Evolution of free amino acids, biogenic amines and volatile compounds in fermented sausages inoculated with Lactiplantibacillus plantarum and Staphylococcus simulans

Lactic acid bacteria and coagulase-negative staphylococci play an important role in the production of fermented sausages,such as inhibiting the growth of undesirable bacteria and antioxidant.In this study,the effects of inoculation with different starter cultures(Lactiplantibacillus plantarum HN108 and Staphylococcus simulans NJ209)on the free amino acids(FAAs),biogenic amines(BAs)and volatile compounds of fermented sausages were investigated using an amino acid analyzer,ultra performance liquid chromatography and gas chromatography-ion mobility spectrometry,respectively.The pH and carbonyl content of the inoculated group was significantly lower than those in the control group(P<0.05).L.plantarum HN108 significantly reduced the content of FAAs and BAs in fermented sausage production(P<0.05),while S.simulans NJ209 promoted the formation of FAAs(especially bitter amino acids)and exhibited slight BAs-reducing activity.In addition,L.plantarum HN108 promoted the formation of volatile compounds such as ketones,alcohols and alkenes in sausages.In conclusion,L.plantarum HN108 could contribute to reducing the content of putrescine and tyramine and forming the desirable flavor compounds in fermented sausages.Thus,L.plantarum HN108 is expected to be a starter culture that can improve the safety and flavor of fermented sausages.

Effect of simulated gastrointestinal digestion on antioxidant,and anti-inflammatory activities of bioactive peptides generated in sausages fermented with Staphylococcus simulans QB7

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.

Co-inoculation of Debaryomyces hansenii and lactic acid bacteria: a strategy to improve the taste and odour profiles of dry sausages

The effects of the co-inoculation of Debaryomyces hansenii separately with 3 lactic acid bacteria(LAB),Lactobacillus sakei,Lactobacillus plantarum and Lactobacillus curvatus,on the taste and odour profi les of dry sausages were investigated.The co-inoculated sausages showed higher free amino acid and organic acid contents than the non-inoculated control and sausages inoculated with D.hansenii alone.Meanwhile,the sausages inoculated with D.hansenii+L.plantarum,D.hansenii+L.sakei and D.hansenii+L.curvatus had the highest contents of aldehydes,esters and alcohols,respectively.The results of electronic tongue,electronic nose and sensory evaluation demonstrated that compared with the sausage inoculated with D.hansenii,the sour taste and fl oral odour increased and the fatty odour decreased in the sausage inoculated with D.hansenii+L.sakei;this was more favourable for the development of a desirable fl avour in sausages.Moreover,the partial least squares regression analysis indicated that 10 taste and 33 odour compounds were mainly responsible for the differences in the flavour profiles among the sausages.Overall,these findings contributed to a more comprehensive understanding of the formation of sensory characteristics in dry sausages co-inoculated with yeast and LAB.

Effect of inoculating mixed starter cultures of Lactobacillus and Staphylococcus on bacterial communities and volatile flavor in fermented sausages

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.

Effect of a compound starter cultures inoculation on bacterial profile and biogenic amine accumulation in Chinese Sichuan sausages

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.

Functional Vegetable-Based Sausages for Consumption by Children

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.

An Analysis of the Consumption of Sausages in Scotland Using Supermarket Data

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.

Inactivation of Yersinia enterocolitica in Fermented Sausages during Fermentation

The purpose of this study was to evaluate the storage conditions as a way to increase the safety of fermented sausage, with the specific objectives to investigate the effect of storage time, pH value, water activity and microbiological status （Lactobacillus spp and Enterobacteriaceae） on the levels of Yersinia enterocolitica in fermented sausages. For this experiment, meat was divided into four equal portions of 10 kg each. The first portion was control group （C1 group） without addition of Y. enterocolitica and starter culture. The second portion （CII group） was inoculated starter, the third portion （EI group） was inoculated with I1. enterocolitica and the fourth portion （Eli group） was inoculated Y.. enterocolitica and starter culture. Sampling was performed by randomly selecting two links of each sausage preparation at the 0, 3rd, 6th, 9th, 15th, 25th and 35th day of drying. Results show that Y. enterocolitica and Enterobacteriaceae were not detected after 25 d of storage. The results indicate that practice utilizing starter culture is satisfactory to reduction of pathogen if present. Thus, inclusion with starter cultures in a maturation period may increase the safety of fermented sausages.

A Lyophilized Water Extract of Melissa officinalis L. as an Effective Natural Antioxidant during the Storage of Dry Fermented Sausages High in a-Linolenic Acid and DHA

A pre-emulsified mixture of linseed and algae oils （15/10） and stabilized with 686 ppm of a lyophilized water extract of Melissa officinalis, was successfully applied in dry fermented sausages to increase the ω-3 PUFA content. The objective of this work was to evaluate the stability of this modified formulation during the storage and to compare it to that of a traditional formulation. Traditional and modified products were stored during 90 days at 4 °C in aerobic conditions. Fatty acid profiles, TBARS and volatile compounds derived from oxidation were analyzed at 0, 30 and 90 days of storage. The fatty acid profiles did not significantly change along the storage period. The stabilizing effect of the natural antioxidants ofM. officinalis could contribute to detect no losses of to-3 PUFA in Modified （30 days： 2.13 g/100 g of product, 90 days： 2.33 g/100 g of product）, whereas in Control products a slightly significant reduction was detected （30 days： 0.34 g/100 g of product, 90 days： 0.29 g/! 00 g of product）. After 90 days, the increases of TBARS and hexanal content were much higher in Control than in Modified （Control： 1.41 mg MDA/kg ＆ 17,915 ng dodecane/kg of dry matter; Modified： 0.48 mg MDA/kg ＆ 2,496 ng dodecane/kg of dry matter）. In conclusion, the lyophilized water extract of M. officinalis protected high ωo-3 PUFA of dry fermented sausages from oxidation along the storage time, guaranteeing the nutritional improvements achieved with the modified formulation.

Optimization Research into Addition Method and Proportion Formula of Rabbit Meat Sausages Fermentation Agent

[Objective] Sausage making using fermentation agents including Staphylococcus xylosus(C18), Lactobacillus plantarum(L26), and Debaryomyces Hansenula(Y163). [Method] With adoption of preliminary experiments and single factor experiment, we measured production pH, and in combination with sensory analysis, we managed to evaluate the fermentation agents, addition method, and addition proportion formula. [Conclusion] At total inoculation of 1×107 cfu/g, and with processing method of simultaneous addition, the optimal addition proportion is L:C:Y =1:2:1.

Effect of proteolytic starter culture isolated from Chinese Dong fermented pork(Nanx Wudl)on microbiological,biochemical and organoleptic attributes in dry fermented sausages

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.

Physicochemical, Biochemical and Instrumental Attributes and Consumer Acceptability of Dry-Fermented Sausages Elaborated with Combined Partial Substitutions of Sodium Chloride and Pork Backfat

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.

Comparative prevalence of pathogenic and spoilage microbes in chicken sausages from Egypt and Greece

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.

Physicochemical properties of silver carp(Hypophthalmichthys molitrix)mince sausages as influenced by washing and frozen storage

Frozen storage of emulsion-type sausages may be one approach to avoid or reduce the use of sodium nitrite,which is associated with health risks.Silver carp(Hypophthalmichthys molitrix)mince(M_(0))was washed for 1(M_(1))or 3(M_(3))times and the impact of washing on the properties frozen storage(−18℃)during 4 months were determined and results were compared to those of conventional silver carp sausages(Mt).Lipid oxidation,as evidenced by changes in thiobarbituric acid reactive substances and FFAs,took place during storage in the order of M_(0)>M_(1)=M_(3)=Mt with M_(0)being highly oxidized(P≤0.05).Total volatile base nitrogen formed during storage and the ranking for the quality loss was as follows M_(0)>M_(1)>M_(3)=Mt.Washing(M_(1)=M_(3))led to less hardness(P≤0.05).Mt had better redness,while M_(1)and M_(3)led to higher expressible moisture,water release and lightness(P≤0.05).Results indicated the lower sensory and consumer-liking properties of frozen M_(1)and M_(3)sausages.Therefore,washing and frozen storage influenced silver carp mince sausages.

Management of Acute Idiopthic Intestinal Invaginal in Infants at Conakry University Hospital

Introduction: Acute intestinal intussusception (AII) has been known for a long time but its diagnosis sometimes remains difficult and its etiologies, particularly the idiopathic forms, poorly elucidated. The objective of this study was to describe the clinical and therapeutic aspects of acute intestinal intussusception in order to contribute to the improvement of the management of this condition in the pediatric surgery department of the Donka National Hospital. Materials and Methods: This is a retrospective descriptive study of patients taken in charge of acute idiopathic intestinal intussusception over a period of 7 years (January 2017 to December 31, 2023). Results: We collected 72 patients operated on for IIA, i.e. a hospital frequency of 1.1% and an incidence of 10.3 cases per year. The mean age was 16.58 months with extremes of 3 months and 28 months. The sex ratio was 12.5 in favor of the boy. The triad of ombredanne dominated the clinical picture and paroxysmal abdominal pain with period of calm represented the main reason for consultation (72 cases) i.e. 100%, followed by vomiting (62 cases) and rectal bleeding (50 cases). Ultrasound was performed in 56 patients visualizing the intussusception sausage in 54 patients or 75%. The most common anatomoclinical variety of intussusception was the ileo-caeco-colic form with 35 cases (or 38%) followed by the ileocolic form 24 cases (33%). The surgical procedure performed was a manual reduction in 54 patients or 75% and an anastomosis resection in 18 patients;the appendectomy of principle was done in 62.25%. The postoperative course was simple in 64 patients or 88.88%. The mortality rate was 6.94 %. Conclusion: AII is a common abdominal surgical emergency in infants. Recognition of the Ombredanne triad especially abdominal pain with a period of calm in children and infants in particular is an important element for vital prognosis. Early diagnosis and close interdisciplinary cooperation between pediatric, radiology and pediatric surgery teams could improve the management of IIA and allow this condition to remain benign in children.

Processing stage-guided effects of spices on the formation and accumulation of heterocyclic amines in smoked and cooked sausages

Heterocyclic amines (HAs) could be generated though sausage processing.The results showed that garlic,black pepper,chili inhibited the formation of HAs (584.29 ng/g,613.11 ng/g,677.23 ng/g) whereas ginger and Sichuan pepper intensified (965.66 ng/g,916.59 ng/g) compare with control sausage 863.86 ng/g.Furthermore,the study showed that garlic,black pepper,chilli all inhibited the formation of total HAs at stage of raw,drying,baking and steaming and had different inhibitory effect at every stage.Black pepper had the best inhibitory effect across four stages and inhibition rate reached 65%,69%,66%,84% after each stage.Chilli was the only one had inhibitory effect on both free and protein-bound HAs at every stage and inhibition rate about free and protein-bound HAs reached 38% and 76% in finished sausage.Adding certain spices properly during processing would be helpful to obtain fewer HAs in sausage.

Mining hyperspectral data for non-destructive and rapid prediction of nitrite content in ham sausages

Accurate and rapid determination of nitrite contents is an important step for guaranteeing sausage quality.This study attempted to mine hyperspectral data in the range of 900-1700 nm for non-destructive and rapid prediction of nitrite contents in sausages.The average spectra of 156 samples were collected to relate to the measured nitrite values by partial least squares(PLS)regression.Optimal wavelengths were respectively selected by successive projections algorithm(SPA)and regression coefficients(RC)to simplify the PLS model.The results indicated that PLS model established with 15 optimal wavelengths(900.5 nm,907.1 nm,908.8 nm,912.1 nm,915.4 nm,920.3 nm,922.0 nm,941.7 nm,979.6 nm,1083.2 nm,1213.2 nm,1353.0 nm,1460.2 nm,1595.6 nm and 1699.9 nm)selected by SPA had better performance with r C,r CV,r P of 0.92,0.89,0.89 and RMSEC,RMSECV,RMSEP of 0.41 mg/kg,0.89 mg/kg,0.49 mg/kg,respectively,for calibration set,cross-validation and prediction set.It was concluded that hyperspectral data could be mined by PLS&SPA for realizing the rapid evaluation of nitrite content in ham sausages.

Unraveling the difference in flavor characteristics of dry sausages inoculated with different autochthonous lactic acid bacteria

The traditional dry sausage is highly appreciated in China because of its unique flavor characteristics.This study aimed to characterize and compare the flavor profile of traditional dry sausage,inoculated with lactic acid bacteria (LAB),including Lactobacillus plantarum MDJ2,Lactobacillus sakei HRB10,Lactobacillus curvatus SYS29,Weissella hellenica HRB6,and Lactococcus lactis HRB0 using headspace solid-phase microextraction gas chromatography-mass spectrometry coupled with electronic nose (E-nose).The control (non-inoculated) sausage presented higher water activity and moisture content compared to the inoculated sausages whereas,the inoculation led to decreased pH values and increased LAB counts during fermentation of dry sausages.Inoculation with LAB increased volatile compound contents and decreased total contents of free amino acids of sausages.E-nose and sensory analysis confirmed that inoculation with LAB,especially W.hellenica HRB6,Lb.sakei HRB10,and Lb.curvatus SYS29 enriched the pleasant odors of dry sausage.Correlation analysis demonstrated that sausages inoculated with W.hellenica HRB6 and Lb.sakei HRB10 showed a correlation with most of the key volatile compounds.In conclusion,W.hellenica HRB6 and Lb.sakei HRB10 are promising starter cultures to enhance the flavor characteristics of dry sausages.

基于性能的超限高层结构设计应用实例

基于性能的抗震设计方法是国际先进技术,适用于复杂超限高层建筑的结构设计。我国规范采用“小震不坏、中震可修、大震不倒”的抗震设防目标,超限高层结构可通过抗震设计来实现我国规范要求的性能目标。该文以重庆某复杂超限高层项目为例,介绍该结构性能化设计的过程。

罕遇地震作用下某图书馆的动力弹塑性分析

某图书馆分为4栋楼且设防震缝形成相对独立的结构单体,均采用钢筋混凝土框架-剪力墙结构,其中3栋楼均存在三项及以上的不规则项。本文选取建筑功能较多且结构较复杂的A栋作为研究对象,其结构存在平面扭转不规则、凹凸不规则和楼板局部不连续等3项不规则,属于超限高层结构。结合A栋结构的超限情况及规范要求,在确保其多遇地震作用和设防地震作用的预期性能目标实现后,采用SAUSAGE软件对其结构进行罕遇地震作用下的动力弹塑性时程分析,分析基底剪力、楼层位移、能量图及等效阻尼比等指标,对整体结构和结构构件的抗震性能进行分析和评价。研究表明,剪力墙均处于无损伤状态,个别框架柱和框架梁出现轻微损伤,本结构满足预期的性能目标。