Browsing by Subject "maltodextrin"
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(2017)The scope of the literature review was to define the process for oil-in-water emulsion formation and the important properties of the emulsions which are suitable for microencapsulation. The aim of this study was to determine how whey protein isolate together with maltodextrin affects the properties of the emulsion. Camelina oil and black currant seed oil were used as core materials. The wall materials used were: maltodextrin (MD) and whey protein isolate (WPI). Six different wall systems consisting WPI in combination with MD at various ratios (1:1, 1:3 and 1:9) were used. In premilinary tests the emulsions were characterized for temperature, creaming index, apparent viscosity, flow behavior index, flow consistency index, droplet size (D4,3 zetasize,), droplet size distribution (PDI, span) and zetapotential. Droplet size and droplet size distributions were measured by a laser light scattering using a Zetasizer and by laser light diffraction instrument, Mastersizer 2000/3000. Oil droplet size was also measured with light blockade using a PAMAS. Rheological properties were characterized with rheometer. In actual test the emulsions were characterized for time (foam removal), temperature, droplet size (D10, D50, D90 ja D4,3), apparent viscosity, flow behavior index and flow consistency index. First degree polynomial was fitted with PLSR to the results. Statistical significances of regression coefficients were analyzed with t-test. In premilinary tests all the emulsions were stable during storage at 25 °C after 24 h. pH and zetapotentials which were all lower than -35 mV refer to good stability of emulsions. Change in droplet size and droplet size distribution was observed. Increasing maltodextrin concentration decreased droplet size (D4,3) and droplet size distribution width (PDI) when measuring by Mastersizer and Zetasizer. Apparent viscosity of the emulsions decreased by increasing maltodextrin concentration. PLS-regression showed that there were statistically differences between wall materials and temperatures, droplet size, size distribution and apparent viscosity. There were also statistically differences between oil and droplet size measured by PAMAS. In actual tests apparent viscosity of the emulsions decreased by increasing maltodextrin concentration. Increasing maltodextrin concentration also decreased the time of foam removal. PLS-regression showed that there were statistically differences between wall materials and temperatures after homogenization, time (foam removal), flow consistency index and apparent viscosity. There were also statistically differences between oil and temperatures, flow behavior index and droplet size distribution width. Whey protein isolate together with maltodextrin affect mostly to apparent viscosity of emulsions.
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(2013)The literature review dealed with the composition of lingonberry, manufacture of juice powder and the effects of different carriers on properties of juice powder, especially glass transition temperature and stickiness. In addition, physical, functional and nutritional properties and the effect of storage conditions on juice powders were covered. The aim of the experimental work was to investigate the effect of spray- and freeze-drying and carriers on glass transition temperature and water sorption of lingonberry juice as well as the stability of vitamin C and phenolic compounds during drying and storage. The same amounts of maltodextrin (MD), whey protein isolate (WPI) or combination of MD/WPI in equal proportions were added to each sample. All samples were spray- and freeze-dried. After storage of powders at different relative humidities, glass transition temperature, water sorption, content of L-ascorbic acid and content of phenolic compounds were examined. Water sorption was examined by static and dynamic vapour sorption methods. The small particle size of containing WPI was problematic with spray-drying because not all of the powder in the drying air could be separated in the cyclone. Adding water back into the spray-dried samples was most difficult when the samples were stored at low relative humidities (0–11%). The smallest water sorption was observed with both static and dynamic vapour sorption methods in samples which contained only MD. Water contents of freeze-dried samples were lower than those of spray-dried samples. BET sorption isotherm described the water sorption behaviour of the lingonberry juice powders well. Glass transition temperatures of all samples decreased as the relative humidity increased. During storage, the amount of phenolic compounds in samples containing WPI remained the same, whereas the amount of phenolic compounds in samples with MD decreased. Enzymatic spectrophotometric determination was un suitable for determing L-ascorbic acid in lingonberry powder because the sample colour disturbed the measurement. MD and the combination of MD and WPI were suitable carriers in lingonberry juice. The amount of phenolic compounds in lingonberry juice powders were preserved well by whey protein isolate. Therefore, the spray-drying process should be developed in a way that brings about increase in particle size of powder containing WPI.
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(2020)Lipid oxidation presents one of the most important challenges for the processing and storage of edible oils by lowering the shelf life, nutritional value, and organoleptic properties of oils. Microencapsulation is a process where oil droplets are coated within a wall material matrix, and it offers a suitable solution to protect edible oils against oxidative deterioration. This study aimed at exploring the effects of wall material composition and relative humidity (RH) on the potential of microencapsulation to protect camelina and blackcurrant seed oils against lipid oxidation. Camelina and blackcurrant seed oils were emulsified using whey protein isolate (WPI) and maltodextrin (MD) as wall materials in 1:1, 1:3, and 1:9 ratio, and the total solids content and wall-to-oil ratio were kept constant. Microencapsulation was conducted by spray drying, and various parameters were analyzed, including emulsion viscosity, water sorption properties, and the surface oil content of microencapsulated powders. The powders were conditioned at 11% and 44% RHs at 21 °C, after which the sample vials were closed to maintain constant water content. The oxidative stability of the conditioned microencapsulated powders was analyzed over 10 weeks of accelerated storage conditions at 40 °C by measuring the volatile secondary lipid oxidation products every two weeks by headspace-solid phase-microextraction-gas chromatography-mass spectrometry method. The results showed that the best oxidative stability during the storage period was obtained by WPI-MD 1:1 ratio in both of the microencapsulated oils, even though this wall material composition resulted in the highest surface oil content and the lowest encapsulation efficiency. In blackcurrant seed oil powders, the water content obtained at 44% RH seemed to provide better protection against lipid oxidation than that of 11% RH. Regarding camelina oil powders, water content obtained in different RHs did not seem to affect the oxidative stability of the powders. However, based on the peak areas of volatile compounds detected at week 10, the water content obtained at 44% RH might provide better storage stability for camelina oil containing powders in long-term storage than that of 11% RH.
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