Thermal and structural characteristics of date-pits as digested by Trichoderma reesei

Samar Mohammed Khalaf Al-Saidi; Zahra Sulaiman Nasser Al-Kharousi; Mohammad Shafiur Rahman; Nallusamy Sivakumar; Hafiz Ansar Rasul Suleria; Muthupandian Ashokkumar; Malik Hussain; Nasser Al-Habsi

doi:10.1016/j.heliyon.2024.e28313

Thermal and structural characteristics of date-pits as digested by Trichoderma reesei

Heliyon. 2024 Mar 16;10(6):e28313. doi: 10.1016/j.heliyon.2024.e28313. eCollection 2024 Mar 30.

Authors

Samar Mohammed Khalaf Al-Saidi¹, Zahra Sulaiman Nasser Al-Kharousi¹, Mohammad Shafiur Rahman¹, Nallusamy Sivakumar², Hafiz Ansar Rasul Suleria³, Muthupandian Ashokkumar⁴, Malik Hussain⁵, Nasser Al-Habsi¹

Affiliations

¹ Department of Food Science and Nutrition, College of Agricultural and Marine Sciences, Sultan Qaboos University, P. O. Box 34-123, Al-Khod 123, Oman.
² Department of Biology, College of Science, Sultan Qaboos University, P. O. Box 34-123, Al-Khod 123, Oman.
³ School of Agriculture, Food and Ecosystem Sciences, Faculty of Science, The University of Melbourne, Parkville, VIC 3010, Australia.
⁴ School of Chemistry, The University of Melbourne, Australia.
⁵ School of Science, Western Sydney University, Australia.

Abstract

The objective of this study was to develop functional date-pits by mold digestion for the potential use in food products. Whole date-pits (WDP) and defatted date-pits (DDP) were digested by mold Trichoderma reesei at 20 °C. T. reesei consumed date-pits as nutrients for their growth, and DDP showed higher growth of molds as compared to the WDP. The mold digested WDP and DDP samples showed an increased water solubility and hygroscopicity as compared to the samples prepared by autoclaved. This indicated that the mold digestion transformed date-pits to hydrophilic characteristics. Thermal analysis indicated a structural change at -3.2 °C for the untreated WDP and it was followed by a glass transition shift (i.e. onset: 138 °C and a specific heat change: 295 J/kg ^oC), and an endothermic peak at 196 °C with enthalpy of 68 J/g for the solids melting-decomposition. Similar characteristics were also observed for treated samples with the two glass transitions. The total specific heat changes for WDP, autoclaved-WDP, and digested-WDP were observed as 295, 367, and 328 J/kg ^oC, respectively. The total specific heat changes for DDP, autoclaved-DDP, and digested-DDP were observed as 778, 1329, and 1877 J/kg ^oC, respectively. This indicated that mold digestion transformed more amorphous fraction in the DDP. The energy absorption intensities of the Fourier Transform Infrared (FTIR) spectra for the selected functional groups decreased by the mold digestion.

Keywords: Amorphous; Crystallinity; Glass transition; Hygroscopicity; Melting; Proton mobility; Trichoderma reesei.