Sunday, July 06, 2008

Study: Freezing is Best Way to Maintain Quality of Royal Jelly

Proteomics Analysis of Major Royal Jelly Protein Changes under Different Storage Conditions
Journal of Proteome Research, July 3, 2008

Abstract: Protein changes in fresh royal jelly (RJ) were compared when stored at −20, 4 °C, and room temperature (RT) for 12 months…

Significantly more protein spots were found in fresh (85 spots) and −20 °C (81 spots) stored RJ than in samples stored at 4 °C (73 spots) and at RT (70 spots) for 1 year. Most identified spots, 56, 57, 51, 46, corresponding to RJ sample of the fresh, −20 °C, 4 °C, and RT, were assigned to major royal jelly proteins (MRJPs).

Marked differences were found in the heterogeneity of the MRJPs, in particular, MRJP3. The quantity of MRJP1 decreased significantly following the temperature trend in all images, but MRJP 2 and -3 did not increase or decrease following the temperature trend, thus, suggesting that MRJP 1−3 are sensitive to temperature. However, MRJP4, 5, glucose oxidase (GOD), peroxiredoxin (PRDX), and glutathione S-transferase (GST) S1 were clearly absent in all images in samples held at RT for 1 year. This indicates that they are the proteins most sensitive to storage temperature and protein markers for freshness of RJ.

Combining chromatography and nanoLC MS/MS results, we tentatively conclude that MRJP5 is a reliable freshness marker and that the best way to maintain quality of RJ is under freezing conditions.

No comments: