Presentation with the title "Usage of NMR Spectroscopy in Profiling/ metabonomics" and the following contents:
- NMR Spectroscopy;
- Spin-spin coupling;
- Why 1H NMR is adequate for the analysis of fruit juices;
- Usage of Amix viewer for Data Analysis;
- Objectives;
- Preparation of phosphate buffer (pH 6 - 7 at 25°C);
- Sample Preparation;
- Main experiment (noesypr) (nuclear Overhauser effect spectroscopy Presaturation);
- Why the Identification of Metabolites;
- Organic acids occuring in Fruit juices;
- Sugars and amino acids occuring in fruit juices;
- Fruit juices;
- Identification of metabolites in the extrakted apple juice;
- Identification of metabolites in the commercial apple juices;
- Investigation of the vitamine C content;
- Mixing of unripe fruits in apple juices;
- Identification of metabolites in the orange juice;
- Identification of metabolites in the multivitamine juice;
- Sugar content in commertial fruit juices;
- Changes in the fruit juice samples after three weeks;
- Investigation of some Coca Cola brands;
- Sugar free Cola (discount brand);
- Summary
Table of Contents
1. NMR Spectroscopy
2. Spin-spin coupling
3. Why 1H NMR is adequate for the analysis of fruit juices
4. Usage of Amix viewer for Data Analysis
5. Objectives
6. Preparation of phosphate buffer (pH 6 - 7 at 25°C)
7. Sample Preparation
8. Main experiment (noesypr) (nuclear Overhauser effect spectroscopy Presaturation)
9. Why the Identification of Metabolites
10. Organic acids occuring in Fruit juices
11. Sugars and amino acids occuring in fruit juices
12. Fruit juices
13. Identification of metabolites in the extrakted apple juice
14. Identification of metabolites in the commercial apple juices
15. Investigation of the vitamine C content
16. Mixing of unripe fruits in apple juices
17. Identification of metabolites in the orange juice
18. dentification of metabolites in the multivitamine juice
19. Sugar content in commertial fruit juices
20. Changes in the fruit juice samples after three weeks
21. Investigation of some Coca Cola brands
22. Sugar free Cola (discount brand)
23. Summary
Objectives and Research Focus
This work aims to evaluate the efficacy of NMR spectroscopy as a profiling and authentication method for various commercial beverages, focusing on metabolite identification and quality control to detect potential adulterations or mislabeling.
- Identification of characteristic metabolites in fruit juices and soft drinks.
- Detection of production-related fraud, such as the use of unripe fruits or improper sugar additives.
- Comparative analysis of metabolite concentrations and sugar content across different market brands.
- Assessment of product stability over time using NMR-based longitudinal observation.
Excerpt from the Publication
Why 1H NMR is adequate for the analysis of fruit juices
NMR is a particularly well-suited detector for the analysis of biological fluids
Non-destructive method, since biomolecules are not irradiated with an electron beam as in the mass-spectrometry
Deriving truly quantitative and structural information
Featuring high throughput (a 1D spectrum is measured in a few minutes),
Excellent reproducibility
Minimal sample preparation (typically, only addition of buffer).
Summary of Chapters
NMR Spectroscopy: Provides a fundamental definition of the technique and its utility in structure elucidation and substance purity control.
Spin-spin coupling: Explains the phenomenon of resonant frequency dependency on chemical bonds and how splitting patterns correlate with neighboring nuclei.
Why 1H NMR is adequate for the analysis of fruit juices: Details the advantages of NMR, such as its non-destructive nature and high reproducibility for biological fluids.
Usage of Amix viewer for Data Analysis: Describes software-based procedures for spectrum overlay, matching, and database creation.
Objectives: Outlines the specific goals, including metabolite identification and sugar content comparison across fruit juices.
Preparation of phosphate buffer (pH 6 - 7 at 25°C): Specifies the chemical composition and pH requirements for optimal signal stability.
Sample Preparation: Details the physical processing of juice samples, including centrifugation and preparation for NMR tubes.
Main experiment (noesypr) (nuclear Overhauser effect spectroscopy Presaturation): Discusses the experimental acquisition parameters and water suppression techniques.
Why the Identification of Metabolites: Highlights how concentration deviations signal quality or authenticity issues, such as sugar addition.
Organic acids occuring in Fruit juices: Lists common organic acid structures found in the analyzed samples.
Sugars and amino acids occuring in fruit juices: Illustrates the chemical structures of key carbohydrates and amino acids detected.
Fruit juices: Provides an overview of the brands and market origins of the tested samples.
Identification of metabolites in the extrakted apple juice: Analyzes the amino acid, sugar, and phenolic regions of extracted samples.
Identification of metabolites in the commercial apple juices: Presents the spectra and identified metabolites for store-bought apple juice varieties.
Investigation of the vitamine C content: Examines the spectral markers of ascorbic acid in specific juice products.
Mixing of unripe fruits in apple juices: Identifies specific markers like quinic acid to detect the use of unripe raw materials.
Identification of metabolites in the orange juice: Details the spectral composition specific to orange juice samples.
dentification of metabolites in the multivitamine juice: Analyzes the complex mixture of metabolites present in multi-fruit products.
Sugar content in commertial fruit juices: Compares the glucose, sucrose, and fructose concentrations across various brands.
Changes in the fruit juice samples after three weeks: Tracks the degradation of specific metabolites over time.
Investigation of some Coca Cola brands: Explores the chemical profiles of standard and zero-sugar soft drinks.
Sugar free Cola (discount brand): Discusses the use of alternative sweeteners like cyclamates in low-sugar products.
Summary: Consolidates the findings regarding NMR's utility in quality control and fraud detection.
Keywords
NMR Spectroscopy, Metabolomics, Fruit Juice, Quality Control, Authenticity, 1H NMR, Sugar Content, Food Fraud, Quinic Acid, Ascorbic Acid, Metabolite Profiling, Soft Drinks, Data Analysis, Amix Viewer, Spectrometry
Frequently Asked Questions
What is the primary scope of this scientific work?
This work explores the application of NMR spectroscopy as a robust method for the profiling and quality assessment of fruit juices and various soft drinks.
What are the main thematic areas covered in the analysis?
The study covers metabolite identification, the quantification of sugar content, the detection of food fraud, and the assessment of sample stability over time.
What is the core research objective of this study?
The primary objective is to demonstrate that NMR spectroscopy can reliably authenticate beverages and detect adulterations by analyzing specific metabolite profiles.
Which scientific method is utilized for the investigation?
The research relies on 1H NMR spectroscopy combined with data processing via the Amix viewer to compare and analyze complex spectra of beverage samples.
What topics are discussed in the main body of the work?
The body discusses sample preparation protocols, experimental acquisition (noesypr), spectral identification of metabolites, and specific case studies involving apple, orange, and multivitamin juices, as well as soft drinks.
Which keywords best describe this research?
Key terms include NMR Spectroscopy, Metabolomics, Food Quality Control, Authenticity, Sugar Profiling, and Adulteration Detection.
How does NMR detect the addition of unripe fruits?
The study identifies specific biomarkers, such as elevated levels of quinic acid, which indicate the inclusion of unripe fruit material in the juice production process.
Why is the phosphate buffer necessary in the sample preparation?
A stable pH between 6 and 7 is crucial because chemical shifts in the NMR spectrum are sensitive to pH changes; stabilization ensures accurate metabolite identification.
What did the longitudinal study reveal about juice shelf life?
After three weeks, the study observed an increase in ethanol, acetic, formic, and fumaric acids, alongside a decrease in glucose, malic, and fructose concentrations.
How does the analysis of "Sugar free" cola differ from standard products?
Sugar-free versions show minimal glucose and sucrose peaks and feature distinct spectral signals for artificial sweeteners, such as cyclamates.
- Arbeit zitieren
- Sadik Mejid (Autor:in), 2016, Usage of NMR Spectroscopy in Profiling Metabonomics, München, GRIN Verlag, https://www.grin.com/document/475230
