Estimation of daily intake of food additives by Japanese young children using the market basket method in 2018.

To estimate the daily intake of food additives by young children aged 1-6 years in Japan, an intake survey was conducted in 2018 using the market basket method for food additives, including twelve types of colourants, three kinds of preservatives, three kinds of sweeteners and two kinds of food manufacturing agents. A list of the daily consumption of processed foods was prepared based on a special survey (MHLW 2011) and used for the estimation. The results of the survey showed that the food additives with the highest daily intake were phosphorus compounds (phosphoric acid and its salts; 11.2 mg/kg bw/day, expressed as phosphorus), followed by propylene glycol (0.80 mg/kg bw/day). The daily intake of other food additives ranged from 0 to 0.20 mg/kg bw/day. The estimated daily intake of each food additives by young children was compared with the acceptable daily intake (ADI) or maximum tolerable daily intake (MTDI). The highest ratio of the estimated daily intake to ADI was 3.2% for propylene glycol, whereas the ratios of the estimated daily intake to ADI for colourants, preservatives and sweeteners ranged from 0 to 1.1% (benzoic acid). The ratio of the estimated daily intake to MTDI for phosphorus compounds was 16%.

Interlaboratory study of DNA extraction from multiple ground samples, multiplex real-time PCR, and multiplex qualitative PCR for individual kernel detection system of genetically modified maize.

In many countries, the labeling of grains, feed, and foodstuff is mandatory if the genetically modified (GM) organism content exceeds a certain level of approved GM varieties. We previously developed an individual kernel detection system consisting of grinding individual kernels, DNA extraction from the individually ground kernels, GM detection using multiplex real-time PCR, and GM event detection using multiplex qualitative PCR to analyze the precise commingling level and varieties of GM maize in real sample grains. We performed the interlaboratory study of the DNA extraction with multiple ground samples, multiplex real-time PCR detection, and multiplex qualitative PCR detection to evaluate its applicability, practicality, and ruggedness for the individual kernel detection system of GM maize. DNA extraction with multiple ground samples, multiplex real-time PCR, and multiplex qualitative PCR were evaluated by five laboratories in Japan, and all results from these laboratories were consistent with the expected results in terms of the commingling level and event analysis. Thus, the DNA extraction with multiple ground samples, multiplex real-time PCR, and multiplex qualitative PCR for the individual kernel detection system is applicable and practicable in a laboratory to regulate the commingling level of GM maize grain for GM samples, including stacked GM maize.

Interlaboratory validation of an event-specific real time polymerase chain reaction detection method for genetically modified DAS59132 maize.

A real-time polymerase chain reaction (PCR) method specific for genetically modified (GM) maize event DAS59132 (E32) was adapted for qualitative detection of low level presence of E32. The method was validated by a collaborative trial with eight participating Japanese laboratories. Sensitivity was assessed with three different samples of corn flour fortified to 0%, 0.05% and 0.1% (w/w) E32 respectively. In addition, a 0.01% E32 DNA solution was used. The detection limit with DNA solution was estimated to be approximately 0.01%. In conclusion, the results of the study confirmed this real-time PCR method as a reliable tool for qualitative detection of E32 maize.