Dry-fermented sausages are a good source of bioactive peptides,whose stability against gastrointestinal(GI)digestion determines their bioaccessibility.This study focused on evaluating the effect of peptide extracts fr...Dry-fermented sausages are a good source of bioactive peptides,whose stability against gastrointestinal(GI)digestion determines their bioaccessibility.This study focused on evaluating the effect of peptide extracts from sausages fermented with Staphylococcus simulans QB7 during in vitro simulated GI digestion,including peptide profiles and antioxidant and anti-inflammatory activities.Peptides present in sausages were degraded during digestion,with molecular weight reduced from>12 kDa to<1.5 kDa.Besides,the content of amino acids increased from 381.15 to 527.07 mg/g,especially tyrosine being found only after GI digestion.The anti-inflammatory activities were increased after GI digestion,however,the changes in antioxidant activities were the opposite.A total number of 255,252 and 386 peptide sequences were identified in undigested,peptic-digested and GI-digested samples,respectively.PeptideRanker,BIOPEP-UWM and admetSAR were used to further predict the functional properties and intestinal absorption of the identified peptide sequences from GI digestion.Finally,18 peptides were discovered to possess either antioxidant or anti-inflammatory capacities.展开更多
The objective of this study was to explore the effects of the inoculation of mixed starter cultures of Lactobacillus and Staphylococcus(labeled L-S)on microbial community and flavor in fermented sausages during the ri...The objective of this study was to explore the effects of the inoculation of mixed starter cultures of Lactobacillus and Staphylococcus(labeled L-S)on microbial community and flavor in fermented sausages during the ripening process.Culture-dependent(colony count)and culture-independent(high-throughput sequencing)methods were employed to evaluate bacterial communities.Volatile compounds were identified by gas chromatography-mass spectrometry,and the results were analyzed by principal component analysis(PCA).The identified bacteria with high relative abundance included Lactobacillus and Pediococcus,and the relative abundances of Leuconostoc and Weissella in fermented sausages were remarkably decreased at the end of the ripening process.At the end of ripening,2-nonenal,tetradecanal,ethylstearate and terpinyl acetate played substantial roles in the flavor development of the L-S fermented sausages.Sensory evaluation showed a high score in the L-S fermented sausages.Sausages can be inoculated with L-S starter culture to improve the safety and flavor of meat products.展开更多
[Objective] This study aimed to develop pumpkin sausage. [Method] The single-factor design and orthogonal design were adopted. In the traditional sausage,fresh pumpkin was added. Based on the results of sensory test a...[Objective] This study aimed to develop pumpkin sausage. [Method] The single-factor design and orthogonal design were adopted. In the traditional sausage,fresh pumpkin was added. Based on the results of sensory test and physical and chemical indexes determination, the optimum recipe for pumpkin sausage was determined. [Result] The optimum recipe for pumpkin sausage was as follows: 100% of pork(fat to lean ratio of 2∶8), 45% of pumpkin particles, 6% of soy protein, 7% of sugar, 3.5% of salt, 1% of spice and 0.5% of monascus red pigment. [Conclusion]The successful preparation of pumpkin sausage will provide consumers with nutrition, health and snack meat product with comprehensive nutrition and unique flavor.展开更多
This paper was designed to verify the influence of phosphate on water-holding capacity (WHC) and texture of emulsiontype sausage prepared with pre-rigor meat, ageing meat or frozen meat. Pre-rigor pork, ageing pork ...This paper was designed to verify the influence of phosphate on water-holding capacity (WHC) and texture of emulsiontype sausage prepared with pre-rigor meat, ageing meat or frozen meat. Pre-rigor pork, ageing pork and frozen pork were pre-blended with five levels of phosphate and made into emulsion-type sausage. The yield, hardness and total expressible fluid (TEF) were measured with texture profile analysis machine and pressiometer when emulsion-type sausage was produced. Meanwhile, hardness and purge loss (PL) were measured during 30 d storage. As emusion-type sausage made by pre-rigor meat, higher yield and relatively stable hardness could be found. It indicated that increasing of phosphate level caused an alleviatable effects in increasing of hardness when emulsion-type sausage made by pre-rigor meat, but opposite effects made by ageing meat or frozen meat. The distribution of PL of emulsion-type sausage was found to be affected by phosphate addition. Significant decrease of PL could not be obtained by increasing of phosphate level during storage. Pre-rigor meat improved WHC and texture of emulsion-type sausage. Problem of WHC and texture of emulsiontype sausage during storage could not be resolved by single use of phosphate at relatively higher level (3%) of NaCl.展开更多
A three-dimensional (3-D) transient model has been developed to investigate plasma deformation driven by a magnetic field and its influence on arc stability in a circuit breaker. The 3-D distribution of electric cur...A three-dimensional (3-D) transient model has been developed to investigate plasma deformation driven by a magnetic field and its influence on arc stability in a circuit breaker. The 3-D distribution of electric current density is obtained from a current continuity equation along with the generalized Ohm's law; while the magnetic field induced by the current flowing through the arc column is calculated by the magnetic vector potential equation. When gas interacts with an arc column, fundamental factors, such as Ampere's law, Ohm's law, the turbulence model, transport equations of mass, momentum and energy of plasma flow, have to be coupled for aria- lyzing the phenomenon. The coupled interactions between arc and plasma flow are described in the fl'amework of time-dependent magnetohydrodynamic (MHD) equations in conjunction with a K-~ turbulence model. Simulations have been focused on sausage and kink instabilities in plasma (these phenomena are related tO pinch effects and electromagnetic fields). The 3-D sjm- ulation reveals the relation between plasma deformation and instability phenomena, which affect arc stability during circuit breaker operation. Plasma deformation is the consequence of coupled interactions between the electromagnetic force and plasma flow described in simulations.展开更多
The effect of sodium chloride(NaCl)curing salt content on protein oxidation,lipid oxidation and lipolysis of Chinese dry sausage was investigated.Two groups Chinese dry sausages with 2%and 4%(m/m)salt content were stu...The effect of sodium chloride(NaCl)curing salt content on protein oxidation,lipid oxidation and lipolysis of Chinese dry sausage was investigated.Two groups Chinese dry sausages with 2%and 4%(m/m)salt content were studied.The degree of protein oxidation increased during the processes in two groups sausages,while the content of phospholipids decreased,neutral lipids and free fatty acids increased.The degree of protein oxidation,lipid oxidation and lipolysis in 4%NaCl content group was higher than those in 2%NaCl content group,while 4%NaCl content group has higher lipase activity.In conclusion,4%NaCl may facilitate the protein oxidation,lipid hydrolysis and oxidation in Chinese dry sausage,and the protein oxidation had strong correlation with lipid oxidation and lipolysis.The results could provide a basis for improving the technology of industrial production.展开更多
The effect of a proteolytic starter culture isolated from Nanx Wudl,on microbiological,biochemical and organoleptic attributes of dry fermented sausages was investigated during processing.Based on preliminary screenin...The effect of a proteolytic starter culture isolated from Nanx Wudl,on microbiological,biochemical and organoleptic attributes of dry fermented sausages was investigated during processing.Based on preliminary screening,the combination of Staphylococcus xylosus SX16 and Lactobacillus plantarum CMRC6,showing excellent proteolytic activity in vitro,was selected as the multi-strain starter(starter LS).For comparison,the single-strain starter culture of L.plantarum CMRC6(starter LB)and non-inoculated control were also tested.During fermentation,lactic acid bacteria and staphylococci dominated the microbiota and suppressed the Enterobacteriaceae growth in LS-inoculated sausages.The addition of LS starter accelerated acidification and proteolysis during ripening,improving the contents of total free amino acids and several essential free amino acids(Phe,Ile and Leu).Volatile compounds analysis revealed that LS-fermented sausage showed the highest abundance of 3-methyl-1-butanol,probably due to the inoculated S.xylosus.The inoculation of LS starter improved the sensory properties of sausages,especially the flavor attribute.Therefore,S.xylosus SX16 and L.plantarum CMRC6 are promising candidates for inclusion as multi-strain starters in the manufacture of gourmet fermented dry sausage.展开更多
The dislike food preferences that children registered regarding vegetables and fish compromise the exposure to those iodine sources and may contribute to cause a nutritional deficiency in this micronutrient, causing s...The dislike food preferences that children registered regarding vegetables and fish compromise the exposure to those iodine sources and may contribute to cause a nutritional deficiency in this micronutrient, causing serious damage of the brain and the central nervous system. Functional foods are becoming well-established in the market, focused on by an adult consumer more interested in healthy eating habits but without the motivation to optimize natural food preparation or to promote a wide variety of food in their diet. This article presents evidence of a new functional product concept, 100% vegetable, fermented soya based and salted by a red algae, that was approved by 900 parents who chose the sensorial features: distinctive aroma (57.9%), soft texture (38.4%), sausage shape (21%) and attractive color (77.9%). Three different varieties were developed: carrot (50% w/w), sugar-beet (50% w/w) and tomato (40% w/w) mini sausages, with tofu (20% w/w) and 0.8 % (w/w) of seaweed, reflecting trends that the younger consumer demands. The sensorial tests performed, after quality control assays, received very satisfactory acceptance by the potential buyer.展开更多
Eight different types of Bologna type cooked sausages apart from the control were produced in order to reduce the fat content (15%, 30%, 45%), replace the animal fat by olive oil (3%, 6.5% and 10%) as well as concomit...Eight different types of Bologna type cooked sausages apart from the control were produced in order to reduce the fat content (15%, 30%, 45%), replace the animal fat by olive oil (3%, 6.5% and 10%) as well as concomitant reduction and replacement of animal fat (30% of fat reduction with 2% of olive oil as an animal fat replacer). Quality attributes such as texture, water binding and color were monitored. Texture and water binding of fat reduced and fat replaced samples were quite similar to the control while color was strongly affected by the fat reduction and replacement. Fat reduction led to a redder cooked sausage and the addition of olive oil to a more yellow product. Chemical analysis revealed no major changes among samples apart from protein and fat content and fatty acid profile. Noteworthy, cooked sausage with more than 6.5% of olive oil achieved the World Health Organization’s recommendation on the nutritional fat index ((polyunsaturated + monounsaturated)/saturated fatty acid ≥ 2) which is very relevant to the development of healthier formulations. Cooked sausages with 45% of fat reduction and 30% fat reduced with 2% of olive oil were considered as the best by the panelists, which in addition had a balanced nutritional content by a lower caloric content. We concluded that fat reduction (up to 45%) and replacement (up to 10%) are possible with acceptable sensory quality and improved nutritional composition. When replacing animal fats by plant oils, the color of the product, which has a strong influence on the sensory acceptability of Bologna type cooked sausages, is affected. Therefore it must be controlled for a proper product development of meat products containing vegetable oils.展开更多
Yeasts are one of the predominant microbial groups in fermented meats.In this study,yeast communities of Chinese Dong fermented pork(Nanx Wudl)were investigated and the technological properties of 73 yeast isolates we...Yeasts are one of the predominant microbial groups in fermented meats.In this study,yeast communities of Chinese Dong fermented pork(Nanx Wudl)were investigated and the technological properties of 73 yeast isolates were evaluated.Through culture-dependent and high-throughput sequencing methods,the main yeast species identified included Pichia membranifaciens,Kazachstania bulderi,Millerozyma farinosa,Candida zeylanoides,Kazachstania exigua,Candida parapsilosis and Saccharomyces cerevisiae.Among these yeasts,P.membranifaciens,M.farinosa,K.exigua and K.bulderi were detected in fermented meats for the first time.A total of 73 yeast isolates was investigated for their lipolytic and proteolytic activities.All yeast species showed lipolytic activity,while proteolytic activity against meat protein was only detected in S.cerevisiae.Assay of aroma-producing potential was performed in a model simulating fermented sausage condition.Inoculation of yeast strains increased volatiles production,especially esters and alcohols.The highest ester production was observed in S.cerevisiae Y70 strain,followed by K.exigua Y12 and K.bulderi Y19.C.zeylanoides Y10 and S.cerevisiae Y70 were the highest producers of benzeneethanol and 3-methyl-1-butanol.S.cerevisiae Y70 with its highest production of branched alcohols and esters could be a promising candidate as aroma enhancer in the manufacture of fermented sausages.展开更多
The effect of process and storage on the volatiles and odorant profi le of Chinese dry sausage was evaluated,as well as its physicochemical parameters.Microbial esterification and wine(27.54%–43.35%),and lipid oxidat...The effect of process and storage on the volatiles and odorant profi le of Chinese dry sausage was evaluated,as well as its physicochemical parameters.Microbial esterification and wine(27.54%–43.35%),and lipid oxidation(11.30%–34.92%)played a key role in flavor profile during process and storage.A significant increase of each volatile was detected during process except gradual decrease of volatiles from spices,while a gradual decrease of each volatile was detected during storage except signifi cant increase of volatiles from lipid oxidation and esterifi cation.15 and 6 odor-active compounds were respectively correlated(P<0.05)with the process and storage time.Level of heptanal,1-octen-3-ol,the ethyl of 2-methylbutanoic,3-methylbutanoic,butanoic,benzoic,hexanoic,heptanoic,octanoic and decanoic acid were best discriminators of process stage,while(E)-2-nonenal,ethyl hexanoate,ethyl heptanoate,and methyl decanoate,were marker compounds of storage time.An objective method was established to evaluate the stages of process and storage for samples.展开更多
Effects of a starter culture composed of Lactobacillus sakei,Pediococcus pentosaceus,Staphylococcus xylosus and S.carnosus at the ratios(m/m)of 1:1:1:1 on bacterial profile and biogenic amine accumulation in Chinese S...Effects of a starter culture composed of Lactobacillus sakei,Pediococcus pentosaceus,Staphylococcus xylosus and S.carnosus at the ratios(m/m)of 1:1:1:1 on bacterial profile and biogenic amine accumulation in Chinese Sichuan sausages were demonstrated.In starter culture-inoculated sausages,Lactobacillus spp.,Pediococcus spp.and Staphylococcus spp.were predominant bacterial genus and their relative abundances ranged from 70.14%to 25.98%,57.66%to 14.08%,and 15.71%to 13.40%during fermentation,respectively.Accordingly,Lactobacillus spp.and Weissella spp.were predominant bacterial genus and their relative abundances ranged from 63.14%to 24.70%and 49.40%to 11.96%during spontaneous fermentation,respectively.Furthermore,the abundances of undesirable microorganisms such as Yersinia spp.,Enterobacter spp.,Acietobacter spp.and Psychrobacter spp.were lower than that of the control.The levels of histamine,putrescine,tyramine and cadaverine in Chinese Sichuan sausages with starter cultures inoculation were significantly lower(P<0.05)than that of the control,and were decreased by 83.09%,69.38%,51.87%and 57.20%,respectively,at the end of the ripening.These results revealed that the starter cultures inoculation was a better alternative for microbial quality improvement and biogenic amine reduction of Chinese Sichuan sausages with good sensory attributes.展开更多
We performed 6 fabrications of dry-fermented sausages to investigate, at laboratory scale, the effects of combined partial substitutions of sodium chloride by potassium chloride and pork backfat by sunflower oil on ke...We performed 6 fabrications of dry-fermented sausages to investigate, at laboratory scale, the effects of combined partial substitutions of sodium chloride by potassium chloride and pork backfat by sunflower oil on key physical-chemical and biochemical parameters, instrumental colour and texture measurements, and the consumer acceptability of the end-products. Regarding the physical-chemical parameters, statistical analysis of results showed that final product weight loss was impacted by fat content and use of sunflower oil;final mean water activity value was only affected by salt level;and animal fat content impacted pH values, only at the end of drying. Regarding the biochemical parameters investigated, we statistically found a marked impact of partial substitution of NaCl by KCl on the proteolysis evolution, of fat level and sodium content on the end-product lipolysis, and finally, a significant effect of animal fat level and incorporation of sunflower oil on both protein and lipid oxidations. However, the new product formulations combining salt and fat substitutions lead to globally acceptable water loss and water activity values and similar rates of proteolysis, lipolysis and lipid oxidation, but less protein oxidation. From a practical point of view, the results clearly showed that sodium and animal fat contents in dryfermented sausages can be drastically reduced with no too marked adverse effect on colour, final textural properties or consumer acceptability. On the basis of these laboratory results, new healthier dry-fermented products can be manufactured by an industrial company in the near future.展开更多
This study was conducted to analyze the effects of sodium nitrite,nisin,potassium sorbate,and sodium lactate against Staphylococcus aureus(S.aureus)growth and staphylococcal enterotoxins(SEs)production in cooked pork ...This study was conducted to analyze the effects of sodium nitrite,nisin,potassium sorbate,and sodium lactate against Staphylococcus aureus(S.aureus)growth and staphylococcal enterotoxins(SEs)production in cooked pork sausage by inoculating sausage samples containing preservative with an S.aureus strain producing staphylococcal enterotoxin A(SEA)and then storing them at 37℃ for 36 h.Samples were analyzed every 3 h to count the S.aureus colonies and to detect SEA.The modified Gompertz model was used to describe S.aureus growth in the samples under various conditions,and the preservatives with a significant antimicrobial effect were selected.In addition,the antimicrobial effects of the selected preservatives under various concentrations were tested.Results showed that sodium nitrite,nisin,and potassium sorbate had a weak effect against S.aureus growth and had no effect against SEA production,whereas sodium lactate could significantly inhibit S.aureus growth and SEA production.Moreover,the antimicrobial effect of sodium lactate was concentration-dependent,wherein sodium lactate concentration<12 g/kg showed no inhibitory effect,but when the concentration was increased to 24 g/kg,sodium lactate could effectively inhibit S.aureus growth and SEA production,and at 48 g/kg,sodium lactate had a significant inhibitory effect.展开更多
Chitosan and Chitin can inhibit the growth of bacteria. The effect of different concentrations of chitosan solutions on the shelf life of Harbin Red-sausage was studied in this paper. Dipping the Red-sausage with chit...Chitosan and Chitin can inhibit the growth of bacteria. The effect of different concentrations of chitosan solutions on the shelf life of Harbin Red-sausage was studied in this paper. Dipping the Red-sausage with chitosan could extend the shelf life significantly. The optimal composition of coating solution was 3% chitosan solution, whose deacetylated rate was 94%, which was dissolved in 2% acetic acid solution. The CFUs of the sausages with the chitosan deacetylated rate 94% treatment were significantly lower than control at the whole storage (P 〈0.05).展开更多
This paper addresses consumers’ choices by examining: current food choices made by different socio-economic groups;price barriers to diet improvement;and ways in which marketing may affect product choice. The study s...This paper addresses consumers’ choices by examining: current food choices made by different socio-economic groups;price barriers to diet improvement;and ways in which marketing may affect product choice. The study seeks: first, to analyze the differences in consumption of sausages of different nutritional composition among different socio-demo- graphic and lifestage groups;and second, using the example of sausages, to measure whether it is possible to improve diet quality without affecting household expenditure. Sausages represent a relatively high proportion of red and processed meat purchases in Scotland, contributing significantly to the fat and sodium in the Scottish diet. The data used consisted of two-years of weekly information from a top-4, UK supermarket. The results suggest that it is possible to purchase the same amount of a lower saturated fat or lower sodium sausage for the same price as a higher saturated fat or sodium sausage. However, it would cost more for some of the groups to replace a sausage that was both higher in saturated fat and higher in sodium with a lower saturated fat, lower sodium version in the household’s food basket.展开更多
This study investigated the spread of foodborne pathogens: Listeria monocytogenes, Es-cherichia coli O157:H7, Staphylococcus aureus and Salmonella in chicken sausage samples collected from retail markets in Greece and...This study investigated the spread of foodborne pathogens: Listeria monocytogenes, Es-cherichia coli O157:H7, Staphylococcus aureus and Salmonella in chicken sausage samples collected from retail markets in Greece and Egypt during 2006 and from Egypt through 2010. Other microbiological parameters;total viable count (TVC), lactic acid bacteria (LAB), pseudomonads (PS), staphylococci (STAPH), Brochothrix thermosphacta (BT), Enterobacteriaceae (EN), Escherichia coli (EC), yeasts and moulds (Y&M) were also counted. Egyptian chicken sausage samples were found to harbor L. mono- cytogenes, Staph. aureus and E. coli O157:H7;with frequencies equivalent to 24%, 60% and 26% of the total samples during 2006 and 37.87%, 64.44% and 41.11% of the total samples during 2010, respectively, while Greek samples were entirely free of theses pathogens. Enrichment techniques indicated the absence of Salmonella from both Greek and Egyptian samples. The obtained results may mobilize food producers and handlers in developing countries to take the due measures reducing food-borne pathogen risks and spoilage flora alongside the poultry chain.展开更多
基金financially supported by the National Natural Science Foundation of China (32272359)Natural Science and Engineering Research Council of Canada (NSERC,RGPIN-2018-04680)the scholarship from the China Scholarship Council (202106670005)。
文摘Dry-fermented sausages are a good source of bioactive peptides,whose stability against gastrointestinal(GI)digestion determines their bioaccessibility.This study focused on evaluating the effect of peptide extracts from sausages fermented with Staphylococcus simulans QB7 during in vitro simulated GI digestion,including peptide profiles and antioxidant and anti-inflammatory activities.Peptides present in sausages were degraded during digestion,with molecular weight reduced from>12 kDa to<1.5 kDa.Besides,the content of amino acids increased from 381.15 to 527.07 mg/g,especially tyrosine being found only after GI digestion.The anti-inflammatory activities were increased after GI digestion,however,the changes in antioxidant activities were the opposite.A total number of 255,252 and 386 peptide sequences were identified in undigested,peptic-digested and GI-digested samples,respectively.PeptideRanker,BIOPEP-UWM and admetSAR were used to further predict the functional properties and intestinal absorption of the identified peptide sequences from GI digestion.Finally,18 peptides were discovered to possess either antioxidant or anti-inflammatory capacities.
基金supported by the Natural Science Research Projects of Shanxi Province (20210302123400) in ChinaAgricultural Valley Construction Research Project of Shanxi Province (SXNGJSKYZX201903)Key Science and Technology Programs in Agriculture of Shanxi Province (201903D211008)
文摘The objective of this study was to explore the effects of the inoculation of mixed starter cultures of Lactobacillus and Staphylococcus(labeled L-S)on microbial community and flavor in fermented sausages during the ripening process.Culture-dependent(colony count)and culture-independent(high-throughput sequencing)methods were employed to evaluate bacterial communities.Volatile compounds were identified by gas chromatography-mass spectrometry,and the results were analyzed by principal component analysis(PCA).The identified bacteria with high relative abundance included Lactobacillus and Pediococcus,and the relative abundances of Leuconostoc and Weissella in fermented sausages were remarkably decreased at the end of the ripening process.At the end of ripening,2-nonenal,tetradecanal,ethylstearate and terpinyl acetate played substantial roles in the flavor development of the L-S fermented sausages.Sensory evaluation showed a high score in the L-S fermented sausages.Sausages can be inoculated with L-S starter culture to improve the safety and flavor of meat products.
文摘[Objective] This study aimed to develop pumpkin sausage. [Method] The single-factor design and orthogonal design were adopted. In the traditional sausage,fresh pumpkin was added. Based on the results of sensory test and physical and chemical indexes determination, the optimum recipe for pumpkin sausage was determined. [Result] The optimum recipe for pumpkin sausage was as follows: 100% of pork(fat to lean ratio of 2∶8), 45% of pumpkin particles, 6% of soy protein, 7% of sugar, 3.5% of salt, 1% of spice and 0.5% of monascus red pigment. [Conclusion]The successful preparation of pumpkin sausage will provide consumers with nutrition, health and snack meat product with comprehensive nutrition and unique flavor.
基金supported by the Key Technology R&D Program of China during the 11th Five-Year PlanPeriod (2006BAD05A15)
文摘This paper was designed to verify the influence of phosphate on water-holding capacity (WHC) and texture of emulsiontype sausage prepared with pre-rigor meat, ageing meat or frozen meat. Pre-rigor pork, ageing pork and frozen pork were pre-blended with five levels of phosphate and made into emulsion-type sausage. The yield, hardness and total expressible fluid (TEF) were measured with texture profile analysis machine and pressiometer when emulsion-type sausage was produced. Meanwhile, hardness and purge loss (PL) were measured during 30 d storage. As emusion-type sausage made by pre-rigor meat, higher yield and relatively stable hardness could be found. It indicated that increasing of phosphate level caused an alleviatable effects in increasing of hardness when emulsion-type sausage made by pre-rigor meat, but opposite effects made by ageing meat or frozen meat. The distribution of PL of emulsion-type sausage was found to be affected by phosphate addition. Significant decrease of PL could not be obtained by increasing of phosphate level during storage. Pre-rigor meat improved WHC and texture of emulsion-type sausage. Problem of WHC and texture of emulsiontype sausage during storage could not be resolved by single use of phosphate at relatively higher level (3%) of NaCl.
文摘A three-dimensional (3-D) transient model has been developed to investigate plasma deformation driven by a magnetic field and its influence on arc stability in a circuit breaker. The 3-D distribution of electric current density is obtained from a current continuity equation along with the generalized Ohm's law; while the magnetic field induced by the current flowing through the arc column is calculated by the magnetic vector potential equation. When gas interacts with an arc column, fundamental factors, such as Ampere's law, Ohm's law, the turbulence model, transport equations of mass, momentum and energy of plasma flow, have to be coupled for aria- lyzing the phenomenon. The coupled interactions between arc and plasma flow are described in the fl'amework of time-dependent magnetohydrodynamic (MHD) equations in conjunction with a K-~ turbulence model. Simulations have been focused on sausage and kink instabilities in plasma (these phenomena are related tO pinch effects and electromagnetic fields). The 3-D sjm- ulation reveals the relation between plasma deformation and instability phenomena, which affect arc stability during circuit breaker operation. Plasma deformation is the consequence of coupled interactions between the electromagnetic force and plasma flow described in simulations.
基金This study was financially supported by National Key R&D Program of China(grant No.2017YFD0400105)Natural Science Foundation of Beijing Municipality(grant No.6192009)Fengtai science and technology new star(grant No.KJXX201902).
文摘The effect of sodium chloride(NaCl)curing salt content on protein oxidation,lipid oxidation and lipolysis of Chinese dry sausage was investigated.Two groups Chinese dry sausages with 2%and 4%(m/m)salt content were studied.The degree of protein oxidation increased during the processes in two groups sausages,while the content of phospholipids decreased,neutral lipids and free fatty acids increased.The degree of protein oxidation,lipid oxidation and lipolysis in 4%NaCl content group was higher than those in 2%NaCl content group,while 4%NaCl content group has higher lipase activity.In conclusion,4%NaCl may facilitate the protein oxidation,lipid hydrolysis and oxidation in Chinese dry sausage,and the protein oxidation had strong correlation with lipid oxidation and lipolysis.The results could provide a basis for improving the technology of industrial production.
基金the National Key R&D Program of China(grant no.2018YFD0400404).
文摘The effect of a proteolytic starter culture isolated from Nanx Wudl,on microbiological,biochemical and organoleptic attributes of dry fermented sausages was investigated during processing.Based on preliminary screening,the combination of Staphylococcus xylosus SX16 and Lactobacillus plantarum CMRC6,showing excellent proteolytic activity in vitro,was selected as the multi-strain starter(starter LS).For comparison,the single-strain starter culture of L.plantarum CMRC6(starter LB)and non-inoculated control were also tested.During fermentation,lactic acid bacteria and staphylococci dominated the microbiota and suppressed the Enterobacteriaceae growth in LS-inoculated sausages.The addition of LS starter accelerated acidification and proteolysis during ripening,improving the contents of total free amino acids and several essential free amino acids(Phe,Ile and Leu).Volatile compounds analysis revealed that LS-fermented sausage showed the highest abundance of 3-methyl-1-butanol,probably due to the inoculated S.xylosus.The inoculation of LS starter improved the sensory properties of sausages,especially the flavor attribute.Therefore,S.xylosus SX16 and L.plantarum CMRC6 are promising candidates for inclusion as multi-strain starters in the manufacture of gourmet fermented dry sausage.
文摘The dislike food preferences that children registered regarding vegetables and fish compromise the exposure to those iodine sources and may contribute to cause a nutritional deficiency in this micronutrient, causing serious damage of the brain and the central nervous system. Functional foods are becoming well-established in the market, focused on by an adult consumer more interested in healthy eating habits but without the motivation to optimize natural food preparation or to promote a wide variety of food in their diet. This article presents evidence of a new functional product concept, 100% vegetable, fermented soya based and salted by a red algae, that was approved by 900 parents who chose the sensorial features: distinctive aroma (57.9%), soft texture (38.4%), sausage shape (21%) and attractive color (77.9%). Three different varieties were developed: carrot (50% w/w), sugar-beet (50% w/w) and tomato (40% w/w) mini sausages, with tofu (20% w/w) and 0.8 % (w/w) of seaweed, reflecting trends that the younger consumer demands. The sensorial tests performed, after quality control assays, received very satisfactory acceptance by the potential buyer.
文摘Eight different types of Bologna type cooked sausages apart from the control were produced in order to reduce the fat content (15%, 30%, 45%), replace the animal fat by olive oil (3%, 6.5% and 10%) as well as concomitant reduction and replacement of animal fat (30% of fat reduction with 2% of olive oil as an animal fat replacer). Quality attributes such as texture, water binding and color were monitored. Texture and water binding of fat reduced and fat replaced samples were quite similar to the control while color was strongly affected by the fat reduction and replacement. Fat reduction led to a redder cooked sausage and the addition of olive oil to a more yellow product. Chemical analysis revealed no major changes among samples apart from protein and fat content and fatty acid profile. Noteworthy, cooked sausage with more than 6.5% of olive oil achieved the World Health Organization’s recommendation on the nutritional fat index ((polyunsaturated + monounsaturated)/saturated fatty acid ≥ 2) which is very relevant to the development of healthier formulations. Cooked sausages with 45% of fat reduction and 30% fat reduced with 2% of olive oil were considered as the best by the panelists, which in addition had a balanced nutritional content by a lower caloric content. We concluded that fat reduction (up to 45%) and replacement (up to 10%) are possible with acceptable sensory quality and improved nutritional composition. When replacing animal fats by plant oils, the color of the product, which has a strong influence on the sensory acceptability of Bologna type cooked sausages, is affected. Therefore it must be controlled for a proper product development of meat products containing vegetable oils.
基金the National Key R&D Program of China(grant no.2018YFD0400404).
文摘Yeasts are one of the predominant microbial groups in fermented meats.In this study,yeast communities of Chinese Dong fermented pork(Nanx Wudl)were investigated and the technological properties of 73 yeast isolates were evaluated.Through culture-dependent and high-throughput sequencing methods,the main yeast species identified included Pichia membranifaciens,Kazachstania bulderi,Millerozyma farinosa,Candida zeylanoides,Kazachstania exigua,Candida parapsilosis and Saccharomyces cerevisiae.Among these yeasts,P.membranifaciens,M.farinosa,K.exigua and K.bulderi were detected in fermented meats for the first time.A total of 73 yeast isolates was investigated for their lipolytic and proteolytic activities.All yeast species showed lipolytic activity,while proteolytic activity against meat protein was only detected in S.cerevisiae.Assay of aroma-producing potential was performed in a model simulating fermented sausage condition.Inoculation of yeast strains increased volatiles production,especially esters and alcohols.The highest ester production was observed in S.cerevisiae Y70 strain,followed by K.exigua Y12 and K.bulderi Y19.C.zeylanoides Y10 and S.cerevisiae Y70 were the highest producers of benzeneethanol and 3-methyl-1-butanol.S.cerevisiae Y70 with its highest production of branched alcohols and esters could be a promising candidate as aroma enhancer in the manufacture of fermented sausages.
基金The authors were very grateful for the financial supports from national key research and development program of China(No.2017YFD0400105).
文摘The effect of process and storage on the volatiles and odorant profi le of Chinese dry sausage was evaluated,as well as its physicochemical parameters.Microbial esterification and wine(27.54%–43.35%),and lipid oxidation(11.30%–34.92%)played a key role in flavor profile during process and storage.A significant increase of each volatile was detected during process except gradual decrease of volatiles from spices,while a gradual decrease of each volatile was detected during storage except signifi cant increase of volatiles from lipid oxidation and esterifi cation.15 and 6 odor-active compounds were respectively correlated(P<0.05)with the process and storage time.Level of heptanal,1-octen-3-ol,the ethyl of 2-methylbutanoic,3-methylbutanoic,butanoic,benzoic,hexanoic,heptanoic,octanoic and decanoic acid were best discriminators of process stage,while(E)-2-nonenal,ethyl hexanoate,ethyl heptanoate,and methyl decanoate,were marker compounds of storage time.An objective method was established to evaluate the stages of process and storage for samples.
基金supported by National Natural Science Foundation of China(31772093)Key innovation projects of Chengdu Science and Technology(2019-YF05-00066-SN)Key Laboratory of Collaborative Control and Remediation of Soil and Water Pollution(GHBK-003)。
文摘Effects of a starter culture composed of Lactobacillus sakei,Pediococcus pentosaceus,Staphylococcus xylosus and S.carnosus at the ratios(m/m)of 1:1:1:1 on bacterial profile and biogenic amine accumulation in Chinese Sichuan sausages were demonstrated.In starter culture-inoculated sausages,Lactobacillus spp.,Pediococcus spp.and Staphylococcus spp.were predominant bacterial genus and their relative abundances ranged from 70.14%to 25.98%,57.66%to 14.08%,and 15.71%to 13.40%during fermentation,respectively.Accordingly,Lactobacillus spp.and Weissella spp.were predominant bacterial genus and their relative abundances ranged from 63.14%to 24.70%and 49.40%to 11.96%during spontaneous fermentation,respectively.Furthermore,the abundances of undesirable microorganisms such as Yersinia spp.,Enterobacter spp.,Acietobacter spp.and Psychrobacter spp.were lower than that of the control.The levels of histamine,putrescine,tyramine and cadaverine in Chinese Sichuan sausages with starter cultures inoculation were significantly lower(P<0.05)than that of the control,and were decreased by 83.09%,69.38%,51.87%and 57.20%,respectively,at the end of the ripening.These results revealed that the starter cultures inoculation was a better alternative for microbial quality improvement and biogenic amine reduction of Chinese Sichuan sausages with good sensory attributes.
文摘We performed 6 fabrications of dry-fermented sausages to investigate, at laboratory scale, the effects of combined partial substitutions of sodium chloride by potassium chloride and pork backfat by sunflower oil on key physical-chemical and biochemical parameters, instrumental colour and texture measurements, and the consumer acceptability of the end-products. Regarding the physical-chemical parameters, statistical analysis of results showed that final product weight loss was impacted by fat content and use of sunflower oil;final mean water activity value was only affected by salt level;and animal fat content impacted pH values, only at the end of drying. Regarding the biochemical parameters investigated, we statistically found a marked impact of partial substitution of NaCl by KCl on the proteolysis evolution, of fat level and sodium content on the end-product lipolysis, and finally, a significant effect of animal fat level and incorporation of sunflower oil on both protein and lipid oxidations. However, the new product formulations combining salt and fat substitutions lead to globally acceptable water loss and water activity values and similar rates of proteolysis, lipolysis and lipid oxidation, but less protein oxidation. From a practical point of view, the results clearly showed that sodium and animal fat contents in dryfermented sausages can be drastically reduced with no too marked adverse effect on colour, final textural properties or consumer acceptability. On the basis of these laboratory results, new healthier dry-fermented products can be manufactured by an industrial company in the near future.
基金Development of Application Technology Project(No:2015-114)issued by Science and Technology Committee of Shanghai Municipal GovernmentNational Key Scientific Instruments Project(No:2013YQ150557)issued by Ministry of Science and Technology of the P.R.China.
文摘This study was conducted to analyze the effects of sodium nitrite,nisin,potassium sorbate,and sodium lactate against Staphylococcus aureus(S.aureus)growth and staphylococcal enterotoxins(SEs)production in cooked pork sausage by inoculating sausage samples containing preservative with an S.aureus strain producing staphylococcal enterotoxin A(SEA)and then storing them at 37℃ for 36 h.Samples were analyzed every 3 h to count the S.aureus colonies and to detect SEA.The modified Gompertz model was used to describe S.aureus growth in the samples under various conditions,and the preservatives with a significant antimicrobial effect were selected.In addition,the antimicrobial effects of the selected preservatives under various concentrations were tested.Results showed that sodium nitrite,nisin,and potassium sorbate had a weak effect against S.aureus growth and had no effect against SEA production,whereas sodium lactate could significantly inhibit S.aureus growth and SEA production.Moreover,the antimicrobial effect of sodium lactate was concentration-dependent,wherein sodium lactate concentration<12 g/kg showed no inhibitory effect,but when the concentration was increased to 24 g/kg,sodium lactate could effectively inhibit S.aureus growth and SEA production,and at 48 g/kg,sodium lactate had a significant inhibitory effect.
文摘Chitosan and Chitin can inhibit the growth of bacteria. The effect of different concentrations of chitosan solutions on the shelf life of Harbin Red-sausage was studied in this paper. Dipping the Red-sausage with chitosan could extend the shelf life significantly. The optimal composition of coating solution was 3% chitosan solution, whose deacetylated rate was 94%, which was dissolved in 2% acetic acid solution. The CFUs of the sausages with the chitosan deacetylated rate 94% treatment were significantly lower than control at the whole storage (P 〈0.05).
文摘This paper addresses consumers’ choices by examining: current food choices made by different socio-economic groups;price barriers to diet improvement;and ways in which marketing may affect product choice. The study seeks: first, to analyze the differences in consumption of sausages of different nutritional composition among different socio-demo- graphic and lifestage groups;and second, using the example of sausages, to measure whether it is possible to improve diet quality without affecting household expenditure. Sausages represent a relatively high proportion of red and processed meat purchases in Scotland, contributing significantly to the fat and sodium in the Scottish diet. The data used consisted of two-years of weekly information from a top-4, UK supermarket. The results suggest that it is possible to purchase the same amount of a lower saturated fat or lower sodium sausage for the same price as a higher saturated fat or sodium sausage. However, it would cost more for some of the groups to replace a sausage that was both higher in saturated fat and higher in sodium with a lower saturated fat, lower sodium version in the household’s food basket.
文摘This study investigated the spread of foodborne pathogens: Listeria monocytogenes, Es-cherichia coli O157:H7, Staphylococcus aureus and Salmonella in chicken sausage samples collected from retail markets in Greece and Egypt during 2006 and from Egypt through 2010. Other microbiological parameters;total viable count (TVC), lactic acid bacteria (LAB), pseudomonads (PS), staphylococci (STAPH), Brochothrix thermosphacta (BT), Enterobacteriaceae (EN), Escherichia coli (EC), yeasts and moulds (Y&M) were also counted. Egyptian chicken sausage samples were found to harbor L. mono- cytogenes, Staph. aureus and E. coli O157:H7;with frequencies equivalent to 24%, 60% and 26% of the total samples during 2006 and 37.87%, 64.44% and 41.11% of the total samples during 2010, respectively, while Greek samples were entirely free of theses pathogens. Enrichment techniques indicated the absence of Salmonella from both Greek and Egyptian samples. The obtained results may mobilize food producers and handlers in developing countries to take the due measures reducing food-borne pathogen risks and spoilage flora alongside the poultry chain.