Distribution of volatile compounds in lean and subcutaneous fat tissues during processing of dry fermented sausages

The distribution of volatile compound among lean and fat tissues during processing of dry fermented sausages manufactured with either nitrite or nitrate was studied. Twelve volatile compounds were quantified by multiple headspace solid-phase microextraction (multiple HS-SPME) in combination with gas chromatography and mass selective detector (GC–MS) in the lean and fat tissues. The lean tissue contained the highest amount of volatile compounds derived from the lipid oxidation process (heptanal, octanal, nonanal, 1-octen-3-ol, 2-pentanone and 2-heptanone), amino acid degradation reactions (2 and 3-methylbutanal) and esterase activity (ethyl 3-methylbutanoate and ethyl hexanoate). However, the compounds pentanal and hexanal showed similar concentration in both tissues. Few differences were observed in the concentration of volatile compounds due to curing agents throughout the ripening stages although they disappeared after vacuum storage. In conclusion, the main tissue contributing to the flavour development in sausages is the intramuscular fat and the protein fraction. However, the fat tissue contributes to flavour perception due to the solubilization of volatile compounds in it.     

Characterization of the headspace volatile compounds of selected Spanish dry fermented sausages

The volatile profile of three different Spanish dry fermented sausages (`salchichón', `fuet' and `chorizo') was studied using dynamic capillary gas–liquid chromatography/mass spectrometry (GC–MS) headspace analysis. Complex mixtures of esters, ketones, alcohols, aldehydes and terpenes characterized retail samples of each of these products. Esters were dominant components of the volatile compounds from one type of salchichón (salchichón 2), terpenes of the other type (salchichón 1) and of one type of fuet (fuet 2). Common to both types of fuet was a number of ketones and alcohols. `Chorizo' had similar high numbers of esters as `salchichón 2' but also had three sulphur-containing compounds which are known components of garlic and are used as an ingredient in chorizo.     

Vacuum-packed ripened sausages: evolution of volatile compounds during storage

BACKGROUND: Various studies have shown the ability of volatile compounds to influence the quality of charcuterie products because of their effect on sensorial properties. To the best of our knowledge, there are no data in the scientific literature concerning the evolution of volatile compounds of vacuum‐packed ripened sausages over time. The aim of this work was to evaluate the evolution of volatile compounds in vacuum‐packed ripened sausages over time, considering that this kind of packaging is the most commonly used to prolong the shelf‐life of these products. RESULTS: Sixty‐nine volatile compounds were identified. Those derived from spices represented the prevailing compounds at the beginning of storage and significantly decreased (P < 0.001) during 5 months of storage, as a result of the well‐known antioxidant activity. Conversely, compounds derived from the autoxidation of lipids, which are among those chiefly responsible of sensorial properties of meat products, significantly increased (P < 0.001). CONCLUSION: The research demonstrated that vacuum packaging influenced the evolution of volatile compounds during storage of ripened sausages. In particular, the increase of volatile compounds derived from autoxidation of the lipid fraction indicated that oxidative processes involved the fatty fraction of ripened sausages also in the scarcity of oxygen. Copyright © 2011 Society of Chemical Industry     

Establishment of the contribution of volatile compounds to the aroma of fermented sausages at different stages of processing and storage

The generation of aroma compounds through the curing process of dry fermented sausages was studied. The most important aroma compounds were determined using their odour-activity values (OAVs). The compound quantification in the headspace (HS) was carried out by solid phase microextraction (SPME) and the total concentration in the sausage by multiple headspace SPME (multiple HS-SPME) using gas chromatography and mass spectrometry. The main compounds that contributed to the aroma of dry fermented sausages were those with the highest oil OAVs such as 3-methyl butanal, 2-methyl butanal, octanal, diacetyl and ethyl 2-methyl butanoate that were important from the beginning of the process. Other compounds were important contributors as they were generated at the end of process, including propanal, pentanal, hexanal, ethyl 3-methyl butanoate, 1-octen-3-ol, 3-methyl butanoic acid, 2-methyl propanoic acid, ethyl hexanoate and nonanal. However, the aroma perceived in the HS was due to compounds with the highest air OAVs such as 3-methyl butanoic acid, ethyl 2-methyl butanoate, nonanal and octanal. In many cases, the percentage of the aroma compound released to the HS was around 10–20% of the total concentration in the sausage.     

Effect of fat content on aroma generation during processing of dry fermented sausages

Dry fermented sausages with different fat contents were produced (10%, 20% and 30%). The effect of fat content and ripening time on sensory characteristics, lipolysis, lipid oxidation and volatile compounds generation was studied. Also, the key aroma components were identified using gas chromatography (GC) and olfactometry. High fat sausages showed the highest lipolysis and lipid oxidation, determined by free fatty acid content and thiobarbituric acid reactive substances (TBARS), respectively. A total of 95 volatile compounds were identified using SPME, GC and mass spectrometry (MS). Fat reduction decreased the generation of lipid derived volatile compounds during processing while those generated from bacterial metabolism increased, although only at the first stages of processing. The consumers preference in aroma and overall quality of high and medium fat sausages was related to the aroma compounds hexanal, 2-nonenal, 2,4-nonadienal, ethyl butanoate and 1-octen-3-ol which contributed green, medicinal, tallowy, fruity and mushroom notes.     

微生物发酵剂对发酵香肠中挥发性成分的影响

采用固相微萃取技术结合GC/MS,以壬烷作内标进行定性和半定量,分析自然发酵和添加发酵剂生产的两组发酵香肠的挥发性成分,共鉴定出39种挥发性成分。其中自然发酵组鉴定出35种,总含量为9.486μg等量壬烷/g发酵香肠;添加发酵剂组鉴定出32种,总含量为18.313μg等量壬烷/g发酵香肠。自然发酵香肠主要挥发性成分由萜烯类(27.71%)、酸类(26.42%)和酯类(25.32%)组成;在添加发酵剂组中,最重要的组成是酯类(42.10%),其次为酸类(26.52%)和萜烯类(18.07%)。     

Stability of linseed oil and antioxidants containing dry fermented sausages: A study of the lipid fraction during different storage conditions

Different packaging conditions (aerobic, vacuum and modified atmosphere) were evaluated in order to study the stability of the lipid fraction of dry fermented sausages manufactured with a partial substitution of pork backfat by linseed oil and antioxidants. After 5 months of storage, α-linolenic acid was better preserved by vacuum and MAP (7.32 and 7.74g/100g fatty acids, respectively) than in aerobic conditions (6.15g/100g fatty acids), without significant differences to values obtained after 2 months of storage for this acid. At the end of the storage, (n-6)/(n-3) fraction in sausages with linseed oil was in all cases lower than 3, in contrast to values obtained for control products that were all higher than 15. Better PUFA/SFA ratios were also observed in modified sausages (0.6-0.7g/100g fatty acids) than control ones (0.3-0.4g/100g fatty acids). No signs of lipid oxidation measured by TBARs and peroxides were detected for modified sausages regardless the packaging system used (TBARs values lower than 0.25ppm and peroxides lower than 4meq O(2)/kg), pointing at a high effectiveness of the antioxidants. Furthermore, vacuum and MAP prevented 2,4-decadienal formation. Nutritional benefits of linseed oil and antioxidants containing products were maintained after 5 months of storage.     

羊肉发酵干香肠在成熟和贮藏过程中感官指标的变化及其相关性

试验通过接种复合发酵剂和添加天然香辛料,采用相同的工艺条件生产4组羊肉发酵香肠,1组为对照组(CO),2组为接种发酵剂组(SC),3组为发酵剂+黑胡椒组(SC+BP),4组为发酵剂+黑胡椒+孜然组(SC+BP+C)。采集成熟后(第7天)及贮藏过程(第14天、第21天和第35天)各组发酵香肠进行感官评价,结果建立了色泽、风味、组织状态和滋味与整体可接受性之间的线性模型公式为Y=0.08X1+0.147X2+0.222X3+0.836X4(R2=0.999),感官特性权重依次为滋味>组织状态>风味>色泽,说明滋味对产品的品质具有决定性作用。发酵剂+黑胡椒(SC+BP)组和发酵剂+黑胡椒+孜然(SC+BP+C)组的色泽评分由于添加黑胡椒的原因,其色泽评分在成熟和贮藏期间一直低于对照组。试验发酵剂组(SC)的羊肉发酵香肠在贮藏2周(第21天)时,各项感官评分均明显高于对照组,而且试验组的膻味评分在贮藏过程中明显低于对照组,说明接种复合发酵剂对羊肉发酵香肠感官品质的提高有一定的作用。     

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 相似文献   

Lysine, disodium guanylate and disodium inosinate as flavor enhancers in low-sodium fermented sausages

Fermented sausages were produced with 50% replacement of NaCl with KCl and with addition of lysine, disodium guanylate, and disodium inosinate. The sausage production was monitored with physical, chemical and microbiological analyses. The final products were submitted to a consumer study. The replacement of NaCl with KCl did not cause changes in the technological process. However, defects in the sensory quality were detected. Lysine at a concentration of 1% with disodium inosinate (300 mg/kg) and disodium guanylate (300 mg/kg) reduced the sensory defects caused by the replacement of 50% NaCl with KCl allowing the preparation of sensory acceptable fermented sausages with a 50% decrease in sodium.     

复合发酵剂和黑胡椒对羊肉发酵干香肠挥发性风味成分的影响

以内蒙古羊肉和羊尾脂肪为原料,接种复合发酵剂和黑胡椒生产羊肉发酵干香肠,利用动态顶空制样（DHS）/吹扫捕集（P＆T）技术结合气-质联机（GC-MS）,分析鉴定了羊肉发酵干香肠在成熟后挥发性风味成分的变化情况,结果检出了52种挥发性风味成分,主要由醛类、酮类、酸类、醇类、萜类、烷烃类、酯类、芳烃类、呋喃类和含氮化合物等十类化合物组成,种类数最多的是烷烃类（10种）,占总种类数的19.23%,其次是萜类（9种）。同时检出了来源于脂肪水解氧化和氨基酸的Strecker降解以及碳水化合物代谢产生的戊醛、3-甲基丁醛、3-羟基-2-丁酮等关键芳香化合物以及来源于黑胡椒的3-蒈烯和D-柠檬精油等,这些成分对羊肉发酵干香肠的风味有重要贡献。     

Characterization of volatile compounds in a fermented and dried fish product during cold storage

ABSTRACT:  The northern European production technique for dry-cured meat sausages was used to produce a sliceable, fermented, and dried fish product rich in omega-3 polyunsaturated fatty acids (PUFA). The fatty fish Atlantic salmon ( Salmo salar) , the lean fish saithe ( Pollachius virens ) (1:1, w/w), Lactobacillus sakei , and 4 different milk protein-based ingredients were used in the recipes. The changes in the volatile compounds during cold storage (+4 °C) of vacuum-packed dried sausages were studied by dynamic headspace gas chromatography-mass spectrometer (GC-MS). Of  the 117 volatile compounds identified, alcohols, alkanes, esters, aldehydes, ketones, and compounds derived from amino acids were the most prevalent groups of volatiles. Thirty volatiles decreased and 17 increased significantly ( P < 0.1) during storage for 15 wk. Despite the high content of PUFA, amino acid catabolism and ester synthesis led to larger changes in the composition of volatiles in the fish product than did lipid oxidation reactions. The milk-protein-based powders that were used to physically stabilize the fish oil did not affect the lipid oxidation compounds.     

自然发酵风干肠生产过程中微生物变化及理化性质的分析

以自然发酵风干肠为研究对象,分析了生产过程中微生物数量和理化指标的变化。微生物方面,按总菌数、乳酸菌、葡萄球菌和酵母菌几个大类研究各自的变化以及相互之间的作用关系;理化方面,分析了pH值、水分含量、水分活度及总氮含量几个重要指标,并阐述了各个理化指标之间及其与微生物变化的关系。     

罐罐肉加工与贮藏过程中挥发性物质变化的研究

为了探明雅安罐罐肉挥发性物质的变化规律,本研究以不同加工与贮藏阶段的罐罐肉为对象,用同时蒸馏萃取结合气相色谱/质谱法对挥发性化合物进行分析。结果显示,罐罐肉在加工与贮藏过程中共检测出120种挥发性物质,醇、醛、酮、烃、酰胺、酯是主要成分,其中以己醛和2,4-癸二烯醛为主的醛类物质相对含量最高（最高达64.42%）。在加工过程中醛、酮、酯显著增加,并检测出酰胺类物质。在贮藏过程中醇、醛、酮的相对含量整体呈现下降趋势,烃类、酰胺类、酯类和其他化合物的相对含量整体呈上升趋势,并新产生了（2E）-2-十一碳烯醛、甲酸己酯、（Z）-9-十八烯酸酰胺和2-戊基呋喃等物质。      

Stability of phenolic compounds in dry fermented sausages added with cocoa and grape seed extracts

The level of eleven target phenolic compounds was evaluated in dry fermented sausages added with vegetable extracts. Grape seed (GSE1 and GSE2) and cocoa extracts, rich in phenolic compounds, were added in the formulation of dry fermented sausages (“salchichón” and “fuet”). Evolution of the major monomeric and oligomeric phenolic compounds of these extracts was evaluated during sausage shelf life by UHPLC-MS/MS. Kind of sausage did not affect significantly overall stability of the target compounds. At the end of the ageing process, catechin and epicatechin were at 54–61%, gallic acid and galloylated flavan-3-ols at 59–91%, oligomeric flavan-3-ols at 72–95% and glycosylated flavonols at 56–88% (in cocoa treatment) and 82–94% (in GSE treatment) of the contents that were added to the meat batter. All phenolic compounds levels did not decrease further significantly after ageing until the end of shelf life. Sensory analyses showed no important differences between control and cocoa added products, while grape seed addition gave these products abnormal sensory profiles. The 0.5% (w/w) addition of vegetal extracts was suitable to enrich dry fermented sausages with health-beneficial polyphenols.     

Influence of hygienic quality of raw materials on biogenic amine production during ripening and storage of dry fermented sausages

The effect of the hygienic status of raw materials on biogenic amine production during ripening and storage (at 4 and 15 degrees C) of fermented sausages was studied. Two portions of fresh lean and back fat pork were stored for 5 days at -20 degrees C (treatment A) and at 4 degrees C (treatment B), respectively. Raw materials of treatment A maintained their hygienic quality high and low amine content. Raw materials of treatment B showed from 1 to 3 log (CFU/g) higher microbial counts and a biogenic amine index near 50 mg/kg, indicating poorer hygienic quality. The quality of raw materials influenced the composition and the concentration of biogenic amines produced during the ripening sausages. Sausages of treatment A (A-sausages) showed a large accumulation of tyramine (up to 100 mg/kg dm) followed by putrescine and cadaverine (<15 mg/kg). In contrast, B-sausages resulted in earlier and much greater amine production, and cadaverine, tyramine, and putrescine levels were 50-, 2.6-, and 6.5-fold higher than those of A-sausages. Other biogenic amines, such as octopamine, tryptamine, phenylethylamine, and histamine were also produced in B-sausages. The higher proteolysis and the lower pH of B-sausages might have favored the decarboxylase activity of microorganisms. Biogenic amine contents of sausages during storage depended on the raw materials used and storage temperature. No significant modification on the amine contents was observed during the storage of A-sausages at either temperature. Greater changes occurred in B-sausages stored at 15 degrees C than in those stored at 4 degrees C. Higher temperatures favored proteolytic and decarboxylase reactions, resulting in increased amine concentrations after storage.     

Traditional dry fermented sausages produced in small-scale processing units in Mediterranean countries and Slovakia. 1: Microbial ecosystems of processing environments

Microbial ecosystems were surveyed in 314 environmental samples from 54 Southern and Eastern European small-scale processing units (PUs) manufacturing traditional dry fermented sausages. The residual microflora contaminating the surfaces and the equipment were analysed after cleaning and disinfection procedures. All the PU environments were colonised at various levels by spoilage and technological microflora with excessive contamination levels in some of the PUs. Sporadic contamination by pathogenic microflora was recorded. Salmonella and Listeria monocytogenes were detected in 4.8% and 6.7% of the samples, respectively, and Staphylococcus aureus was enumerated in 6.1% of the samples. Several critical points were identified, such as the machines for S. aureus and the tables and the knives for L. monocytogenes; this knowledge is crucial for the improvement of hygiene control systems in small and traditional meat processing industries. The variability of the residual contamination emphasized the different cleaning, disinfecting and manufacturing practices routinely followed by these small-scale processing units.     

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.     

Konjac gel as pork backfat replacer in dry fermented sausages: processing and quality characteristics

The effect of replacing animal fat (0%, 50% and 80% of pork backfat) by an equal proportion of konjac gel, on processing and quality characteristics of reduced and low-fat dry fermented sausage was studied. Weight loss, pH, and water activity of the sausage were affected (P<0.05) by fat reduction and processing time. Low lipid oxidation levels were observed during processing time irrespective of the dry sausage formulation. The fat content for normal-fat (NF), reduced-fat (RF) and low-fat (LF) sausages was 29.96%, 19.69% and 13.79%, respectively. This means an energy reduction of about 14.8% for RF and 24.5% for LF. As the fat content decreases there is an increase (P<0.05) in hardness and chewiness and a decrease (P<0.05) in cohesiveness. No differences were appreciated (P>0.05) in the presence of microorganisms as a result of the reformulation. The sensory panel considered that NF and RF products had acceptable sensory characteristics.