Author(s):
Nascimento, Ana C. ; Motta, Carla ; Rego, Andreia ; Delgado, Inês ; Santiago, Susana ; Assunção, Ricardo ; Matos, Ana Sofia ; Santos, Mariana ; Castanheira, Isabel
Date: 2025
Persistent ID: http://hdl.handle.net/10362/184657
Origin: Repositório Institucional da UNL
Subject(s): Digestion methods; Dry-ashing; Elemental content; Graphite block acid digestion; Microwave; Pseudocereals; Food Science; Microbiology; Health(social science); Health Professions (miscellaneous); Plant Science; SDG 3 - Good Health and Well-being
Description
Publisher Copyright: © 2025 by the authors.
Pseudocereals have gained attention due to their adaptability to different climates, high nutritional value, and suitability for gluten-free and plant-based diets. However, a challenge lies in the necessary adaptations in the diet pathways, mainly due to the lack of matrix-matching metrological tools. To address this problem, we developed a classification system to support laboratory decisions without shaped Proficiency Testing (PT) or Certified/Standard References Material. This system evaluates method performance through limit of detection (LOD), maximum uncertainty, and statistical comparison. For that matter, the mineral contents (Cu, Mn, Fe, Zn, Mg, P, Ca, K, and Na) of quinoa (Chenopodium quinoa), amaranth (Amaranthus caudatus), and buckwheat (Fagopyrum esculentum) were determined, using three different digestion methods, including dry-ashing, microwave, and graphite block acid digestion. A decision was reached concerning the optimal digestion method to be employed, with the results classified into three categories: (i) “rejected if results failed in two categories; (ii) “use with caution” if results were not satisfactory in one category; or (iii) “accepted”, if the results passed in all the categories. The system efficacy was exemplified by the effectiveness of dry-ashing and graphite block acid digestion by comparison with microwave digestion. Neither dry-ashing nor graphite block acid digestion can be recommended as an alternative method to the microwave digestion method when all the prioritized nutrient minerals are understudied. Although the microwave method is preferable for multi-elemental analysis, it is possible to obtain, with caution, comparable results from all the digestion methods if a higher relative combined uncertainty is defined (target uncertainty < 11%) under the assumption that this is suitable for the study.
