Safety assessment of sodium acetate, sodium diacetate and potassium sorbate food additives.

Cytotoxicity and genotoxicity of sodium acetate (SA), sodium diacetate (SDA), and potassium sorbate (PS) was tested on Human Umbilical Vein Endothelial Cells (HUVEC). Cytotoxicity was investigated by MTT assay and flow cytometry analysis, while genotoxicity was evaluated using DNA fragmentation and DAPI staining assays. The growth of treated HUVECs with various concentrations of SA, SDA and PS decreased in a dose-and time-dependent manner. The IC50 of 487.71, 485.82 and 659.96 µM after 24 h and IC50 of 232.05, 190.19 and 123.95 µM after 48 h of treatment were attained for SA, SDA and PS, respectively. Flow cytometry analysis showed that early and late apoptosis percentage in treated cells was not considerable. Also neither considerable DNA fragmentation nor DNA smear was observed using DAPI staining and DNA ladder assays. Overall, it can be concluded that the aforementioned food additives can be used as safe additives at low concentration in food industry.

Toxicity assessment of the extractables from multi-layer coextrusion poly ethylene bags exposed to pH=5 solution containing 4% benzyl alcohol and 0.1 M sodium acetate.

A non-target analysis was developed for the analysis of extractables from multi-layer coextrusion bags exposed to 4% benzyl alcohol solution and 0.1 M sodium acetate at pH = 5 for defined periods (15 day, 45 day and 90 day) according to manufacturer instructions based on the ultra-performance liquid chromatography (UPLC) quadrupole-time of flight mass spectrometry (Q-TOF MS). In order to confirm the extractables, principal component analysis (PCA) was used to indicate the differences among samples of different periods. Then, the extractables were identified based on searching the self-built library or online searching. The total content of extractables of 90 day samples was 589.78 µg/L, and the content was in the range of acceptable levels for pharmaceutical manufacturers. The risk assessment of the extractables were evaluated by Toxtree and T.E.S.T. software to avoid the animals bioexperiment.

Effects of inorganic nitrogen (NH4Cl) and biodegradable organic carbon (CH3COONa) additions on a pilot-scale seawater biofilter.

Biofilters degrade a small fraction of the natural organic matter (NOM) contained in seawater which is the leading cause of biofouling in downstream processes. This work studies the effects of chemical additions on NOM biodegradation by biofilters. In this work, biofiltration of seawater with an empty bed contact time (EBCT) of 6 min and a hydraulic loading rate of 10 mh(-1) reduces the biological oxygen demand (BOD7) by 8%, the dissolved organic carbon (DOC) by 6% and the UV absorbance at 254 nm (A254) by 7%. Different amounts of ammonium chloride are added to the seawater (up to twice the total dissolved nitrogen in untreated seawater) to study its possible effect on the removal of NOM by a pilot-scale biofilter. Seawater is amended with different amounts of easily biodegradable dissolved organic carbon (BDOC) supplied as sodium acetate (up to twice the DOC) for the same purpose. The results of this work reveal that the ammonium chloride additions do not significantly affect NOM removal and the sodium acetate is completely consumed by the biofiltration process. For both types of chemical additions, the BOD7, DOC and A254 in the outlet stream of the biofilter are similar to the values for the untreated control. These results indicate that this biofilter easily removes the BDOC from the seawater when the EBCT is not above 6 min. Furthermore, nitrogen does not limit the NOM biodegradation in seawater under these experimental conditions.

Development of a simplified, economical polyacrylamide gel staining protocol for phosphoproteins.

Pro-Q Diamond (Pro-Q DPS) is a commercially available stain that binds the phosphate moiety of phosphoproteins with high sensitivity and linearity. To conserve consumable costs we demonstrate that threefold diluted Pro-Q DPS offers the same sensitivity and linearity of signal to that obtained with undiluted Pro-Q DPS. The optimal conditions for Pro-Q DPS indicate that fixation, staining, and destaining of gels longer than 1 h, 2 h, and four 30-min incubations, respectively, are not required. The fixation and destaining solutions, but not the threefold diluted Pro-Q DPS, can be re-used without compromising the signal intensity or linear dynamic range. This modified protocol of Pro-Q DPS reduces the cost at least by fourfold, making the stain economically attractive for large-scale analysis of phosphoproteins.