Customer Insight SGF International -
Juice Analysis with NMR

Fruit and vegetable juices are popular around the world for their perceived health benefits, including lowering blood pressure, improving circulation and reducing the risk of obesity.[i] Many people consume juice as part of a healthy diet as it is a good source of vitamins, minerals and plant compounds.[ii]

Due to its popularity, juice is a target for economically motivated adulteration (EMA). EMA in the juice industry involves unethical suppliers diluting or substituting ingredients with ones of a lower quality for economic gain. This practice is damaging the high-value juice industry, deceiving consumers and pushing honest producers out of the market. It has been estimated that the food and drink industry loses between 10-15 million USD per year from EMA.[iii]

Industrial association SGF International is working with Bruker BioSpin to help combat EMA in the global juice industry and support its members across the world.

SGF International and its services

Founded in 1974 in Germany, SGF (Safe – Global – Fair) International is an independent, non-governmental, international association that acts as an instrument of industrial self-control, maintaining free and fair market conditions in the juice industry and helping combat food fraud. SGF International works to monitor products on the global juice market to ensure fair competition for stakeholders across the industry and audit good manufacturing practices (GMP) including safety, traceability and general hygiene.

SGF International currently has members from 350 companies, with 446 company sites across 47 countries from all major countries in the producer, bottler and fruit and vegetable processing industries including Brazil, India, Poland, Germany, South Africa, Argentina, Spain and Italy.

Juice-Profiling with NMR

SGF International entered a collaboration with Bruker to build an updated juice analysis methodology based on nuclear magnetic resonance (NMR).

Markus explains the need for this: “We have always found that around one to two percent of juice samples are flagged as possibly being fraudulent. Over the past couple of years, there have been shortages in the supply of oranges which has led to volatile commodity pricing – an opportunity for fraudsters to infiltrate the market with fake product.”

Markus continues: “Joining SGF International is voluntary, and our services protect members against unfair competition and support their due diligence. For example, if a member was seeking to verify product quality, we can compare their sample to our database of reference samples to confirm its authenticity.

“NMR spectroscopy is well suited to the analysis of juice samples as it can run simultaneous and automated analyses of many quantitative and statistical parameters with minimal sample preparation. The Bruker NMR Juice-Profiling method streamlines juice authenticity testing as data can be acquired from over 60 samples in one run within minutes.”

From a single data set, the NMR Juice-Profiling method 4.0 simultaneously evaluates a multitude of European Fruit Juice Association (AIJN) Code of Practice quality and authenticity parameters for each fruit and vegetable juice.

Markus adds: “At SGF International, we need an effective and easy method to analyze samples that can provide results in a short timeframe. The Juice-Profiler 4.0 allows us to collect multiple data sets and build the database to test a wide range of samples with high confidence in the results. We are looking to see if the geographical origin of the sample has the same parameters as the reference database, and if not, we ask why. Was a different method of production used? Is there a national variation? Or is there an issue with the sample? This helps protect our members.”

Prior to using NMR spectroscopy, SGF International used only conventional methods to analyze juice samples – these included physical chemical analysis, stable isotope analysis, deoxyribonucleic acid (DNA) analysis and chromatographic and spectroscopic methods.

Since adopting the Juice-Profiler 4.0, SGF International uses NMR in conjunction with conventional methods to screen and analyze juice samples from its members. Markus provides an example: “When we receive a sample, we run it on the Juice-Profiler 4.0 to screen for quantitative and statistical parameters to determine its origin, botanical species and processing methods. If it flags something unexpected, we then perform further analysis using other methods to confirm the results. This allows us to collect univariate and multivariate quantitative data using both targeted and untargeted approaches to understand exactly what is in a sample.”

He continues: “The Juice-Profiler 4.0 is an important screening tool for us to perform targeted analysis on fruit and vegetable juice samples. Combining it with untargeted analysis gives us the perfect solution to analyze samples to enable authenticity, safety and quality of juice.”

Expanding the reference library

The database that SGF International uses to reference juice samples holds over 49,000 juice samples from all over the world and includes 27 fruit type models and 43 country of origin models. Verifications of juice from concentrate and not from concentrate, and detection of juice blends and atypical profiles of samples are stored in the database for confirmation of samples with statistical evaluation using their NMR profiles.

Markus explains the process of building the database: “We measure different parameters in fruit and vegetable juice, including sugar, malic acid, citric acid and amino acid. By observing their changes over time, for example in different seasons or from year to year, we can observe any slight variations in samples.”

To build the reference library, SGF International takes samples from members throughout the supply chain, in a process known as ‘step control’. Markus explains: “For example, for orange juice, we take oranges from raw material delivery, the orange juice and the concentrate – all from the same geographical location – to run analyses at every stage of production and monitor the samples throughout the process. These would then be added to the database for future reference.”

Markus says: “The database of reference samples enables us to support the AIJN Code of Practice by using the data collected to verify possible changes to the reference standard for individual parameters. Having the database means it’s possible to provide full, unequivocal traceability of a juice sample that has been compared to the reference standard.”

Working towards a juicier future

Using NMR spectroscopy and the reference library, SGF International is able to safeguard its members against fraudulent practices, increase buyer confidence when purchasing fruit and vegetable juice, and ensure the industry adheres to the highest quality control measures.

On expanding the database, Markus shares his hopes: “As a next step we’re looking to add statistical models for raw materials, and of course more product types, geographical origins and fruit and vegetable varieties. I would also like to see how we can measure a larger number of quantitation parameters – that’s one of our major goals.”

Looking to the future, Markus talks about the rising impact of climate change on the juice industry: “We are seeing more deviations in typical juice samples. This could be due to several factors including extreme weather phenomena, or climate patterns such as El Nino and La Nina. These weather changes will have a major impact on the availability of commodities and, therefore, prices.”

[i] Ruxton CHS, Myers M. Fruit Juices: Are They Helpful or Harmful? An Evidence Review. Nutrients. 2021; 13(6):1815. https://doi.org/10.3390/nu13061815.

[ii] Khomich LM, Kopytko MV. Juices in a healthy diet: recommendations for consumption based on chemical composition data. Vopr Pitan. 2022;91(6):102-109. doi:10.33029/0042-8833-2022-91-6-102-109.

[iii] Cox, A., Wohlschlegel, A., Jack, L. and Smart, E., 2020. The cost of food crime. Food Standard Agency (Research Project code: FS 301065).

About Markus Jungen
Markus is a food engineer with a passion for authenticity and quality. Since 2009, Markus has worked at SGF International as Technical Manager where he is responsible for authenticity, quality and safety control along the supply chain – from tree to bottle. Part of his role involves evaluating juice audit results and looking at univariate and multivariate data to determine whether juice samples are authentic.