Investigating the crystallinity of hard candies prepared and stored at different temperatures with low field-NMR relaxometry

Kuzu S., ÖZEL B., Uguz S. S., Dogdu S., Marangoz M. A., Grunin L., ...Daha Fazla

Journal of the Science of Food and Agriculture, 2024 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Basım Tarihi: 2024
  • Doi Numarası: 10.1002/jsfa.13847
  • Dergi Adı: Journal of the Science of Food and Agriculture
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Periodicals Index Online, Aerospace Database, Agricultural & Environmental Science Database, Analytical Abstracts, Aquatic Science & Fisheries Abstracts (ASFA), BIOSIS, CAB Abstracts, Chemical Abstracts Core, Communication Abstracts, Food Science & Technology Abstracts, INSPEC, Metadex, Pollution Abstracts, Veterinary Science Database, DIALNET, Civil Engineering Abstracts
  • Anahtar Kelimeler: 1H-NMR, crystallinity, hard candy, moisture content, second moment, T1
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

Background: In this study, hard candies were produced by using sucrose, glucose syrup and water. They were cooked at different temperatures, changing from 135 to 145 °C with an interval of 2.5 °C. They were stored at different storage temperatures, which were 25, 4, −18 and −80 °C. Hard candies placed at room temperature were stored for 2 months. In order to understand the crystallization characteristics of the hard candies, time domain (TD) proton nuclear magnetic resonance (1H-NMR) parameters of longitudinal relaxation time (T1) and second moment (M2) measurements were conducted. Moisture contents of the hard candies were determined by Karl–Fischer titration. X-ray diffraction experiments were also conducted as the complementary analysis. Results: Increasing cooking temperature increased the crystallinity and decreased the moisture content of the hard candies significantly (P ≤0.05). Furthermore, storage temperature and storage time had significant effects on the crystallinity of the hard candies (P ≤0.05). The results of T1 and M2 correlated with each other (r > 0.8, P ≤ 0.5) and both produced the highest value at the cooking temperature of 145 °C and storage temperature of 4 °C (P ≤ 0.05). The values of T1 and M2 were obtained as 245.9 ms and 13.0 × 10−8 Hz2, respectively, for the cooking temperature of 145 °C and storage temperature of 4 °C. Conclusion: This study demonstrated that the crystallinity of hard candies can be observed and examined by TD-NMR relaxometry, as an alternative to commonly used methods. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.