Evaluation of Water Ammonium Ion Test Kit and Its Feasibility for the Analysis of Protein in Food
The traditional method for the determination of protein in food needs the operations of digestion, distillation, absorption, and titration; therefore, it is complicated and time-consuming and requires professional personnel. Is there a more convenient and faster detection method that can directly de...
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| Format: | Article |
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MDPI AG
2022-07-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/27/15/4689 |
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| author | Dan Wu Qile Xia Jianfeng Zhou Xingqian Ye |
| author_facet | Dan Wu Qile Xia Jianfeng Zhou Xingqian Ye |
| author_sort | Dan Wu |
| collection | DOAJ |
| description | The traditional method for the determination of protein in food needs the operations of digestion, distillation, absorption, and titration; therefore, it is complicated and time-consuming and requires professional personnel. Is there a more convenient and faster detection method that can directly determine the ammonium ions in protein digestion solution to obtain the protein content of food and avoid the distillation–absorption–titration process? The feasibility of water ammonium ion test kits for food protein rapid detection was discussed here. After digestion, the protein in food transforms into ammonium ions in the digestion solution. Because of the variety of food, there are many different inorganic ions left in the food digestion solution, and at the same time, digestion agents are added in the digestion process and become potential interference factors in ammonium determination. Therefore, the detection accuracy of ammonium test kits needs to be evaluated first, including their anti-interference ability. The standard curve of ammonium was established by the test kit. When the ammonium concentration was 0.00–2.50 mg/L, the absorbance at 620 nm was linearly related to the ammonium concentration, the determination coefficient R<sup>2</sup> was 0.9995, and the detection limit of this method was 0.01 mg/L. The influences of temperature, pH value, and reaction time on the test kit method were discussed. The precision was 0.90–3.33%; the repeatability was 1.71–4.86%; and the recovery rate of tap water, river water, and sea water was controlled within 90–103%. The anti-interference ability of the evaluated test kit was better than that of the national standard detection method. The test kit, combined with sample pretreatment and protein conversion formula, was used to detect protein in different types of food (milk powder, rice flour, wheat flour, soy, banana, milk, fish food, chicken food, and dog food). The results showed that there were no significant differences (ρ > 0.05) between the national method and the test kit method. The ammonium ion test kit method shortened the determination time and had higher sensitivity, showing its potential for the rapid determination of food protein. |
| first_indexed | 2024-03-09T05:11:14Z |
| format | Article |
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| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-09T05:11:14Z |
| publishDate | 2022-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-9bb4e883e471475887e86249c5240ff22023-12-03T12:48:58ZengMDPI AGMolecules1420-30492022-07-012715468910.3390/molecules27154689Evaluation of Water Ammonium Ion Test Kit and Its Feasibility for the Analysis of Protein in FoodDan Wu0Qile Xia1Jianfeng Zhou2Xingqian Ye3Department of Food Nutrition, College of Biosystems and Food Science, Zhejiang University, Hangzhou 310058, ChinaKey Laboratory of Post-Harvest Handling of Fruits, Food Science Institute, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, ChinaCixi Environmental Protection Monitoring Station, Ningbo 315300, ChinaDepartment of Food Nutrition, College of Biosystems and Food Science, Zhejiang University, Hangzhou 310058, ChinaThe traditional method for the determination of protein in food needs the operations of digestion, distillation, absorption, and titration; therefore, it is complicated and time-consuming and requires professional personnel. Is there a more convenient and faster detection method that can directly determine the ammonium ions in protein digestion solution to obtain the protein content of food and avoid the distillation–absorption–titration process? The feasibility of water ammonium ion test kits for food protein rapid detection was discussed here. After digestion, the protein in food transforms into ammonium ions in the digestion solution. Because of the variety of food, there are many different inorganic ions left in the food digestion solution, and at the same time, digestion agents are added in the digestion process and become potential interference factors in ammonium determination. Therefore, the detection accuracy of ammonium test kits needs to be evaluated first, including their anti-interference ability. The standard curve of ammonium was established by the test kit. When the ammonium concentration was 0.00–2.50 mg/L, the absorbance at 620 nm was linearly related to the ammonium concentration, the determination coefficient R<sup>2</sup> was 0.9995, and the detection limit of this method was 0.01 mg/L. The influences of temperature, pH value, and reaction time on the test kit method were discussed. The precision was 0.90–3.33%; the repeatability was 1.71–4.86%; and the recovery rate of tap water, river water, and sea water was controlled within 90–103%. The anti-interference ability of the evaluated test kit was better than that of the national standard detection method. The test kit, combined with sample pretreatment and protein conversion formula, was used to detect protein in different types of food (milk powder, rice flour, wheat flour, soy, banana, milk, fish food, chicken food, and dog food). The results showed that there were no significant differences (ρ > 0.05) between the national method and the test kit method. The ammonium ion test kit method shortened the determination time and had higher sensitivity, showing its potential for the rapid determination of food protein.https://www.mdpi.com/1420-3049/27/15/4689ammonium ion test kitproteinrapid determination |
| spellingShingle | Dan Wu Qile Xia Jianfeng Zhou Xingqian Ye Evaluation of Water Ammonium Ion Test Kit and Its Feasibility for the Analysis of Protein in Food Molecules ammonium ion test kit protein rapid determination |
| title | Evaluation of Water Ammonium Ion Test Kit and Its Feasibility for the Analysis of Protein in Food |
| title_full | Evaluation of Water Ammonium Ion Test Kit and Its Feasibility for the Analysis of Protein in Food |
| title_fullStr | Evaluation of Water Ammonium Ion Test Kit and Its Feasibility for the Analysis of Protein in Food |
| title_full_unstemmed | Evaluation of Water Ammonium Ion Test Kit and Its Feasibility for the Analysis of Protein in Food |
| title_short | Evaluation of Water Ammonium Ion Test Kit and Its Feasibility for the Analysis of Protein in Food |
| title_sort | evaluation of water ammonium ion test kit and its feasibility for the analysis of protein in food |
| topic | ammonium ion test kit protein rapid determination |
| url | https://www.mdpi.com/1420-3049/27/15/4689 |
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