Modelling citrate metabolism in fruits: responses to growth and temperature

Abstract

Citrate production and degradation during the last stage of fruit development were modelled by representing the fluxes through the enzymes of the citrate cycle and the malic enzyme, the transport of metabolites between the cytosol and the mitochondria, and the stoichiometry equations that relate these reactions. After solving the corresponding system of equations, the rate of citrate synthesis (or degradation) was expressed as a simple function of temperature, mesocarp weight, and respiration. The model was applied to peach fruit, and its parameters were estimated from the data of a 2-year field experiment. The predictions of the model were in agreement with experimental data. Simulations were made to analyse the responses to variations of temperature and fruit growth. Increasing fruit growth before stone hardening stimulated citrate production, while increasing fruit growth after stone hardening reduced it. Delaying the date at which the maximum growth rate was reached enhanced citrate production during most of the period. In the last weeks before harvest, increasing temperature depressed citrate production, while, at the beginning of the period studied, it enhanced it.

Physicochemical properties and aroma volatile profiles in a diverse collection of California-grown pomegranate (Punica granatum L.) germplasm

“…Subsequently, care must be taken when using the Brix:TA evaluation as it is often used to track the flavor change of a given cultivar through growth and development into maturity (Fawole & Opara, 2013;Schwartz, Tzulker, et al, 2009). Also, high citric acid levels may mask the perception of sucrose and fructose sweetness, whereas high malic acid levels can enhance sucrose perception (Lobit, Genard, Wu, Soing, & Habib, 2003). This could explain why the Brix:TA ratio did not correlate well with taste in Israeli-grown Wonderful (Ben-Arie et al, 1984).…”

Tomato (Solanum lycopersicum) health components: from the seed to the consumer

“…An increased desire by consumers for healthy food has, in part, encouraged the recent development of models of fruit quality. Models of peach fruit quality have been developed for biochemicals which influence taste, such sugars, (Génard and Stouty 1996), citric acid (Lobit et al 2003) and malic acid (Lobit et al 2006). Fruit quality models have also been developed for post-harvest conditions in order to predict keeping quality of horticultural products (Schouten et al 2002).…”

Changes in root growth and relationships between plant organs and root hydraulic traits in American elm (Ulmus americana L.) and red oak (Quercus rubra L.) seedlings due to elevated CO2 level

“…The smaller the RMSD in comparison to the measurements, the better the goodness-of-fit (Kobayashi and Salam, 2000;Lobit et al, 2003).…”