The influence of Debaryomyces hansenii and Candida utilis on the aroma formation in garlic spiced fermented sausages and model minces

The influence of the yeast starter cultures Debaryomyces hansenii and Candida utilis on fermented meat aroma was studied in model minces and in commercial-type fermented sausages. Volatile compounds from model minces and sausages were collected using diffusive and dynamic headspace sampling respectively and were identified by gas chromatography/mass spectrometry (GC/MS). A triangle test was carried out on the sausages to detect whether the yeast influenced the sausage odour. C. utilis demonstrated high metabolic activity in the model minces, producing several volatile compounds, in particularly esters. C. utilis also seemed to ferment the amino acids valine, isoleucine and leucine into compounds important for the aroma of sausages. D. hansenii on the contrary, had very little effect on the production of volatile compounds in the model minces. In the sausage experiment both yeast cultures died out before the ripening process ended and the sensory analysis showed only a slight difference between the sausages. A fungistatic test of the garlic powder added to the sausages indicated that garlic inhibits the growth of the yeast starter cultures.     

Effects of starter cultures on the formation of flavour compounds in dry sausage

The purpose of this work was to study the impact of starter cultures on the production of flavour compounds in dry sausages. The effect of six starter cultures corresponding to different combinations of lactic acid bacteria (Lactobacillus sake L110, Pediococcus acidilactici 725, P. pentosaceus 716) and different Staphylococcus species (S. carnosus 833, S. warneri 863, S. saprophyticus M31) strains were tested in a total of 30 dry sausages without spices. The analysis of flavour compounds using a dynamic headspace apparatus coupled to a gas chromatograph and a mass spectrometer enabled us to identify about 80 volatile compounds. They were of various origins—lipids oxidation, fermentations, amino acid catabolism and animal feedstuffs. The influence of the starters and especially the flavouring strains proved to have a major effect on the level of volatile compounds in dry sausages. The flavour tests led to more accurate determination of the sensory characteristics of important molecules in the flavour of dry sausages. The sensory analyses showed that the butter odour of dry sausages largely depends on the catabolism of carbohydrates and that curing and rancid odours were correlated with some typical compounds of lipid oxidation.     

Comparison of the compositional, microbiological, biochemical and volatile profile characteristics of three Italian PDO fermented sausages

Three Italian PDO fermented sausages, Varzi, Brianza and Piacentino, were compared for compositional, microbiological, biochemical and volatile profile characteristics. Mean values for the gross composition varied especially due to moisture, fat, total protein and nitrate concentration which reflected differences in the ingredients and some technological parameters. Cell numbers of the major microbial groups were almost similar among sausages. The major differences were found for Brochothrix thermosphacta, enterococci and moulds. Apart from their use as starters, Lactobacillus sakei and Lactobacillus curvatus were the dominant lactic acid bacteria and, as well as Staphylococcus xylosus, dominated the population of coagulase-negative staphylococci. Sausages differed for the hydrolysis of myofibrillar proteins and secondary proteolysis. Varzi, the sausage subjected to prolonged fermentation at 23–25 °C for 10 days before ripening, showed the highest degree of secondary proteolysis. Varzi and Brianza, the two fermented sausages manufactured by using microbial starters, showed the highest concentration and similar profiles of free amino acids. The peptidase activities contained in the aqueous extracts agreed with the above findings. A total of 52 volatile components, mainly alcohols, aldehydes and terpenes, were identified by solid-phase micro-extraction coupled with gas chromatography–mass spectrometry analysis. The volatile profiles of the three Italian PDO fermented sausages differed in part and, except for terpenes, the highest levels of the other chemical classes were found in Varzi and Brianza sausages. The composition of free fatty acids of the three Italian PDO sausages was rather similar. Monounsaturated fatty acids (MUFA) were found at the highest relative percentage followed by saturated (SFA) and polyunsaturated (PUFA) fatty acids. Oleic, palmitic, linoleic and stearic were the main free fatty acids found in all fermented sausages.     

Energy content, sensory properties, and microbiological shelf life of German bologna-type sausages produced with citrate or phosphate and with inulin as fat replacer

ABSTRACT:  The aim of this study was to determine the feasibility of reducing energy content (9% to 48%) in bologna-type sausages by replacing fat with inulin and to study the effects of substituting citrate for phosphate in the traditional sausage formula. German-type mortadella was produced, and fat was replaced with increasing amounts of inulin as a frozen gel to yield 3%, 6%, 9%, and 12% inulin in the final product. In another part of the study, citrate was substituted for the phosphate in the recipe. All sausages produced were sliced, packaged under a modified atmosphere (70% N₂, 30% CO₂), and stored for 23 d at +7 °C. Sausage quality was determined by chemical and instrumental texture profile analyses, color measurement, sensory evaluation, and microbiological testing. Replacing fat with inulin led to significant energy content reductions of up to 47.5% (with 12% inulin). However, the sensory properties of these sausages were also different from those of the control mortadella: fracturability fell, hardness and adhesiveness rose, and color became darker. In general, the substitution of citrate for phosphate significantly reduced the negative effects of inulin. There were no significant differences in microbiological stability between different inulin batches but there were significant differences between phosphate and citrate batches. Overall, the energy content of bologna-type sausages produced with citrate and with up to 6% inulin as a fat replacer was 22% lower than that of the control sausages. Furthermore, the sensory attributes (texture, color) of these 6% inulin–citrate sausages were comparable to the control sausages, and the sausages were microbiologically stable for 23 d of storage.     

Effect of the addition of pancreatic lipase on the ripening of dry-fermented sausages - Part 2. Free fatty acids, short-chain fatty acids, carbonyls and sensory quality

The effect of the addition of nine different amounts (3–500 units) of pancreatic lipase on the composition of free fatty acids (FFA), short-chain fatty acids and carbonyls, as well as the sensory quality, has been studied on dry fermented sausages. The lipase produced a greater release of all fatty acids in relation to the control sausages. The greater the pancreatic lipase content, the higher the release of these fatty acids, the most important ones being myristic, palmitoleic and oleic acids. A lower release of linoleic acid was observed, probably because of its oxidative degradation. At the end of the ripening in all lipase-added batches, a clear increase of the carbonyl content was noticed in relation to conventional sausages. No consistent changes were observed in the short-chain fatty acid fraction. In the sensory evaluation, the highest significant differences (P < 0·01) between control sausages and lipase-added batches were observed when 60 and 90 lipase units were used. According to the chemical and sensory analyses, it can be concluded that the addition of 60 and 90 units to sausages seems to be useful to enhanced the flavour of these products.     

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.     

Effect of wine addition on microbiological characteristics,volatile molecule profiles and biogenic amine contents in fermented sausages

The aim was to evaluate the effect of wine addition during manufacturing of dry fermented sausages, in terms of safety aspects (biogenic amine accumulation), aroma profile and sensory characteristics. Three batches of salami were produced: without wine addition and with 7.5% or 15% (v/w) of white wine. The fermented sausages showed characteristics that can increase product diversification. Some of the sensory features (i.e. increased salty perception) can represent an important strategy because of the trend to reduce salt intake for health reasons. The presence of wine immediately reduced the pH and is a source of ethanol, which can have an inhibitory effect against undesirable microflora. The microbiological results observed regarding Enterobacteriaceae and enterococci were encouraging. The addition of wine did not negatively affect the ripening time or increase the presence of biogenic amines. The samples containing wine showed reduced concentrations of putrescine.     

Combined use of Pronase E and a fungal extract (Penicillium aurantiogriseum) to potentiate the sensory characteristics of dry fermented sausages

A combination of an extract of Penicillium aurantiogriseum and Pronase E was used in an attempt to enhance the sensory characteristics of dry fermented sausages, specifically, a salami-like one named "salchichón". The addition of Pronase E alone (600 units/kg) produced a rise in free amino acids and biogenic amines and also an increase in the ammonia content. Addition of the protease and fungal extract (100.87 mg protein/kg of mixture) brought about a decrease in the level of free amino acids and a larger increase in the ammonia content than the batch added with only Pronase E. There was also an increase in the amount of specific volatile compounds such as 2- and 3-methylbutanal, 2- and 3-methylpropanal and 2- and 3-methyl-1-butanol produced by the breakdown of amino acids in these fermented sausages. Values of pH, a(w) and dry matter were not affected by addition of the protease or fungal extract. In contrast, addition of Pronase E produced a notable change in the textural characteristics, reducing the hardness, cohesiveness, gumminess, chewiness and cutting force. Sensory analysis showed that fermented sausages manufactured with Pronase E and Penicillium aurantiogriseum extract had better odour, flavour, texture and, as a consequence, better general acceptability.     

Comparison of the effects of a commercial and an autochthonous Pediococcus acidilactici and Staphylococcus vitulus starter culture on the sensory and safety properties of a traditional Iberian dry‐fermented sausage “salchichón”

The effect of the addition of an autochthonous starter culture and commercial starter culture on the physico‐chemical and sensory characteristics of the dry‐fermented sausage ‘salchichon’ was investigated. Sausages were prepared with a mixture of Pediococcus acidilactici MC184 and Staphylococcus vitulus RS34 as the autochthonous starter culture (P184S34), ripened for 86 days, and compared with a commercial starter batch (CS1). Strains of acid lactic bacteria and Staphylococcus were identified in the samples along the ripening process which demonstrated that the inoculation of sausages assures their implantation during the ripening process. However, P184S34 starter culture showed a higher inhibitory effect on enterobacteria and coliform flora than the CS1 batches, guaranteeing a better quality hygienic sausages. Dry‐fermented sausages ripened with P184S34 showed higher amounts of NPN and volatile compounds derived from amino acid catabolism than the CS1 batches. Especially important was the result found in biogenic amines, since the P184S34 reduced their accumulation compared to the commercial starter batch. The inoculation of a decarboxylase‐negative autochthonous starter culture P184S34 reduced the biogenic amine accumulation guaranteeing safety and homogeneity of the products without producing a negative effect on the sensory characteristics of the traditional fermented sausages.     

Changes in selected biochemical and sensory parameters as affected by the superficial inoculation of Penicillium camemberti on dry fermented sausages

An atoxigenic strain of Penicillium camemberti was superficially inoculated on fermented sausages in an attempt to improve their sensory properties. The growth of this mould on the surface of the sausages resulted in an intense proteolysis and lipolysis, which caused an increase in the concentration of free amino acids, free fatty acids (FFA) and volatile compounds. Many of these were derived from amino acid catabolism and were responsible for the "ripened flavour", i.e. branched aldehydes and the corresponding alcohols, acids and esters. The development of the fungal mycelia on the surface of the sausages also protected lipids from oxidation, resulting in both lower 2-thiobarbituric acid (TBARS) values and lipid oxidation-derived compounds, such as aliphatic aldehydes and alcohols. The sensory analysis of superficially inoculated sausages showed clear improvements in odour and flavour and, as a consequence, in the overall quality of the sausages. Therefore, this strain is proposed as a potential starter culture for dry fermented sausage production.     

Biogenic amines in Spanish fermented sausages as a function of diameter and artisanal or industrial origin

The distribution of biogenic amines in three types of fermented meat sausages (chorizo, fuet and salchichón) was examined with respect to the degree of acidification. The aim was to determine whether low‐acid sausages (artisanal/traditional) have a different biogenic amine profile than more acidic products (industrial). Despite wide variability, tyramine was always found and was generally the major amine, followed by putrescine. Their contents in both industrial and artisanal sausages were similar, but correlated with the diameter of the product. In contrast, industrial sausages showed a higher average content of cadaverine and histamine, especially in chorizo, which also showed the highest content of free amino acids. Moreover, a multiple analysis of variance confirmed that the processing plant had a significant influence on the overall biogenic amine composition of products, histamine being the most important amine accounting for this effect. Copyright © 2005 Society of Chemical Industry     

Safety improvement and preservation of typical sensory qualities of traditional dry fermented sausages using autochthonous starter cultures

Traditional dry fermented sausages are manufactured without addition of starter cultures in small-scale processing units, their fermentation relying on indigenous microflora. Characterisation and control of these specific bacteria are essential for the sensory quality and the safety of the sausages. The aim of this study was to develop an autochthonous starter culture that improves safety while preserving the typical sensory characteristics of traditional sausages. An autochthonous starter composed of Lactobacillus sakei, Staphylococcus equorum and Staphylococcus succinus isolated from a traditional fermented sausage was developed. These strains were tested for their susceptibility to antibiotics and their production of biogenic amines. This starter was evaluated in situ at the French traditional processing unit where the strains had been isolated. Effects of the autochthonous starter were assessed by analysing the microbial, physico-chemical, biochemical and sensory characteristics of the sausages. Inoculation with the chosen species was confirmed using known species-specific PCR assays for L. sakei and S. equorum and a species-specific PCR assay developed in this study for S. succinus. Strains were monitored by pulse-field gel electrophoresis typing. Addition of autochthonous microbial starter cultures improved safety compared with the traditional natural fermentation of sausages, by inhibiting the pathogen Listeria monocytogenes, decreasing the level of biogenic amines and by limiting fatty acid and cholesterol oxidation. Moreover, autochthonous starter did not affect the typical sensory quality of the traditional sausages. This is the first time to our knowledge that selection, development and validation in situ of autochthonous starter cultures have been carried out, and also the first time that S. equorum together with S. succinus have been used as starter cultures for meat fermentation. Use of autochthonous starter cultures is an effective tool for limiting the formation of unsafe compounds in traditional sausage while preserving their original and specific sensory quality.     

香辛料精油对鲶鱼肉风干肠品质及安全性的影响

为了提高鲶鱼肉风干肠的品质与安全性,选取丁香、八角、肉桂、紫苏、牛至五种香辛料精油分别添加到腌制好的鱼肉馅中,经灌肠、风干后制成鲶鱼肉风干肠。对风干肠的感官品质、水分含量、水分活度(A_W)、pH、色差、硫代巴比妥酸(thiobarbituric acid reactive substance,TBARs)值、生物胺含量、亚硝酸盐残留量、N-亚硝胺含量进行测定,分析不同香辛料精油对鲶鱼肉风干肠品质及安全性的影响。结果表明:添加丁香和牛至精油可使鲶鱼肉风干肠具有较适宜的水分含量(29.4%;29.1%)和A_W(0.79;0.79);丁香、紫苏、牛至组a^*值显著高于其他组(P<0.05);6组鲶鱼肉风干肠的pH(4.98～5.16)均低于5.4,都属于高酸发酵肉制品。八角精油组鲶鱼肉风干肠TBARs值比对照组降低了66.3%;紫苏精油对鲶鱼肉风干肠亚硝酸盐清除率达到62.2%。肉桂精油和八角精油可以降低风干肠中生物胺的积累,紫苏精油和牛至精油对风干肠中N-亚硝胺的抑制率达87.56%和81.48%,很大程度上提升了风干肠...     

Characterization of Micrococcaceae isolated from Iberian dry-cured sausages

The populations of Micrococcaceae in different types of Iberian dry-cured sausages from central-west Spain were characterized and their technological and antimicrobial properties determined in order to evaluate their suitability as starter cultures in dry-cured sausage manufacture. Of a total of four hundred strains isolated from two manufacturers, one hundred and sixty-six were selected to evaluate nitrate reductase, proteolytic, lipolytic, and antimicrobial activities, and growth at different values of pH and water activity (a_w). Most of the strains were identified as Staphylococcus except for eight isolates assigned to Kocuria spp. The species most often isolated was Staphylococccus xylosus. Others were, in descending order of abundance, S. aureus, S. lugdunensis, S. saprophyticus, S. sciuri, S. chromogenes, and S. capitis. The distributions of the minority Staphylococcus species were different for the two manufacturers. All the investigated strains were able to grow at pH and a_w greater than 5.0 and 0.85, respectively, the values usually found in Iberian dry-cured sausages. Five S. xylosus strains showed antimicrobial activity against some indicator strains which were investigated. Seven strains with the best properties were pre-selected and tested for their lipolytic and proteolytic activities against pork fat and myofibrillar and sarcoplasmic pork proteins, respectively, and for their low biogenic amines production. Most of the strains showed proteolytic and lipolytic activities, but none produced histamine, tyramine, phenylethylamine, or spermine. Three strains, identified as Staphylococcus xylosus, possess useful properties which make them candidates for testing as starter cultures in pilot processing of Iberian sausages.     

燕麦复合火腿肠的感官、质构及保水特性研究

为了探索燕麦粉添加量对燕麦复合火腿肠品质特性的影响,分别对复合火腿肠进行感官评定及质构测定(质构剖面分析),并对这两种评价测定方法的结果进行相关性分析,同时也对复合火腿肠的保水特性进行测定。感官和质构测定结果表明:燕麦粉添加量为14%时,复合火腿肠具有较理想的质构,感官总体接受性好;质构测定硬度与感官评定硬度呈显著相关性(r=0.898),质构测定黏聚性与感官评定硬度、弹性呈显著相关性(r分别为-0.863和-0.825)。保水性测定结果表明:随着燕麦粉添加量的增加,复合火腿肠保水能力逐渐上升(94.33%～94.83%),当添加量达到17%以后,保水能力变化不大,增加趋势平缓,可以看出,燕麦粉的添加可能有利于提高复合火腿肠的保水性。因此,将适量的燕麦粉与肉品复合可以制作出能被消费者接受、质构和保水性很好的燕麦复合火腿肠。     

Effect of lupin seed proteins on quality characteristics of fermented sausages

Lupin seed flours (LSF) and lupin seed protein isolates (LSPI) from a sweet (S) variety of Lupinus albus and a bitter (B) variety of Lupinus albus ssp. Graecus were used in the manufacture of fermented sausages at 2% level, based on the weight of meat and pork back fat, and hydrated to a protein/water ratio 1/4, to replace beef and pork meat on a protein to protein basis. LSF and LSPI had no effect (p>0.05) on the microbial counts, the pH, the moisture content and weight losses, the instrumentally measured colour numbers (L*, a*, b*), the firmness, the appearance and the sensory evaluated colour of fermented sausages. Fermented sausages produced with LSPI from the bitter variety had similar (p>0.05) sensory attributes to the control and lower (p<0.05) TBA values after the 28th day of storage. Fermented sausages produced with LSPI from the sweet variety had acceptable sensory attributes but TBA values higher than 1 mg of malonaldehyde/kg. LSF from both varieties had a high pro-oxidant effect and affected negatively the odour and taste of fermented sausages.     

Relationship between biogenic amine contents and the size of dry fermented sausages

Three trials were carried out to study the influence of the diameter on biogenic amine contents and related parameters (pH, humidity and proteolysis) in fermented sausages. The first trial was done on three groups of Spanish dry fermented sausages with different diameter. In the second, two sections (centre and edge) of salchichón sausages were examined. The last trial consisted in the study of the ripening of two batches of sausages fermented under the same conditions but with two different diameters. Biogenic amine contents varied among the different type of products as well as among the same type of samples. Generally, amine levels in the biggest diameter sausages were higher than in the thinnest sausages. Amine contents were higher in the central part of the sausages than in the edge. During the ripening, larger tyramine amounts were formed in sausages with the biggest diameter. Statistical correlations were found among the diameter, the pH, the proteolysis and some amines. The results of the three trials agree with the hypothesis that the diameter is a factor that may affect the formation of biogenic amines during sausage fermentation.     

Utilization of cereal and fruit fibres in low fat dry fermented sausages

The effect of addition of cereal and fruit dietary fibres on the sensory properties of reduced-fat, dry fermented sausages was studied. Dry fermented sausages with 6 and 10% pork backfat were manufactured, with addition of cereal (wheat and oat) and fruit (peach, apple and orange) dietary fibres, at 1.5 and 3% concentrations. The energy value reduction of the final products was close to 35% and their final fibre contents, after ripening, were 2 and 4%, respectively. The ripening process was monitored by physico-chemical and microbiological analysis. Sensory properties were analyzed using triangular and hedonic tests and, a texture profile analysis was carried out. A correlation principal component analysis was performed. The results showed that the sensory and textural properties of batches with 3% dietary fibre were the worst, due to their hardness and cohesiveness. The best results were obtained with sausages containing 10% pork backfat and 1.5% fruit fibre especially those with orange fibre, which gave organoleptic characteristics similar to conventional high fat products. Thus, reduced fat sausages fortified with dietary fibre can be obtained with an acceptable sensory profile.     

Changes of physicochemical, microbiological, and textural properties during ripening of Italian low-acid sausages. Proteolysis, sensory and volatile profiles

In this study low-acid sausages were studied to characterize their physicochemical, microbiological, and textural properties during ripening. The final a(w) was 0.87-0.88, whereas pH values stayed around their initial values during processing. Lactic acid bacteria increased very slowly in number and a small increase of Micrococcaceae was also noticed. Low-acid sausages showed low hardness and cohesiveness, and were easily distinguishable by sensory analysis from other industrial and artisan sausages. Under the conditions of the study, observed volatile compounds were mainly from spices and wine. The respective contribution of muscle and indigenous bacterial enzymes to proteolysis was determined by comparing changes in low-acid sausages to those containing an antibiotic-antimycotic mixture or sugar. A large part of the degradation of myofibrillar proteins appeared due to endogenous enzymes, although bacterial proteinases contributed to the degradation of these proteins. The role of microorganisms in proteolysis was more evident in the degradation of sarcoplasmic proteins.     

Characterization of Staphylococcus xylosus and Staphylococcus carnosus isolated from Slovak meat products

The aims of this study were to isolate, identify and characterize the population of coagulase-negative staphylococci in different types of Slovak traditional sausages and to determine the metabolic properties of selected Staphylococcus xylosus and S. carnosus strains for the selection of potential starter cultures to use in the processing of sausages. The strains were tested for lactic acid production, survival in the presence of bile and sensitivity to antibiotics. Bacteriocin production, adhesion ability as well as biogenic amine (BA) production by isolates were also analysed. Most of the isolates were identified as S. xylosus and S. carnosus. Lactic acid values ranged from 0.40 to 1.03 mmol/l and strains survived in the presence of 1% bile. Most of the strains studied were sensitive to all antibiotics. Two strains, S. xylosus SO3/1M/1/2 and S. carnosus SO2/F/2/5 inhibited Listeria innocua and Pseudomonas sp. S. xylosus strains did not produce any BA, while S. carnosus SO2/F/2/5 did. S. xylosus SO3/1M/1/2 and S. carnosus SO2/F/2/5 appeared as the most adhesive strains. S. xylosus SO3/1M/1/2 with antimicrobial activity against Enterococcus avium EA5, L. innocua LMG13568 and Pseudomonas sp. SO1/1M/1/4, adhesion ability and free BA production could be used as starter culture in sausage manufacture.