Claire Gaiani

University of Lorraine | UdL · Laboratoire d'Ingénierie des Biomolécules (LlBio)

Spray drying (SD) is extensively used to encapsulate lactic acid bacteria in large-scale industrial applications; however, bacteria combat several harms that reduce their viability. In this study, a novel technique called electrostatic spray drying (ESD) was used to explore the benefits and disadvantages of using electrostatic charge and lower temp...

Hibiscus sabdariffa is a tropical plant with red calyxes whose anthocyanins, phenols, and antioxidant activity make it attractive to consumers both from a nutritional and medicinal standpoint. Its seasonality, perishability, and anthocyanin instability, led to the setup of stabilization methods comprising drying and powdering. However, its properti...

For the first time on food powders, environmental Atomic Force Microscopy (AFM) was used to probe single particle surface properties in real time by variating relative humidity (RH) and temperature. Low, intermediate, and high dextrose equivalent (DE) maltodextrins values were used as a model matrix. Humidity ramps from 20 to 80% at constant temper...

Lacticaseibacillus rhamnosus GG, or LGG, is one of the most studied probiotic bacterium worldwide. The health benefit properties of LGG are mainly ensured by SpaCBA pili, which are polymeric proteins located at the cell surface. These pili confer the ability to interact with the surrounding environment and notably to adhere to intestinal cells main...

Atomic force microscopy (AFM) is a very powerful, versatile, and highly resolutive tool. Its application to study food sciences products has been emerging for the past few years, particularly for food powders. This chapter aims to review how AFM was used in order to have a better understanding of how particle surface properties can significantly im...

Over the past two decades, atomic force microscopy (AFM) has emerged as one the most popular tools for in situ study of physical, chemical, and biological processes that take place at the cellular to molecular level. Besides, it allows nanoscale characterization in an easy/fast way without the need of any complex procedures or sample preparation. T...

The growing global population demands increased food production, and the demand for plant- and animal-based foods is rising. The modern food and agricultural industries globally contribute about 17.3 billion metric tonnes of carbon dioxide per year, 57% of which is from animal-based and 29% from plant-based food production. Thus, the animal-based f...

Flaxseed (Linum usitatissimum L.) mucilage is one of the most studied plant seed gums in terms of its techno-functional and health-promoting properties. Nonetheless, the interplay of flaxseed gum (FG) with other food biopolymers, such as milk proteins, under in vitro digestion conditions remains underexplored. The aim of the present work was to inv...

High-protein dairy powders are ingredients mainly produced by spray-drying, then subjected to aging during transport and storage. They often undergo physicochemical changes at this stage, such as the development of the Maillard reaction, primarily because of their intrinsic chemical properties, but also as a result of nonoptimal storage conditions....

Gelation kinetics, rheological and morphological properties of enzymatic curds of raw skim dromedary and cows’ milk and reconstituted milk prepared from powders produced by spray-drying these raw milk samples were investigated. Processing (spray-drying and reconstitution) significantly increased whey release by curds. Whey release was more pronounc...

This review is primarily focused on the comparison of three emerging techniques: electrospraying, nano spray drying, and electrostatic spray drying techniques. There are persistent advances to develop efficient drying technique for sensitive bioactives and to overcome their hurdles. These processes involve electrostatic forces as a promising factor...

Probiotic bacteria such as Lactobacillus rhamnosus GG (LGG) play an important role in maintaining a healthy microbiota environment. Oral administration is the only way to deliver probiotic bacteria to the small intestine. Due to the harsh environment of the gastrointestinal tract, only a small proportion of probiotic bacteria can reach the target s...

3D bioprinting is considered as a promising technology to build living-like models. 3D constructs containing different cell types can be generated which is crucial to simulate the heterogeneity and complexity of the human cells microenvironment. As, 3D bioprinting is a computer assisted process that generates 3D structures with a controlled archite...

Reconstitution kinetics of three maltodextrins powders with different dextrose-equivalent (DE) values (low, intermediate, high DE) were evaluated under the glassy and rubbery states. Reconstitution times were found mostly shear rate of agitation in water and DE dependent in the glassy state, with shorter reconstitution times for high shear rates an...

This paper reports on the impact of alfalfa galactomannan (AAG, 0.1, 0.5 or 1% wt.) on the colloidal changes and digestibility of sodium caseinate (NaCN) and whey protein isolate (WPI) dispersions (10% wt.) under in-vitro digestion conditions. Static light scattering and confocal microscopy-assisted assessment of the NaCN-based gastric chymes confi...

Whey protein concentrate powders can be strongly affected by storage conditions inducing both chemical and structural protein modifications. In the present work, a combination of different storage conditions were evaluated, leading to the evaluation of 6 different batches that were chosen in order to evaluate the impact of the following parameters:...

Protein inadequacy is the major problem for most plant-based dairy yoghurt substitutes. This study investigated three limited degree of hydrolysis (DH: 1%, 5%, and 9%) of almond protein and the combined effect of DH and hydrolysed almond protein (HP) to non-hydrolysed almond protein (NP) ratios (HP/NP: 40:60, 20:80, 10:90 and 5:95) on the physicoch...

In the present work the structuring and stabilising potential of flaxseed gum (FG) in whey protein isolate (WPI) cryo-hydrogels was investigated. The FG presence (0.1–1% wt.) in the heat-treated WPI dispersions (10% wt.) induced strong segregative phase separation phenomena, which were associated with a depletion flocculation mechanism. The cryotro...

Reconstitution kinetics of various food powders in fixed mixing conditions were followed by laser granulometry. Obtained reconstitution profiles were fitted using a sum of first-order indicial responses. This descriptive modelling approach allowed linking each of the main reconstitution steps (swelling, dispersion, and solubilization) to a single f...

The article presents a grain-scale experimental approach for the study of a model that swells granular food material. During the swelling phase, both the evolution of particle size using image analysis and the spatially resolved field of diffusion coefficient of water inside the grains were studied using MRI measurements. A concentrically penetrati...

The cryotropic gelation of food biopolymers is an alternative method to impart bespoke structural, textural, and functional characteristics to food colloids. The present work aims to explore the structuring performance of whey protein isolate (WPI) in the presence of alfalfa (Medicago sativa L.) galactomannan (AAG) under cryogenic processing. Aqueo...

The present work aimed at investigating an extraction protocol based on consecutive steps of isoelectric point (pH ~ 4.25) mediated gum swelling and deproteinisation as an alternative method to produce flaxseed gum extracts of enhanced techno-functional characteristics. The osidic and proximate composition, structure conformation, flow behaviour, d...

Reconstitution of six fruit powders, compacted and non-compacted, were studied. It appears that powder reconstitution behavior under sheared conditions was significantly different with regards to the water activity (aw). At low aw, the powders exhibit a glassy state with a stiff surface measured by Atomic Force Microscopy and porous/angular shapes...

The influence of the protein, fat and sugar in almond milk on the formation of the acidic gel was investigated by determining their physicochemical and microstructural properties. The protein, fat and sugar in the almond milk were varied from 2% to 6%, 0.8%–7% and 0.6%–7%, respectively and fermented using Lactobacillus delbrueckii subsp. bulgaricus...

Lactic acid bacteria (LAB) have been studied for several decades to understand anddetermine their mechanism and interaction within the matrix into which they are introduced. Thisstudy aimed to determine the spatial distribution ofLacticaseibacillus rhamnosusGG (LGG) in a dairymatrix and to decipher its behaviour towards milk components, especially...

Powder rheology and its sensitivity to surrounding environmental condition by controlling the surface properties of the particles is one of the major challenges of the powder industries. Indeed, handling large quantities needs powders with good flowability, adequate compressibility and few electrostatic charges. We have performed a chemical treatme...

Cryotropic gelation is one of the most common approaches to design novel hydrogels with multifaceted technological and biological functionalities. In the present paper, we studied the ability of highly galactosyl-substituted galactomannans, i.e. fenugreek and alfalfa gum, to form physically crosslinked hydrogels via cryogenic processing. Cycling of...

Alterations in surface chemical composition relating to rehydration properties of spray-dried camel milk powders during accelerated storage (11-33% RH, 37°C) over 18 weeks were investigated. The results showed that the surface of the fresh spray-dried camel milk powder (t = 0) was dominated by lipids (78%), followed by proteins (16%) and lactose (6...

Brewers’ Spent Grain (BSG) is the primary waste of the beer brewing process, which comprises a plethora of nutritionally appealing ingredients such as proteins, dietary fibres, essential lipids and micronutrients. In our previous study [1], the acid-induced gelation capacity of BSG protein isolate as influenced by the thermal pre-treatment severity...

Two sets of spray‐drying conditions were applied on skim dromedary and cow's milks to determine the effect of air outlet temperature (75 and 85 °C) and milk type on proximate composition, particle size distribution, and flow properties of spray‐dried powders. The particle size distribution was more influenced by the chemical composition than the sp...

Dairy powders are usually subjected to environmental variations during storage and/or shipment that strongly impact their chemical, nutritional and structural features. Nevertheless, these modifications are rarely investigated at the particle surface level, which represents the interface in contact with air, water, materials or other powders and di...

Thirty-six food powders corresponding to a wide range of physicochemical characteristics (bulk and surface chemical composition, median particle size, span, water activity) and manufacturing processes (grinding, freeze-drying, spray-drying, crystallization) were investigated for their reconstitutability. Their reconstitution profiles were acquired...

3.1 Water activity is related to water vapor pressure in a material, and it is a useful parameter relating to glass transition, water content and water plasticization. The glass transitions of dairy solids, particularly that of lactose, determine the dehydration characteristics and successful spray-drying conditions of dairy liquids. Water and glas...

Controlling the powder flow by the surface properties of the particles as well as understanding their flowability under different processing dynamics are amongst the major challenges of the powder industry. Indeed, handling large quantities needs powders with good flowability, adequate compressibility and few electrostatic charges. We have performe...

Brewers’ spent grain (BSG) is a major side stream of the beer-brewing sector, which comprises a plethora of food macromolecules and micronutrients. In the present work, BSG protein isolates were assessed for their ability to form gels via delta-gluconolactone induced acidification. The impact of the thermal pre-treatment (native, heating at 72, 85...

Pili are polymeric proteins located at the cell surface of bacteria. These filamentous proteins play a pivotal role in bacterial adhesion with the surrounding environment. They are found both in Gram-negative and Gram-positive bacteria but differ in their structural organization. Purifying these high molecular weight proteins is challenging and has...

In the present work, a galactomannan extract of low protein residue (< 1.3 % wt dry basis) was isolated from alfalfa (Medicago sativa L.) seed endosperm meal. The alfalfa gum (AAG) comprised primarily mannose and galactose at a ratio of 1.18:1, had a molecular weight of 2 × 10 6 Da and a radius of gyration of 48.7 nm. The average intrinsic viscosit...

The aim of this study was to evaluate the effect of air outlet temperature (75 and 85 °C) and milk type on proximate composition, water activity, particle size distribution, color, and rehydration ability of spray-dried skim dromedary and cow’s milk powders. While the water activity of powders was close to 0.4 when spray-dried at 75 °C air outlet t...

Some food and ferment manufacturing steps such as spray-drying result in the application of viscous stresses to bacteria. This study explores how a viscous flow impacts both bacterial adhesion functionality and bacterial cell organization using a combined experimental and modeling approach. As a model organism we study Lactobacillus rhamnosusGG (LG...

Surface protection against biofilms is still an open challenge. Current strategies rely on coatings that are meant to guarantee antiadhesive or antimicrobial effects. While it seems difficult to ensure antiadhesion in complex media and against all the adhesive arsenal of microbes, strategies based on antimicrobials lack from sustainable functionali...

This study investigated the effect of pH on the denaturation extent, the surface chemical composition, the water sorption isotherm and the glass transition temperature of camel and bovine whey protein’s powders. The LC-MS analysis indicated that the β-Lactoglobulin was the most denaturized protein in bovine whey powders regardless the pH value, whi...

This work was conducted to study the influence of particle size and shape on the flow behaviour of semi‐ripe plantain powders. An improved plantain variety (Big Ebanga), two hybrids (FHIA 21, PITA 3), and a local variety (Corne 1, as reference material) were powdered by successive drying, milling, and sieving into three granulometric classes: unsie...

The present study focuses on the impact of lipid content (1.5, 13.8, and 26% (w/w)) and pretreatment of dairy concentrates (air incorporation by whipping prior to spray-drying) on the physicochemical and technofunctional characteristics of dairy powders. Spray-drying was performed according to the following conditions: 200 °C inlet air temperature...

While competition targeting food-borne pathogens is being widely documented, few studies have focused on competition among non-pathogenic food bacteria. Carnobacterium maltaromaticum is a genetically diverse lactic acid bacterium known for comprising several bacteriocinogenic strains with bioprotective potentialities against the food-borne pathogen...

Links between flow properties and formulation of powders of 100 and 500 µm mean particle sizes were investigated. To determine the influence of surface treatment, the flow properties of glass beads were analyzed after various surface treatments leading to hydrophilic, hydrophobic, and lactose-coated surfaces. Furthermore, to investigate the influen...

Since several millenaries, humans resort to microbes in dairy-derived food and beverages production worldwide. Determining accurately how these microorganisms are able to modify raw components from their environment, i.e. the dairy matrix, is of great interest in food industry to improve shelf life, flavor and texture. This chapter aims to describe...

This study aimed at investigating the chemical composition and microstructure of spray dried camel and cow milk powders' surfaces with two different milk-fat contents (1 and 20g 100 g−1). The SEM (Scanning Electron Microscopy) micrographs showed that spherical particles with a ‘brain’-type surface for both milk powders were produced. The surface ro...

In the last decade, there has been an increasing interest in the potential health effects associated with the consumption of lactic acid bacteria (LAB) in foods. Some of these bacteria such as Lactobacillus rhamnosus GG (LGG) are known to adhere to milk components, which may impact their distribution and protection within dairy matrices and therefo...

The scope of the present work was the development of an ice cream containing substantial amount of phenolic compounds by substituting sucrose by a Muscat de Hamburg grape pulp and skin matter (GPSM)-enriched bulking agent at the level of 25 to 100% w/w. Sucrose replacement by GPSM reinforced the pseudoplastic and thixotropic character of the ice cr...

Protein supplements have received increasing attention by consumers over the last few decades. However, hundreds of them have recently exhibited irregularities including lower quantities of proteins than disclosed values. This study aimed to evaluate the nutritional quality of six commercial protein supplement powders (calcium caseinate, milk prote...

The range of foods featuring lactic acid bacteria (LAB) with potential associated health benefits has expanded over the years from traditional dairy products to meat, cereals, vegetables and fruits, chocolate, etc. All these new carriers need to be compared for their efficacy to protect, carry, and deliver LAB, but because of their profusion and th...

Influence of diverse botanical sources (wheat, maize, waxy maize, cassava, potato, rice or waxy rice) on in vitro native starch digestibility has been investigated. Physicochemical properties (chemical composition, particles size and shape, surface features) of starch granules were determined with a view to explaining digestibility differences betw...