Biotehnološka proizvodnja i svojstva fruktoznog sirupa

In response to the growing demand for the consumption of natural, healthy and low-calorie food, a large number of so-called alternative sugars has emerged since the early 80s, among them fructose. This sugar is a ketohexose, known as D-fructose or levulose, and is considered the sweetest sugar found in nature. Currently, fructose is mostly produced through the acid hydrolysis of sucrose, or through the multi-enzymatic hydrolysis of starch. Processes involving specific enzymes like inulinases, acting on widely available fructose polysaccharides such as inulin, have been studied as alternatives to the current approaches, in order to reduce time, complexity and costs involved in this process. Fructose syrup is used worldwide, mainly because of its sweetening power and functional properties. The present work aims to provide an overview of the properties of fructose and of the present and envisaged production processes, within the scope of a biotechnological approach.Zbog sve većih zahtjeva potrošača za prirodnom, zdravom i niskokaloričnom hranom, već od ranih 1980-ih godina razvijen je veliki broj tzv. alternativnih šećera, među njima i fruktoza, ketoheksoza, poznata kao D-fruktoza ili levuloza, koja je najslađi šećer u prirodi. Trenutačno se proizvodi najčešće kiselinskom hidrolizom saharoze ili enzimskom hidrolizom škroba. Da bi se dobio što brži, jednostavniji i jeftiniji postupak, istraženi su procesi u kojima se primjenjuju specifični enzimi poput inulinaza, što djeluju na razne fruktozne polisaharide (npr. inulin). Fruktozni se sirup koristi u cijelom svijetu uglavnom zbog svoje slatkoće i funkcionalnih svojstava. Svrha je ovoga rada prikazati postupke biotehnološke proizvodnje fruktoze te opisati njezina svojstva

Anatomy and fructan distribution in vegetative organs of Dimerostemma vestitum (Asteraceae) from the campos rupestres

Among the compounds stored by plants, several functions are assigned to fructans, such as source of energy and protection against drought and extreme temperatures. In the present study we analyzed the anatomy and distribution of fructans in vegetative organs of Dimerostemma vestitum (Asteraceae), an endemic species from the Brazilian campos rupestres. D. vestitum has amphistomatic and pubescent leaves, with both glandular and non-glandular trichomes. In the basal aerial stem the medulla has two types of parenchyma, which differ from the apical portion. The xylopodium has mixed anatomical origin. Interestingly, although inulin-type fructans with high degree of polymerization were found in all analyzed organs except the leaves, the highest amount and maximum degree of polymerization were detected in the xylopodium. Inulin sphero-crystals were visualized under polarized light in the medulla and in the vascular tissues mainly in the central region of the xylopodium, which has abundant xylem parenchyma. Secretory structures accumulating several compounds but not inulin were identified within all the vegetative organs. The presence of these compounds, in addition to inulin, might be related to the strategies of plants to survive adverse conditions in a semi-arid region, affected seasonally by water restriction and frequently by fire

Fructose Syrup: A Biotechnology Asset

In response to the growing demand for the consumption of natural, healthy and low-calorie food, a large number of so-called alternative sugars has emerged since the early 80s, among them fructose. This sugar is a ketohexose, known as D-fructose or levulose, and is considered the sweetest sugar found in nature. Currently, fructose is mostly produced through the acid hydrolysis of sucrose, or through the multi-enzymatic hydrolysis of starch. Processes involving specific enzymes like inulinases, acting on widely available fructose polysaccharides such as inulin, have been studied as alternatives to the current approaches, in order to reduce time, complexity and costs involved in this process. Fructose syrup is used worldwide, mainly because of its sweetening power and functional properties. The present work aims to provide an overview of the properties of fructose and of the present and envisaged production processes, within the scope of a biotechnological approach

Metabolic And Structural Changes During Early Maturation Of Inga Vera Seeds Are Consistent With The Lack Of A Desiccation Phase.

Inga vera, native to South America, is an important leguminous species used for ecological restoration of riparian forests and its seeds are among the most recalcitrant ones described up to date. In this work, we analysed the metabolic profile, cell ultrastructure as well as cell wall polysaccharides of I. vera seeds in order to better understand its maturation, which allows embryo germination without a quiescent phase. Increased amounts of citric, glutamic, pyroglutamic, and aspartic acids from stages I to II (120 and 129 days after flowering (DAF)) corroborate the hypothesis of high metabolism, shifting from fermentative to aerobic respiration at seed maturity. This phase was characterized by an extensive vacuolization of embryonic cells, which also indicate high metabolic activity. The proportion of arabinose in the cell walls of embryonic axis (approx. 20%) was lower than those found in some orthodox seeds (nearly 40%), suggesting that arabinose-containing polysaccharides, which are thought to provide more flexibility to the cell wall during natural drying, are less abundant in I. vera seeds. Taken together, our results provide evidence that the major changes occurred during early stages of seed maturation of I. vera, indicating that the rapid temporary metabolic shift observed between stages I and II may be related to the lack of desiccation phase, moving directly to germination.170791-80