Taste dimer

Monellin an intensely sweet tasting dimeric protein the A-chain contains 44, the B-chain SO amino acid residues. M. tastes 3,000 times (weight basis) or 90,000 times (molar basis) sweeter than sucrose. It was discovered in the tesh fruits of an African berry, DioscoreophyUum cumminsU ( wild red berry ) of the Menispermaceae. Another sweet protein is Thaumatin (see). 

Peptides have long been recognized as important flavor compounds in processed foods. The taste of peptides per se is veil known in cheeses (1), meat (2), hydrolyzed vegetable protein including soy products T3), cocoa (A, 5) and to a lesser extent in roasted malt (6), corn steep liquor (7) and aged sake (8). Structurally, food peptides can occur as linear protein fragments (1-3, 5), cyclic dimers (diketopiperazines, DKPs)(A, 6-81 and cyclic trimers (7). 

Cryst powder fairly hygroscopic characteristic odor sweet, cooling taste, mp about 75-80. The normal form is a dimer, slowly sol in 1 part water, 15 parts alcohol. When freshly prepd reverts rapidly to monomer in soln. The monomer is very sol in water, alcohol, ether, acetone. 

The relatively little-polymerized catechins and procyanidins (dimers, trimers, etc.) are the least reactive with proteins. The solution tasted more acid than astringent. 

C3oH,o03, Mr 458.73, mp. 100-101 C. A component of the latex m the toadstools Lactarius fuliginosus and L picinus (Basidiomycetes). When the fruit bodies are injured the mild-tasting ester is enzymatically saponified to 4-methoxy-2-(3-methyl-2-butenyl) phenol which is responsible for the bitter taste of the fungi. The phenol is unstable and after some time is oxidized to 6-methoxy-2,2-dimethyl-2//-chromene, 2-(l-hydroxy- 1 -methylethyl)-5-methoxybenzofuran, dimeric compounds, and red pigments. M. is thus probably responsible for the pink discoloration of the milk juices on bruising these toadstools. 

Commercial PSs are normally rather pure poljmers. The amount of styrene, ethylbenzene, styrene dimers and trimers, and other hydrocarbons is minimized by effective devolatilization or by the use of chemical initiators (30). Polystyrenes with low overall volatile content have relatively high heat-deformation temperatures. The very low content of monomer and other solvents, eg, ethylbenzene, in PS is desirable in the packaging of food. The negligible level of extraction of organic materials from PS is of crucial importance in this application because of taste and odor issues. 

The flavor of flying oils and fried products is mainly due to the volatile compounds which influence the aroma. Nonvolatile products may also change the taste and the mouth-feel. Billek et al. (Billek et aL, 1978) reported that RBD soybean oil contains about 1.2% oxidized triacylglycerols. The nonvolatile oxidized compounds include cyclic carbon-to-carbon linked dimers, noncyclic hydroxyl dimers, carbon-to-carbon or carbon-to-oxygen... 

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