Inverted sugar syrup, also called invert syrup, invert sugar, simple syrup, sugar syrup, sugar water, bar syrup, syrup USP, or sucrose inversion, is a

syrup In cooking, a syrup (less commonly sirup; from ar, شراب; , beverage, wine and la, sirupus) is a condiment that is a thick, viscous liquid consisting primarily of a solution of sugar in water, containing a large amount of dissolved suga ...

mixture of the

monosaccharide Monosaccharides (from Greek '' monos'': single, '' sacchar'': sugar), also called simple sugars, are the simplest forms of sugar and the most basic units (monomers) from which all carbohydrates are built. They are usually colorless, water-sol ...

glucose Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, usi ...

and

fructose Fructose, or fruit sugar, is a ketonic simple sugar found in many plants, where it is often bonded to glucose to form the disaccharide sucrose. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorb ...

, that is made by hydrolytic saccharification of the

disaccharide A disaccharide (also called a double sugar or ''biose'') is the sugar formed when two monosaccharides are joined by glycosidic linkage. Like monosaccharides, disaccharides are simple sugars soluble in water. Three common examples are sucrose, ...

sucrose Sucrose, a disaccharide, is a sugar composed of glucose and fructose subunits. It is produced naturally in plants and is the main constituent of white sugar. It has the molecular formula . For human consumption, sucrose is extracted and refi ...

. This mixture's

optical rotation Optical rotation, also known as polarization rotation or circular birefringence, is the rotation of the orientation of the plane of polarization about the optical axis of linearly polarized light as it travels through certain materials. Circular ...

is opposite to that of the original sugar, which is why it is called an ''invert'' sugar. It is

sweeter Sweetness is a basic taste most commonly perceived when eating foods rich in sugars. Sweet tastes are generally regarded as pleasurable. In addition to sugars like sucrose, many other chemical compounds are sweet, including aldehydes, ketones, ...

than table sugar, and foods that contain invert sugar retain moisture better and crystallize less easily than do those that use table sugar instead.

Baker A baker is a tradesperson who bakes and sometimes sells breads and other products made of flour by using an oven or other concentrated heat source. The place where a baker works is called a bakery. History Ancient history Since grains ...

s, who call it ''invert syrup'', may use it more than other

sweeteners A sugar substitute is a food additive that provides a sweetness like that of sugar while containing significantly less food energy than sugar-based sweeteners, making it a zero-calorie () or low-calorie sweetener. Artificial sweeteners may be ...

Production

Plain water

Inverted sugar syrup can be made without acids or enzymes by heating it up alone: two parts granulated sugar and one part water, simmered for five to seven minutes, will be partly inverted. The amount of water can be increased to increase the time it takes to reach the desired final temperature, and increasing the time increases the amount of inversion that occurs. In general, higher final temperatures result in thicker syrups, and lower final temperatures, in thinner ones.

Additives

Commercially prepared

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecule ...

-catalyzed solutions are inverted at . The optimum pH for inversion is 5.0.

Invertase Invertase is an enzyme that catalyzes the hydrolysis (breakdown) of sucrose (table sugar) into fructose and glucose. Alternative names for invertase include , saccharase, glucosucrase, beta-h-fructosidase, beta-fructosidase, invertin, sucrase, ...

is added at a rate of about 0.15% of the syrup's weight, and inversion time will be about 8 hours. When completed the syrup temperature is raised to inactivate the invertase, but the syrup is concentrated in a vacuum evaporator to preserve color. Though inverted sugar syrup can be made by heating table sugar in water alone, the

reaction Reaction may refer to a process or to a response to an action, event, or exposure: Physics and chemistry *Chemical reaction *Nuclear reaction *Reaction (physics), as defined by Newton's third law * Chain reaction (disambiguation). Biology and me ...

can be sped up by adding

lemon juice The lemon (''Citrus limon'') is a species of small evergreen trees in the flowering plant family Rutaceae, native to Asia, primarily Northeast India (Assam), Northern Myanmar or China. The tree's ellipsoidal yellow fruit is used for culina ...

cream of tartar Potassium bitartrate, also known as potassium hydrogen tartrate, with formula K C4 H5 O6, is a byproduct of winemaking. In cooking, it is known as cream of tartar. It is processed from the potassium acid salt of tartaric acid (a carboxylic ...

, or other

catalyst Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

s, often without changing the flavor noticeably. Common sugar can be inverted quickly by mixing sugar and

citric acid Citric acid is an organic compound with the chemical formula HOC(CO2H)(CH2CO2H)2. It is a colorless weak organic acid. It occurs naturally in citrus fruits. In biochemistry, it is an intermediate in the citric acid cycle, which occurs in t ...

at a ratio of about 1000:1 by weight and adding water. If

which is about five percent citric acid by weight is used instead then the ratio becomes 50:1. Such a mixture, heated to and added to another food, prevents crystallization without tasting sour. Commercially prepared hydrochloric-acid catalyzed solutions may be inverted at the relatively low temperature of . The optimum pH for acid-catalyzed inversion is 2.15. As the inversion temperature is increased, the inversion time decreases. They are then given a pH neutralization when the desired level of inversion is reached. In confectionery and

candy making Candy making or candymaking is the preparation and cookery of candies and sugar confections. Candy making includes the preparation of many various candies, such as hard candies, jelly beans, gumdrops, taffy, liquorice, cotton candy, cho ...

is commonly used as the acidulant, with typical amounts in the range of 0.15–0.25% of the sugar's weight. The use of cream of tartar imparts a honey-like flavor to the syrup. After the inversion is completed, it may be neutralized with

baking soda Sodium bicarbonate ( IUPAC name: sodium hydrogencarbonate), commonly known as baking soda or bicarbonate of soda, is a chemical compound with the formula NaHCO3. It is a salt composed of a sodium cation ( Na+) and a bicarbonate anion ( HCO3� ...

using a weight of 45% of the cream of tartar's weight.

For fermentation

All constituent sugars (sucrose, glucose, and fructose) support fermentation, so invert sugar solutions of any composition can be fermented. Syrup is used to feed microbiological life, which requires oxygen found in the water. For example,

kombucha Kombucha (also tea mushroom, tea fungus, or Manchurian mushroom when referring to the culture; Latin name ''Medusomyces gisevii'') is a fermented, lightly effervescent, sweetened black tea drink commonly consumed for its purported health b ...

is produced by fermenting inverted sugar syrup with tea using a '' symbiotic culture of bacteria and yeast'' (

SCOBY Symbiotic culture of bacteria and yeast (SCOBY) is a culinary symbiotic fermentation culture ( starter) consisting of lactic acid bacteria (LAB), acetic acid bacteria (AAB), and yeast which arises in the preparation of sour foods and beverag ...

), and

yeast in winemaking The role of yeast in winemaking is the most important element that distinguishes wine from fruit juice. In the absence of oxygen, yeast converts the sugars of the fruit into alcohol and carbon dioxide through the process of fermentation.Jeff C ...

is used for

ethanol fermentation Ethanol fermentation, also called alcoholic fermentation, is a biological process which converts sugars such as glucose, fructose, and sucrose into cellular energy, producing ethanol and carbon dioxide as by-products. Because yeasts perform thi ...

. Cold water can hold more dissolved oxygen than warm water, but granulated sugar does not dissolve easily in cold water. Water in a container with wide bottom

surface area The surface area of a solid object is a measure of the total area that the surface of the object occupies. The mathematical definition of surface area in the presence of curved surfaces is considerably more involved than the definition of ...

improves the

solubility In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution. The extent of the solub ...

of the sucrose, which only has to be mixed a few times periodically to form a homogeneous solution. Also, a mixer or

blender A blender (sometimes called a mixer or liquidiser in British English) is a kitchen and laboratory appliance used to mix, crush, purée or emulsify food and other substances. A stationary blender consists of a blender container with a rotating me ...

may be used to rotate the sugar, in turns, if necessary.

In other foods and products

Honey Honey is a sweet and viscous substance made by several bees, the best-known of which are honey bees. Honey is made and stored to nourish bee colonies. Bees produce honey by gathering and then refining the sugary secretions of plants (primar ...

which is mostly a mixture of glucose and fructose, being similar to invert syrup therefore, can remain a liquid for longer periods of time. * Jam contains invert sugar formed by the heating process and the acid content of the fruit. This sugar preserves the jam for long periods of time. * Golden syrup is a syrup of about 55% invert syrup and 45% table sugar (sucrose). * Fondant filling for chocolates is unique in that the conversion enzyme is added, but not activated by acidification (microenvironment pH adjustment) or cofactor addition depending on the enzyme(s), before the filling is enrobed with chocolate. The very viscous (and thus formable) filling then becomes less viscous with time, giving the creamy consistency desired. This results from the sub-optimal enzyme(s) conditions purposely created by withholding activation factors, which allows only a fraction of the enzyme(s) to be active, or allows all enzyme(s) to proceed at only a fraction of the biological rate iologically, it's realistically a combination of both: a reduced number of functional enzymes, with the ones that do function having reduced catalytic kinetics/rates * Cadbury Creme Eggs are filled with inverted sugar syrup produced by processing fondant with invertase. * Sour Patch Kids also contain inverted sugar to add sweet flavor.

Sweetened beverages

Inverted sugar syrup is the basis in

sweetened beverage A sweetened beverage is any beverage with added sugar. It has been described as "liquid candy". Consumption of sweetened beverages has been linked to weight gain, obesity, and associated health risks. According to the CDC, consumption of sweetene ...

s. * Sweet reserve is a

wine Wine is an alcoholic drink typically made from fermented grapes. Yeast consumes the sugar in the grapes and converts it to ethanol and carbon dioxide, releasing heat in the process. Different varieties of grapes and strains of yeasts are ...

term referring to a portion of selected unfermented grape

must Must (from the Latin ''vinum mustum'', "young wine") is freshly crushed fruit juice (usually grape juice) that contains the skins, seeds, and stems of the fruit. The solid portion of the must is called pomace and typically makes up 7–23% of ...

, free of microorganisms, to be added to wine as a sweetening component. When wine ferments, glucose is fermented at a faster rate than fructose. Thus, arresting fermentation after a significant portion of the sugars have fermented results in a wine where the residual sugar consists mainly of fructose, while the use of Süssreserve will result in a wine where the sweetness comes from a mixture of glucose and fructose. * Alcoholic beverage manufacturers often add invert sugar in the production of drinks like gin, beer and sparkling wines for flavoring.

Candi sugar Candi sugar is a Belgian sugar product commonly used in brewing beer. It is particularly associated with stronger Belgian style ales such as dubbel and tripel. Chemically, it is an unrefined sugar beet derived sugar which has been subjected to ...

, similar to invert sugar, is used in the brewing of Belgian-style beers to boost alcohol content without drastically increasing the body of the beer; it is frequently found in the styles of beer known as dubbel and tripel.

Chemistry

Table sugar (sucrose) is converted to invert sugar by

hydrolysis Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions in which water is the nucleophile. Biological hydrolysis ...

. Heating a mixture or solution of table sugar and water breaks the

chemical bond A chemical bond is a lasting attraction between atoms or ions that enables the formation of molecules and crystals. The bond may result from the electrostatic force between oppositely charged ions as in ionic bonds, or through the sharing o ...

that links together the two simple-sugar components. The balanced chemical equation for the hydrolysis of sucrose into glucose and fructose is: : Sugar-inversion

:C₁₂H₂₂O₁₁ (sucrose) + H₂O (water) → C₆H₁₂O₆ (glucose) + C₆H₁₂O₆ (fructose)

Optical rotation

Once a sucrose solution has had some of its sucrose turned into glucose and fructose the solution is no longer said to be pure. The gradual decrease in purity of a sucrose solution as it is hydrolyzed affects a chemical property of the solution called

that can be used to figure out how much of the sucrose has been hydrolyzed and therefore whether the solution has been inverted or not.

Definition and measurement

Plane polarized light can be shone through a sucrose solution as it is heated up for hydrolysis. Such light has an 'angle' that can be measured using a tool called a

polarimeter A polarimeter is a scientific instrument used to measure the angle of rotation caused by passing polarized light through an optically active substance.shapes of the molecules ('chemical structures') of sucrose, glucose, and fructose are all

asymmetrical Asymmetry is the absence of, or a violation of, symmetry (the property of an object being invariant to a transformation, such as reflection). Symmetry is an important property of both physical and abstract systems and it may be displayed in pr ...

the three sugars come in several different forms, called stereoisomers. The existence of these forms is what gives rise to these chemicals' optical properties. When plane polarized light passes through a pure solution of one of these ''forms'' of one of the sugars it is thought to hit and 'glance off' certain asymmetrical

s within the molecule of that form of that sugar. Because those particular bonds (which in cyclic sugars like sucrose, glucose, and fructose include an anomeric bond) are different in each form of the sugar, each form rotates the light to a different degree. When any one form of a sugar is purified and put in water, it rapidly takes other forms of the same sugar. This means that a solution of a pure sugar normally has all of its stereoisomers present in the solution in different amounts which usually do not change much. This has an 'averaging' effect on all of the optical rotation angles (

\alpha

values) of the different forms of the sugar and leads to the pure sugar solution having its own 'total' optical rotation, which is called its 'specific rotation' or 'observed specific rotation' and which is written as

alpha /math>.

In the circumstance of 20 °C, the specific optical rotation of sucrose is known to be 66.6°, glucose is 52.2°, and fructose is −92.4°.

Effects of water

Water molecules do not have

chirality Chirality is a property of asymmetry important in several branches of science. The word ''chirality'' is derived from the Greek (''kheir''), "hand", a familiar chiral object. An object or a system is ''chiral'' if it is distinguishable from i ...

, therefore they do not have any effect on the measurement of optical rotation. When plane polarized light enters a body of pure water its angle is no different than when it exits. Thus, for water,

alpha /math> = 0°. Chemicals that, like water, have specific rotations that equal zero degrees are called 'optically inactive' chemicals and like water, they do not need to be considered when calculating optical rotation, outside of the concentration and path length.

Mixtures in general

The overall optical rotation of a mixture of chemicals can be calculated if the proportion of the amount of each chemical in the solution is known. If there are

N

-many optically active different chemicals ('

chemical species A chemical species is a chemical substance or ensemble composed of chemically identical molecular entities that can explore the same set of molecular energy levels on a characteristic or delineated time scale. These energy levels determine the wa ...

') in a solution and the

molar concentration Molar concentration (also called molarity, amount concentration or substance concentration) is a measure of the concentration of a chemical species, in particular of a solute in a solution, in terms of amount of substance per unit volume of sol ...

(the number of moles of each chemical per

liter The litre (international spelling) or liter (American English spelling) (SI symbols L and l, other symbol used: ℓ) is a metric unit of volume. It is equal to 1 cubic decimetre (dm3), 1000 cubic centimetres (cm3) or 0.001 cubic metre (m3 ...

of liquid solution) of each chemical in the solution is known and written as

C_i

(where

i

is a number used to identify the chemical species); and if each species has a specific rotation (the optical rotation of that chemical were it made as a pure solution) written as

alpha i

, then the mixture has the overall optical rotation

\displaystyle \alpha = \frac = \sum_^N \left(\frac\right) alpha i = \sum_^N \chi_i alpha i

Where

\chi_i

is the

mole fraction In chemistry, the mole fraction or molar fraction (''xi'' or ) is defined as unit of the amount of a constituent (expressed in moles), ''ni'', divided by the total amount of all constituents in a mixture (also expressed in moles), ''n''tot. This ...

of the

i \mathrm

species.

Fully hydrolyzed sucrose

Assuming no extra chemical products are formed by accident (that is, there are no

side reaction A side reaction is a chemical reaction that occurs at the same time as the actual main reaction, but to a lesser extent. It leads to the formation of by-product, so that the yield of main product is reduced: : + B ->[] P1 : + C ->[] P2 P1 is th ...

s) a completely hydrolyzed sucrose solution no longer has any sucrose and is a half-and-half mixture of glucose and fructose. This solution has the optical rotation

= \frac(52.7^\circ - 92.0^\circ) = -19.7^\circ

Partly hydrolyzed sucrose

If a sucrose solution has been partly hydrolyzed, then it contains sucrose, glucose and fructose and its optical rotation angle depends on the relative amounts of each for the solution;

\displaystyle \alpha = \chi_s alpha s +\chi_g alpha g +\chi_f alpha f

Where

s

g

, and

f

stand for sucrose, glucose, and fructose. The particular values of

\chi

do not need to be known to make use of this equation as the inversion point (per cent amount of sucrose that must be hydrolyzed before the solution is inverted) can be calculated from the specific rotation angles of the pure sugars. The reaction

stoichiometry Stoichiometry refers to the relationship between the quantities of reactants and products before, during, and following chemical reactions. Stoichiometry is founded on the law of conservation of mass where the total mass of the reactants equ ...

(the fact that hydrolyzing one sucrose molecule makes one glucose molecule and one fructose molecule) shows that when a solution begins with

x_0

moles of sucrose and no glucose nor fructose and

x

moles of sucrose are then hydrolyzed the resulting solution has

x_0-x

moles of sucrose,

x

moles of glucose and

x

moles of fructose. The total number of moles of sugars in the solution is therefore

x+x_0

and the reaction progress (per cent completion of the hydrolysis reaction) equals

\frac \times 100 \%

. It can be shown that the solution's optical rotation angle is a function of (explicitly depends on) this per cent reaction progress. When the quantity

\frac

is written as

r

and the reaction is

r \times 100\%

done, the optical rotation angle is

s) r\right)

By definition,

\alpha

equals zero degrees at the 'inversion point'; to find the inversion point, therefore, alpha is set equal to zero and the equation is manipulated to find

r

. This gives

\displaystyle r_ = \frac = 0.629

Thus it is found that a sucrose solution is inverted once at least

62.9 \%

of the sucrose has been hydrolyzed into glucose and fructose.

Monitoring reaction progress

Holding a sucrose solution at temperatures of hydrolyzes no more than about 85% of its sucrose. Finding

\alpha

when r = 0.85 shows that the optical rotation of the solution after hydrolysis is done is −12.7° this reaction is said to invert the sugar because its final optical rotation is less than zero. A polarimeter can be used to figure out when the inversion is done by detecting whether the optical rotation of the solution at an earlier time in its hydrolysis reaction equals −12.7°.

References

External links

* * {{Authority control Brewing ingredients Monosaccharides Sugar substitutes Food science Syrup