Invertase honey

Invert sugar a mixture of equal parts o-glucose and D-fructose which, in contrast to dextrorotatory sucrose, is levorotatoiy (see Mutarotation). I.s. is generated by acid or enzymatic hydrolysis of sucrose. Because bees have the corresponding invertase, honey is 70-80% I.s. The sweet taste is essentially due to the fructose. 

Occurrence. The sugar, discovered by Berthelot in 1859, is a constituent of the sweet exudations of many plants such as the honeydew of limes and poplars, and the manna exuded from insect-produced wounds of the Douglas fir, Virginia pine, larch, etc. In dry seasons when the supply of flower nectar is insufficient, bees may collect these mannas or honeydews, and the honeys may contain considerable quantities of melezitose (151). When the quantity of the trisaccharide is great, crystallization of the honey may take place in the comb. Probably because of the resistance of the melezitose to hydrolysis by invertase, honeys which contain this sugar will not serve as food for bees. 

In most European countries, honey is defined in similar terms. However, certain quality factors considered by Europeans, especially the Germans, of importance in the marketing of honey are the levels of the enzymes invertase and diastase, and of 5-(hydroxymethyl)-2-furaldehyde. White has discussed these requirements in relation to suggested standards for the Codex Alimentarius.32 The German insistence on these requirements is outlined in a volume of Apiacta.33... 

As regards the occurrence of /3-D-linked disaccharides in the absence of a /3-D-linked substrate, one is tempted to conclude that these oligosaccharides are synthesized by the enzymic reversion of D-glucose by a /3-D-glucosidase. As White and Maher100 have found that their honey-invertase preparation had no /3-D-glucosidase activity, it would appear that these sugars are carried into the hive as constituents of nectar. 

Matsumoto et al (41) prepared a multi-enzyme electrode using glucose oxidase, invertase, mutarotase, fructose-5-dehydrogenase, and catalase to simultaneously detect glucose, fructose, and sucrose in fruit juices and soft drinks. Detection of multi-components by enzyme sensors was also reported in analysis of sucrose and glucose in honey (42) and drinks (43), and L-malate and L-lactate in wines (44). 

The protein content of honey is usually around 0.2% (Anklam, 1998 Iurlina and Fritz, 2005). A small portion of this fraction consists of enzymes, notably invertase, diastase, amylase, glucose oxidase, catalase (Anklam, 1998), a-glucosidase, and p-glucosidase (Won et al., 2008). Some are derived from bees, whereas others come from the nectar. Enzyme activity varies among honey samples since the amount of bee saliva, the source of bee enzymes, found in honey varies with the conditions of honey production (Anklam, 1998). 

Regarding sucrose, the maximum content permitted is 5 g/100 g (Table 4.2), with exceptions for some types of honey. High sucrose content can mean that honey collection occurred prematurely and the sucrose was not completely dissociated into glucose and fructose by the action of invertase secreted by the hypopharyngeal glands of bees (Sodre et al., 2007). 

Dextran-sucrase Invertase Sugar syrups Ice cream Artificial honey Candy... 

D-Fructose in the human diet derives mainly from sucrose, fruits, and honey. Sucrose is /I-D-fructofuranosyl a-D-glucopyranoside, and, after hydrolysis by invertase (EC 3.2.1.26), to D-glucose and D-fructose, can be absorbed from the small intestine. In the human intestine, invertase, as well as a-D-glucosidases, is developed very early in fetal life, and even appears much earlier than lactase (EC 3.2.1.23). There is no significant, intestinal transport of unhydrolyzed sucrose, and, in animal experiments, sucrose administered by injection is quantitatively excreted in the urine.1 Intestinal invertase is produced by mucosal cells localized in the brush-border membrane of the mucosal epithelia. Invertase is not secreted,1-4 and little or no invertase (sucrase) has been found in the intestinal lumen.1 The specific localization of sucrase at the mucosal, luminal interface is thought to be of functional importance in coupling sucrose digestion to transport.1... 

Nectar is from 5 to 80 percent sugar but is less than 0.2 percent in protein, so nectar is the carbohydrate supply for the hive [4]. The conversion of nectar into honey requires the physical removal of water by rapid movements of the wings of the bees and the addition to nectar of the enzyme invertase included in the salivary glands of the bees. When the... 

Invertase (p-fructosi-dase) from yeast and Aspergillus Sucrose (S.) -> Glucose -l-Fructose (Invert sugar I.) I. is sweeter and more easily digested than S., and is used in artificial honey, ice cream, chocolate creams, etc. 

Occurs in Aphispemi honeydew. Isol. from a honey invertase digest of sucrose. Shows anticarious props. Monohydrate or trihydrate. 

The function of the hypopharyngeal glands is known only in the honey bee. In nurse worker bees, they secrete a portion of the bee milk , the food given to larvae which is a complex mixture of lipids, vitamins and proteins. They also secrete invertase and an enzyme that oxidizes glucose to an acid (Cruz Landim and Hadek, 1969). 

When sucrose is hydrolyzed, it yields one molecule of D-fructose and one molecule of D-glucose. This hydrolysis is catalyzed by an enzyme, invertase, and produces a mixture known as invert sugar. Invert sugar derives its name from the fact that the mixture is levorotatory, whereas sucrose is dextrorotatory. Thus, the sign of rotation has been "inverted" in the course of hydrolysis. Invert sugar is somewhat sweeter than sucrose, owing to the presence of free fructose. Honey is composed mostly of invert sugar, which is the reason it has such a sweet taste. 

Fructose is the sweetest common sugar, being about twice as sweet as sucrose consequently, invert sugar is sweeter than sucrose. The enzyme invertase, which bees use in making honey, accomplishes the same chemical result as does the acid-catalyzed hydrolysis of sucrose. 

Glucoinvertases. Besides fructosidases, invertases are known that are a-glucosidases. The distinction between glucoinvertases and maltases has not been established clearly in most cases. Enzymes found in honey are glucotransferases. Incubation of sucrose with nectar of flowers of... 

The most prominent enzymes in honey are a-glucosidase(invertase or saccharase), a- and P-amylases (diastase), glucose oxidase, catalase and acid phosphatase. Average enzyme activities are presented in Table 19.14. Invertase and diastase activities, together with the hydroxymethyl furfural content, are of significance for assessing whether or not the honey was heated. 

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