Odor maple

Properties Wh. cryst. powd. nutty odor, maple odor on dilution sol. in alcohol, propylene glycol si. sol. in water, fixed oils m.w. 112.12 m.p. 106 C flash pt. 212 F... 

Definition Obtained by solvent extract of the dried seeds of fenugreek, Trigonella foenum-graecum, followed by repeated purification Properties Lt. tan powd. to dk. bm. vise, semisolid sweet roasted caramellic bm. maple odor, deep cocoa nuance bitter taste sol. in water Storage Store airtight in cool, dry place protect from light... 

As the name implies, the odor of urine in maple syrup urine disease (brancbed-chain ketonuria) suggests maple symp or burnt sugar. The biochemical defect involves the a-keto acid decarboxylase complex (reaction 2, Figure 30-19). Plasma and urinary levels of leucine, isoleucine, valine, a-keto acids, and a-hydroxy acids (reduced a-keto acids) are elevated. The mechanism of toxicity is unknown. Early diagnosis, especially prior to 1 week of age, employs enzymatic analysis. Prompt replacement of dietary protein by an amino acid mixture that lacks leucine, isoleucine, and valine averts brain damage and early mortality. 

Yalcin, S.S., Tekinalp, G. and Ozalp, I. (1999) Peculiar odor of traditional food and maple syrup urine disease. Pediatr. Int. 41, 108-109. 

A 9-week-old boy, healthy at birth, begins to develop symptoms of ketoacidosis, vomiting, lethargy, seizures and hypertonia. Urine has characteristic odor of maple syrup. 

In addition to mating-disruption pheromones, there are a number of naturally occurring, nonpheromonal attractants and repellents. Many are typically used as food additives or in cosmetics or perfumes, and are derived from diverse plant and animal sources. Capsaicin [44], the spicy component of chili peppers, is used in several bird, deer, and rodent repellents. Maple lactone [45], a common food additive and flavoring, is used in traps to attract cockroaches with its stale beer odor. Methyl... 

T There is a relatively rare genetic disease in which the three branched-chain a-lceto acids (as well as their precursor amino acids, especially leucine) accumulate in the blood and spill over into the urine. This condition, called maple syrup urine disease because of the characteristic odor imparted to the urine by the a-lceto acids, results from a defective branched-chain a-lceto acid dehydrogenase complex. Untreated, the disease results in abnormal development of the brain, mental retardation, and death in early infancy. Treatment entails rigid control of the diet, limiting the intake of valine, isoleucine, and leucine to the minimum required to permit normal growth. ... 

Maple syrup urine disease (MSUD) is a recessive disorder in which there is a partial or complete deficiency in branched-chain o-ketoacid dehydrogenase, an enzyme that decarboxylates leucine, isoleucine, and valine (see Figure 20.10). These amino acids and their corre sponding a-keto acids accumulate in the blood, causing a toxic effect that interferes with brain functions. The disease is characterized by feeding problems, vomiting, dehydration, severe metabolic acidosis, and a characteristic maple syrup odor to the urine. If untreated, the disease leads to mental retardation, physical disabilities, and death. 

In a rare autosomal recessive condition (discovered in 1954) the urine and perspiration has a maple syrup odor/ High concentrations of the branched-chain 2-oxoacids formed by transamination of valine, leucine, and isoleucine are present, and the odor arises from decomposition products of these acids. The branched-chain amino acids as well as the related alcohols also accumulate in the blood and are found in the urine. The biochemical defect lies in the enzyme catalyzing oxidative decarboxylation of the oxoacids, as is indicated in Fig. 24-18. Insertions, deletions, and substitutions may be present in any of the subunits (Figs. 15-14,15-15). The disease which may affect one person in 200,000, is usually fatal in early childhood if untreated. Children suffer seizures, mental retardation, and coma. They may survive on a low-protein (gelatin) diet supplemented with essential amino acids, but treatment is difficult and a sudden relapse is apt to prove fatal. Some patients respond to administration of thiamin at 20 times the normal daily requirement. The branched-chain oxoacid dehydrogenase from some of these children shows a reduced affinity for the essential coenzyme thiamin diphosphate.d... 

Wood smoke Light-colored particles of cellulose ash, pleasant aromatic odor. Smoke from special kinds of wood (e.g.. hickory, maple) is used to cure ham, fish, etc., also to preserve crude robber. 

For centuries, people have observed the transport and transformations of chemicals in the environment without really thinking in terms of "environmental chemistry". The odor of flowers (or of stockyards), the Fall coloration of maple leaves, and the bleaching of fabrics were all taken for granted. Even into the Age of Chemistry, no one really worried much about where the smoke went or why the water tasted funny. That has changed. 

Dancis, Levitz, and Westall (1960) collected further data that led them to propose the biochemical defect shown in Figure 18-28. In one case, they examined a patient whose urine first showed the maple syrup odor when he was 4 months old. At the age of 10 months (March 1956), the child was admitted to the hospital because he had a fever, and he showed grossly retarded motor development. 

Isovaleric acidemia. This is believed to be a defect in the step from isovaleryl Co A to beta-methyl cro-tonyl Co A, in the metabolism of leucine. Rather than a maple syrup odor, there is an odor of sweaty feet . The patient has various neurologic disturbances and mental retardation. Isovaleric acid is elevated in the plasma. It is treated by restricting dietary intake of leucine. 

Although alcaptonuria is a relatively harmless condition, such is not the case with other errors in amino acid metabolism. In maple syrup urine disease, the oxidative decarboxylation of a-ketoacids derived from valine, isoleucine, and leucine is blocked because the branched-chain dehydrogenase is missing or defective. Hence, the levels of these a-ketoacids and the branched-chain amino acids that give rise to them are markedly elevated in both blood and urine. Indeed, the urine of patients has the odor of maple syrup—hence the name of the disease (also called branched-chain ketoaciduria). Maple syrup urine disease usually leads to mental and physical retardation unless the patient is placed on a diet low in valine. 

In maple syrup urine disease, the enzyme complex that decarboxy-lates the transamination products of the branched-chain amino acids is defective (see Figure 7-11). Valine, isoleucine, and leucine accumulate. Urine has the odor of maple syrup. Mental retardation occurs. 

Properties Colorless solid maple syrup odor. D 0.966, refr index 1.457-1.461. Sol in ale very sltly sol in water. 

Urine has color of Mental retardation, Odor of maple syrup (E5, E12, Dl, GI9, H17,... 

E. The correct response is very low levels of phoiylalanine hydroxylase, a key oizyme in the metabolic sequelae of phenylketonuria, that is, elevated phenylalanine, phoiylpyruvale, and para-hydroxyphenylpyruvate in blood. Homogentisic acid is an intermediate in the breakdown of tyrosine to fumarate and acetoacetate. Vitamin is required in the metabolism of branched-chain amino acids not phenylalanine. The a-keto acids of the branched chain amino acids produce the maple-syrup odor. 

In maple syrup urine disease, also called branched chain ketoaciduria, the a-keto acids derived from leucine, isoleucine, and valine accumulate in large quantities in blood. Their presence in urine imparts a characteristic odor that gives the malady its name. All three a-keto acids accumulate because of a deficient branched chain a-keto acid dehydrogenase complex. (This enzymatic activity is responsible for the conversion of the a-keto acids to their acyl-CoA derivatives.) If left untreated, affected individuals experience vomiting, convulsions, severe brain damage, and mental retardation. They often die before 1 year of age. As with phenylketonuria, treatment consists of rigid dietary control. 

Cyclotene is a commercially available product, frequently used as flavoring ingredient. It has a sweet and very powerful, caramellic-spicy odor, often described as walnut, maple, licorice, celery, tobacco, etc. (Arctander, 1967). It is spicy for Holscher et al. (1990). At 1 ppm in water, the odor is maple-like, burnt for Nishimura and Mihara (1990) with an odor threshold of 0.3 ppm in water. Brule et al. (1971) find a flavor threshold of 2 ppm in water. 

It has a strong caramel-like odor (Shaw et al., 1968), sweet, sugary at 1 ppm in water (Nishimura and Mihara, 1990). The flavor is maple, caramel, weak (Chemisis, 1967). Fors (1983) reported enhancing flavor characteristics. 

This lactone is the flavoring compound formed by the aging of a-ketobutyric acid (Sulser et al., 1967). The flavor is described as malt, molasses, maple, burnt sugar (Chemisis, 1965), with a strong seasoninglike aroma at a concentration of 0.1 ppm and a taste threshold of 1-5 ppb for Sulser et al. (1972). Manley et al. (1980) reported a maple-like, remarkably persistent curry-like odor and wondered if the enolization or the instability of the compound could be responsible for the two notes. It is a potent odorant of roasted powder and brew of arabica coffee with odor descriptions similar to those of G.12, and an odor threshold of 2-4ng/m , air (Blank et al., 1992a,b), of 7.5 ppb in water (Semmelroch et al., 1995). 

The odor is caramellic-sweet, but rather pungent, of good tenacity. It is described as having a sweet, fruity, cooked and maple flavor (Chemisis, 1964). The flavor is first sour, then sweet, caramellic-fruity, bread-like, depending on the concentration used. A sour taste is mostly noticed at high concentration (Arctander, 1967). 

The flavor of the tautomer mixture is perceived as burnt sugar, maple, cereal, chicory (Chemisis, 1978). The odor threshold reported by Semmelroch et al. (1995) was 1.15 ppm in water with a caramel-like quality. The odor threshold in air given by Blank et al. (1992b) was 0.5-1.5 p,g/m3. A flavor threshold of 21 ppb was reported by Huber (1992). By their enantioselective separation (see in 1.100), Bruche et al. (1995) determined that only one isomer of the less abundant tautomer 1.101b had a very intensive roasted almonds odor, the other isomer being less intensive of the two other tautomers, one is odorless, and the other reminiscent of the odorant 1.101b, is nearly odorless. Therefore ca 85 % of the mixture have no influence on the aroma. 

A much more difficult type of application is one in which a foreign odor is to be removed from honey, maple syrup, or other materials that have a bouquet or natural flavor composed of constituents present in minute quantities. Such applications require what may be termed fractionating adsorption. Unfortunately an undesired fractionation often results, and the removal of desired components of the bouquet leaves the product with an unbalanced flat flavor however, success has at times been achieved. A method occasionally found helpful is to allow the liquid to remain in contact with minute quantities of carbon the time of contact may range from a day to a month or more. Off-flavored brandies, whiskies, and other alcoholic beverages have been so treated. One explanation of the improvement is that the desired type of fractionation takes place during the longer contact another interpretation is that activated carbon catalyzes beneficial chemical changes. 

When transaminated, the three branched-chain amino acids (valine, leucine, and isoleucine) form compounds that have the characteristic odor of maple symp. An enzyme known as branched-chain a-keto acid dehydrogenase converts these compounds into CoA esters. People who do not have this enz3me have the genetic disease known as maple syrup urine disease—so-called because their urine smells like maple syrup. 

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