monocytogenes, Salmonella (S.) Typhimurium and Staphylococcus (S.) aureus. Overall, lactobacilli displayed high inhibition activity against the pathogens S. aureus, L. monocytogenes, and S. Typhimurium. Although the mechanisms for the inhibition of pathogen growth need to be further elucidated, these findings enhance our understanding of LAB diversity and functionality in alheira sausages, contributing to product safety and quality.
Encapsulation of Lactobacillus plantarum in alginate spheres provides higher probiotic viability in dry‐sausages during chilled storage (60 days) and more appropriate physicochemical properties.
...Summary
The impact of free and encapsulated Lactobacillus plantarum addition on the physicochemical and microbiological properties during chilled storage (60 days) of dry‐fermented sausages have been studied. Control (C) treatment was performed without probiotic incorporation, and the reformulation was comprised of L. plantarum as free cells (F) in alginate spheres (EA), in water‐in‐oil simple emulsion (ESM) and in water‐in‐oil‐in‐water double emulsion (EDM). After 60 days of storage, lower (P < 0.05) lipid oxidation was observed in F and EA (0.602–0.625 mg MDA kg−1) while it was higher (P < 0.05) in EDM (1.949 mg MDA kg−1). Treatments C and ESM presented intermediate TBARS levels compared to other treatments at the end of storage. All dry‐fermented sausages presented high levels of lactic acid bacteria during the whole chilled storage (8.06–9.29 log CFU g−1 at day 0 and 8.02–9.35 log CFU g−1); however, EA treatment presented the highest L. plantarum viability even at 60 days of storage (8.34 log CFU g−1). Therefore, the strategy of L. plantarum inoculation in alginate spheres seems to be the best strategy for the delivery of probiotics during chilled storage of dry‐fermented sausages.
PDF
