New article published in 12(4A) - ENAN / INAC 2024

Radiation influence on antioxidant capacity, bioactive compounds and extractability of coffee processing residues

Abstract: During the agro-industrial process, the complete reuse of waste is an important part of the process's sustainability. However, in most cases, these materials are inadequately discarded, bringing environmental, economic, and social implications. In this context, residue reuse represents an opportunity to develop by-products, in addition to adding value to the raw material. However, conventional treatment processes end up negatively altering the quantity and expressiveness of compounds and nutrients present in this residue. Therefore, ionizing radiation has stood out as a promising technique among the current resources available for residue reuse and microbial load reduction. Thus, the objective of this work is to apply ionizing radiation to coffee processing residues, such as husk and straw, with the aim of preserving and improving the compounds and antioxidant activity. For this purpose, doses of 5 kGy were used on husk and straw residue. The samples were subjected to extraction through physical and chemical processes to obtain an extract from the residue. The extracts were analyzed to identify total phenolic content (TPC), antioxidant activity (ABTS, FRAP, and ORAC), extraction efficiency (EE), and cytotoxicity assays. An improvement in TPC of 26.0% for husk and 19.5% for straw was observed. For antioxidant capacity, an improvement of 14.1%, 16.1%, and 33.3% for husk was observed in ABTS, FRAP, and ORAC analyses, respectively. The 5 kGy dose provided an increase in compound extractability of 26.7% (straw) and 191.9% (husk). In cytotoxicity tests, no significant differences were observed between the irradiated residue and the control. However, an effect related to extract concentration was observed. The irradiation process proved to be a promising technique for agro-industrial residue management. This technique, in addition to promoting already known microbiological benefits, also improved the quantity of compounds, antioxidant activity, and compound extractability. Thus, the present proposal highlights the application of nuclear energy as a viable solution and technological innovation for the reuse of agro-industrial residue. Read full article. 

Calibration and evaluation of the MTS-N dosimeter for absorbed dose measurement in blood components

Abstract: The use of ionizing radiation has significantly expanded, particularly in the healthcare sector, where the irradiation of blood components prevents transfusion-associated graft-versus-host disease (TA-GvHD). The ISO ASTM 51939:2017 standard establishes a minimum dose of 25 Gy for this procedure, requiring a precise and traceable dosimetric system. This study investigates the calibration of MTS-N thermoluminescent dosimeters at the Gamma Irradiation Laboratory (LIG) of CDTN, which currently uses radiochromic films for routine dosimetry. The dosimeters were calibrated using a RISØ TL/OSL DA-20 reader, and the results indicated that doses above 5 Gy caused reader saturation, distorting the TL emission curve. The introduction of attenuating filters maintained linearity up to 25 Gy, and the calibration coefficient was determined as 6.774×10⁻⁷ Gy/Count, confirming the system’s suitability for dosimetry in blood irradiation at LIG/CDTN. Read full article.