Records 1 - 20 / 447
Handbook of Indigenous Foods Involving Alkaline Fermentation
Sarkar, P.K. ; Nout, M.J.R. - \ 2014
Boca Raton, FL : CRC Press (Fermented Foods and Beverages Series ) - ISBN 9781466565302 - 629
fermentation - fermented foods - foods - food microbiology - food preservation - food products - food quality - beverages - fermentatie - gefermenteerde voedingsmiddelen - voedingsmiddelen - voedselmicrobiologie - voedselbewaring - voedselproducten - voedselkwaliteit - dranken
This book details the basic approaches of alkaline fermentation, provides a brief history, and offers an overview of the subject. The book discusses the diversity of indigenous fermented foods involving an alkaline reaction, as well as the taxonomy, ecology, physiology, and genetics of predominant microorganisms occurring in AFFs. Presented in nine chapters, the book explains how microorganisms or enzymes transform raw ingredients into AFFs. It discusses the safety aspects of AFFs, and considers the challenges associated with the technological aspects in modernizing AFFs. It stresses the significance of the microbiological and biochemical processes in the fermentations, as well as the factors that influence the development of the characteristic microbiota, and the biochemical and organoleptic changes induced by them. It also proposes solutions, discusses the value of AFFs and related dominant microorganisms, and assesses the future of AFFs. The authors highlight commonly known foods and beverages of plant and animal origin. They provide insight into the manufacture, chemical and microbiological composition, processing, and compositional and functional modifications taking place as a result of microbial and enzyme effects. The text examines safety, legislation, traditional and industrialized processes, as well as new product development, and opportunities for developing commodities from Africa, Asia, Europe, Latin America, and the Middle East. In addition, it also assesses the value of food processing by-products, biotechnology, and engineering of solid-state processes, modern chemical and biological analytical approaches to safety, and health and consumer perception.
Vis langer houdbaar dankzij vriesdroger op zonne-energie
Bartels, P.V. - \ 2014
visproducten - vis - voedselbewaring - voedselverspilling - vriesdroging - droogmethoden - visverwerking - gedroogde vis - afrika - fish products - fish - food preservation - food wastage - freeze drying - drying methods - fish processing - dried fish - africa
In veel Afrikaanse landen gaat vis verloren omdat er geen koeling voorhanden is. Een vriesdroger die is ontwikkeld door de Wageningse onderzoeker Paul Bartels en Ebbens Engineering is veel verspilling te voorkomen. De gedroogde vis is ook zonder koeling lang houdbaar.
Impact of sorbic acid and other mild preservation stresses on germination and outgrowth of Bacillus cereus spores
Melis, C.C.J. van - \ 2013
Wageningen University. Promotor(en): Tjakko Abee, co-promotor(en): Masja Nierop Groot. - Wageningen : Wageningen University - ISBN 9789461737755 - 138
bacillus cereus - sorbinezuur - behoud - kieming - kiemremmers - groei - voedselbewaring - voedselmicrobiologie - bacillus cereus - sorbic acid - preservation - germination - germination inhibitors - growth - food preservation - food microbiology
Weak organic acids such as sorbic acid, lactate, and acetic acid are widely used by the food industry as preservatives to control growth of micro-organisms. With the current trend towards milder processing of food products, opportunities arise for spore-forming spoilage and pathogenic microorganisms such as Bacillus cereus, that may survive the use of milder heating regimes. Dormant spores produced by B. cereus can survive processing conditions and their subsequent outgrowth increases the risk of premature spoilage and food safety issues. As a consequence, the use of additional preservation hurdles, such as acidification with weak organic acid additives to ensure the quality and safety of a product is important. Sorbic acid is widely used as an antimicrobial compound because of its strong inhibitory properties against bacteria and other spoilage organisms. Its effectivity has also been ascribed to its hydrophobic character, resulting in an additional mode of action not observed with other less lipophilic organic acids such as lactic acid and acetic acid. In this project the impact of sorbic acid on spore germination and outgrowth was studied at transcriptome level and was linked to the distinct phenotypic responses observed for spores exposed to different levels of sorbic acid. The various stages of spore germination and outgrowth could be recognized by distinct gene expression profiles representing either the germination phase, transition state between germination and outgrowth or outgrowing cells, respectively. A subset of genes was specifically expressed in sorbic acid-exposed germinating spores and included functions related to cell envelope, (multi) drug transporters and amino acid metabolism. At high concentrations of sorbic acid (3mM of the undisssociated form, HSA), nutrient-induced germination of B. cereus ATCC 14579 spores was completely blocked. This blockage was shown to be reversible and could be bypassed by known non-nutrient triggers that activate spores in a receptor-independent way, pointing to a possible interference of HSA with the signaling event between germinant receptors and proposed SpoVA-channels, possibly by accumulation into the spore’s inner membrane. Additional experiments with other inhibiting compounds, including organic acids and their structurally similar alcohol counterparts, showed that the lipophilic properties are an important determinant of its efficacy to block germination. Building on current knowledge on the interaction of germination-relevant protein clusters, we discuss a hypothetical model on the mode of action of sorbic acid and other short-chain lipophilic compounds in germination inhibition of B. cereus spores. In addition to the interference or even blockage of germination, sorbic acid may increase outgrowth heterogeneity when applied at lower concentrations (0.25-1.5 mM) that still allow outgrowth. The first stages of outgrowth were shown to specifically occur heterogeneously when spores were exposed to multiple stresses simultaneously. Heterogeneity effects were most pronounced for combined stress-effects where heat-treated spores were also exposed to low pH stress. Under these conditions, a large subpopulation of spores was delayed between initial germination and swelling and further outgrowth. For the food producing industry, it would be desirable to have reliable parameters to predict the behavior of surviving spores in a food product. Data presented in this thesis show that germination rate is not a good predictor for outgrowth heterogeneity when applied as a single indicator. In conclusion, the work described in this thesis strive to obtain a better understanding on the impact that preservation stresses, including (sorbic) acid stress, have on the germination and outgrowth (heterogeneity) of B. cereus spores. The results obtained in this project may contribute to the rational design of new concepts for improved food preservation and safety.
|DCS-bewaren... Klaar voor de start? : Minder schilvlekjes op Elstar : plan van aanpak Elstar, deel 2
Geijn, F.G. van de; Montsma, M.P. - \ 2011
De Fruitteelt 101 (2011)28. - ISSN 0016-2302 - p. 6 - 7.
appels - opslag - voedselbewaring - zuurstof - technieken - kwaliteitscontroles - apples - storage - food preservation - oxygen - techniques - quality controls
DCS-bewaring is uitgegroeid tot een toepasbaar laag zuurstofbewaarsysteem. Met dit systeem van Food & Biobased Research behoudt de bewaarder niet alleen kwaliteit in de lange bewaring, maar blijft de hardheid vooral in de uitstalperiode op peil. Specifiek voor Elstar is voordeel te behalen in de vorm van minder schilvlekjes.
Bacillus cereus: emetic toxin production and gamma hypothesis for growth
Biesta-Peters, E.G. - \ 2011
Wageningen University. Promotor(en): Marcel Zwietering; Leon Gorris, co-promotor(en): Martine Reij. - [S.l.] : S.n. - ISBN 9789085859932 - 192
bacillus cereus - groei - bacteriële toxinen - voedselbewaring - voedselveiligheid - bacillus cereus - growth - bacterial toxins - food preservation - food safety
Bacillus cereus is a food spoilage microorganism and a pathogen. Growth of B. cereus can
be prevented or delayed by adding growth limiting compounds to the food product or
by altered storage conditions. Combinations of growth limiting factors can show synergy,
or be multiplicative without synergy (gamma hypothesis). For food safety management,
it is important to understand if combinations are synergistic or not, to avoid making faildangerous
or overly fail-safe predictions. Therefore, the aim of this PhD project was to
validate the gamma hypothesis for specific combinations of hurdles commonly used in
food production. Since the relationship between growth and toxin production of B. cereus
is little understood, a second aim was to investigate the production of the emetic toxin
cereulide in more detail. Several new lines of research were set-up to deliver on these
aims. For growth data collection to quantify hurdle effects and to study combinations
of hurdles, the relative rate to detection method was found to be preferred over two
other methods evaluated. The gamma hypothesis was validated for combinations of pH
and undissociated acid. For combinations of pH and water activity lowering solutes, the
gamma hypothesis could neither be validated nor rejected. The validity of the gamma
hypothesis appeared to be dependent on the models chosen for the single hurdle effects,
which are subsequently combined into the gamma model. A systematic way of model
selection is therefore advocated. Investigating cells in the transition from lag phase (λ)
to exponential growth phase, it was found that trends in physiological processes could
be observed for different culture conditions, independent of the duration of λ. Esterase
activity and electron transport chain activity were found to be useful quantitative markers
for this transition phase. A new method to produce synthetic cereulide showing biological
activity was developed, allowing accurate quantification of cereulide in samples. The
use of valinomycin as a standard, the current procedure, underestimates the amount of
cereulide by approximately 10 %. Considering the onset of emetic toxin production, LCMS
analysis of B. cereus F4810/72 grown in BHI showed that cereulide production does
not start before cells are in mid to late stationary phase, although significant variation
was noted possibly related to variability in the growth parameters maximum specific
growth rate (μmax) and λ. Addition of salt to the growth medium delayed the production
of cereulide. This research has been able to deliver several new insights and tools that are
useful for food safety management of the emetic toxin producer B. cereus.
Alternatieven voor koeling : factsheet
Broeze, J. ; Sluis, S. van der - \ 2009
koelen - koeling - voedselbewaring - voedseltechnologie - cooling - chilling - food preservation - food technology
Wat zijn de alternatieven voor koeling? Wat zijn de nieuwe technieken voor voedselconservering?
European boost for food technology research
Thoenes, E. ; Vries, H.S.M. de - \ 2009
Wageningen Update (2009)1. - ISSN 1569-3279 - p. 10 - 11.
voedseltechnologie - voedselbewaring - voedselonderzoek - voedselverwerking - food technology - food preservation - food research - food processing
They set themselves ambitious goals: to maintain food texture, improve shelf life, and reduce energy consumption during preservation processes. The EU-funded ‘NovelQ’ consortium, consisting of 36 research partners from across Europe, is co-ordinated by the Agrotechnology and Food Sciences Group (AFSG) of Wageningen UR. Halfway through the five-year term, Wageningen Update examines the state of affairs and the experiences thus far.
Bacillus cereus acid stress responses
Mols, J.M. - \ 2009
Wageningen University. Promotor(en): Tjakko Abee; Marcel Zwietering, co-promotor(en): Roy Moezelaar. - [S.l. : S.n. - ISBN 9789085854944 - 176
bacillus cereus - stressreactie - voedselbewaring - bacillus cereus - stress response - food preservation
Bacillus cereus is a ubiquitous Gram-positive organism, which frequently causes foodborne
illnesses. The widespread prevalence of B. cereus makes it a common contaminant in
fresh foods where it also can cause spoilage. To prevent food-borne diseases and food
spoilage, foods are often processed and/or preserved. In recent years, consumers’
preferences have directed to fresher and tastier foods and this has acted as a driver for food
industry to use milder processing and preservation techniques. Examples of hurdles that can
be applied to preserve foods are low pH and the addition of organic acids. B. cereus may
overcome these adverse conditions by displaying an adaptive stress response. The response
of B. cereus upon exposure to these hurdles was investigated using two model strains,
ATCC 14579 and ATCC 10987. Comparative analysis revealed numerous strain-specific
genes and differences in metabolic capacities, including a urease encoding gene cluster in
ATCC 10987 and a nitrate respiration cluster in ATCC 14579. A survey including ATCC
10987 and 48 environmental and outbreak-associated isolates revealed urease activity, i.e.,
the conversion of urea in ammonia and carbon dioxide, to be present in 10 isolates.
However, the activity appeared to be too low to contribute to acid resistance in the strains
tested. To search for other acid resistance mechanisms, comparative phenotype and
transcriptome analyses of strains ATCC 14579 and ATCC 10987 cells exposed to organic
and/or inorganic acid shocks were performed. Upon exposure to low pH with or without the
addition of lactic acid or acetic acid, common acid resistance mechanisms and induction of
the nitrate reductase cluster in the more acid resistant strain ATCC 14579 were revealed.
Furthermore, a major oxidative response was displayed, which included the induction of
several oxidative stress related genes and the production of inactivation-associated reactive
oxygen species (ROS), such as hydroxyl radicals, peroxynitrite, and superoxide. ROS were
detected using fluorescent probes in combination with flow cytometry, including a newly
developed method using a specific probe that enables superoxide detection in Grampositive
and Gram-negative bacteria. The formation of ROS was also shown upon exposure
to heat and was found to be oxygen dependant. Correspondingly, assessment of B. cereus
stress survival capacity revealed increased heat- and acid-resistance with cells grown and
exposed to stresses in the absence of oxygen. The excess ROS may originate from stressinduced
dysfunction of the aerobic electron transfer chain, which was indicated by the
induction of alternative electron transfer chain components upon exposure to organic and
inorganic acid shocks. Upon exposure to stress, superoxide is generated through the
premature leakage of electrons to oxygen at sites in the electron transfer chain at elevated
rates. Subsequently, superoxide may promote the formation of other ROS, which can cause
cellular damage leading to cell death. The induction of oxidative stress related genes has
been reported in numerous other studies involving a wide range of bacteria exposed to
different adverse conditions. However, a clear relation between the formation of ROS and
the applied environmental stress was up to now not established. Secondary oxidative responses, including the formation of ROS, are possibly common bacterial responses to
severe stresses under aerobic conditions. This thesis describes genomic differences between
B. cereus strains and the acid stress response of these strains on transcriptome and
phenotype levels, including measurements of intracellular ROS. The findings in this study
can contribute to further understanding of bacterial stress responses and secondary
oxidative responses. Furthermore, the results obtained may aid to optimize and select
(combinations of) stresses to apply in hurdle technology, thus enabling design of safe,
milder food processing and preservation techniques.
Development of appropriate processing technology for fruit export by smallholder farmers : technical assistance in the processing of products of Equator Products Ltd. in Kenya : report of research activities in 2008
Bartels, P.V. - \ 2008
Wageningen : Agrotechnology and Food Sciences Group (A&F report / Agrotechnology and Food Sciences Group 990) - ISBN 9789085853428 - 49
voedselbewaring - drogen - droogmethoden - drogers - zonne-energie - zonne-energieverwarming - decontaminatie - spaanse pepers - kenya - food preservation - drying - drying methods - driers - solar energy - solar heating - decontamination - chillies - kenya
Seafood research from fish to dish : quality, safety and processing of wild and farmed fish
Luten, J.B. - \ 2006
Wageningen : Wageningen Academic Publishers - ISBN 9789086860050 - 567
zeevruchten - visproducten - visverwerking - voedselkwaliteit - voedselveiligheid - lipiden - voedselbewaring - houding van consumenten - methodologie - seafoods - fish products - fish processing - food quality - food safety - lipids - food preservation - consumer attitudes - methodology
In this book, scientists from various disciplines address the advances in seafood research with respect to quality, safety, consumer’s demands and processing of wild and farmed fish. The nutritional properties of marine lipids and lipid oxidation from model systems to seafood are presented. Several contributions on the effects of natural anti-oxidants to prevent oxidation are also included. Effects of dietary factors on muscle tissue quality, pre-rigor processing and brining of farmed cod are covered. The development of rigor mortis and the quality of muscle in relation to commercial and experimental slaughter techniques are also discussed. Consumer’s knowledge, perception and need for information about seafood are discussed. Topics such as shelf life and microbial quality of seafood are covered in a range of contributions. Inactivation of micro organisms or biopreservation of seafood are included. Attention is paid to the development of the Quality Index Method for the evaluation of the quality of fresh fish and products. The characterisation and the quality of processed by-products are also presented. The presence of trace elements and organic contaminants in variety of seafood products is highlighted. Finally, several contributions regarding advanced methodologies to determine the quality of seafood are presented.
Reductie van het nitrietgebruik bij de biologische vleeswarenbereiding
Stegeman, D. ; Jansen, W.W.J.T. ; Zegveld, A. ; Verkleij, T.J. ; Stekelenburg, F.K. - \ 2006
Wageningen : Agrotechnology & Food Sciences Group (Rapport / Wageningen UR, Agrotechnology & Food Science Group 658) - ISBN 9789085850182 - 52
vleeswaren - biologische voedingsmiddelen - nitriet - voedseladditieven - voedselbewaring - kleurstoffen in voedsel - aromatische stoffen - voedselveiligheid - meat products - organic foods - nitrite - food additives - food preservation - food colourants - flavourings - food safety
Bij de productie van veel soorten vleeswaren wordt nitriet gebruikt voor het verkrijgen van een door de consument gewenste stabiele roze kleur, voor de smaak en voor de microbiologische stabiliteit. Over de toepassing van nitriet bij de bereiding van biologische vleeswaren bestaat al jaren een discussie. Om deze discussie te ondersteunen is er een experimentele studie uitgevoerd, waarin het effect op de kleur en de kleurstabiliteit tijdens de bewaring van biologische vleeswaren, geproduceerd met een verlaagde hoeveelheid nitriet, werd onderzocht. Daarnaast zijn challengetesten met vleeswaren uitgevoerd, met als doel de ontwikkelingsmogelijkheden van Clostridium botulinum in vleesproducten met verlaagd nitrietgehalte te bestuderen. Geconcludeerd wordt dat de kans op de ontwikkeling van C. botulinum bacteriën en de vorming van botuline toxien relatief klein is voor gepasteuriseerde vleesproducten zonder nitriet die gekoeld bewaard worden en qua productsamenstelling lijken op de in het onderzoek onderzochte modelvleesproducten
Pulsed electric field inactivation in a microreactor
Fox, M.B. - \ 2006
Wageningen University. Promotor(en): Remko Boom, co-promotor(en): Paul Bartels. - [S.l.] : S.n. - ISBN 9789085045175 - 123
elektrisch veld - inactivatie - voedselbewaring - micro-organismen - electric field - inactivation - food preservation - microorganisms
Pulsed electric fields (PEF) is a novel, non-thermal pasteurization method which uses short, high electric field pulses to inactivate microorganisms. The advantage of a pasteurization method like PEF compared to regular heat pasteurization is that the taste, flavour, texture and nutritional value are much less affected. At the moment, the PEF process faces several challenges, to which microtechnology could be an aid. The small electrode distance in microtechnological reactors enables the use of relatively low voltages and therefore a better control of the pulses. Secondly, the temperature can be controlled because of the high surface-to-volume ratio. It is therefore possible to separate the electric field inactivation kinetics and heat inactivation kinetics. This thesis describes the design of a PEF microreactor, inactivation experiments on several model systems combined with a comparison to a single cell electroporation microtechnological chip and the conceptual design of anupscaledPEF microreactor.
Reductie van nitrietgebruik bij biologische vleeswarenbereiding : een literatuuroverzicht
Stegeman, D. ; Verkleij, T.J. ; Stekelenburg, F.K. - \ 2005
Wageningen : Agrotechnology & Food Innovations (Rapport / Wageningen UR, Agrotechnology & Food Innovations 560) - ISBN 9789067549790 - 44
vleeswaren - biologische voedingsmiddelen - nitriet - voedseladditieven - voedselbewaring - kleurstoffen in voedsel - aromatische stoffen - meat products - organic foods - nitrite - food additives - food preservation - food colourants - flavourings
Nitrite is a commonly used additive in the production of meat products like cold meats. It is used as a preservative and gives the product the well known pink colour and flavour. In organic meat products, nitrite is defined an undesirable additive. In the present literature survey, an overview of the functions of nitrite and possible, organic and conventional, alternatives to reduce or replace nitrite are given. From the survey it can be concluded that simply abandoning nitrite in the production of organic meat products is not possible without changes in appearance and controlling product safety.
Quality, energy requirement and costs of drying tarragon (Artemisia dracunculus L)
ArabHosseini, A. - \ 2005
Wageningen University. Promotor(en): J. Mueller, co-promotor(en): W. Huisman; Ton van Boxtel. - Wageningen : - ISBN 9789085042976 - 115
dragon - artemisia dracunculus - energieproductiekosten - drogen - voedselbewaring - droogkwaliteit - luchtdroging - extractie - etherische oliën - keukenkruiden - medicinale planten - iran - nederland - tarragon - artemisia dracunculus - energy cost of production - drying - food preservation - drying quality - air drying - extraction - essential oils - culinary herbs - medicinal plants - iran - netherlands
Tarragon ( Artemisia dracunculus L.) is a favorite herbal and medicinal plant. Drying is necessary to achieve longer shelf life with high quality, preserving the original flavor. Essential oil content and color are the most important parameters that define the quality of herbal and medicinal plants. Hot air batch drying is the most common drying method for these plants but affects the essential oil content and color. The drying conditions affect essential oil content and color as well as the energy consumption and costs. Process engineers and farmers need to know how they have to dry to obtain the best quality. The objective of this work is to investigate the conditions for optimal drying in terms of quality, energy consumption and costs.
Adsorption and desorption experiments were done to find the equilibrium moisture content and water exchange between the material and surrounding air during drying and storage at temperatures of 25ºC to 70ºC and relative humidities of 5% to 90%. Drying of tarragon leaves and chopped plants was investigated separately and the best model was selected from the drying equations in literature. The effect of drying temperature and relative humidity on the essential oil content and color change was studied. Experiments were done at temperatures of 40ºC to 90ºC and the optimal conditions were. Long‑term effects of the drying conditions were also investigated during the storage time. Material dried at 45, 60 and 90ºC was stored and the essential oil content and color of the material was measured after 15, 30, 60 and 120 days of storage. Drying at 45ºC was found as the best condition based on the changes of essential oil and color during drying and storage.
Optimization of drying of tarragon was studied based on the results of the sorption isotherms, drying equations and the changes of essential oil content and color during drying and storage. Models were made for the drying process, energy consumption and cost calculation. The current conditions in The Netherlands and
Improving the safety of fresh fruit and vegetables
Jongen, W.M.F. - \ 2005
Cambridge : CRC (Woodhead publishing in food science and technology ) - ISBN 9781855739567 - 639
fruit - groenten - voedselveiligheid - pathogenen - voedselbewaring - gevaren - risicoschatting - decontaminatie - fruit - vegetables - food safety - pathogens - food preservation - hazards - risk assessment - decontamination
Fresh fruit and vegetables have been identified as a significant source of pathogens and chemical contaminants. As a result, there has been a wealth of research on identifying and controlling hazards at all stages in the supply chain. Improving the safety of fresh fruit and vegetables reviews this research and its implications for food processors.
|De optimale perencel
Geijn, F.G. van de - \ 2005
De Fruitteelt 95 (2005)45. - ISSN 0016-2302 - p. 10 - 11.
peren - pyrus - houdbaarheid (kwaliteit) - opslagkwaliteit - gewaskwaliteit - koelsystemen - toegepast onderzoek - voedselbewaring - fruitbewaarplaatsen - pears - keeping quality - storage quality - crop quality - cooling systems - applied research - food preservation - fruit stores
Binnen het KwaliCon-project is een studie verricht naar het definiëren van de optimale Conference-bewaarcel. Vochtverlies was een belangrijk aandachtspunt en de vraag is of dit zonder verpakken, afdekken, bevochtigen of andere technieken is te minimaliseren. Diverse technieken zijn onderzocht
|KwaliCon-onderzoek heeft positief effect op kwaliteit Conference
Schaik, A.C.R. van; Jager, A. de - \ 2005
De Fruitteelt 95 (2005)45. - ISSN 0016-2302 - p. 8 - 9.
peren - pyrus - opslagkwaliteit - koudeopslag - houdbaarheid (kwaliteit) - gewaskwaliteit - toegepast onderzoek - voedselbewaring - fruitbewaarplaatsen - pears - storage quality - cold storage - keeping quality - crop quality - applied research - food preservation - fruit stores
Het afgeronde KwaliCon-onderzoek was bedoeld om het bewaarproces te verbeteren en de kwaliteit van Conference-peren te behouden. Via de resultaten van dit project zijn diverse toepassingen ontwikkeld waardoor de bewaarkwaliteit sterk is verbeterd. De belangrijkste doelstelling was om slappe nekken bij de Conference-bewaring tegen te gaan
|Dynamic control system voor verlengen kwaliteit
Peppelenbos, H.W. - \ 2005
Versmanagement 2 (2005)1. - ISSN 1572-798X - p. 46 - 47.
aardappelen - verse producten - voedselbewaring - houdbaarheid (kwaliteit) - bewaartijd - voedselkwaliteit - opslag - meting - potatoes - fresh products - food preservation - keeping quality - storage life - food quality - storage - measurement
Op het instituut Agrotechnology & Food Innovations van de universiteit Wageningen wordt onderzoek gedaan naar de beste condities waarbij producten vers blijven. Bijvoorbeeld bij Nederlandse appels: ze hebben één oogstmoment maar zijn dankzij het uitgekiende bewaarsysteem Dynamic Control System toch het hele jaar leverbaar. Dr. Herman Peppelenbos, groepshoofd van Postharvest Quality of Fresh Products bij Agrotechnology & Food Innovations over dit systeem
|Nieuwe conserveringstechnieken op punt van doorbreken
Groote, Y. de; Bartels, P.V. - \ 2004
ZuivelZicht 96 (2004)3. - ISSN 0165-8573 - p. 21 - 23.
conservering - conserveermiddelen - voedselbewaring - houdbaarheid (kwaliteit) - bewaartijd - voedingsmiddelen - technologie - technieken - conservation - preservatives - food preservation - keeping quality - storage life - foods - technology - techniques
Nieuwe technologieën voor het langer houdbaar maken van voedsel staan op het punt om door te breken in de zuivelindustrie. Vooral het gebruik van hoge druk en pulserende elektrische velden zijn veelbelovend voor niche producten, meent dr. Paul Bartels.
Survival strategies of Listeria monocytogenes - roles of regulators and transporters
Wemekamp-Kamphuis, H.H. - \ 2003
Wageningen University. Promotor(en): Frans Rombouts, co-promotor(en): Tjakko Abee; J.A. Wouters. - [S.l.] : S.n. - ISBN 9789058089335 - 152
listeria monocytogenes - voedselbewaring - koudeshock - bacteriële eiwitten - osmoregulatie - genetische regulatie - celmembranen - eiwittransport - listeria monocytogenes - food preservation - cold shock - bacterial proteins - osmoregulation - genetic regulation - cell membranes - protein transport
Outbreaks of the food-borne pathogen Listeria monocytogenes are mainly associated with ready-to-eatfoods. Survival strategies of L. monocytogenes in relation to minimally processed foods were studied.
L.monocytogenespossesses several mechanisms to regulate transcription, e.g. the cold-shock proteins and the alternative sigma factorsB. Studies showed thatsBplays a crucial role in survival and adaptation to acidic conditions, HHP treatment and freezing by inducing the transcription of several genes.
To survive adverse conditions, L. monocytogenes accumulates solutes such as theosmolytesbetaine and carnitine, and (proline-containing) peptides. The transportersBetL,GbuandOpuCmediate betaine and carnitine uptake in the cell, ensuring low-temperature and high-osmolarity growth.OpuB, a fourthtransporter, is not involved in betaine or carnitine accumulation. Strains carrying anopuC oropuBdeletion were impaired in their ability to cause infection in mice.
Understanding the growth and survival of L. monocytogenes and knowledge of virulence factors will contribute to adequate food-safety measures.