TD-NMR and ILT Analysis for Rapid Detection of Apple Juice Adulteration
Food Analytical Methods, cilt.19, sa.12, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 19 Sayı: 12
- Basım Tarihi: 2026
- Doi Numarası: 10.1007/s12161-026-03312-4
- Dergi Adı: Food Analytical Methods
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex, Food Science & Technology Abstracts, INSPEC, Natural Science Collection (ProQuest), Biological Science Database (ProQuest)
- Anahtar Kelimeler: Adulteration, Apple juice, Relaxation time, TD-NMR
- Marmara Üniversitesi Adresli: Evet
Özet
Fruit juices are an important part of a balanced diet because they are rich in vitamins, minerals, phenolic compounds, and other bioactive components. Common practices include water dilution, sugar addition, and mixing with lower-cost fruit juices, which may alter product composition and mislead consumers. Apple juice is particularly relevant to authenticity studies because its composition can be modified by these practices. Water, sugar, and orange juice were selected as representative adulterants because they introduce different compositional changes to the juice matrix. Various analytical techniques, including chromatography, spectroscopy, mass spectrometry, and high-field proton nuclear magnetic resonance spectroscopy, have been applied to fruit juice authentication. In this study, time-domain nuclear magnetic resonance (TD-NMR) was used to detect adulterations in apple juice created by the addition of water, orange juice, and sugar. For this purpose, the spin–lattice (T1) and spin–spin (T2) relaxation times of the samples were measured, and structural changes associated with adulteration were revealed by evaluating the T2 distributions through inverse Laplace transform (ILT) analysis applied to Carr-Purcell-Meiboom-Gill (CPMG) data. ILT analysis facilitated the separation of distinct water populations and relaxation components, thereby enabling a more detailed characterization of adulteration-induced structural modifications. The results demonstrated that the relaxation behavior of T1 and T2 varied significantly depending on the type of adulteration: water addition increased both T1 and T2 times, orange juice addition increased T1 but decreased T2, while sugar addition reduced both relaxation times. The occurrence of multiple peaks in the ILT analysis further confirmed that different adulteration types could be differentiated under the tested conditions. The novelty of this study lies in the combined application of T1, T₂, and ILT analysis to characterize water, orange juice, and sugar adulteration in apple juice. This approach provides complementary relaxation-based information for differentiating the tested adulteration conditions under the investigated experimental settings. As a result, the combined assessment of T1 and T2 relaxation measurements with ILT analysis demonstrated that TD-NMR is a rapid, non-destructive, reliable, and highly accurate technique for detecting apple juice adulteration.