Sulfite Contamination in Century Eggs and Imported Dry Products Using ALERT Sulfite Detection Kit

Abstract

Sodium Hydrosulfite (Na₂S₂O₄) is a food additive used as an antioxidant and bleaching agent to prevent oxidation in food products and whiten them to result in a more appealing color. Sodium Hydrosulfite in food is a leading cause of type 1 hypersensitivity allergic reaction, therefore the quantity of Sodium Hydrosulfite used in food is strictly controlled. In order to determine whether certain food products in Bangkok are safe from sulfite, we decided to conduct an experiment.

A total of 75 food samples were selected and bought from 9 different locations in Bangkok Metropolitan Region to be examined for sulfite residue. There were 5 different sample groups; Squids, Century eggs, Chicken feet, Dried products and dried fruits. The sample was then cut into smaller pieces. The Alert Sulfite detection kit was used to determine sulfite residue levels.

            28 out of 75 samples were sulfite contaminated which was 37.33%. The most contaminated product was Century eggs, out of 14 century eggs sampled, 9 samples yielded a positive result from the ALERT sulfide test kit. Followed by Dried fruits and Dry products, squids, and chicken feet respectively.

The results indicated that sulfite concentrations increase with products that required extensive periods of preservation. This is evident from the results that showed less sulfite concentration in fresh products like chicken feet and squid than preserved products like century eggs and dried food. People who are susceptible or vulnerable to sulfites should refrain from preserved food and instead turn to fresh and organic products instead.