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Consumers, traders and processors consider post-harvest physiological deterioration (PPD) an important constraint. In Experiment 1, PPD was assessed three consecutive years in roots from five genotypes through seven storage days. PPD, scopoletin and dry matter content (DMC) was recorded during storage. Year, genotype, duration of storage and their interactions were significant. PPD was associated with duration of storage period, DMC and scopoletin contents. Ambient moisture and temperature during storage influenced PPD. In Experiment 2, roots from seven clones were harvested 10 months after planting from 30 consecutive biweekly plantings. PPD was assessed 0, 2 and 7 days after harvest. In 13 harvests, roots from plants pruned six days earlier were also evaluated. Results indicated large seasonal variation across genotypes. Pruning reduced PPD and DMC. Complex and contrasting relationships among the variables analysed were found. There is no uniform model explaining the relationship between PPD and the independent variables considered.

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Bioinorganic topics are ubiquitous in the inorganic chemistry curriculum; however, experiments to enhance understanding of related topics are scarce. In this proposed laboratory, upper undergraduate students assess the biological interaction of molybdenocene dichloride (Cp 2 MoCl 2 ) with bovine serum albumin (BSA) by fluorescence spectroscopy. Specifically, learners study the quenching mechanism by performing a binding titration of a bovine serum albumin (BSA) solution with molybdenocene dichloride at physiological pH at three temperatures to determine the biomolecular quenching constant as defined in the Stern−Volmer equation. The temperature dependency of the quenching constant allows estimation of thermodynamic parameters which in turn permits an assessment of the nature of the intermolecular interactions involved. This educational activity promotes graph interpretation and integration of concepts such as metallocene−protein interaction, fluorescence quenching, Gibbs energy, entropy, and enthalpy, where students learn to propose a quenching mechanism and to assess the intermolecular forces that may be involved. The proposed experiment can be implemented in various educational settings such as inorganic chemistry, biochemistry, biophysical chemistry, and analytical chemistry.