Improvement of the Sensory Properties of Dry Fermented Sausages by the Superficial Inoculation and/or the Addition of Intracellular Extracts of Mucor racemosus

ABSTRACT: The effect of inoculation of the "salchichón" (dry fermented sausage) surface with an atoxigenic, proteolytic, and lipolytic strain of Mucor racemosus and/or the addition of a intracellular extract of the same mold on the ripening process was studied. Four batches of salchichón were manufactured: control, superficially inoculated, added with intracellular extract, and a combination of both treatments. Superficial mold modified the amino and free fatty acid contents, volatile compounds, and sensory properties. Intracellular extract degraded free amino acids, producing a rise in ammonia and volatile compounds. Both treatments combined improved significantly the sensory properties, which were given scores higher than control sausages at the end of ripening.     

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.     

Microbial and physico-chemical changes during the ripening of dry fermented sausages superficially inoculated with or having added an intracellular cell-free extract of Penicillium aurantiogriseum

The effect of inoculation of the "salchichón" (dry fermented sausage) surface with an atoxygenic, proteolytic and lipolytic strain of Penicillium aurantiogriseum and/or the addition of an intracellular cell-free-extract (ICFE) of the same mould on the ripening process was studied. Four batches of salchichón were manufactured: control, superficially inoculated, added with the intracellular cell free extract and combination of both treatments. Superficial mould modified Micrococcaceae counts, pH, free amino acids, lipid fractions, TBARS and some organic acids. The ICFE degraded free amino acids, producing a rise in ammonia. Both treatments combined accelerate the proteolysis and lipolysis of the sausages and also the further amino acid degradation.     

Use of Lactococcus lactis subsp. cremoris NCDO 763 and α-ketoglutarate to improve the sensory quality of dry fermented sausages

The aim of the present work was to enhance the degradation of free amino acids in dry fermented sausages as precursors of volatile compounds responsible for the ripened flavour. For this purpose, Lactococcus lactis subsp. cremoris NCDO 763, its intracellular cell free extract (ICFE) and α-ketoglutarate were added to sausages. Papain was also used to increase the amount of free amino acids. When L. lactis was inoculated in sausages, an increase in the proteolytic phenomena was observed. The addition of α-ketoglutarate increased transamination phenomena in batches where it was added. The enhancement of these phenomena determined a noticeable rise in the content of glutamic acid (the main final product in transamination reactions) and a decrease, among other amino acids, of valine and leucine, with the formation of high amounts of their derivatives 2-methylpropanal and 3-methylbutanal. These aldehydes are responsible for the ripened flavour of dry fermented sausages. Sensory analysis showed an improvement of odour and flavour when L. lactis and α-ketoglutarate were combined. On the other hand, the intracellular cell free extract of L. lactis did not show any important activity in relation to amino acid breakdown even when used together with α-ketoglutarate and/or papain.     

Volatile compound generation in dry fermented sausages by the surface inoculation of selected mould species

The effect of the inoculation of dry fermented sausage surface with an atoxigenic, proteolytic and lipolytic strain of Mucor racemosus, Penicillium aurantiogriseum and Penicillium camemberti on the volatile composition was studied. The analysis of the headspace volatile compounds using gas chromatography/mass spectrometry enabled the identification of 55 volatiles. The study showed that every mould species produced a different volatile profile which was also different from that of the control sausages. Compounds derived from amino acid catabolism, i.e. branched aldehydes and the corresponding alcohols, were produced in higher amounts in sausages inoculated with Penicillium spp. On the other hand, volatiles coming from the microbial esterification were related to sausages inoculated with M. racemosus. The development of the fungal mycelia on the sausage surface protected lipids from oxidation, thus giving rise to fewer lipid oxidation products in the inoculated sausages.     

Effect of autochthonous starter cultures isolated from Siahmazgi cheese on physicochemical,microbiological and volatile compound profiles and sensorial attributes of sucuk,a Turkish dry-fermented sausage

The effect of adding autochthonous starter cultures isolated from Siahmazgi cheese, on the physicochemical parameters and microbial counts of sucuk was investigated during the ripening period. SPME–GC/MS was used in volatile compound analysis and a trained group of panelists carried out sensory analysis of the final product. After preliminary screening, three strains of Lactobacillus plantarum, which possess desirable technological properties, were used to prepare three starter cultures: LBP7, LBP10 and LBP14. The addition of LBP7 and LBP14 starter cultures had a significant effect (P < 0.05) on lightness, leading to higher L values compared to control sausages during the ripening period. Both LBP7 and LBP14 sausages showed higher counts of lactic acid bacteria, lower growth of Enterobacteriaceae and Gram-positive catalase-positive cocci and greatly lowered the pH value compared to control sausages throughout the ripening process. At the end of the ripening process, lactic acid bacteria counts were affected (P < 0.05) by the addition of starter culture since higher counts were observed in sausages prepared with LBP7 (9.14 log CFU/g) and LBP14 (8.96 log CFU/g) batches. The decrease of water activity during the ripening of sausages was not affected by the various starters. The texture profiles of all sausages were similar except for LBP10, which showed lower hardness and gumminess during ripening. Under the conditions of the study, volatile compounds were mainly from spices, and no marked differences were found among inoculated sausages. However, sensory evaluation revealed that most of the sensory attributes were scored higher for inoculated sausages than for the control ones. Therefore, LBP7 and LBP14 could be promising candidates for inclusion as starter cultures for the manufacture of sucuk.     

脂肪添加量对发酵香肠脂质和蛋白质氧化及挥发性化合物形成的影响

通过研究不同脂肪添加量（5%、10%、15%和20%）的香肠在发酵过程中脂质和蛋白质的氧化水平,并对发酵前后的挥发性化合物进行分析,最后对香肠进行感官评价。结果表明,随着脂肪添加量的增加,硫代巴比妥酸值显著增加,肌原纤维蛋白的羰基含量增加,总巯基含量降低（P＜0.05）,说明增加脂肪添加量会促进发酵香肠中脂肪和蛋白质的氧化;挥发性化合物分析可知,脂肪添加量较高的发酵香肠,因脂质自动氧化产生的醛、酮、酸、醇、酯和烷烃类化合物含量也相应增加（P＜0.05）;感官评价结果表明,脂肪添加量为15%的发酵香肠,其整体可接受性最佳（P＜0.05）。     

Enhancement of the flavour development of dry fermented sausages by using a protease (Pronase E) and a cell‐free extract of Penicillium camemberti

The present work was an attempt to improve the organoleptic properties of dry fermented sausages by enhancing the release of amino acids and their further transformation into ammonia, ketoacids and some volatile compounds responsible for the ripened flavour. For this purpose a protease (Pronase E from Streptomyces griseus) and a cell‐free extract (CFE) of a Penicillium camemberti strain selected for its L ‐amino‐oxidase activity were used. The addition of Pronase E alone led to a large increase in the content of free amino acids. The CFE showed deaminative activity, which gave rise to the accumulation of some important volatile compounds such as 2‐methylpropanal and 2‐ and 3‐methylbutanal. Organoleptic analysis reflected an improvement in the quality of the sausages, especially when the two treatments were combined. © 2002 Society of Chemical Industry     

Use of bacterial extracts to enhance amino acid breakdown in dry fermented sausages

The effect of the intracellular cell-free extracts (ICFEs) of two bacterial strains (Lactobacillus sakei GO and Bacillus pumilus) on the amino acid catabolism and the sensory properties of dry fermented sausages, was investigated. Extracts were added to sausages alone or in combination with a protease, papain. Amino acid breakdown was monitored by the changes in free amino acids, ammonia and amine content during the ripening process. A 15% decrease in the content of free amino acids was observed in sausages added with the ICFE from L. sakei GO. Furthermore, the extract of L. sakei GO significantly reduced (54-68%) the content of the amino acids considered as precursors of the typical ripened flavour, i.e., valine, leucine and isoleucine. Chemical changes were not reflected in a significant improvement of the sensory quality of sausages added with the ICFEs. The potential use of the bacterial ICFEs studied in the present work for the manufacture of dry fermented sausages, and its comparison with the use of fungal extracts, are discussed.     

Impact of Debaryomyces hansenii strains inoculation on the quality of slow dry-cured fermented sausages

Debaryomyces hansenii strains, M4 and P2, isolated from natural fermented sausages were inoculated in slow fermented sausages to study their effect on processing parameters, microbial population, volatile compound and sensory characteristics. The inoculation of D. hansenii strains, M4 and P2, did not affect the ripening process as no differences in pH and Aw were detected. The dominance of the inoculated yeast strains along the process was followed by RAPDs of M13 minisatellite. The inoculated yeasts, P2 and M4, were recovered at the end of the ripening process although P2 appeared in higher counts than M4. The sausages inoculated with P2 resulted in a decrease in lipid oxidation values (TBARS) and a reduction of lipid-oxidation derived aldehydes in addition to a highest acid compound abundance. M4 inoculated sausages resulted in highest sulphur containing compound abundance. However, no differences in consumer acceptance were detected. Moreover, both yeast strains were responsible for the generation of ethyl methyl-branched ester compounds in the dry-cured sausages.     

Contribution of enterococci to the volatile profile of slightly-fermented sausages

The volatile profiles of slightly-fermented sausages inoculated with eight different enterococci strains were determined and compared with a fermented sausage manufactured without any inoculation. The volatile profile was determined by solid-phase microextraction (SPME) and gas chromatography coupled to mass spectrometry (GC/MS). A total of 121 volatile and semi-volatile compounds were identified in the samples of the final products (day 21). Terpenes from spices added during manufacture of dry-fermented sausages were the main group of compounds in the volatile profile. Other groups included alcohols (18% of total volatile compounds), aldehydes (16%), alkanes and alkenes (12%), and ketones (10%). These are derived from lipids, proteins or carbohydrates and formed during fermentation and ripening. In terms of global volatile composition, the batches inoculated with enterococci strains were similar to those obtained for non-inoculated batch. However, some quantitative differences in the volatile profiles of different batches were found, mainly in the compounds formed from amino acid catabolism (i.e.: propanol, isoamyl), from free fatty acid oxidation (i.e.: hexanal, hexanol), or from carbohydrate fermentation (i.e.: 2-butanone, acetoin). In comparison with non-inoculated sausages, some batches were more resistant to oxidation; they contained fewer volatile compounds arising from lipid oxidation. The use of different selected enterococci strains did not alter the volatile profile of slightly-fermented sausages. The enterococci strains provide similar volatile compounds to those usually reported in the literature.     

Effects of muscle shortening and proteolysis on Warner-Bratzler shear force in beef longissimus and semitendinosus

The effect of the addition of the fungal protease EPg222 on the sensory characteristics of dry fermented sausage "salchichón" ripened with commercial starter cultures was investigated. Sausages were prepared with purified EPg222 and Staphylococcus carnosus, Staphylococcus xylosus, and Lactobacillus sakei as starter cultures, ripened for 145 days and compared with a control batch only inoculated with the starter cultures. Dry fermented sausages ripened with EPg222 and starter cultures showed higher amount of NPN and volatile compounds derived from amino acid catabolism, than control ripened only with starter cultures. Several branched aldehydes, acids and alcohols such as 2- and 3-methylbutanoic acid and 2-methylpropanol were detected only in enzyme treated samples. Sensory analysis reflected higher values for aroma intensity of sausages treated with EPg222 and lower values of hardness than control. The effect of EPg222 may be of great interest to improve sensory characteristics of dry fermented sausages ripened with starter cultures.     

桑椹多酚对广式腊肠风味的影响

植物多酚因能有效抑制肉制品的过氧化近年来备受关注,然而由此造成肉制品风味的变化还鲜有报道。鉴于此,将不同剂量的桑椹多酚提取物（0.5 g/kg和1.0 g/kg）加入到肉糜中,制成广式腊肠,分析多酚添加前后广式腊肠的挥发性风味、游离脂肪酸、游离氨基酸的组成和含量变化,以及桑椹多酚对广式腊肠感官评价的影响。研究发现,添加桑椹多酚后,腊肠中挥发性风味物质由空白组的49种减少到32种,腊肠游离脂肪酸的含量明显下降。值得注意的是,由于蛋白质水解增强,添加桑椹多酚后,腊肠中呈味氨基酸（Glu和Arg）的释放得到促进。储藏末期（10 d）,添加1.0 g/kg桑椹多酚的腊肠游离氨基酸的含量达到5904.91 mg/100 g,较对照组提高了10.82%。总体而言,桑椹多酚的添加会抑制腊肠中某些挥发性风味物质的形成,抑制腊肠中的肉腥味,促进呈味氨基酸的释放,但对腊肠游离脂肪酸组成的影响并不显著。     

Effect of Penicillium roqueforti and incorporation of whey cheese on volatile profiles and sensory characteristics of mould‐ripened Civil cheese

In this study, four different types of mould‐ripened Civil cheese were manufactured. A defined (nontoxigenic) strain of a Penicillium roqueforti (SC 509) was used as secondary starter for the manufacture of mould‐ripened Civil cheese with and without addition of the whey cheese Lor; in parallel, secondary starter‐free counterparts were manufactured. A total of 83 compounds were identified. Ketones, alcohols and esters were the principal classes of volatile components. Principal component analysis of the headspace volatiles grouped cheeses by age and type. P. roqueforti inoculated cheese was clearly separated from the other cheeses at 180 days of ripening, and these cheeses were characterised with high levels of ketones (e.g., 2‐butanone, 2‐heptanone). Differences in the panel scores between the cheese samples were not significant during the first stage of ripening (up to 60 days); as ripening proceeded, these differences were become evident and P. roqueforti inoculated cheeses received higher scores than others. Addition of Lor in the manufacture of mould‐ripened Civil cheese caused lower points by the sensory panel, and the cheese inoculated with P. roqueforti and Lor‐free was the best type of mould‐ripened Civil cheese. The results showed that the use of P. roqueforti in the manufacture of mould‐ripened Civil cheese has significant impact on the volatile profiles and sensory attributes.     

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.     

Contribution of a selected fungal population to proteolysis on dry-cured ham

The proteolytic changes taking place in dry-cured hams lead to increases in free amino acids. Such free amino acids not only contribute to flavour, but also serve as precursors of volatile compounds. Several months of ripening time are required to allow the particular flavour to develop. The fungal population allowed to grow on the surface of some types of dry-cured could play a key role on proteolysis, as it has been shown for dry-cured sausages. The purpose of this work was to study the possible contribution of fungi to proteolysis in dry-cured ham. For this, a strain each of non-toxigenic Penicillium chrysogenum (Pg222) and Debaryomyces hansenii (Dh345), selected for their proteolytic activity on myofibrillar proteins, were inoculated as starter cultures. Changes in the high ionic strength-soluble proteins of an external muscle (adductor) revealed in only 6 months higher proteolysis in the inoculated hams when compared to non-inoculated control hams. Proteolytic strains among the wild fungal population on non-inoculated control hams prevented from obtaining similar differences at the end of processing. However, inoculation with Pg222 and Dh345 led to higher levels for most free amino acids at the external muscle in fully dry-cured hams. In addition, the concentration for some of the more polar free amino acids (i.e. Asp, Glu, Ser and Gln) in inoculated hams was higher at external than at internal (biceps femoris) muscles. These promising results deserve further studies to know the impact of a selected fungal population on the volatile compounds and sensory properties of dry-cured ham.     

Maturity Acceleration of Italian Dried Sausage by Staphylococcus carnosus—Relationship Between Maturity and Flavor Compounds

ABSTRACT: The mature flavor of Salame Milano, an Italian dried sausage, was increased in two ways: by increasing maturation time or with a strain of Staphylococcus carnosus. The sensory and volatile profiles of the sausages were determined and the data analyzed by analysis of variance and chemometrics. Sausages with S. carnosus 833 matured more than 2 wk faster than control sausages. Maturity correlated significantly with higher amounts of branched-chain aldehydes and alcohols and both branched- and straight-chain methyl ketones—compounds arising from the breakdown of the amino acids leucine, isoleucine, and valine, or from microbial β-oxidation of fatty acids. Also, sulfur compounds arising from added garlic correlated positively with mature flavor.     

The effect of yeast extract addition on quality of fermented sausages at low NaCl content

Fermented sausages with 25% or 50% of their NaCl replaced by KCl and supplemented with 1% or 2% concentrations of yeast extract were produced. The sausage production process was monitored with physical, chemical and microbiological analyses. After production, the sausage samples were submitted to a consumer study and their volatile compounds were extracted by solid-phase microextraction and analyzed by GC-MS. The replacement of NaCl by KCl did not significantly influence the physical, chemical or microbiological characteristics. The sensory quality of the fermented sausages with a 50% replacement was poor compared with the full-salt control samples. The use of yeast extract at a 2% concentration increased volatile compounds that arose from amino acids and carbohydrate catabolism. These compounds contributed to the suppression of the sensory-quality defects caused by the KCl introduction, thus enabling the production of safe fermented sausages that have acceptable sensory qualities with half as much sodium content.     

NaCl添加量对发酵牦牛肉灌肠成熟过程中理化品质及挥发性风味物质的影响

研究添加0.0％、1.5％、3.0％、4.5％NaCl的发酵牦牛肉灌肠成熟过程中理化性质、菌落总数以及挥发性风味物质的变化.结果表明,NaCl添加量4.5％的发酵牦牛肉灌肠pH值和亮度值显著高于其余3组(P＜0.05);随着NaCl添加量的减少,硬度、胶着性、咀嚼性呈下降趋势,而储能模量、菌落总数呈上升趋势;此外,Na...     

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.