Assignment 1: Properties of Pyruvic Acid

Boiling Point
1. 164°C JECFA
2. 165°C Sigma-Aldrich
3. 165°C Oxford University
4. 165°C
CRC Handbook

5. 164-166°C Alfa Aesar

Melting Point
1. 11-12°C Alfa Aesar
2. 11-12°C Sigma AldrichC
3. 12°C Oxford University
4. 12°C Bedoukian Research
5. 13.8°C
CRC Handbook

Density (at 25°C)
1. 1.248-1.268 (specific gravity) Bedoukian Research
2. 1.267g/mL Sigma Aldrich
3. 1.26 g/cm3 Oxford University
4. 1.2272 g/cm3
CRC Handbook

5. 1.260-1.281 (specific gravity) JECFA

Flash Point
1. 82°C Sigma-Aldrich
2. 82°C Oxford University
3. 83°C Alfa Aesar
4. 83°C ScienceLab
5. 82°C (180°F) Bedoukian Research

Refractive Index
1. 1.4295 Alfa Aesar
2. 1.428
CRC Handbook

3. 1.424-1.435 JECFA
4. 1.428 Sigma-Aldrich
5. 1.423-1.433 Bedoukian Research

Assignment 2: For my paper, I will be researching the history and effects of monosodium glutamate (MSG).

"The winding monosodium glutamate trail." Cooper, P. Food and Cosmetics Toxicology Vol: 13 Issue: 1 Date: 02/1975 Pages: 124 - 126
[Full marks JCB]

1. A study that treated newborn rats with MSG in doses of either 1.25, 2.5, or 5 g/kg/day over a five day period found that rats that had received the higher dose had more behavioral problems and reduced motor activity. Another study by Johnston showed that newborn rats who were injected with MSG and other similar compounds such as aspartate and methylaspartate experienced convulsions similar to those experienced by felines injected with the same compounds.

2. A study by Olney showed that glutamic, aspartic, and cysteic acids contained in casein hydrolysates given to neonatal mice led to acute degeneration of neurons in the developing hypothalamus, with similar effects occurring whether the dosages were given orally or parenterally. However, Arthur et al. found that weanling mice were able to metabolize large quantities of these amino acids with no significant changes to their enzymes, while newborn mice could not - responding to these amino acids with a two to three times increase in enzymatic activity in the brain and liver.

3. A study by Wen. et al showed that large amounts of MSG have no detrimental effect on infant squirrel monkeys, weanling rats, and sucking mice when consumed with a normal diet.

4. Stegink et al. showed that glutamate in pigs was mostly metabolized in the liver, with no significant changes in free amino acid concentration in the brain, muscle, or cerebrospinal fluid when the amount of MSG administered is small.

5. Further studies by Stegink used Carbon-14 radiolabeling found 65-80% of the radioactivity in glucose, glutamate, and lactate. However, there was no labeled glutamate or aspartate found in the cerebrospinal fluid.

6. While there is little evidence to show that MSG taken orally can give rise to neurodegenerative disorders, more research should be done on how parenteral nutrients often injected into newborn infants have an effect on the central nervous system.