Maintaining a specific quality of the food and drinks today is a challenge for any manufacturer, because of today's modern methods by which impurities and fraud such as incorrect labeling of the product type or the type and origin of the ingredients. NMR spectroscopy is a reliable method to detect any deviation of the content to the informations on the Labelling.
In the beginning NMR spectroscopy was only used to solve the organic and inorganic structural problems. For example, reaction products can be determined, reaction mechanisms are elucidated or structural isomers are identified. In recent decades, however, through a lot of methodological and instrumental developments many new useful applications were added. Today the NMR spectroscopy finds an important application in the Metabolomic studies for example in biological fluids such as urine, plasma and blood. Together with standardized NMR spectra databases as reference for the identification of the metabolites that are contained in the sample. Benefits are the ease of use and low cost, for example a 1D spectrum is measured in a few minutes, this can be very well reproduced with minimal effort for sample preparation (typically only the addition of buffer).
Table of Contents
2. Introduction
3. Objective
4. Results and discussion
4.1 Identification of metabolites in the extracted apple juice
4. 1. 1 Identification of metabolites in the commercial apple juices
4. 1. 2 Investigation of the vitamine C content
4. 1. 3 Comparison of the relative metabolite concentration
4. 1. 4 Mixing of unripe fruits in apple juices
4. 2 Identification of metabolites in the orange juices
4. 3 Identification of metabolites in the multivitamine juices
4. 4 Sugar content in commercial fruit juices
4. 5 Changes in the fruit juice sample after three weeks
5. Investigation of Coca Cola
5. 1 Comparison of spectra
5. 2 Identification of metabolites
5. 3 Differences between premium- and discountbrands
6. Experimental Section
6.1 Sample and standard preparation
6.1.1 Preparation of fruit juices
6.1.2 Preparation of phosphate buffer (pH 6 - 7 at 25°C)
6.1.3 Preparation of samples for NMR
6.1.4 1H NMR measurement at 400 MHz
6.2 Running an NMR Experiment using TOPSPIN as software
6.2.1 Insertion of sample tube into the spinner
6.2.2 Creating a new directory (edc)
6.2.3 Locking and shimming
6.2.4 Acquiring FID signal and modifying acquisition parameters
6.2.5 Processing the 1H NMR spectra with TOPSPIN
6. 3 Working with Amix viewer
6. 3. 1 Displaying the spectra with Amix Viewer
6. 3. 2 How to show a series of spectra on top of selected spectrum
6. 3. 3 Matching spectra
6. 3. 4 Creating a new spectra base (Sbase)
6. 3. 5 Displaying spectra in overlaid mode
6. 3. 6 Displaying a series of spectra in horizontal- and vertical splitting
6. 3. 7 Showing a series of spectra on top of selected spectrum
6. 3. 8 Annotating peaks
Objectives and Scope
This report investigates the composition of various fruit juices and soft drinks using 1D 1H NMR spectroscopy to identify and compare metabolites, evaluate sugar content, distinguish between product qualities, and detect potential food fraud.
- Identification of sugars, amino acids, and organic acids in fruit juices and Coca Cola.
- Comparative analysis of premium and discount beverage brands.
- Evaluation of relative sugar content and metabolite concentration profiles.
- Detection of food adulteration markers and changes in juice composition over time.
- Utilization of NMR spectroscopy for quality control and authentication purposes.
Excerpt from the Book
4. 1. 2 Investigation of the vitamine C content
Many fruit juices or beverages packaging are labeled to contain nutritional ingredients such as vitamins. These labels do not give always the real amounts that are included in the product. This can be found out with NMR-spectroscopy as following.
Summary of Chapters
2. Introduction: Discusses the role of modern food quality challenges and the application of NMR spectroscopy in metabolomics to detect fraud and authenticate food contents.
3. Objective: Outlines the goal of identifying metabolites and comparing sugar content across various commercial fruit juices and soft drinks.
4. Results and discussion: Details the findings from the 1H NMR analysis of various fruit juices, including metabolite identification, quality comparison, and detection of sugar-related fraud.
5. Investigation of Coca Cola: Examines and compares spectra of normal and diet cola products to identify differences in ingredients like sugar, caffeine, and cyclamate.
6. Experimental Section: Provides the technical methodology for sample preparation, NMR measurement parameters, and the usage of software tools like TOPSPIN and Amix.
Keywords
NMR spectroscopy, Metabolomics, Fruit juice, Coca Cola, Food quality, Metabolite identification, Sugars, Organic acids, Amino acids, Food fraud, High fructose corn syrup, Quality control, 1H NMR, Metabolite profiling, Food analysis
Frequently Asked Questions
What is the core purpose of this study?
The study aims to use 1D 1H NMR spectroscopy to analyze the composition of different commercial fruit juices and soft drinks, primarily focusing on identifying their metabolite profiles and comparing them for quality assessment.
What are the primary areas covered in this report?
The report covers apple, orange, and multivitamin juices, as well as Coca Cola, investigating their metabolite content, sugar ratios, and differences between premium and discount brands.
What is the main research question or goal?
The objective is to identify metabolites like sugars and organic acids, compare their concentrations, search for advertised vitamin ingredients, distinguish between product categories, and evaluate the relative sugar content in beverages.
Which scientific methodology is employed?
The study utilizes 1D 1H NMR spectroscopy at 400 MHz for composition analysis, data processing with TOPSPIN, and visual comparison using the Amix viewer software.
What topics are discussed in the main part?
The main part covers the identification of metabolites in various juices, the investigation of vitamin C labeling, the assessment of relative sugar concentrations, and the analysis of beverage stability over time.
Which keywords characterize this work?
Keywords include NMR spectroscopy, metabolomics, food quality, metabolite identification, sugar content, and authentication.
How does the study identify food fraud in fruit juices?
The study identifies markers such as quinic acid in apple juice to detect the use of unripe fruits and monitors sugar content ratios to identify potential deviations from standard quality expectations.
What does the analysis of Coca Cola reveal about its ingredients?
The NMR analysis distinguishes between sugar-containing and diet versions of Coca Cola, confirming the presence of artificial sweeteners like cyclamate and caffeine in diet variants, while identifying glucose and sucrose in normal variants.
- Quote paper
- Sadik Mejid (Author), 2016, Usage of NMR Spectroscopy in Profiling Metabonomics, Munich, GRIN Verlag, https://www.grin.com/document/475232
