Summary Lactulose is a synthetic disaccharide. It can be obtained from lactose by chemical, enzymatic or by electro‐activation synthesis. This review provides the comprehension of lactulose production and its application in medical, pharmaceutical and functional food applications. Lactulose can be used in medical and pharmaceutical applications for the treatment of diseases such as chronic constipation, therapy of portal systemic encephalopathy, inflammatory bowel disease, reducing blood ammonia levels, colon carcinogenesis, tumour prevention and immunology, mineral absorption and for the inhibition of the secondary bile acid formation. However, with the growing interest in functional foods, the use of nondigestible oligosaccharides such as prebiotic ingredients has increased considerably during the recent years. In this context, lactulose as a well‐recognised prebiotic offers excellent possibilities to develop new functional foods. It can be added to several foods.

The aim of the present work was to study and develop an innovative, clean, and environmentally friendly process for lactulose synthesis by electroactivation of lactose. In this work, the electrode material (type 304 stainless steel, titanium, and copper), dimensionless interelectrode-membrane distance at the cathodic compartment (0.36, 0.68, and 1), and the membrane:electrode surface area ratio (0.23, 0.06, and 0.015) were considered to be the factors that could affect the kinetic conversion of lactose into lactulose. The reactions were conducted under an initial lactose concentration of 0.15mol/L at 10°C, Froude number (mixing speed) of 2.05×10(-2), and electric current intensity of 300mA for 30min. The highest lactulose formation yield of 32.50% (0.05mol/L) was obtained by using a copper electrode, interelectrode-membrane distance of 0.36, and membrane:electrode surface area ratio of 0.23. The 2-parameter Langmuir, Freundlich, and Temkin isotherm models were used for the prediction of the lactose isomerization kinetics as well as the 3-parameter Langmuir-Freundlich isotherm model. It was shown that the lactose isomerization kinetics into lactulose followed the Temkin and Langmuir-Freundlich models with coefficients of determination of 0.99 and 0.90 and a relative error of 1.42 to 1.56% and 4.27 to 4.37%, respectively.

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SummaryIn this work, we applied a nonintrusive measurement method based on the Red-Green-Blue (RGB) image analysis system to study the segregation and percolation in a mixture of white wheat flour and bleached wheat bran. This method intended to quantify the presence of one or several colours in the surface of mixed ingredients. The mixing of flour particles with bleached and unbleached wheat bran was studied using a 90 mm closed rotating cube. This system forced the particles to roll relative to each other so as to favourite the segregation by percolation in order to hide one colour by another. The obtained results showed a possibility of obtaining homogeneous colour when the wheat flour was mixed with the bleached wheat bran at a volume ratio of 20/5%-10%. By increasing to ratio up to 20/15% (flour/bran), the RGB system showed a presence of two colours in the surface of the mixture. Moreover, the RGB method confirmed the presence of two heterogeneous colours when the wheat flour was mixed with the unbleached wheat bran whatever the ratio (20/5%, 10% and 15%).Keywords Percolation, segregation, static mixer, wheat bran, wheat flour. IntroductionThe mixing of solids, powders or granular materials is a key operation in many industrial fields such as pharmaceuticals, food powders and granular ingredients, agricultural powders, cement and plastics. This operation allows achieving the specifications and usage properties of the desired products. Moreover, mixing is largely responsible for the homogeneity of the final product. The mixing is an essential step during which many problems can occur which can have significant influence on the product quality because the notion of homogeneity of a solid mixture is very important.Unlike fluids, the powder mixing is still poorly understood. This is probably due to the mesoscopic nature of these environments and lack of models describing the behaviour of mixed powders. According to A€ ıt Aissa (2011), the powder differs from the liquid mixing by three aspects: (i) there is no relative movement of the solid particles without energy as for liquids or gases, (ii) the rate of powder homogenisation depends only on the particle flow properties, operating conditions and mechanical stresses imposed by the stirring device and (iii) although the molecules of a liquid in a mono-phase system may be different and diffuse at different speeds, they will always reach a state of perfect mixing. The homogenisation of solids is, however, often accompanied by a process of segregation, which often does not allow obtaining a perfect blend. Thus, the final state of the mixture is a balance between homogenisation and segregation. Finally, the size of a solid particle is always much higher than that of molecule of any liquid or gas. In fact, once the particles set in motion, they can also mix well or segregate according to the movement imposed on the system and the characteristics of the components.Segregation is an undesirable phenomenon in particle mixing because it significantly affects the blend qu...

Low-grade dark maple syrup was successfully discolored on activated carbon. Several experimental parameters were tested, namely, the mixing time (20, 40, and 60 min), concentration of the activated carbon (0.1, 0.3, and 0.5 g/100 mL), type of activated carbon (I, II, and III), activated carbon particle size (25, 50, and 75 μm), stirring speed (200, 400, and 600 rpm), and temperature (40, 60, and 80 °C). The obtained results showed that the discoloration is optimal by applying the following parameters: a mixing time of 40 min with a type III activated carbon at a concentration of 0.3 g/100 mL. These parameters yielded a light transmittance at 560 nm of 83.70 ± 0.21%, which ranks the syrup in the extra clear class according to the Canadian classification. The results showed that among the tested carbons, the adsorption on the type III carbon followed the Langmuir, Freundlich, and Langmuir–Freundlich adsorption isotherms. Regarding the effect of the particle size, the obtained results showed that a mean size of 25 μm combined with a stirring speed of 200 rpm and working temperature of 80 °C was the most effective one. The optimized conditions showed a good adequacy with the Langmuir and Freundlich models. The discoloration process by using the type III activated carbon followed the pseudo-second-order kinetics.

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