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This study evaluated the kinetics of water vapour adsorption on the surface of starch molecules derived from wheat. The aim of the study was to determine an equation that would allow estimation of water content in tested material in any time-point of the adsorption process aimed at settling a balance with the environment. An adsorption isotherm of water vapour on starch granules was drawn. The parameters of the Guggenheim, Anderson, and De Boer equation were determined by characterizing the tested product and adsorption process. The equation of kinetics of water vapour adsorption on the surface of starch was determined based on the Guggenheim, Anderson, and De Boer model describing the state of equilibrium and on the model of a first-order linear inert element describing the changes in water content over time.
The grasspea breeding programme in Poland resulted in development of 2 official varieties of Polish grasspea: small seed form-Derek and large seed form-Krab. The present study was to characterise basic physico-chemical properties of starch from these varieties.
The properties oť potato starch saturated with Na, K, Ca and H cations were studied in extrudates cooked at 60°-65°-75°C, 90°-105°-120°C and 140°-155°-170°C. The morphological features of the extrudates, their specific gravity and expansion ratio as well as starch properties depended on the temperature of extrusion and type of saturating cations. The higher were the temperatures of extrusion, the higher was the solubility of the extrudates, but lower rétrogradation degree and the amount of sediment obtained from centrifuged pastes. The starches saturated with Na, K, Ca and H cations, either non-extruded or extruded at 60°-65°-75°C and 90°-105o-120°C exhibited different solubility and rétrogradation degree; the starches extruded at 140°-155o-170°C were totally soluble and their rétrogradation degree was similar. Some differences in water absorption capacity of the extruded starches saturated with different cations were observed - the extrudates of Na, K and Ca starches exhibited higher water absorption capacity than non-extruded starches, while the water absorption capacity of extruded hydrogen starch was lower than before extrusion.
Background. The retrogradation which occurs during the processes food storage is an essential problem in food industry. In this study, the ability to retrogradate of native starches and maltodextrins of different botanical origin was analysed. Material and methods. The materials were starches of various botanical origin, including commercial samples: potato, tapioca, wheat, com, waxy com starches, and laboratory isolated samples: triticale and rice starches. The above starches were used as material for laboratory production of maltodextrins of medium dextrose equivalents (DE in the rangę fforn 8.27 to 12.75). Starches were analysed for amylose content, while the ratio of nonbranched/long-chain-branched to short-chain-branched fractions of maltodextrins was calculated from gel permeation chromatography data. The susceptibility to retrogradation of 2% starch pastes and 2% maltodextrin Solutions was evaluated according to turbidimetric method of Jacobson. Results. The greatest starch in turbidance of starch gels was observed within initial of the test. days. Initial retrogradation degree of cereal starches was higher than that of tuber and root starches. The waxy com starch was the least prone to retrogradate. The increase in turbidance of maltodextrin Solutions were minimal. Waxy com maltodextrin was not susceptible to retrogradation. Among other samples, the lowest susceptibility to retrogradation after 14 days was found for rice maltodextrin, while the highest for wheat and triticale maltodextrin. Conclusions. On the basis of this study, the retrogradation dependence on the kind of starches and the maltodextrins was established and the author stated that all the maltodextrins have a much less ability to retrogradation than the native starches.
The aim of this study was to verify the glycaemia-lowering activity of L-arabinose. The experiment was conducted on 3 individual days, each separated by a week. At the beginning of each week rats were subjected to an oral glucose, sucrose or starch tolerance test. Five minutes prior to each test rats were gavaged with water (a control), an aqueous solution of acarbose (a positive control) and L-arabinose. There was no effect of L-arabinose on glycaemia in the glucose tolerance test, whereas it reduced postprandial glycaemia after 15 min of the sucrose tolerance test. In the starch tolerance test, the glycaemia after L-arabinose ingestion was signifi cantly decreased both at time intervals and in total. Inhibition of enzyme activity involved in starch digestion (amylase, maltase) may be suggested as the most probable mechanism responsible for the observed effects.
Celem pracy było określenie wpływu fizycznej i amylolitycznej modyfikacji ziarna kukurydzy na zawartość wybranych składników w uzyskanych produktach. Materiałem badawczym były ziarna kukurydzy handlowej typu flint, odmiany Delitop, poddane przemiałowi „na sucho”. Uzyskano cztery asortymenty przemiału ziarna kukurydzy: łom (2,5- 6,0 mm), kaszę (0,75- 1,25 mm), kaszkę (0,25-0,75 mm), mąkę (< 0,25 mm), które wraz z ziarniakiem (około 10 mm) stanowiły pięć surowców poddanych modyfikacji amylolitycznej i fizycznej. Zaproponowana w niniejszej pracy modyfikacja amylolityczna, polegająca na hydrotermicznej obróbce mieszaniny reakcyjnej enzymami amylolitycznymi (jednoczesne działanie α-amylazy i amylazy maltogennej) wraz z modyfikacją fizyczną, polegającą na rozdziale zawiesiny poreakcyjnej na dwie fazy, umożliwia otrzymanie nowych modyfikatów ziarna kukurydzy lub produktów jego przemiału, charakteryzujących się zmienioną zawartością wybranych składników (zwiększenie zawartości białka i tłuszczu, zmniejszenie zawartości skrobi). Uzyskane modyfikaty kukurydziane – ze względu na zawartość wybranych składników – mogą być stosowane jako składniki wyrobów spożywczych, a także jako komponenty mieszanek paszowych.
4 Austrian varieties of rye (‘Walstaudenroggen’, ‘Echo’, ‘Schlager’ and ‘Esprit’) and one Polish variety (‘Dańkowskie Złote’) were investigated. There were differences in grains composition as well as in starch properties. Among all varieties, the best one ‘Waldstaudenroggen’ was distinguished due to a high content of soluble carbohydrates, Iow level of amylose and high molecular mass of starch. Basing on those permises it was found, that the mentioned above properties, influenced high quality of rye variety. Despite growing in different climatical conditions, the Polish variety ‘Dańkowskie Złote’ did not differ in the analysed features from the Austrian ones.
The long-term outlook for cassava starch is uncertain, this is despite the economic advantage afforded to this product by recent decline in cassava price. The problems are due to a restricted portfolio of functional properties coupled with a final product that is variable in-terms of its quality. The quality of extracted cassava starch is dependent on many factors, especially processing. One key problem area is that of drying the dewatered cake. In this study, it was shown that the properties of dried starch were different to those of its non-dried counterpart (cake). After drying swelling power and solubility decreased, these changes were in-line with those exhibited by heat-moisture treated starch prepared by incubating 25% moistened starch at 100°C for 16 hr. Dried starch had higher peak temperature than its original cake but lower pasting temperature, which contrasted to the effect of heat-moisture treatment. Dried starch from moist cake had a broader endothermic peak indicated by a larger gelatinization temperature range and lower peak height index, similar to heat-moisture treated starch. Despite apparent changes in functional properties during drying of cassava starch, the cause of the change is not entirely known. Generally, changes reflect a hybrid of heat-moisture treatment and hydrothermal effect.
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