A novel propylene glycol alginate gel based colorimetric tube for rapid detection of nitrite in pickled vegetables

• Published in: Food chemistry 2022-03, Vol.373 (Pt B), p.131678-131678, Article 131678
• Main Authors: Zhang, Jing, Yang, Jianfei, Chen, Jing, Zhu, Yuanting, Hu, Kun, Ma, Qian, Zuo, Yong
• Format: Article
• Language: English
• Subjects: Alginates; Colorimetric; Colorimetry; Nitrite; Nitrites - analysis; PGA gel; Pickled vegetable; Vegetables
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2021.131678

•A simple and fast gel colorimetric tube for nitrite detection was developed.•The colorimetric tube exhibited great selectivity and anti-interference ability.•The method is helpful for real-time and on-site detection of nitrite in vegetables. The detection of nitrite is of great significance because it is closely related to food safety. In this work, a rapid colorimetric method was developed for nitrite detection based on the reaction of propylene glycol alginate (PGA) gel interface. In the reaction of nitrite and 4-Aminoacetophenone, diazo compound formed, which could be further transformed to purplish red compound by reacting with N-(1-Naphthyl)ethylenediamine (NED). Nitrite exhibited a linear relationship with the grayscale of the gel interface in the range of 0.3–9 μg mL−1 with a detection limit of 0.3 μg mL−1. The method was applied to detect nitrite in four types of pickled vegetables with recovery of 80.9–119.02% and relative standard deviation of 0.11–6.73%. Notably, the detection process can be accomplished within 5 min. The proposed colorimetric method exhibited advantages of simplicity, quickness and sensitivity, showing potential application prospects for the real-time and on-site detection of nitrite in pickled vegetables.