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Abstract: Strawberry breeding programs for strawberry (Fragaria × ananassa Duch.) focus on developing cultivars with enhanced flavor and improved levels of health-related compounds. To assist this trend, a number of techniques were integrated into a single instrumental platform for high-throughput quality analysis of new strawberry cultivars. This platform was used to monitor the intrinsic properties of strawberries during ripening and to identify differences in sensory quality among nine strawberry cultivars. Through multivariate statistical analysis, 1-penten-3-ol was identified as a marker for unripe strawberries, whereas esters as methyl butanoate, pentyl acetate and methyl hexanoate distinguish ripe strawberries. Furthermore, ripe strawberries were characterized by higher sugar levels and decreased acidity and firmness. Additionally, the high-throughput platform could successfully discriminate between the different tested cultivars. [Copyright &y& Elsevier]

Abstract: Different instrumental techniques are used to evaluate the integrated flavour profile, including taste and volatile components, of a common export banana cultivar (Gran Enano) during ripening. Besides standard techniques to assess fruit quality (firmness, soluble solids content), gas chromatography-mass spectrometry (GC–MS) with headspace solid-phase micro-extraction (HS SPME) was used for the quantification of the different volatile components. The most important taste components with respect to sweetness (d-glucose, d-fructose, sucrose) and sourness (l-malic acid and citric acid) were determined using an enzymatic high-throughput (EHT) method. The different parameters were monitored during a ripening process starting from a green colour stage until fully ripened bananas. Clear differences were observed between bananas at different ripening stages with respect to the main instrumental attributes (total acid and sugar content, total volatile production, SSC, and firmness) and the individual volatile components. In addition, differences in flavour profile were observed between ethylene and non-ethylene treated bananas at the same colour stage and between bananas from different origins. [Copyright &y& Elsevier]

The velocity of air generated by air-assisted crop sprayers is one of the parameters that determine the fate of pesticide droplets. If the velocity magnitude and direction are not properly adjusted, off target deposition causes severe environmental pollution and increases the cost of production. A computational fluid dynamics (CFD) model has been developed and used to investigate the effect of sprayer ground speed on the three dimensional (3D) airflow patterns of a cross flow air sprayer, without considering crop interaction. Transient simulations based on a moving boundary condition were performed. The simulation was done for three tractor ground speeds (0, 6 and 10kmh−1) and two fan rotational speeds (1360 and 1836min−1). Good agreement was found between measurements and simulations of transient velocity profiles as well as the vertical maximum jet velocity distribution at different distances from the jet outlet. Due to a large variation in magnitude and direction of the jet outlet velocity, the power-law maximum air jet velocity decay was not the same at every vertical position. Instead, a complex 3D jet profile was established. The decay of the moving sprayer was best described with an inverse-linear relationship with normal distance from the jet outlet. The decay coefficient was linearly proportional to the ground speed to jet outlet velocity ratio, which ranged from 0 to 0·13. [Copyright &y& Elsevier]

Abstract: A model was developed to describe the growth of the spoilage organism Pseudomonas fluorescens LMG 7207 at different gas conditions containing high oxygen and elevated carbon dioxide concentrations. The bacteria were grown on a nutrient agar surface at 7°C. Three carbon dioxide levels (0%, 12.5% and 25%) were combined with different levels of high oxygen concentrations (above 20%) based on a mixture design. High O2 and CO2 concentrations decreased the maximum specific growth rate () and prolonged the lag time (). The model parameters were estimated in a one-step nonlinear least-squares regression. Two overall models were compared: (1) the Baranyi equation with a first-order linear response surface model to describe and as a function of O2 and CO2 and (2) the Baranyi equation with insertion of the first-order equation for and with linearly related to . Both models described the growth very well. To assess the validity of each overall model, an additional experiment with six gas conditions was carried out. The best correspondence between observed and predicted growth data was obtained with model 1, as based on different validation parameters (MSE, adjusted , Bias and Accuracy factors). The 95% confidence limits for a new prediction were estimated for each validation gas condition using a Monte Carlo procedure. [Copyright &y& Elsevier]

Pressure drops through batches of apples and chicory roots were measured. The results were correlated by means of Darcy–Forchheimer equations. The equations were modified to incorporate the effect of shape, surface roughness and confinement based on physical considerations. The confinement parameters were determined by means of computational fluid dynamics (CFD) simulations of confined beds by means of the Brinkman-modified Ergun equation. The confined pressured drop fitted the experimental data much better than the basic Ergun equation for packings of infinite dimensions. The differences in pressure drop between chicory root beds of different alignment with the airflow and with or without the presence of soil were explained by the relative contribution of surface friction and particle drag. [Copyright &y& Elsevier]