Energy-dispersive X-ray fluorescence spectrometry as a tool for zinc, iron and selenium analysis in whole grain wheat

Background and aims: Crop biofortification programs require fast, accurate and inexpensive methods of identifying nutrient dense genotypes. This study investigated energy-dispersive X-ray fluorescence spectrometry (EDXRF) for the measurement of zinc (Zn), iron (Fe) and selenium (Se) concentrations in whole grain wheat. Methods: Grain samples were obtained from existing biofortification programs. Reference Zn, Fe and Se concentrations were obtained using inductively coupled plasma optical emission spectrometry (ICP-OES) and/or inductively coupled plasma mass spectrometry (ICP-MS). One set of 25 samples was used to calibrate for Zn (19–60 mg kg–1) and Fe (26–41 mg kg–1), with 25 further samples used to calibrate for Se (2–31 mg kg–1 ). Calibrations were validated using an additional 40–50 wheat samples. Results: EDXRF limits of quantification (LOQ) were estimated as 7, 3 and 2 mg kg–1 for Zn, Fe, and Se, respectively. EDXRF results were highly correlated with ICP-OES or -MS values. Standard errors of EDXRF predictions were ±2.2 mg Zn kg–1, ±2.6 mg Fe kg–1, and ±1.5 mg Se kg–1. Conclusion: EDXRF offers a fast and economical method for the assessment of Zn, Fe and Se concentration in wheat biofortification programs

Towards the creation of a wine quality prediction index: Correlation of chardonnay juice and wine compositions from different regions and quality levels

Cozzolino, D ORCiD: 0000-0001-6247-8817Wine quality depends upon the composition of the grapes used in its production, which in turn depends on the weather and soil of the growing region together with viticultural practices. Region is used by many winemakers as a proxy for quality but objective quality measures are lacking. This study examined the compositional aspects of Chardonnay wines produced with berries from different regions. Through descriptive analysis, distinct sensory profiles were recognised for three diverse regions in South Australia (Adelaide Hills, Eden Valley, Riverland), which helped to pinpoint compounds relating to higher- and lower-quality Chardonnay wines. Correlations between the content of elements, fatty acids, free volatiles and conjugated glycosides in berries from different quality levels, and the composition of their corresponding wines, were investigated. Higher berry concentrations of linalool, (E)-linalool oxide, (Z)-3-hexen-1- ol, decanoic acid, vitispirane, Cu, Zn, and behenic acid, and lower °Brix and pH levels were related to higher quality wines.Associated Grant:D.C., S.E.P.B and D.W.J. acknowledge the financial support from the School of Agriculture, Food and Wine, University of Adelaide