Hélène Gerard-Simonin

• PhD HDR
• Lecturer at Université Bourgogne Europe

Favoriser l’approvisionnement local dans la restauration collective est considéré comme un levier important de réduction de l’impact environnemental de l’activité agricole et alimentaire. Ce travail étudie les effets de choix organisationnels et logistiques des acteurs de la production et de la transformation sur la performance environnementale de...

Favoriser l’approvisionnement local dans la restauration collective est considéré comme un levier important de réduction de l’impact environnemental de l’activité agricole et alimentaire. Ce travail étudie les effets de choix organisationnels et logistiques des acteurs de la production et de la transformation sur la performance environnementale de...

The sensitivity of Paenibacillus sp. and Terribacillus aidingensis spores to combined action of HP, nisin and moderate heating were investigated for the first time. The results showed that the effect of HP on spores varies with pressure level, treatment temperature, spore species and presence of nisin. T. aidingensis spores were more resistant than...

Bacterial spores are extremely resistant life-forms that play an important role in food spoilage and foodborne disease. The return of spores to a vegetative cell state is a three-step process, these being activation, germination, and emergence. High-pressure (HP) processing is known to induce germination in part of the spore population and even to...

During slow freezing, spermatozoa undergo membrane alterations that compromise their ability of fertilizing. These alterations are cause either by cold shock or by the use of cryoprotectants known to be cytotoxic. However, little is known about the membrane changes that occurred during freezing. Here, we combined Generalized Polarization (GP), Time...

Today, there is no effective non-thermal method to inactivate unwanted bacterial spores in foods. High-Pressure (HP) process has been shown to act synergistically with moderate heating and the bacteriocin nisin to inactivate spores but the mechanisms have not been elucidated. The purpose of the present work was to investigate in depth the synergy o...

L’utilisation d’additifs conservateurs est souvent nécessaire pour assurer la sécurité microbiologique des produits carnés réfrigérés faiblement acides. Le projet ANR BLac HP (2014-2019) a étudié une nouvelle stratégie de stabilisation des produits carnés réfrigérés pour assurer le contrôle des flores indésirables à la fois végétatives et sporulées...

Fluidized bed drying is a dehydration process often applied to microorganisms and used for food particles stabilization. Despite its common use in yeast production, this process can lead to cell death depending on the strain and the growth conditions. During fermentation, yeasts undergo nutritional stressful environments according to media composit...

Effect of high pressure (HP) treatment on the antimicrobial properties and the structure of nisin was evaluated. Nisin solutions at pH 2.8 or 6.1 were treated by HP at 500 MPa – 10 min – 20 °C and their antimicrobial potency was determined. It appeared that HP clearly impacted the antimicrobial activity of nisin, with respective activity loss of 22...

Fluidized bed drying is a dehydration process often applied for microorganisms and food particles stabilization. Despite its common use in the industry of yeast, this process can lead to cell death depending on the strain and the growth conditions. During fermentation, yeasts undergo nutritional stressful environments according to media composition...

High pressure (HP) was first introduced at the end of the nineteenth century in the field of materials chemistry. The first application of high pressure in the food industry was proposed by Hite in 1899 to pasteurize milk and fruit products. The high hydrostatic pressure (HHP) treatment is considered as a nonthermal process, alternative to heat tre...

A multi-criteria framework combining safety, hygiene and sensorial quality was developed to investigate the possibility of extending the shelf-life and/or removing lactate by applying High Hydrostatic Pressure (HHP) in a ready-to-cook (RTC) poultry product. For this purpose, Salmonella and L. monocytogenes were considered as safety indicators and E...

Water crystallization and thawing has long been incriminated in cell death in cryopreservation protocols.We recently studied the role of cold-induced injuries in the occurrence of cell death during freezing of Escherichia coli K12TG1. We showed that extreme cold stress, arising under the supercooling step, is an important cause of cell death in cry...

N° d'article 201511121820

Active dried yeast cells have been widely used in the food industry for several applications in baking, wine and beer production, etc. These organisms are unstable when being removed from their environment and exposed to stabilization processes (drying, freezing, freeze drying...) (1, 4). The high temperature gradients currently applied in these pr...

Meat and seafood products represent a high proportion of the applications of high-pressure processing (HPP) in the world. Mainly used for decontamination purposes, this innovative process has proved to be a reliable technology for ensuring food safety and extending the shelf life of these perishable and fragile foods. However, meat and seafood may...

Injuries in living cells caused by water freezing during a freeze-thaw process have been extensively reported. In particular, intracellular water freezing has long been incriminated in cell death caused by a high cooling rate, but this supposition could not always be demonstrated. This work aims to discriminate the role of water freezing, dehydrati...

Non-uniform microwave heating is the main drawback in assuring the microbiological safety of food products. The focus of this study is to compare the efficiency of the inactivation of Escherichia coli K12, entrapped within calcium alginate gel, during a microwave and a water bath processing with a holding phase at set points of 55 °C and 57 °C. Mic...

The objective of this study was to develop a probabilistic model in order to determine the contamination level of Salmonella and Listeria monocytogenes in ready-to-cook poultry meat, after a high pressure (HP) treatment. The model included four steps: i) Reception of raw meat materials, mincing and mixing meat, ii) Partitioning and packaging into 2...

The contribution of modified atmosphere packaging (MAP) in extending the shelf-life of high-pressure treated raw poultry sausages was examined by considering microbial and oxidative stability (TBARs) aspects. Raw poultry sausages packaged under air or modified atmosphere (50% CO2 – 50% N2) were pressurized at 500 MPa during 5 min at a maximum tempe...

Spores of Bacillus sporothermodurans are known to be contaminant of dairy products and to be extremely heat-resistant. The induction of endospore germination before a heat treatment could be an efficient method to inactivate these bacteria and ensure milk stability. In this study, the nutrient-induced germination of B. sporothermodurans LTIS27 spor...

This study evaluates the efficiency of the inactivation of Escherichia coli K12, entrapped within calcium alginate gel, by microwave processing compared to a conventional approach i.e. by heating in a water bath. Microbial thermal inactivation equations coupled with heat transfer and Maxwell’s equations are integrated into a 3D Finite Elements mode...

To investigate the combined effect of hydrostatic pressure (HP), moderate temperature and nisin on the inactivation of Bacillus sporothermodurans spores which are known to be contaminant of dairy products and to be extremely heat-resistant. A central composite experimental design with three factors, using response surface methodology, was used. By...

The effect of high-pressure treatment (350 MPa, 6 min, 20 °C) combined with sodium chloride (1.5–3.0%) and phosphates (0.25–0.5%) on the texture, water retention, color and thermal properties was assessed in pork meat batters. A principal component analysis was used to identify the relationship between thermal denaturation and the functional proper...

Starch can be gelatinized during high pressure processing in the presence of water, but to a greater or lesser extent. Starch gelatinization is often accompanied by the formation of amylose complexes, in particular when a thermal treatment is used. Four different starches were considered in this study: potato, broad bean (Vicia faba), pea and tapio...

12th IFAC Symposium on Computer Applications in BiotechnologyThe International Federation of Automatic Control16-18, 2013, December. Mumbai, India

High Pressure has traditionally been used for many years in the fields of geology and chemistry. This technique was first applied in the food industry, in Japan, in the late 1980s. This technology, also named pascalization, consists in maintaining the product at very high hydrostatic pressure (100-1000 MPa) for a definite time and temperature. The...

The interaction of high pressure (up to 500 MPa at 20 °C for 6 min) with sodium chloride (0%–3%) or sodium nitrite (0 mg/kg–100 mg/kg) on the outgrowth of four endogenous flora of pork meat was investigated during storage after a cold-chain break. First, the effect of high pressure was investigated. Next, high-pressure treatments at 350 MPa were co...

Bacillus sporothermodurans produces highly resistant endospores that can survive ultra-high-temperature treatment in milk. The induction of endospore germination before a heat treatment could be an efficient method to inactivate these bacteria and ensure milk sterility. In this work, the rate of spore germination of B. sporothermodurans LTIS27 was...

For years, high‐pressure processing has been viewed as useful for pasteurizing food while maintaining the quality of fresh food. However, even at moderate pressure, this process is not without effects on food, especially on meat products. These effects are especially important because pressure greater than 400 MPa is generally necessary to achieve...

Une étude, menée conjointement par le CTCPA et les UMR GEPEA et SECALIM d’ONIRIS, s’est intéressée à la caractérisation de l’effet des hautes pressions hydrostatiques sur la viande de porc, en combinaison avec le sel. L’intérêt était d’évaluer le potentiel de ce procédé innovant pour diminuer l’ajout de sel dans la formulation des produits de la fi...

Our study focuses on a foodborne pathogen, Campylobacter, which is responsible for the most frequent bacterial enteritis worldwide. Membrane integrity of Campylobacter jejuni NCTC 11168 cells treated at high pressure (300 MPa, 20°C, 10 min) at pH 7.0 and pH 5.6 was measured by fluorescence spectroscopy of propidium iodide (PI) uptake. The percentag...

This work deals with optimising the cell survival of rhizobacteria encapsulated in alginate beads filled with starch. Immobilisation of rhizobacteria was done by dripping alginate-starch solution mixed with rhizobacteria into a calcium solution. Beads were analysed based on matrix formulation, bacteria growth phase, osmoprotectants and nature of ca...

High Pressure has traditionally been used for many years in the fields of geology and chemistry. This technique was first applied in the food industry, in Japan, in the late 1980s. This technology, also named pascalization, consists in maintaining the product at very high hydrostatic pressure (100-1000 MPa) for a definite time and temperature. The...

a b s t r a c t Bacillus sporothermodurans is a milk spoilage bacterium producing resistant endospores that survive ultra-high temperature treatment. The inactivation of B. sporothermodurans LTIS27 spores by combined hydrostatic pressure and heat treatments was studied. A central composite experimental design was used to evaluate the effect of pres...

We investigated the influence of pH and osmolarity on the high-pressure-induced gelatinization of waxy corn and waxy rice starches in salt solutions, and the properties of the resulting gels. Gelatinization kinetics, the gel swelling power of starches, their structure and their rheological properties were studied for starch suspensions treated at 5...

High pressure/high temperature (HPHT) processing is an innovative way to sterilize food and has been proposed as an alternative to conventional retorting. By using elevated temperatures and adiabatic compression, it allows the inactivation of vegetative microorganisms and pathogen spores. Even though the microbial inactivation has been widely studi...

High pressure is a potential technology for the texturization of food products at ambient temperature. In this area, waxy starches are particularly interesting because they gelatinize quickly under sufficient pressure. However, gelatinization may be influenced by other components in the food matrix. Here, we investigate the influence of increasing...

IntroductionExample 1: Effects of Combined Hyperosmotic and Temperature PerturbationExample 2: Effects of Combined High Hydrostatic Pressure, Low Temperature, and Hyperosmotic PerturbationsConclusions References

High pressure (HP) applied to starch suspensions is a promising technology as an alternative to conventional thermal treatment. It may allow the development of new textures which may retain flavors and nutrients while providing food safety. The properties of corn starch and two waxy starch suspensions, rice and corn, were studied after or during HP...

Yeasts are often exposed to variations in osmotic pressure in their natural environments or in their substrates when used in fermentation industries. Such changes may lead to cell death or activity loss. Previous work by our team has allowed us to relate the mortality of cells exposed to a combination of thermal and osmotic treatments to leakage of...

Linoleic acid hydroperoxide (HPOD), substrate of hydroperoxide lyase, an enzyme of the lipoxygenase pathway, can be transformed into many aromatic compounds, the so-called "green notes". The presence of linoleic acid hydroperoxide in the culture medium of Yarrowia lipolytica, the yeast expressing the cloned hydroperoxide lyase of green bell pepper,...

Yeasts are often exposed to variations in osmotic pressure in their natural environments or in their substrates when used in fermentation industries. Such changes may lead to cell death or activity loss. Although the involvement of the plasma membrane is strongly suspected, the mechanism remains unclear. Here, the integrity and functionality of the...

The survival of Bradyrhizobium japonicum under hyperosmotic treatments achieved at various temperatures was investigated. The bacterial viability was measured at a combination of different levels of osmotic pressure (1.4-49.2 MPa) in glycerol solutions and temperature (4-28 degrees C). Viability was dependent on these two variables, with low temper...

An understanding of membrane destabilization induced by osmotic treatments is important to better control cell survival during biotechnological processes. The effects on the membranes of the yeast Saccharomyces cerevisiae of perturbations similar in intensity (same amount of energy) but differing in the source type (heat, compression and osmotic gr...

Fourier Transform Infrared spectroscopy (FTIR) was used to determine the phase transition temperature of whole Saccharomyces cerevisiae W303-1 A cells as a function of Aw in binary water-glycerol media. A phase transition occurred at 12 degrees C in water, at 16.5 degrees C at Aw=0.75, and at 19.5 degrees C at Aw=0.65. The temperature ranges over w...