András Koris

Dry degumming of vegetable oils by membrane filtration

Abstract Phospholipid removal from crude soybean and sunflower-seed oil by membrane filtration was studied in this paper. A laboratory scale membrane apparatus were designed and built for this research at our department. Oil filtrations were carried out at temperature 40–60°C, pressure 2–5 bar and velocity of flow 0.3–0.4 L/m3. After oil filtration the system and the membrane were cleaned with organic solvents. The SP015A membrane had constant retention on phospholipids (70–77%). With adding some water to the oil we were able to improve the retention to ∼97%.

Biological Activities of Lactose-Derived Prebiotics and Symbiotic with Probiotics on Gastrointestinal System

Lactose-derived prebiotics provide wide ranges of gastrointestinal comforts. In this review article, the probable biochemical mechanisms through which lactose-derived prebiotics offer positive gastrointestinal health are reported along with the up-to-date results of clinical investigations; this might be the first review article of its kind, to the best of our knowledge. Lactose-derived prebiotics have unique biological and functional values, and they are confirmed as ‘safe’ by the Food and Drug Administration federal agency. Medical practitioners frequently recommend them as therapeutics as a pure form or combined with dairy-based products (yoghurt, milk and infant formulas) or fruit juices. The biological activities of lactose-derived prebiotics are expressed in the presence of gut microflora, mainly probiotics (Lactobacillus spp. in the small intestine and Bifidobacterium spp. in the large intestine). Clinical investigations reveal that galacto-oligosaccharide reduces the risks of several types of diarrhea (traveler’s diarrhea, osmotic diarrhea and Clostridium difficile associated relapsing diarrhea). Lactulose and lactosucrose prevent inflammatory bowel diseases (Crohn’s disease and ulcerative colitis). Lactulose and lactitol reduce the risk of hepatic encephalopathy. Furthermore, lactulose, galacto-oligosaccharide and lactitol prevent constipation in individuals of all ages. It is expected that the present review article will receive great attention from medical practitioners and food technologists.

Modelling the Partial Demineralization Process of Cow Milk by Superpro Designer

Abstract Milk and dairy products contain a number of biologically active compounds (proteins, lipids, vitamins and minerals) that are essential for human nutrition. The most common procedures for demineralization are based on ion exchange-, nanofiltration- and electrodialysis-based technologies. In this study, the application of membrane filtration-based partial demineralization of cow milk was investigated and the process modelled. Using design equations, the partial demineralization process was designed and the economy of the process calculated. The modelling and simulation of the partial demineralization process was carried out by the SuperPro Designer programme. As the first step the unit operations of the demineralization technology were defined using the tools of the programme. The SuperPro Designer possesses industrial tools with reactor models, chemical components, a database of mixtures, and price estimations. By analysing the influence of the operation parameters, the feasibility of the proposed process was investigated. From the results of the modelling it can be concluded that the partial demineralization process can be successfully implemented, achieving the expected demineralization rates with a relatively good payback time of two years.

Microencapsulation of Vegetable Oil: Alternative Approaches Using Membrane Technology and Spray Drying

Abstract Microencapsulation technology is a method that is widely used in the food industry. By comparing the latest encapsulation techniques, a significant number of publications concern membrane technology. The term “membrane- based encapsulation” entails that the first step of the technique is the preparation of emulsion with the help of microporous membranes. Generally, in microencapsulation technologies, the wall material is dissolved in a continuous phase and oil is dispersed within it. In the present investigation, a new method of preparing microcapsules composed of vegetable oil and maltodextrin was developed. In the first step, the wall material (maltodextrin) was dissolved in oil and considered as a dispersed phase, subsequently, it was introduced into a continuous phase (water) through a microporous membrane. A comparative study was conducted between conventional microencapsulation techniques and one developed in our laboratory. The average particle size of microcapsules prepared by our method is smaller than the size allowed by other methods. After encapsulation preparation, fine-tuned microcapsules were produced by spray drying. However, the main disadvantage of our proposed technology is rapid membrane fouling, because of high concentrations of solute in the dispersed phase. This problem can be eliminated by judicious and systematic investigations.

Production of hypoallergenic antibacterial peptides from defatted soybean meal in membrane bioreactor: A bioprocess engineering study with comprehensive product characterization

Hypoallergenic antibacterial low-molecular-mass peptides were produced from defatted soybean meal in a membrane bioreactor. In the first step, soybean meal proteins were digested with trypsin in the bioreactor, operated in batch mode. For the tryptic digestion of soybean meal protein, optimum initial soybean meal concentration of 75 g/L, temperature of 40 °C and pH=9.0 were determined. After enzymatic digestion, low-molecular-mass peptides were purified with cross-flow flat sheet membrane (pore size 100 µm) and then with tubular ceramic ultrafiltration membrane (molecular mass cut-off 5 kDa). Effects of transmembrane pressure and the use of a static turbulence promoter to reduce the concentration polarization near the ultrafiltration membrane surface were examined and their positive effects were proven. For the filtration with ultrafiltration membrane, transmembrane pressure of 3·105 Pa with 3-stage discontinuous diafiltration was found optimal. The molecular mass distribution of purified peptides using ultrafiltration membrane was determined by a liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry setup. More than 96% of the peptides (calculated as relative frequency) from the ultrafiltration membrane permeate had the molecular mass M≤1.7 kDa and the highest molecular mass was found to be 3.1 kDa. The decrease of allergenic property due to the tryptic digestion and membrane filtration was determined by an enzyme-linked immunosorbent assay and it was found to exceed 99.9%. It was also found that the peptides purified in the ultrafiltration membrane promoted the growth of Pediococcus acidilactici HA6111-2 and they possessed antibacterial activity against Bacillus cereus.