In the meat industry there are some processes like drying or storage of salted meat products in which the knowledge of water sorption phenomena in salted proteins could be very useful. The sorption and desorption of most salted products is a singular process with three differentiated steps: a(w) < 0.75, a(w) = 0.75 and a(w) > 0.75. SAFES methodology allows the analysis of different elements in a system: the components, phases and states of aggregation in the food during the process to understand the process stages with a suitable level of complexity. It also analyzes the transport functions, chemical reactions and the phenomena occurring during the processing of the product. The aim of this paper is to analyze the sorption phenomena of water in salted proteins using the SAFES methodology for the three different steps of the water desorption process. Salted pork meat isotherms at different three different salt concentrations and three various temperatures were analyzed in order to observe differences between them, in terms of mass transport, reactions, etc. With SAFES methodology, differences in the behaviour of the system, depending on the amount of NaCl added to the pork meat were observed. Differences in mass fluxes were found in relation to temperature and NaCl concentration.

Three experimental devices (joined cylinders, dry salting and a drying cell) were used to generate moisture and sodium chloride (NaCl) profiles in gels (gelatin, different starch/gelatin ratios) maintained at constant temperature (10 and 20°C). The moisture and chloride concentrations profiles were measured by a destructive method (slicing: 1 and 5 mm of thickness / analysis of moisture (oven) and chloride (potentiometric titration)). A drying cell was set up in order to generate salt and moisture gradients in salt added gelatin gels maintained at constant temperature and to obtain a large range of moisture fluxes (from 0,00003 to 0,0003 kg water per square meter and per second). For those investigated moisture fluxes, binary diffusion of moisture and chlorides seems to be the predominant phenomenon. Apparent diffusivities were either estimated by applying a direct data treatment method to measured profiles or identified by using a mathematical model taking the retraction of the gel into account. The direct data treatment method does not require any assumption on the D=f(X) relation. It can be applied to profiles with relatively few measurements - approximately 10 - when smoothing the experimental points by using a neural network. The two methods provided similar estimations of apparent moisture and chlorides diffusivities. The values depend neither on the strengh of gelatin gels (Bloom) nor on the anhydrous composition of the gel (ratio starch/gelatin). Apparent chloride diffusitivity is relatively constant and lower than mutual salt-water diffusivity. Apparent moisture diffusitivity decreases with moisture content when measured on gels during dehydration but, increases with decreasing moisture content in the gels during re-hydration. The addition of sodium chloride causes an increase of the apparent moisture diffusivity by a factor 10. | Trois dispositifs expérimentaux (cylindres accolés, salage à sec, cellule de séchage) ont été utilisés pour générer des profils de teneurs en eau et en chlorure de sodium (NaCl) dans des gels (gélatine, mélanges amidon/gélatine) à 10 et 20 °C. Ces profils ont été mesurés par analyses chimiques après découpe de tranches de gel d'épaisseurs 1 et 5 mm. Dans le cas du séchage, un dispositif original a permis de maintenir la température du gel constante et de faire varier la densité de flux d'eau évaporée de 0,00003 à 0,0003 kg d'eau par mètre carré et par seconde. Dans cette gamme, aucun effet d'entraînement du sel par l'eau n'a pu être mise en évidence. Les diffusivités apparentes ont été estimées soit en appliquant un traitement direct aux profils mesurés soit par identification avec un modèle de transfert couplé eau-sel qui tient compte de la rétraction du gel. Le traitement direct ne nécessite aucune hypothèse sur la forme de la relation D=f(X) ; il peut être appliqué à des profils constitués d'un nombre limité de mesures - environ 10 - grâce à un lissage par un réseau de neurones. Les deux méthodes ont fourni des estimations concordantes des diffusivités apparentes de l'eau et des chlorures. Elles ne dépendent ni de la force du gel (Bloom) ni de la composition du gel anhydre (ratio amidon/gélatine). Celle des chlorures est relativement constante et inférieure à la diffusivité mutuelle sel-eau. Celle de l'eau dépend de la teneur en eau initiale du gel, diminue avec la diminution de la teneur en eau en déshydratation mais augmente en réhydratation. L'ajout du chlorure de sodium provoque une augmentation de la diffusivité apparente de l'eau d'un facteur 10.

Three experimental devices (joined cylinders, dry salting and a drying cell) were used to generate moisture and sodium chloride (NaCl) profiles in gels (gelatin, different starch/gelatin ratios) maintained at constant temperature (10 and 20°C). The moisture and chloride concentrations profiles were measured by a destructive method (slicing: 1 and 5 mm of thickness / analysis of moisture (oven) and chloride (potentiometric titration)). A drying cell was set up in order to generate salt and moisture gradients in salt added gelatin gels maintained at constant temperature and to obtain a large range of moisture fluxes (from 0,00003 to 0,0003 kg water per square meter and per second). For those investigated moisture fluxes, binary diffusion of moisture and chlorides seems to be the predominant phenomenon. Apparent diffusivities were either estimated by applying a direct data treatment method to measured profiles or identified by using a mathematical model taking the retraction of the gel into account. The direct data treatment method does not require any assumption on the D=f(X) relation. It can be applied to profiles with relatively few measurements - approximately 10 - when smoothing the experimental points by using a neural network. The two methods provided similar estimations of apparent moisture and chlorides diffusivities. The values depend neither on the strengh of gelatin gels (Bloom) nor on the anhydrous composition of the gel (ratio starch/gelatin). Apparent chloride diffusitivity is relatively constant and lower than mutual salt-water diffusivity. Apparent moisture diffusitivity decreases with moisture content when measured on gels during dehydration but, increases with decreasing moisture content in the gels during re-hydration. The addition of sodium chloride causes an increase of the apparent moisture diffusivity by a factor 10. | Trois dispositifs expérimentaux (cylindres accolés, salage à sec, cellule de séchage) ont été utilisés pour générer des profils de teneurs en eau et en chlorure de sodium (NaCl) dans des gels (gélatine, mélanges amidon/gélatine) à 10 et 20 °C. Ces profils ont été mesurés par analyses chimiques après découpe de tranches de gel d'épaisseurs 1 et 5 mm. Dans le cas du séchage, un dispositif original a permis de maintenir la température du gel constante et de faire varier la densité de flux d'eau évaporée de 0,00003 à 0,0003 kg d'eau par mètre carré et par seconde. Dans cette gamme, aucun effet d'entraînement du sel par l'eau n'a pu être mise en évidence. Les diffusivités apparentes ont été estimées soit en appliquant un traitement direct aux profils mesurés soit par identification avec un modèle de transfert couplé eau-sel qui tient compte de la rétraction du gel. Le traitement direct ne nécessite aucune hypothèse sur la forme de la relation D=f(X) ; il peut être appliqué à des profils constitués d'un nombre limité de mesures - environ 10 - grâce à un lissage par un réseau de neurones. Les deux méthodes ont fourni des estimations concordantes des diffusivités apparentes de l'eau et des chlorures. Elles ne dépendent ni de la force du gel (Bloom) ni de la composition du gel anhydre (ratio amidon/gélatine). Celle des chlorures est relativement constante et inférieure à la diffusivité mutuelle sel-eau. Celle de l'eau dépend de la teneur en eau initiale du gel, diminue avec la diminution de la teneur en eau en déshydratation mais augmente en réhydratation. L'ajout du chlorure de sodium provoque une augmentation de la diffusivité apparente de l'eau d'un facteur 10.

A novel green solvent-based ultrasonic assisted dispersive liquid–liquid microextraction (GS-UADLLME) method was developed for the preconcentration of cadmium and lead ions in various real samples prior to determination by graphite furnace atomic absorption spectrometry (GFAAS). In order to extract trace amounts of cadmium and lead ions, 2-amino-3-sulfhydrylpropanoic acid (l-cysteine) (as a green ligand), tetrafluoroborate ion (BF₄⁻) (as an ion pair agent) and 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF₄] (as acceptor phase) were used. Different effective factors in the microextraction procedure such as pH of the sample solution, sample solution volume, acceptor phase volume, l-cysteine and tetrafluoroborate concentrations, centrifugation conditions and salting addition were thoroughly optimized. Under the optimum conditions, the calibration graphs were linear in the range of 0.8–180 and 2.5–190 ng L⁻¹ with a correlation coefficient (r²) higher than 0.9967 for the measurement of cadmium and lead ions, respectively. The limits of detection for the determination of Cd(ii) and Pb(ii) for the proposed method were 0.2 and 0.7 ng L⁻¹, respectively. The relative standard deviations (n = 5) for the analyte determination were lower than 3.4%. In order to investigate the method’s accuracy, cadmium and lead contents of a certified reference material, SRM 1643e (NIST), were determined and the results from the proposed method were in very good agreement with the certified values. The suggested method was successfully applied to the determination of cadmium and lead ions in real samples such as real water, soil, rice and tea samples.