Bitter thresholds

Thus, Tressl et al.219 characterised eight 2-(l-pyrrolidinyl)-2-cyclopentenones and 11 cyclopcnt(/ )azcpin-8( lf/)-oncs from proline-monosaccharide and proline-cyclic enolone systems. The compounds possessed bitter tastes, with the former exhibiting concomitant astringency. The bitter thresholds in water of Structure 33 and 34 were 50 and 10 ppm, respectively. 

Bacitracin] (Aspartame) is sweet Animal hormone Bitter (threshold... 

Gardner, R.J. (1980). Correlation of Bitterness Thresholds of Amino Acids and Peptides with Molecular Connectivity. J.ScLFood Agric., 31,23. 

Limonin and nomilin are two bitter limonoids present in citrus juices. Systematic organoleptic tests showed that the bitterness threshold is 6 ppm (5) for limonin, and 6 ppm (6) or 3 ppm (7) for nomilin. The bitterness due to limonin develops gradually in juices after extraction from certain varieties of oranges, grapefruit, lemon, Natsudaidai, mandarin and some other minor citrus such as Iyokan and Ponkan. This phenomenon is generally referred to as "delayed bitterness". 

Cellulose acetate jels and beads were used to effectively remove limonin below the bitterness threshold from citrus juies (43). The resins can be regenerated readily by washing with a small volume of warm water. The process has been used commercially in Australia in debittering bitter orange juices (47). 

Sulfate monohydrate. C H NjOjgS.HjO. Atrophate, Atro-pisol, Atrosed, Granules or powder, mp 190-194° Almost inactive optically- Very bitter, pH 5,4. One gram dissolves in 0,4 ml water 5 ml cold, 2,5 ml boll, ale in 2.5 ml glycerol, 420 ml chloroform, 3000 ml ether, Bitterness threshold 1 10,000, Incompatible with alkalies tannin salts of mercury or gold, vegetable decoctions or infusions, borax, bromides iodides, benzoates. LD orally in rats 622... 

Tetrahydrate, monoclinic prisms. Also forms a dihydrate. Very bitter taste. Bitterness threshold 1 220,000. Very poisonousl Becomes anhydr at 100°. One gram dissolves in 0.8 ml methanol. 1.3 ml alcohol, 5 ml chloroform, 25 ml ethyl acetate, 36 ml glycerol, about 100 ml benzene, 187 ml ether, 1320 ml water, 750 ml boiling water. pH of satd water solo 9.5. pK, 6.04, pKj 11.7. Camion.- Handle dry powder in hood only. LDn Orally in rats 1 mg/kg, RTECS Vol. 1, R J. Lewis, R- L. Tatken. Eds. (1979) p 324. 

Very bitter prisms from alcohol or acetic acid. Bitterness threshold 1 50,000. Practically inso] in hot water, petr ether, benzene, ether, or in cold methanol, ale, acetone and acetic acid. Sol in at] solns of alkalies or their carbonates forming a yellow soln that turns brown on standing. 

Very bitter needles from methanol, mp 195°. [alD +52,5° (pyridine), uv max (ethanol) 209 nm Oog e 3,78), Practically insol in water. One gram dissolves in 30 ml acetone, 50 ml ethyl acetate, 75 ml methanol sol also in chloroform, methylene chloride. Bitterness threshold 1 60,000. Easily isomerized to isocolumbin. 

Crystals from djl methanol, mp 186-188°. uv mas (methanol) 277 nm. Soluble in chloroform, methanol slightly sol in water. Practically insol in ether, petr ether. Bitterness threshold ] 20,000,... 

Very bitter rectangular plates from dilute methanol, mp 212. [a]j +34.5 (c — 5.09 in CHC1 ). uv max —255 nm (t 11,650). Sol in benzene, ale, acetone, chloroform, pyridine. acetic acid, hot ethyl acetate. Sparingly sol in ether, petr ether Bitterness threshold 1 60,000. 

Dihydrate, bitter, silky needles. Effloresces on exposure to warm air. Does not lose all its water below 120. One gram dissolves in 16 ml water, in 0.5 ml boiling water, in 1.0 ml alcohol, in about 7.0 ml glycerol, in about 1 ml chloroform, in about 350 ml ether. pH (1% aq soln) 6.0-7.0. Bitterness threshold 1 30,000. Protect from light therap cat Antimalarial. 

Aldin, E.A. C.A. Reitmeier PA. Murphy. Bitterness threshold and descriptive analyses of soy iso-flavones and saponins./ FoodSci. 2006, 71, S211-215. 

IMP had a similar effect but increased the bitter threshold even more. The effect of MSG on the basic tastes at supra-threshold levels is similar except MSG was found to contribute to saltiness [9], This may be partially due to the Na ion in the MSG. 

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