Philippe Bohuon

Osmotic treatment of fish and meat products

In the review, the mass fluxes occurring during the operation are identified and the potential of osmotic treatment (OT) as an alternative to conventional processes is evaluated. Product quality development during processing and storage is assessed. Pilot and industrial applications are investigated. In terms of prospects, some future research areas that have not yet been investigated are presented.

Soaking process in ternary liquids : Experimental study of mass transport under natural and forced convection

Abstract Cross mass transport during the soaking process of model food gel (gelatin, carraghenan) in concentrated solutions (salt-sucrose-water) at 10 °C was investigated using a rotating gel disc device. The concentration profiles in gel were analyzed. The experimental results confirmed the theory that component concentrations are not functions of the disc radius. Two sets of experiments were carried out to study the influence of the main process variables (solute concentration, processing time) on mass transport under forced and natural convection. The results showed that the presence of sucrose enhanced water loss and hindered salt penetration whatever the hydrodynamic conditions. Rotation speed increased water loss as solute concentration increased but had no effect on salt gain, while it hindered sucrose gain. Photographs also showed the presence of very strong natural convection phenomena.

Kinetics of anthocyanin degradation and browning in reconstituted blackberry juice treated at high temperatures (100-180°C).

Monomeric anthocyanin degradation and nonenzymatic browning (NEB) index have been determined in reconstituted blackberry juice heated at high temperature in a hermetically sealed cell. Statistical analysis demonstrated that, when the temperature range (100-180 degrees C) was divided into two subranges (100-140 and 140-180 degrees C) for anthocyanin degradation, reaction kinetics were well represented by two sequential first-order reactions. The activation energy for NEB from 100 to 180 degrees C (106 kJxmol(-1)) was slightly higher than the anthocyanin value at the lower temperature range (92 kJxmol(-1)), but was more than twice the value for the higher range (44 kJxmol(-1)). The reaction rate constant at 140 degrees C for anthocyanin degradation (3.5 x 10(-3) s(-1)) was two times that for the NEB index (1.6 x 10(-3) s(-1)). Hence, anthocyanin degradation was faster than the appearance of NEB products. The non-isothermal method developed allows estimating kinetic parameters and thereby generating temperature profiles of heat processes that would help preserve the nutritional properties of foods during high-temperature processes.

Pulsed vacuum brining of poultry meat: interpretation of mass transfer mechanisms

Abstract Pulsed vacuum brining (PVB) of meat products in salt-concentrated solutions gives rise to hydrodynamic mechanisms that facilitate solution infiltration into the meat structure. Previous studies have shown that these mechanisms can only function with porous structures. The estimated apparent porosity of meat is 1.69% (v/v). The difference in total pressure is the key to efficient infiltration––it forces occluded and/or dissolved gases from the meat during vacuum processing and then, upon the return to atmospheric pressure, solution infiltrates the pores from which the gases were expelled. Transfers between the occluded solution and the inner surfaces of the meat pores then occur within the product throughout brining under atmospheric pressure conditions. The solution is expelled again from the product in the next vacuum cycle. During PVB of poultry meat, solution infiltration and internal transfer account for respectively 9–22% and 7–17% of the salt gain obtained with this process.

Current Food Classifications in Epidemiological Studies Do Not Enable Solid Nutritional Recommendations for Preventing Diet-Related Chronic Diseases: The Impact of Food Processing

To date, observational studies in nutrition have categorized foods into groups such as dairy, cereals, fruits, and vegetables. However, the strength of the association between food groups and chronic diseases is far from convincing. In most international expert surveys, risks are most commonly scored as probable, limited, or insufficient rather than convincing. In this position paper, we hypothesize that current food classifications based on botanical or animal origins can be improved to yield solid recommendations. We propose using a food classification that employs food processes to rank foods in epidemiological studies. Indeed, food health potential results from both nutrient density and food structure (i.e., the matrix effect), both of which can potentially be positively or negatively modified by processing. For example, cereal-based foods may be more or less refined, fractionated, and recombined with added salt, sugars, and fats, yielding a panoply of products with very different nutritional values. The same is true for other food groups. Finally, we propose that from a nutritional perspective, food processing will be an important issue to consider in the coming years, particularly in terms of strengthening the links between food and health and for proposing improved nutritional recommendations or actions.

Effect of deep-fat frying on ascorbic acid, carotenoids and potassium contents of plantain cylinders

The influence of thermal treatment (frying of plantain) on the micronutrients ascorbic acid, potassium and carotenoids is evaluated. Cylinders (diameter 30 mm, thickness 10 mm) of plantain (Musa AAB ‘barraganete’) were fried at four thermal treatments (120–180°C and from 24 to 4 min) to obtain products with approximately the same water content (≈0.8±0.02 kg/kg1) and fat content (≈0.15±0.06 kg/kg). The thermal study used the cook value and the mean cook value as indicators of the effect of several different treatment temperatures and times on quality. Deep-fat frying had no significant effect on carotenoid contents at any frying conditions, and on potassium content, except at 120°C and 24 min (loss ≤ 11%). There was a significant, but not complete, loss (≤45%) of ascorbic acid. The process with the greatest effect was low temperature and long time (120°C/24 min), as observed for potassium and ascorbic acid. These results are in agreement with other studies that demonstrated short thermal treatments at high temperatures protect food nutritional quality, as shown by the cook value and the mean cook value. In our work, deep-fat frying of plantain preserved most of the micronutrient contents that were evaluated.

Pulsed vacuum brining of poultry meat: experimental study on the impact of vacuum cycles on mass transfer

Abstract Salting of meat products is often accelerated by using a continuous vacuum salting–tumbling process. The pulsed vacuum brining (PVB) process involves plunging a food product into a concentrated salt solution followed by an alternation of cycles under partial vacuum and then atmospheric pressure conditions. The effects of key vacuum cycle variables on mass transport were studied by PVB of turkey meat in different concentrated sodium chloride solutions. PVB led to a product that was more salted and less dehydrated than products brined under atmospheric pressure brining conditions, thus boosting mass yields. Food products obtained by PVB have a more uniform salt and water distribution from the surface to the core. This study demonstrated that the number of vacuum cycles, processing with a long vacuum phase under a low residual pressure and a shorter atmospheric pressure phase enhanced the effects of PVB on mass transfers (increased salt gain, decreased water loss, thus increasing mass yields).

Chemical equilibrium of minced turkey meat in organic acid solutions.

The distribution of acid (HA), anions (A(-)), free protons (H(3)O(+)) and bound protons (H(b)), in homogenized turkey meat was evaluated at various meat/water mass ratios of (1/4-1/10) during titration with acetic acid (0.25N) or lactic acid (0.2N). H(b) concentration was determined by titration with hydrochloric acid (0.075N) and a correlation for [H(b)]=f(pH) was proposed. A procedure was used to calculate the fractions of the various species in equilibrium, starting from an initial acid concentration in a meat/water system and assuming the accuracy of the pK(a) value of the pure weak acids despite the chemical complexity of meat. Calculated results were in very good agreement (±0.15) with experimental pH values, whatever the acid, meat batch or meat/water mass ratios used. Less than 1% of the total protons were free (H(3)O(+)) and determined the meat pH.

Heat and Mass Transfer in Fry Drying of Wood

This article describes the coupled heat and mass (water, oil) transport phenomena in parallelepiped samples of beech (Fagus sylvatica) fried in peanut oil between 120 and 180°C. The aim was to evaluate the suitability of simultaneous fry drying and oil impregnation as an alternative wood treatment process. Water loss and oil impregnation were continuously assessed during the process. Temperature and pressure were measured at the center of the sample. The water in the peripheral layers of the wood vaporizes at atmospheric pressure. The water at the center of the wood vaporizes at overpressures of the order of 2.8 × 105 Pa. High fluxes of water were recorded of about 0.006 kg/(m2s). The impregnated oil can amount to 20% of the mass of the removed water.

Influence of sodium chloride and pH during acidic marination on water retention and mechanical properties of turkey breast meat

Turkey breast cubes underwent acidic marination in the presence of salt. The transfer of water, salt and acid was measured, and texture was assessed on the cooked meat. While significant mass gains were observed during marination, from 20 minutes of immersion onwards, only long durations produced an overall matter balance greater than that of non-marinated meat. From the first minutes of immersion, these transfers caused hardening, regardless of the presence of salt in the marinade. For longer durations, only in the absence of salt was significant tenderizing seen in comparison to the non-marinated control. This effect appears to be due on the one hand to passing the isoelectric pH of the meat during acidification, and on the other hand to setting up antagonistic mechanisms breaking down or reinforcing connective tissues by acid and salt respectively. The high degree of tenderization observed in a water-acid solution can be explained partly by dilution of the fiber load per section unit due to protein solubilization.