The effect of some gram-negative bacteria on the ripening and quality of dry sausage

The possible use of gram-negative bacteria as starter cultures in dry sausage was studied by inoculating the following gram-negative bacteria into dry sausage both alone and with Lactobacillus plantarum: Aeromonas x, Aeromonas 19. Vibrio costicolus, Achromobacter 22, Achromobacter guttatus, Achromobacter X, Escherichia coli, or Proteus vulgaris. Sausage without any inoculation and sausage containing Micrococcus sp. + Lactobacillus plantarum were used as references. Aeromonas x and 19 strains had a very favourable effect on the quality of dry sausage when inoculated together with lactobacilli. Both strains reduced nitrate, and the colour formed during the first 3 days. The pH value of Aeromonas + Lactobacillus sausages decreased so quickly that the consistency of these sausages developed within one week and was at least as good as, and often firmer than in Micrococcus + Lactobacillus sausages. The consistency of Aeromonas 19 + Lactobacillus sausages was better at the 0.05 significance level than that of Micrococcus + Lactobacillus samples. The aroma and flavour of Aeromonas + Lactobacillus sausages were as good as or better than those of Micrococcus 4- Lactobacillus sausages. The aroma and flavour of Aeromonas 19 + Lactobacillus sausages were significantly better (significance level 0.001) than Micrococcus-f Lactobacillus sausages. The flavour of Aeromonas x + Lactobacillus sausages was better at the 0.05 level than Micrococcus + Lactobacillus sausages. The number of bacteria, roughly the number of lactobacilli. was often significantly higher in Aeromonas + Lactobacillus sausages (range 2—4 x 108/g between 3 and 21 days of ripening) than in Micrococcus + Lactobacillus sausages (range 8 X 107 1.5 X 108/g between 3 and 21 days of ripening). For this reason the former sausages ripened more quickly than the latter. Vibrio 21 and three Achromobacter strains did not thrive in dry sausage and disappeared during the first 7 days of ripening. When inoculated together with lactobacilli, Escherichia coli had almost as favourable an effect as micrococci on the quality of dry sausage. Inoculations of E. coli alone and Proteus vulgaris, both alone and with lactobacilli, did not improve the quality of dry sausage. P. vulgaris actually had a detrimental effect. Conclusion The investigation has proved that gram-negative bacterial strains Aeromonas x and 19 inoculated with lactobacilli improve the quality of dry sausage and that, especially with the Aeromonas 19 + Lactobacillus inoculum, better dry sausage was obtained than with micrococci and lactobacilli

Towards a Complete Automation Feature Recognition System for Sheet Metal Manufacturing

Sheet metal processing is automated, but the step from product models to the production machine control still requires human intervention. This may cause time consuming bottlenecks in the production process and increase the risk of human errors. In this paper we present a system, which automatically recognizes features from the CAD-model of the sheet metal product. By using these features, the system produces a complete model of the particular sheet metal product. Then the model is used as an input for the sheet metal processing machine. Currently the system is implemented, capable to recognize more than 11 of the most common sheet metal structural features, and the procedure is fully automated. This provides remarkable savings in the production time, and protects against the human errors. This paper presents the developed system architecture, applied algorithms and system software implementation and testing.© 2017 World Academy of Science, Engineering and Technology.fi=vertaisarvioimaton|en=nonPeerReviewed

InDEx – Industrial Data Excellence

InDEx, the Industrial Data Excellence program, was created to investigate what industrial data can be collected, shared, and utilized for new intelligent services in high-performing, reliable and secure ways, and how to accomplish that in practice in the Finnish manufacturing industry.InDEx produced several insights into data in an industrial environment, collecting data, sharing data in the value chain and in the factory environment, and utilizing and manipulating data with artificial intelligence. Data has an important role in the future in an industrial context, but data sources and utilization mechanisms are more diverse than in cases related to consumer data. Experiences in the InDEx cases showed that there is great potential in data utili zation.Currently, successful business cases built on data sharing are either company-internal or utilize an existing value chain. The data market has not yet matured, and third-party offerings based on public and private data sources are rare. In this program, we tried out a framework that aimed to securely and in a controlled manner share data between organizations. We also worked to improve the contractual framework needed to support new business based on shared data, and we conducted a study of applicable business models. Based on this, we searched for new data-based opportunities within the project consortium. The vision of data as a tradeable good or of sharing with external partners is still to come true, but we believe that we have taken steps in the right direction.The program started in fall 2019 and ended in April 2022. The program faced restrictions caused by COVID-19, which had an effect on the intensity of the work during 2020 and 2021, and the program was extended by one year. Because of meeting restrictions, InDEx collaboration was realized through online meetings. We learned to work and collaborate using digital tools and environments. Despite the mentioned hindrances, and thanks to Business Finland’s flexibility, the extension time made it possible for most of the planned goals to be achieved.This report gives insights in the outcomes of the companies’ work within the InDEx program. DIMECC InDEx is the first finalized program by the members of the Finnish Advanced Manufacturing Network (FAMN, www.famn.fi).</p

Effectiviness of open innovation competitions

Innovations are important as business life is becoming more and more competitive. Innovative products and solutions are important for companies, and they are investing large amount of money to develop breakthrough innovations. Due to these results, companies have started to search ideas outside of their organizations and new business fields. One possible method search ideas is to organize open innovation competitions where problem is presented to large groups of presenters. This study is a case study, by which we are exploring the success factors for student-company competitions and phenomena that makes competitions innovative-creative. Target of this study is to find out most suitable way of organizing competitions to gain maximal results from these competitions. In addition, we were interested to know what kind of effects of these competitions can produce. The results of our study showed that innovation competitions can help achieve significant results, e.g. bigger or smaller product innovations, and changes to big international organizations. An important result for the company is also the fact that competitions are used to find talented people who continue to develop innovative products.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

Eräiden gram-negatiivisten bakteerien vaikutus kestomakkaran kypsymiseen ja laatuun

The possible use of gram-negative bacteria as starter cultures in dry sausage was studied by inoculating the following gram-negative bacteria into dry sausage both alone and with Lactobacillus plantarum: Aeromonas x, Aeromonas 19. Vibrio costicolus, Achromobacter 22, Achromobacter guttatus, Achromobacter X, Escherichia coli, or Proteus vulgaris. Sausage without any inoculation and sausage containing Micrococcus sp. + Lactobacillus plantarum were used as references. Aeromonas x and 19 strains had a very favourable effect on the quality of dry sausage when inoculated together with lactobacilli. Both strains reduced nitrate, and the colour formed during the first 3 days. The pH value of Aeromonas + Lactobacillus sausages decreased so quickly that the consistency of these sausages developed within one week and was at least as good as, and often firmer than in Micrococcus + Lactobacillus sausages. The consistency of Aeromonas 19 + Lactobacillus sausages was better at the 0.05 significance level than that of Micrococcus + Lactobacillus samples. The aroma and flavour of Aeromonas + Lactobacillus sausages were as good as or better than those of Micrococcus 4- Lactobacillus sausages. The aroma and flavour of Aeromonas 19 + Lactobacillus sausages were significantly better (significance level 0.001) than Micrococcus-f Lactobacillus sausages. The flavour of Aeromonas x + Lactobacillus sausages was better at the 0.05 level than Micrococcus + Lactobacillus sausages. The number of bacteria, roughly the number of lactobacilli. was often significantly higher in Aeromonas + Lactobacillus sausages (range 2—4 x 108/g between 3 and 21 days of ripening) than in Micrococcus + Lactobacillus sausages (range 8 X 107 1.5 X 108/g between 3 and 21 days of ripening). For this reason the former sausages ripened more quickly than the latter. Vibrio 21 and three Achromobacter strains did not thrive in dry sausage and disappeared during the first 7 days of ripening. When inoculated together with lactobacilli, Escherichia coli had almost as favourable an effect as micrococci on the quality of dry sausage. Inoculations of E. coli alone and Proteus vulgaris, both alone and with lactobacilli, did not improve the quality of dry sausage. P. vulgaris actually had a detrimental effect. Conclusion The investigation has proved that gram-negative bacterial strains Aeromonas x and 19 inoculated with lactobacilli improve the quality of dry sausage and that, especially with the Aeromonas 19 + Lactobacillus inoculum, better dry sausage was obtained than with micrococci and lactobacilli.Gram-negatiivisten bakteerien mahdollista käyttöä starterkulttuureina kestomakkarassa tutkittiin siirrostamalla seuraavia gram-negatiivisia bakteereita kestomakkaraan yksinään ja Lactobacillus plantarumin kanssa: Aeromonas x, Aeromonas 19, Vibrio costicolus, Achromobacter guttatus, Achromobacter 22, Achromobacter X, Escherichia coli tai Proteus vulgaris. Ilman bakteerilisäystä valmistettuja makkaroita sekä mikrokokki + laktobasillilisäyksellä valmistettuja makkaroita käytettiin vertailunäytteinä tutkimuksessa. Kaksikymmentäkaksi koesarjaa kestomakkaraa valmistettiin ja tutkittiin kypsymisajan ollessa 21 vuorokautta. Seuraavia johtopäätöksiä voidaan tehdä bakteeri-inokulaatioiden vaikutuksista kestomakkaran kypsymisprosessiin ja laatuun: 1. Ilman bakteerilisäystä valmistettujen näytteiden väri, konsistenssi, aromi ja maku olivat yleensä huonoimmat mikrokokki + laktobasillimakkaroiden ollessa paljon parempia ja jopa kilpaillen laadussa muiden koemakkaroiden kanssa. Mikrokokeilla ja laktobasilleilla siirrostettujen makkaroiden väri kehittyi kolmessa ja konsistenssi seitsemässä vuorokaudessa. Aromi ja väri olivat myös hyväksyttäviä viikon vanhoissa näytteissä. Mikrokokki pelkisti nitraattia kolmessa päivässä siten, että keskimääräinen nitriittimäärä nousi 34.1 ppm;ään ja laski sen jälkeen. Mikrokokkimäärä oli hieman yli 107/g koko kypsymisajan, kun taas laktobasillimäärä kohosi 107/g:sta 108/g:aan kolmessa päivässä. pH-arvo laski kolmessa vuorokaudessa 5.70:sta 5.28:aan. 2. Kannat Aeromonas x ja Aeromonas 19 vaikuttivat suotuisasti kestomakkaran väriin, mutta muuten näytteiden laatu oli kontrollimakkaroiden tasoa. Aeromonas-kannat eivät muodostaneet makkaran laatuun vaikuttavia määriä happoa kestomakkarassa eivätkä siten parantaneet konsistenssia. Aromi ja maku olivat hieman parempia kuin kontrollimakkaroissa. 3. Aeromonas x ja 19 kannoilla oli varsin suotuisa vaikutus kestomakkaran laatuun laktobasillien kanssa inokuloituina. Molemmat kannat pelkistivät nitraattia värin muodostuessa kolmen ensimmäisen päivän aikana. Aeromonas + laktobasillimakkaroiden pH-arvo laski jopa nopeammin ja alemmaksi kuin mikrokokki -f laktobasillimakkaroissa ollen noin 5.20 kolmen päivän kypsytyksen jälkeen. Aeromonas + laktobasillinäytteiden konsistenssi kehittyi yhdessä viikossa ja oli ainakin yhtä hyvä ja usein parempikin kuin mikrokokki laktobasillimakkaroissa. Aeromonas 19 + Lactobacillus-makkaroiden konsistenssi oli parempi kuin Micrococcus + Lactobacillus-näytteiden merkitsevyystasolla 0.05. Aeromonas + laktobasillimakkaroiden aromi ja maku olivat yhtä hyviä tai parempia kuin mikrokokki + laktobasillinäytteiden. Aeromonas 19 + Lactobacillus -makkaroiden aromi ja maku olivat merkitsevästi (merkitsevyystaso 0.001) parempia kuin Micrococcus + Lactobacillus-makkaroiden. Aeromonas x + Lactobacillus-näytteiden maku oli merkitsevyystasolla 0.05 parempi kuin Micrococcus + Lactobacillus-makkaroiden. Kokonaisbakteerimäärä, vastaten suurin piirtein laktobasillimäärää, oli usein merkitsevästi suurempi aeromonas + laktobasillimakkaroissa (vaihteluväli 24 x 108/g 321 kypsytysvuorokauden aikana) kuin mikrokokki + laktobasillimakkaroissa (vaihteluväli 8 x 107 1.5 x 108/g 321kypsytysvuorokaudenaikana). Tästä syystä edelliset makkarat kypsyivät nopeammin kuin jälkimmäiset. 4. Vibrio costicolus ja kolme Achromobacter-kantaa eivät vain viihtyneet huonosti kestomakkarassa, vaan hävisivät täydellisesti seitsemän ensimmäisen kypsytysvuorokauden aikana. Pelkästään Escherichia coli bakteerilla siirrostetut makkarat olivat laadultaan samaa luokkaa kuin kontrollimakkarat. Laktobasillien kanssa inokuloituna E. coli vaikutti paljolti mikrokokkien tavoin. Kuitenkin Micrococcus + Lactobacillus-makkarat olivat joka suhteessa hieman parempia kuin E. coli + Lactobacillus-makkarat. Proteus vulgaris vaikutti haitallisesti kestomakkaran laatuun sekä yksin että laktobasillien kanssa inokuloituna. Loppupäätelmä: Tutkimus osoitti, että gram-negatiiviset bakteerikannat Aeromonas x ja 19 laktobasillien kanssa inokuloituna vaikuttavat edullisesti kestomakkaran laatuun. Etenkin Aeromonas 19 + Lactobacillus-inokulaation avulla saatiin parempaa kestomakkaraa kuin lisättäessä makkaraan mikrokokkeja ja laktobasilleja

The Effect of some gram-negative bacteria on the ripening and quality of dry sausage

vokkirjasto Aj-KDiss. : Helsingin yliopistoEräiden gram-negatiivisten bakteerien vaikutus kestomakkaran kypsymiseen ja laatuu

Cooked meat products made of coarsely ground pork: the main bacterial strains of bacterial flora, their heat resistance and effect on spoilage

Keitettyjen karkeahienonnetusta lihasta valmistettujen lihavalmisteiden pintaosan ja sisäosan bakteeriflooraa tutkittiin pilaantumishetkellä, kun valmisteita oli säilytetty 7°C tai 4°C:ssa. Flooraa hallitsevat bakteerikannat eristettiin ja niiden lämpöresistenssiä tutkittiin APT-liemessä, APT-agarilla ja karkeahienonnetussa suolatussa sianlihassa. Valmisteiden pintaosan bakteeriflooraa hallitsevat kannat olivat kokkimaisia maitohappobakteereja lukumäärien vaihdellessa välillä 3,5-7,8 log pmy (pesäkkeen muodostava yksikkö)/g. Valmisteiden sisäosan bakteerifloora sisälsi valtaorganismeina kokkimaisia maitohappobakteereja, kokkimaisia maitohappobakteereja ja pseudomonadeja tai pseudomonadeja. Kaksi lämpöresisteintä maitohappobakteeria olivat streptokokkeja. Sisäosan bakteerien kokonaislukumäärät vaihtelivat välillä 2,5-6,0 log pmy/g. Valmisteiden pintaosasta eristetyt bakteerikannat säilyivät lisääntymiskykyisinä vain satunnaisesti, kun niitä lämpökäsiteltiin 15 min 72°C:ssa APT-Iiemessä. Useimmat valmisteiden sisäosasta eristetyistä kannoista säilyivät lisääntymiskykyisinä vähintään kolmessa kokeessa kuudesta, kun niitä lämpökäsiteltiin 30 min 72°C:ssa APT-llemessä. On merkille pantavaa, että kaikki sisäosasta eristetyt pseudomonadikannat säilyivät Iisääntymiskykyisinä, kun niitä lämpökäsiteltiin 60 min 72°C:ssa APT-liemessä, ja usein, kun niitä lämpökäsiteltiin karkeahienonnetussa sianlihassa 5 min 72°C:ssa. Inokuloitujen pseudomonadien lukumäärä laski, kun lämpökäsiteltyjä koelihoja säilytettiin 4°C:ssa. Siten ne eivät todennäköisesti ole vakava pilaantumistekijä karkeahienonnetusta lihasta valmisteluissa lihavalmisteissa tai keitetyissä lihavalmisteissa yleensä. Lämpöresisteimpien streptokokkien lukumäärä (pmy) laski APT-liemessä jyrkemmin kuin karkeahienonnetussa sianlihassa, jossa lasku oli noin yksi log-yksikkö 15 minuutissa. Kun lämpökäsiteltyjä karkeahienonnettuja ja suojattuja sianlihoja säilytettiin 4 viikkoa 4°C:ssa, streptokokkien lukumäärä nousi enintään yhden log-yksikön. Kuitenkin myöskään streptokokit eivät aiheuttane pilaantumista, koska niiden lukumäärä laskee lämpökäsittelyn aikana selvästi ja nousee kylmävarastoinnin aikana vain vähän.This study was conducted to investigate the bacterial flora of the surface layer and the core of meat products made of coarsely ground pork at the moment of spoilage when stored at 7°C or 4°C. The dominating strains were isolated, their heat resistance was studied in APT-broth, on APT-agar and in coarsely ground cured pork, and their growth after heating and effect on spoilage were followed in coarsely ground cured pork. The first signs of spoilage appeared in the surface layer of the products. The strains were coccoid lactic acid bacteria with counts ranging from 3.5 to 7.8 log cfu (colony forming units)/g. They survived only accidentally after heating for 15 minutes at 72°C in APT-broth. The core of the products contained only coccoid lactic acid bacteria or only pseudomonads or both as the main bacterial strains. The counts ranged from 2.6 to 6.0 log cfu/g. Most of the strains isolated from the core survived after heating for 30 minutes at 72°C in APT-broth in at least three tests out of six. The most noticeable result of the study was the occurence of heat-resistant pseudomonads in the core. It must he pointed out that all pseudomonads found survived after heating for 60 minutes at 72°C in APT-broth, and often after heating for 15 minutes at 72°C in coarsely ground cured pork (core 72°C). The cfu number of the two most heat-resistant streptococcus strains decreased only 1 log unit over 15 minutes at 72°C in coarsely ground cured pork. The numbers of inoculated pseudomonads decreased but those of streptococci rose by a maximum of 1 log unit when the experimental porks were kept at 4°C after heating. This indicates that streptococci and pseudomonads probably do not constitute a serious spoilage factor in cooked meat products, but spoilage is generally effected by bacteria which have contaminated the surface layer of the products after heat treatment.vokKeitettyjen karkeahienonnetusta lihasta valmistettujen lihavalmisteiden bakteeriflooran hallitsevat bakteerikannat, niiden lämpöresistenssi ja vaikutus pilaantumisee

Keitettyjen karkeahienonnetusta lihasta valmistettujen lihavalmisteiden bakteerillooran hallisevat bakteerikannat, niiden lämpöresistenssi ja vaikutus pilaantumiseen

This study was conducted to investigate the bacterial flora of the surface layer and the core of meat products made of coarsely ground pork at the moment of spoilage when stored at 7°C or 4°C. The dominating strains were isolated, their heat resistance was studied in APT-broth, on APT-agar and in coarsely ground cured pork, and their growth after heating and effect on spoilage were followed in coarsely ground cured pork. The first signs of spoilage appeared in the surface layer of the products. The strains were coccoid lactic acid bacteria with counts ranging from 3,5 to 7.8 log cfu (colony forming units)/g. They survived only accidentally after heating for 15 minutes at 72°C in APT-broth. The core of the products contained only coccoid lactic acid bacteria or only pseudomonads or both as the main bacterial strains. The counts ranged from 2.6 to 6.0 log cfu/g. Most of the strains isolated from the core survived after heating for 30 minutes at 72°C in APT-broth in at least three tests out of six. The most noticeable result of the study was the occurence of heat-resistant pseudomonads in the core. It must be pointed out that all pseudomonads found survived after heating for 60 minutes at 72°C in APT-broth, and often after heating for 15 minutes at 72°C in coarsely ground cured pork (core 72°C). The cfu number of the two most heat-resistant streptococcus strains decreased only 1 log unit over 15 minutes at 72°C in coarsely ground cured pork. The numbers of inoculated pseudomonads decreased but those of streptococci rose by a maximum of 1 log unit when the experimental porks were kept at 4°C after heating. This indicates that streptococci and pseudomonads probably do not constitute a serious spoilage factor in cooked meat products, but spoilage is generally effected by bacteria which have contaminated the surface layer of the products after heat treatment.Keitettyjen karkeahienonnetusta lihasta valmistettujen lihavalmisteiden pintaosan ja sisäosan bakteeriflooraa tutkittiin pilaantumishetkellä, kun valmisteita oli säilytetty 7°C tai 4°C:ssa. Flooraa hallitsevat bakteerikannat eristettiin ja niiden lämpöresistenssiä tutkittiin APT-liemessä, APT-agarilla ja karkeahienonnetussa suolatussa sianlihassa. Valmisteiden pintaosan bakteeriflooraa hallitsevat kannat olivat kokkimaisia maitohappobakteereja lukumäärien vaihdellessa välillä 3,5-7,8 log pmy(pesäkkeen muodostava yksikkö)/g. Valmisteiden sisäosan bakteerifloora sisälsi valtaorganismeina kokkimaisia maitohappobakteereja, kokkimaisia maitohappobakteereja ja pseudomonadeja tai pseudomonadeja. Kaksi lämpöresisteintä maitohappobakteeria olivat streptokokkeja. Sisäosan bakteerien kokonaislukumäärät vaihtelivat välillä 2,5-6,0 log pmy/g. Valmisteiden pintaosasta eristetyt bakteerikannat säilyivät lisääntymiskykyisinä vain satunnaisesti, kun niitä lämpökäsiteltiin 15 min 72°C:ssa APT-liemessä. Useimmat valmisteiden sisäosasta eristetyistä kannoista säilyivät lisääntymiskykyisinä vähintään kolmessa kokeessa kuudesta, kun niitä lämpökäsiteltiin 30 min 72°C:ssa APT-liemessä. On merkille pantavaa, että kaikki sisäosasta eristetyt pseudomonadikannat säilyivät lisääntymiskykyisinä, kun niitä lämpökäsiteltiin 60 min 72°C:ssa APT-liemessä. ja usein, kun niitä lämpökäsiteltiin karkeahienonnetussa sianlihassa 5 min 72°C:ssa. Inokuloitujen pseudomonadien lukumäärä laski, kun lämpökäsiteltyjä koelihoja säilytettiin 4°C:ssa. Siten ne eivät todennäköisesti ole vakavapilaantumistekijä karkeahienonnetusta lihasta valmistetuissa lihavalmisteissa tai keitetyissä lihavalmisteissa yleensä. Lämpöresisteimpien streptokokkien lukumäärä (pmy) laski APT-liemessä jyrkemmin kuin karkeahienonnetussa sianlihassa, jossa lasku oli noin yksi log-yksikkö 15 minuutissa. Kun lämpökäsiteltyjä karkeahienonnettuja ja suolattuja sianlihoja säilytettiin 4 viikkoa 4°C:ssa, streptokokkien lukumäärä nousi enintään yhden log-yksikön. Kuitenkin myöskään streptokokit eivät aiheuttane pilaantumista, koska niiden lukumäärä laskee lämpökäsittelyn aikana selvästi ja nousee kylmävarastoinnin aikana vain vähän

Cooked meat products made of coarsely ground pork: the main bacterial strains of bacterial flora, their heat resistance and effect on spoilage

This study was conducted to investigate the bacterial flora of the surface layer and the core of meat products made of coarsely ground pork at the moment of spoilage when stored at 7°C or 4°C. The dominating strains were isolated, their heat resistance was studied in APT-broth, on APT-agar and in coarsely ground cured pork, and their growth after heating and effect on spoilage were followed in coarsely ground cured pork. The first signs of spoilage appeared in the surface layer of the products. The strains were coccoid lactic acid bacteria with counts ranging from 3,5 to 7.8 log cfu (colony forming units)/g. They survived only accidentally after heating for 15 minutes at 72°C in APT-broth. The core of the products contained only coccoid lactic acid bacteria or only pseudomonads or both as the main bacterial strains. The counts ranged from 2.6 to 6.0 log cfu/g. Most of the strains isolated from the core survived after heating for 30 minutes at 72°C in APT-broth in at least three tests out of six. The most noticeable result of the study was the occurence of heat-resistant pseudomonads in the core. It must be pointed out that all pseudomonads found survived after heating for 60 minutes at 72°C in APT-broth, and often after heating for 15 minutes at 72°C in coarsely ground cured pork (core 72°C). The cfu number of the two most heat-resistant streptococcus strains decreased only 1 log unit over 15 minutes at 72°C in coarsely ground cured pork. The numbers of inoculated pseudomonads decreased but those of streptococci rose by a maximum of 1 log unit when the experimental porks were kept at 4°C after heating. This indicates that streptococci and pseudomonads probably do not constitute a serious spoilage factor in cooked meat products, but spoilage is generally effected by bacteria which have contaminated the surface layer of the products after heat treatment