Liver Sausage Research Articles

Seroprevalence in blood donors reveals widespread, multi-source exposure to hepatitis E virus, southern France, October 2011

The apparent seroprevalence of hepatitis E Virus (HEV)varies greatly among developed countries depending on the geographical area and the sensitivity of immunoassays. We used a validated assay to determine the prevalence of HEV IgG and IgM antibodies among 3,353 blood donors living in southern France,who gave blood during the two first weeks of October 2011 and participated in the study. Demographic and epidemiological information was collected using aspecific questionnaire. We also screened 591 samples for HEV RNA. Overall IgG seroprevalence was 39.1%and varied from 20% to 71.3% depending on the geographical area (p < 0.001) while IgM seroprevalence was 3.31%. Anti-HEV IgG was significantly correlated with increasing age (p < 0.001), eating uncooked pork liver sausages (p < 0.001), offal (p = 0.003), or mussels(p = 0.02). Anti-HEV IgM was associated with being male (p = 0.01) and eating uncooked pork liver sausages(p = 0.02). HEV RNA was detected in one of the 99 anti-HEV IgM-positive samples, but in none of the 492 anti-HEV IgM-negative samples. HEV is hyperendemic in southern France. Dietary and culinary habits alone cannot explain the epidemiology of HEV in this region, indicating that other modes of contamination should be investigated.

Detection of hepatitis E virus in pork liver sausages

Hepatitis E infection is regarded as an emerging public-health concern. The disease is normally self-limiting (mortality rate 1%), but chronic infections have recently been observed in transplanted patients. The etiological agent HEV is a small RNA virus infecting both humans and animals. In humans, the disease may be food-borne and pig is a main reservoir for zoonotic strains. In the present study, we evaluated the presence of HEV and swine fecal cross-contamination in pork liver sausages sold at a grocery store in Italy. HEV genome detection was performed by RT-qPCR, using harmonized protocols that included a process control (murine norovirus) and an internal amplification control. Swine fecal cross-contamination was assessed by determination of the ubiquitous porcine adenovirus.Overall, HEV genome belonging to genotype 3 was detected in both raw (10 out of 45 slices, 250mg each, 22.2%) and dry (1 of 23 slices, 4.3%) liver sausages, but infectivity of the virus was not demonstrated. This pilot study fosters more investigations on HEV presence in pork-derived food, to assess the possible risk for the consumers.

Ochratoxin A reduction in meat sausages using processing methods practiced in households

The aim of this study was to investigate the possibilities of ochratoxin A (OTA) reduction in home-made meat products. Meat sausages (n = 50) produced from raw materials coming from pigs exposed to OTA-contaminated feed, were subject to common heat processes practiced in households (cooking, frying and baking). Concentrations of OTA in pre- and post-processed products were quantified using a validated immunoassay method, enzyme-linked immunosorbent assay, and confirmed using a high-performance liquid chromatography with fluorescence detection. In line with the differences in recipes used and the degree of OTA accumulation in raw materials, OTA concentrations established in Mediterranean and roast sausages were lower than those found in liver and blood sausages. Baking of contaminated sausages at the temperatures of 190–220°C (for 60 min) resulted in significant reduction of OTA levels (75.8%), while 30-min cooking (at 100°C) and frying (at 170°C) proved to be significantly less effective (e.g. yielding OTA reductions of 7.4% and 12.6%, respectively). The results pointed out that despite high OTA stability, heat processes are capable of reducing its concentration in home-made meat products, depending on the processing modality used.

Method for HEV detection in raw pig liver products and its implementation for naturally contaminated food

It is now recognized that Hepatitis E virus (HEV) infection is not confined to developing countries. HEV infection is a growing public health concern in industrialized countries where the disease is mainly autochthonous, caused by HEV genotypes 3 and 4 and is today considered to be zoonotic.HEV causes acute hepatitis in humans, predominantly through contamination of food and water. Due to the low concentrations found in food and water samples, an efficient and rapid virus concentration method is required for routine control. Because of the absence of a reliable cell culture method for the main enteric viruses most commonly involved in the outbreaks, reverse transcription quantitative real time PCR (RT-qPCR) is now widely used for the detection of RNA viruses in all types of samples. The aim of this study was to provide a rapid and sensitive method for detecting HEV in pig liver products. A method which includes a virus concentration step by PEG has been chosen from 9 protocols to be further validated. We used a one-step duplex RT-qPCR for detecting HEV and the murine norovirus (MNV-1) used as a process control for monitoring the quality of the whole extraction procedure. The mean recovery rates of the HEV and MNV-1 obtained from pig liver sausages were respectively 3.94% and 2.92%, increasing in figatelli to 18.38% and 13.11% respectively. This method also proved to be effective for HEV detection in naturally contaminated foodstuffs containing raw pig liver.

Hepatitis E Virus Genotype 4, Denmark, 2012

Hepatitis E Virus Genotype 4, Denmark, 2012

Protective Effects of Processing Condition and Antioxidant on Vitamin A in Chicken Liver Sausage

In this study, the protective effects of processing conditions and antioxidants on vitamin A in chicken liver sausage were investigated. The optimal cooking conditions were determined: 80°C 30min. Under this condition, vitamin A loss rate was lowest. Different types of antioxidants vitamin C (ascorbic acid)EDTA-2Na (ethylenediaminetetraacetic acid disodium salt)BHT (2,4-di-tert.-butyl hydroxytoluene) were added to protect vitamin A. The results indicated the added antioxidants have obvious protective effects on vitamin A, and the protection effect of BHT is better than the others.

Hepatitis E virus seroprevalence and risk factors for individuals in working contact with animals

BackgroundIn industrial countries genotypes 3 and 4 of HEV are detected in swine, wild boar, deer and rabbits, and they are associated with autochthonous infections suggesting the existence of zoonotic HEV infections, compatible with the putative involvement of undercooked pork and big game products as a source of infection. ObjectivesTo evaluate the prevalence of anti-HEV antibodies in different population groups in contact with animals and to investigate risk factors for HEV infection. Study designSerum samples were collected from 859 healthy French subjects, including pig farm workers, forestry workers and individuals without working contact with animals (control group). In addition, 58 swine veterinarians were included in the study. Subjects were interviewed using a structured questionnaire, and anti-HEV antibodies were investigated using a sensitive and specific sandwich ELISA. ResultsAnti-Hepatitis E virus (HEV) antibodies were detected in 26% of control population, and in 36% and 44% of forestry and pig farm workers, respectively. In addition, an increase in seroprevalence from the north to the south of France was observed (30.2% versus 40.7%). Consumption of pork liver sausage (AOR 4.4, p<10−4), occupational contact with animals (AOR 1.58, p=0.038 for forestry workers and AOR 2.51, p<10−4 for pig farm workers), and living in southern France (AOR 1.47, p=0.02), were independent risk factors. Wearing working gloves and boots might reduce HEV infection. ConclusionsOccupational exposure to animals and consuming raw or undercooked pork liver sausage or pork liver play a significant role in HEV transmission in industrial countries.

Ochratoxin A in raw materials and cooked meat products made from OTA-treated pigs

The aim of this study was to determine ochratoxin A (OTA) concentrations in the raw materials and cooked meat products made from pigs sub-chronically exposed to OTA. The treated animal group (n=5) was administered with 300μg OTA/kg of feed for 30days, whereas the control group (n=5) was left untreated. OTA concentrations were quantified using immunoassay (ELISA) and high performance liquid chromatography with fluorescence detection (HPLC-FD). OTA concentration was the highest in the kidney, followed by the lungs, liver, blood, spleen, heart, and adipose tissue. As for the final meat products, the highest average OTA concentration was detected in black pudding sausages (14.02±2.75μg/kg), then in liver sausages (13.77±3.92μg/kg), while the lowest was found in pâté (9.33±2.66μg/kg). The results pointed out that a sub-chronic pig exposure leads to the accumulation of OTA in raw materials and consequently in meat products, whose level of contamination is directly dependent on OTA contents in raw materials used for their production.

Changes in sensory properties and consumer acceptance of reduced fat pork Lyon-style and liver sausages containing inulin and citrus fiber as fat replacers

The effects of fat reduction in Lyon-style (25% fat) and liver sausages (30% fat) using inulin, citrus fiber and partially rice starch were studied in terms of sensory properties and consumer acceptance. Fat reduced Lyon-style sausages (3 to 17% fat) and liver sausages (3 to 20% fat) were respectively compared to the full-fat controls. Reducing fat in Lyon-style sausages decreased meat flavor, aftertaste meat flavor, greasiness and juiciness, and enhanced color intensity, spiciness, spicy aftertaste, raspy throat, coarseness and firmness scores. But adding inulin and citrus fiber led to sensory characteristics similar to the full-fat reference. Regarding liver sausages, attribute scores in greasiness, creaminess, lumpiness and foamy were decreased with fat reduction and simultaneous addition of fibers. Color intensity, spiciness, firmness and attribute furred tongue were increased. Consumer tests revealed acceptable fat reduced (32 to 90% less than control) and fiber enriched (1.0 to 5.6%) sausages. Drivers of liking were found to relate not only to high-fat but also to low-fat samples.

Er:YAG Laser Activation of Sodium Hypochlorite for Root Canal Soft Tissue Dissolution

The aim of this in vitro study was to investigate the effect of Er:YAG laser irradiation on the ability of sodium hypochlorite (NaOCl) to dissolve soft tissue during endodontic procedures. Two acrylic glass plates, each containing a semi-canal, were bolted together to form a complete canal. This geometry permitted one semi-canal to be filled with fine liver sausage of bovine origin dyed by methylene blue and the other with NaOCl (4.00-4.99% available chlorine; Sigma-Aldrich Corporation, St. Louis, MA), which was then activated by Er:YAG laser irradiation (KEY Laser 3; KaVo, Biberach, Germany) using a plain-ended fiber tip and a range of output energy and repetition rate. To achieve relatively low output energy from high input energy, the laser beam was attenuated by placing glass slides in the beam path. The resultant images acquired were analyzed using pixel-based analysis. Samples were statistically analyzed (two-way ANOVA, P < 0.05, univariate, bifactorial; IBM SPSS Statistics 19, SPSS Inc., Chicago, IL). Both output energy and repetition rate significantly influenced the tissue dissolution ability of NaOCl (P < 0.05). Within the limitations of this in vitro study, we conclude that laser activation of NaOCl at 200 mW output power leads to effective soft tissue dissolution. This finding can be of use to endodontists pursuing effective soft tissue dissolution from their irrigants.

Autochthonous Infections with Hepatitis E Virus Genotype 4, France

During January–March 2011, diagnoses of hepatitis E virus (HEV) infection increased in Marseille University hospitals in southeastern France. HEV genotype 4, which is described almost exclusively in Asia, was recovered from 2 persons who ate uncooked pork liver sausage. Genetic sequences were 96.7% identical to those recently described in swine in Europe.

Textural, physicochemical and sensory properties compensation of fat replacing in pork liver pâté incorporating emulsified canola oil

Saturated animal fat was replaced in pork pâté with pre-emulsified canola in a 3% sodium caseinate/0.5% xanthan gum solution in order to obtain a stable oily phase. Fat was replaced with different proportions of emulsified canola oil. The inclusion of emulsified oil in pâté enhanced cocking yield and moisture but increased fluids release. Nonetheless, total fat content remained practically constant, meaning no detrimental effect on caloric content. Replacing 50% of lard with emulsified oil did not affect color of the samples. Texture was improved since emulsified oil addition resulted in softer and more spreadable pâté. Samples with 50% of emulsified oil were more stable to lipid oxidation at 8 days of storage, with lower thiobarbituric acid-reactive substances and volatile compounds resulting from oxidation reactions. Emulsified canola can be employed to replace fat until 50% in pâté or liver sausage with good functional properties, improving texture and reducing lipids rancidity.

Pathogenesis and Treatment of Hepatitis E Virus Infection

Hepatitis E has been considered to be a travel-associated, acute, self-limiting liver disease that causes fulminant hepatic failure in specific high-risk groups only. However, hepatitis E virus (HEV) infection can also be acquired in industrialized countries-HEV genotype 3 infection is a zoonosis, with pigs and rodents serving as animal reservoirs. In recent years, cases of chronic HEV infection that were associated with progressive liver disease have been described in several cohorts of immunocompromised individuals, including recipients of organ transplants. The topic of hepatitis E is therefore re-emerging and has raised the following important questions: what is the risk for HEV infection in Western countries (eg, from eating uncooked meat)? How frequently does chronic hepatitis E develop among human immunodeficiency virus-infected patients and recipients of organ transplants? What are the treatment options? What is the current status of vaccine development? What do we know about the pathogenesis of HEV infection, and why does it have a more severe course in pregnant women? This review summarizes the current knowledge on the pathogenesis and treatment of HEV infection.

Hepatitis E Virus in Pork Liver Sausage, France

We investigated viability of hepatitis E virus (HEV) identified in contaminated pork liver sausages obtained from France. HEV replication was demonstrated in 1 of 4 samples by using a 3-dimensional cell culture system. The risk for human infection with HEV by consumption of these sausages should be considered to be high.

The Changes of Natural Microflora in Liver Sausage with Kimchi Powder during Storages

The objectives of this study were to apply the Baranyi model to predict the growth of natural microflora in liver sausage with added kimchi powder. Kimchi powder was added to the meat products at 0, 1, 2, and 3% levels. To determine and quantify the natural microflora in the meat products, total plate counts and counts of anaerobic bacteria and lactic acid bacteria were examined throughout the 28 d of storage. The obtained data were applied to the Baranyi growth model. The indices used for comparing predicted and observed data were <TEX>$B_f$</TEX>, <TEX>$A_f$</TEX>, root mean square error (RMSE), and <TEX>$R^2$</TEX>. Twelve predictive models were characterized by a high <TEX>$R^2$</TEX> and small RMSE. The Baranyi model was useful in predicting natural microflora levels in these meat products with added kimchi powder during storage.

Hepatitis E virus in Italy: molecular analysis of travel-related and autochthonous cases

Human hepatitis E virus (HEV) is considered an emerging pathogen in industrialized countries. The aim of the present study was to contribute to the body of knowledge available on the molecular epidemiology of acute hepatitis E in Italy. Three sets of HEV-specific primers targeting the ORF1 and ORF2 were used to examine serum samples collected from acute hepatitis patients positive for anti-HEV IgG and/or IgM, between 2007 and 2010. Seventeen patients (39.5%) tested HEV RNA-positive: 12 infections, due to genotype 1, were associated with travel to endemic areas (Bangladesh, India and Pakistan), while five infections, due to genotype 3, were presumably autochthonous. Risk factors identified in this group included exposure to raw seafood, pork liver sausages and wild boar. Results from the present study confirm that human HEV infection in Italy is caused by different genotypes, depending on whether the infection is travel-related or autochthonous.

Evaluation of Extraction Methods for Efficient Detection of Enteric Viruses in Pork Meat Products

We report an in-house protocol for extraction and purification of nucleic acids of enteric viruses, which gives more consistent results than representative commercial methods. The protocol uses 4 M guanidine thiocyanate, 0.5% N-lauroylsarcosine sodium salt, and 25 mM sodium citrate pH 7.0 supplemented with 0.14 M β-mercaptoethanol for lysis of virus particles. The addition of TRIzol followed by chloroform-based separation of the aqueous phase is used to purify nucleic acids from the lysate. RNA precipitation is performed using lithium chloride. This protocol was compared with QIAGEN’s RNeasy Kit and bioMerieux’s NucliSens method, by evaluating the ability of each to detect enteric viruses in a complex food matrix. Three different pork products, i.e., cooked ham, liver, and Spanish fermented sausage (“chorizo”) were artificially contaminated with decreasing numbers of murine norovirus 1 and human adenovirus 2. The extracted and purified viral nucleic acids were detected by real-time polymerase chain reaction (PCR) assays. Whereas the two commercial extraction methods did not facilitate robust results (quantification was only possible with some viruses and/or some matrices), when coupled with the in-house protocol the linearity and the efficiency of the quantitative reverse transcription-PCR (qRT-PCR) assays were close to 1 in all the food matrices, independent of the virus. Scalability of the in-house method was evaluated by analysis of 1 and 2.5 g of spiked pig liver samples, and quantification was possible on 1 g samples contaminated with any of the two model viruses. Therefore, the in-house protocol facilitates robust qRT-PCR-based quantitative detection of viruses in pork products, and is moreover relatively cheap and simple to perform.

Pig Liver Sausage as a Source of Hepatitis E Virus Transmission to Humans

The source and route of autochthonous hepatitis E virus (HEV) infections are not clearly established in industrialized countries despite evidence that it is a zoonosis in pigs. We investigated the role of figatellu, a traditional pig liver sausage widely eaten in France and commonly consumed raw, as a source of HEV infection. A case-control study was conducted of 3 patients who presented autochthonous hepatitis E and 15 members of their 3 different families. Anti-HEV immunoglobulin G and immunoglobulin M antibody testing was performed with commercial assays. HEV RNA was detected in serum samples of patients and in pig liver sausages by means of real-time polymerase chain reaction and sequenced by means of in-house sequencing assays. Genetic links between HEV sequences were analyzed. Acute or recent HEV infection, defined by detection of anti-HEV immunoglobulin M antibodies and/or HEV RNA, was observed in 7 of 13 individuals who ate raw figatellu and 0 of 5 individuals who did not eat raw figatellu (P=.041). Moreover, HEV RNA of genotype 3 was recovered from 7 of 12 figatelli purchased in supermarkets, and statistically significant genetic links were found between these sequences and those recovered from patients who ate raw figatellu. Our findings strongly support the hypothesis of HEV infection through ingestion of raw figatellu.

Polycyclic aromatic hydrocarbons in German smoked meat products

The contents of the 15+1 EU priority PAH were analysed from 113 representative commercial smoked German meat products collected in the year 2006 with a Fast-GC/HRMS method. The median of benzo[a]pyrene content was 0.03 μg/kg and therefore greater than a factor of 100 below the maximum level of 5 μg/kg. The highest content of benzo[a]pyrene was detected in a Frankfurter-type sausage (0.43 μg/kg). The sum content of benzo[a]pyrene, benzo[a]anthracene, chrysene and benzo[b]fluoranthene (“PAH4”), as proposed by the European Food Safety Authority to be a good marker for PAH in food, was 0.28 μg/kg in median, and the sum content of the 15+1 EU priority PAH was 0.64 μg/kg in median. The analysed smoked meat products showed an increasing presence of PAH in the following order: cooked ham (n = 17) < raw sausages (n = 25) < liver sausages (n = 25) < raw ham (n = 23) < Frankfurter-type sausages (n = 23). The correlation coefficient (R) between BaP and the sum of the 15+1 EU priority PAH was 0.90. To increase the safety of the consumer, a lowering of the BaP maximum level to 1 μg/kg is proposed and critical aspects using “PAH4” as a marker for PAH in food surveillance are discussed.

Effect of Kimchi Powder Levels and Pork Skin on the Quality Characteristics of Liver Sausages

The aim of this study was to evaluate the effect of kimchi powder levels (0, 1, 2, and 3%) and pork skin (5%) on the quality characteristics of liver sausages. The additions of the kimchi powder and pork skin improved the color, cooking yield, and sensory properties of the sausages. The addition of the pork skin and increasing concentrations of the kimchi powder significantly increased cooking yields. The moisture and protein contents of the sausages made with kimchi powder and pork skin were higher than those of the control (p<0.05). Due to the low pH of the kimchi powder, the pH values of the batter and sausages with added kimchi powder were lower than those of the treatment without kimchi powder (p<0.05). The control had the lowest hardness, gumminess, and chewiness values (p<0.05). For the sensory attributes of the samples, color, flavor, juiciness, and overall acceptability were higher in the treatments made with kimchi powder than in the treatments without kimchi powder, in which the treatment with 2% kimchi powder had the highest overall acceptability (p<0.05). In conclusion, the additions of kimchi powder and pork skin improved the quality characteristics of liver sausages.