Browsing by Subject "puolukkamehujauhe"

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  • Mikkonen, Tiia (Helsingfors universitet, 2012)
    The literature review dealed with composition of lingonberry, effects of processing on phenolic compounds and spray drying juices with the help of carrier agents. The aim of the experimental work was to spray dry lingonberry juice with the help of carrier agents, examine the properties of juice powders and explore how juice powders suit for selected applications. The total content of phenolic compounds was also measured from the lingonberry juice and powders. Maltodextrin DE 5–8 (MD), whey protein isolate (WPI) and combination of carrier agents (MD+WPI) were used as carrier agents while yield, glass transition temperature, colour, solubility and total content of phenolic compounds were the properties examined. A milk based lingonberry smoothie, lingonberry marmalade, lingonberry marshmallow and lingonberry spread were developed as applications. The spray drying of the lingonberry juice and subsequent applications were successful. The highest yield (20.9%) was achieved when MD was used as a carrier agent. WPI had the lowest yield (9.8%). MD-juice powders had the highest glass transition temperature at all relative humidities used (0, 11, 24, 33 and 44%) and WPI-juice powder had the lowest. Commercial juice powder had the darkest colour (garnet) and MD+WPI-juice powder was the lightest (light pink). MD-juice powder had the poorest solubility and commercial powder had the best, although MD was a carrier agent in both. The total content of phenolic compounds in lingonberry juice was 246.4 mg/100 g and in the best juice powder (WPI) 3.6 mg/100 g. Juice powders had differences in colour when used in applications and smoothies also had differences in stability of foam. MD and commercial powder formed a stabile foam structure but WPI-smoothies separated into liquid and foam phases. Lingonberry juice powders did not affect the structure of marmalades or marshmallows. In lingonberry spreads commercial juice powder blended the best into margarine. Lingonberry juice powders are interesting products. Lingonberry juice powders would suit well in different applications to add colour and taste. Due to low glass transition temperature, powders were difficult to handle. With some further research this stickiness problem could be solved.
  • Suihkonen, Terhi (Helsingfors universitet, 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.