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There is a growing interest in healthier foods and cleaner labels. In particular, foods containing a lower sugar concentration but with the same organoleptic properties and the same shelf life are becoming a new challenge. To this end, we performed a first set of experimentations on two simple broths (LFM1 and LFM2), which differed in their glucose concentration (250 g/L and 200 g/L, respectively), and a second set of fermentations on two diluted tomato pastes (TP1 and TP2), with the same glucose concentration but different in the presence (TP2) or absence (TP1) of yeast extract. These substrates were fermented by Yarrowia lipolytica ATCC 8661 at 30°C for 192 hr, to understand its ability in simultaneous production of erythritol and citric acid. Although the process should be optimized, in all the cases tested we obtained the erythritol and the citric acid production. Practical application: The aim of the present study was the simultaneous production of erythritol and citric acid on a food matrix. This is a preliminary study to obtain, directly by fermentation, a natural sweetener able to give the food product, in particular tomato paste, a sweet taste without adding artificial sweeteners. At the same time, we tried to produce citric acid as a natural preservative to improve shelf life. In this way, we wish to obtain, through several experimentations, semifinished products for the production of vegetal soups and sauces.

Celiac Disease (CD) is an autoimmune disease characterized by inflammation of the intestinal mucosa due to an immune response to wheat gliadins. It presents in subjects with genetic susceptibility (HLA-DQ2/DQ8 positivity and non-HLA genes) and under the influence of environmental triggers, such as viral infections and intestinal microbiota dysbiosis. The only treatment currently available in CD is a gluten-free diet for life. Despite this, the intestinal dysbiosis that is recorded in celiac subjects persists, even with adherence to dietary therapy. In this review, we have analyzed the literature over the past several decades, which have focused on the use of pro-, pre- and post-biotics in vitro and in vivo in CD. The study of probiotics and their products in CD could be interesting for observing their various effects on several different pathways, including anti-inflammatory properties.

Two natural mixtures, Allium sativum fermented extract (BGE) and cannabinol oil extract (CBD), were assessed for their ability to inhibit and remove Pseudomonas aeruginosa biofilms on soft contact lenses in comparison to a multipurpose Soft Contact Lens-care solution present on the Italian market. Pseudomonas aeruginosa (ATCC 9027 strain) and Pseudomonas aeruginosa clinical strains isolated from ocular swabs were tested. Quantification of the biofilm was done using the microtiter plate assay and the fractional inhibitory concentration index was calculated. Both forms of Pseudomonas aeruginosa generated biofilms. BGE at minimal inhibitory concentration (MIC) showed inhibition percentages higher than 55% for both strains, and CBD inhibited biofilm formation by about 70%. The care solution at MIC inhibited biofilm formation by about 50% for both strains tested. The effect of BGE on the eradication of the microbial biofilm on soft contact lenses at MIC was 45% eradication for P. aeruginosa ATCC 9027 and 36% for P. aeruginosa clinical strain. For CBD, we observed 24% biofilm eradication for both strains. For the care solution, the eradication MICs were 43% eradication for P. aeruginosa ATCC 9027 and 41% for P. aeruginosa clinical strain. It was observed that both the test soft contact lenses solution/BGE (fractional inhibitory concentration index: 0.450) and the test soft contact lenses solution/CBD (fractional inhibitory concentration index: 0.153) combinations exhibited synergistic antibiofilm activity against most of the studied bacteria. The study showed that BGE and CBD have good effect on inhibition of biofilm formation and removal of preformed biofilms, which makes them promising agents that could be exploited to develop more effective care solutions.

Background In vivo assays cannot always be conducted because of ethical reasons, technical constraints or costs, but a better understanding of the digestive process, especially in infants, could be of great help in preventing food-related pathologies and in developing new formulas with health benefits. In this context, in vitro dynamic systems to simulate human digestion and, in particular, infant digestion could become increasingly valuable. Objective To simulate the digestive process through the use of a dynamic model of the infant gastroenteric apparatus to study the digestibility of starch-based infant foods. Design Using M.I.D.A (Model of an Infant Digestive Apparatus), the oral, gastric and intestinal digestibility of two starch-based products were measured: 1) rice starch mixed with distilled water and treated using two different sterilization methods (the classical method with a holding temperature of 121°C for 37 min and the HTST method with a holding temperature of 137°C for 70 sec) and 2) a rice cream with (premium product) or without (basic product) an aliquot of rice flour fermented by Lactobacillus paracasei CBA L74. After the digestion the foods were analyzed for the starch concentration, the amount of D-glucose released and the percentage of hydrolyzed starch. Results An in vitro dynamic system, which was referred to as M.I.D.A., was obtained. Using this system, the starch digestion occurred only during the oral and intestinal phase, as expected. The D-glucose released during the intestinal phase was different between the classical and HTST methods (0.795 grams for the HTST versus 0.512 for the classical product). The same analysis was performed for the basic and premium products. In this case, the premium product had a significant difference in terms of the starch hydrolysis percentage during the entire process. Conclusions The M.I.D.A. system was able to digest simple starches and a more complex food in the correct compartments. In this study, better digestibility of the premium product was revealed.

This work reports experimental results on the heat transfer between a fluidised bed of fine particles and a submerged surface. Experiments have been carried out using different bed materials (polymers, ballotini, corundum, carborundum and quartz sand) with Archimedes number between 2 and 50. Dry air at ambient pressure and temperature has been used as fluidising gas. Three different exchange surfaces, namely a sphere and two cylinders with different base diameter and same height, have been used. Experimental results show that the heat transfer coefficient increases with particle Archimedes number and is almost independent from particle thermal conductivity for K p / K g > 30. Finally, the comparison of heat transfer coefficient for the different surfaces shows that the effect of the surface geometry may account for a 30% variation in the heat transfer coefficient, with higher differences occurring for coarser particles.

This paper presents a semi empirical single particle model for the description of heat transfer coefficient between a submerged surface and a fluidized bed. The model is applied to several experimental data and gives a satisfactory description of the effect of pressure, temperature and bed material properties on the heat transfer coefficient either in bubbling or slugging fluidized beds. The model considers the averaged surface void fraction as the only regression parameter for the description of experimental data. Surface void fraction results to be a function of Archimedes number and minimum fluidization bed voidage and its value is consistent with the numerical and experimental data reported in literature.

In recent times, the possible application of fluidisation technologies to the surface treatments of engineering materials becomes a subject of growing interest both for manufacturing and chemical industries. Heat and mass transfer rates between the surface and the fluidised bed strongly influence the performance of the surface treatment. Experimental results of heat transfer between a submerged surface and a fluidised bed are presented in this article. This work is focused on the influence of bed material properties and surface geometry on heat transfer coefficient. Experimental tests show that the heat transfer coefficient is notably affected by the shape of the immersed surface resulting higher for surfaces with better aerodynamic shape. An interpretative model, based on the dimensional analysis, has been used for the description of the experimental results.

Hybrid catalytic combustion technology, which is a staged process comprising a preliminary catalytic partial oxidation (CPO) step followed by a homogeneous flame combustion with interstage heat removal, was tested for the first time with mixtures of methane and hydrogen. Short contact time CPO experiments were run to elucidate the effect of the progressive substitution of methane with H2 in the fuel feed to the structured catalytic reactor, which was operated under self-sustained conditions at high temperature. Furthermore, a prototype radiant hybrid burner was realized and safely operated at atmospheric pressure with up to 80% vol. of H2 in the fuel and a primary equivalence ratio in the range 2.4–4.0. Outstanding NOx emission levels were attained with pure methane feed, which were also confirmed with H2-rich fuels, due to the effective reduction of both thermal and prompt NOx formation.

The main experimental and modelling findings on heat and mass transfer in fluidized beds are reviewed with particular attention to combustion and gasification processes. The survey is separated into two sections. The first section reports the main features of heat transfer in fluidized beds starting from the large number of studies focused on surface-bed heat transfer. These features are then used to support the understanding of the less-studied particle-bed and gas-bed heat transfer mechanisms. The second section describes in detail particle-bed and gas-bed mass transfer in fluidized beds. In both sections the effect of the main process parameters (physical properties of gas and particles, bed geometry and hydrodynamic regimes) on the heat and mass transfer coefficients are discussed in order to provide guidelines for the design, the optimization and the operation of fluidized bed combustors and gasifiers. © 2013 Woodhead Publishing Limited. All rights reserved.

Thermal conductivity of apple and potato samples was measured by means of a specifically designed apparatus based on Fitch's method. The thermal conductivity was determined at various moisture contents at the sample mean temperature of 30 °C. As expected the conductivity decreases with the decrease in moisture content. Thermal conductivity data were correlated with moisture content using a straight line.

An experimental investigation on sulfur dioxide removal in a pilot-scale spray dryer from the flue gas generated by combustion of low-sulfur (S) heavy oil is reported. A limewater slurry was sprayed through an ultrasonic two-fluid atomizer in the spray-dry chamber, and the spent sorbent was collected downstream in a pulse-jet baghouse together with fly ash. Flue gas was sampled at different points to measure the desulfurization efficiency after both the spray-dry chamber and the baghouse. Parametric tests were performed to study the effect of the following variables: gas inlet temperature, difference between gas outlet temperature and adiabatic saturation temperature, lime-to-S ratio, and average size of lime particles in the slurry. Results indicated that spray drying is an effective technology for the desulfurization of low-S fuel oil flue gas, provided operating conditions are chosen carefully. In particular, the lowest gas inlet and outlet temperatures compatible with baghouse operation should be selected, as should a sufficiently high lime-to-S ratio. The attainment of a small lime particle size in the slurry is critical for obtaining a high desulfurization efficiency. A previously presented spray-dry flue gas desulfurization model was used to simulate the pilot-scale desulfurization tests, to check the ability of the model to predict the S capture data and its usefulness as a design tool, minimizing the need for pilot-scale experimentation. Comparison between model and experimental results was fairly good for the whole range of calcium/S ratios considered.