The distribution of laser light in the tissue of Golden Delicious and Idared apples was measured with backscattering imaging and simulated with Monte Carlo (MC) method. The settings of the vision system (sensitivity and resolution) and the parameters of the laser modules (wavelength, power and beam diameter) were used in a time resolved MC model to optimize the computation. The 1 ns pulse containing 1.42 × 10
(at 670 nm) and 2.49 × 10
(at 785 nm) photons was selected for the simulation of backscattering on the fruit surface. The statistical effect of the scattering coefficient (µ
), absorption coefficient (μ
), and anisotropy factor (
) on photon flux and shape of the backscattering profile was evaluated within ±20 % range relative to expected mean values for apple tissue (µ
= 0.63 cm
= 30.0 cm
= 0.8). The multi-factor ANOVA test pointed out the highest importance (p<0.001) of the anisotropy factor compared to the scattering and absorption coefficients. Decreasing value of anisotropy factor enhanced the maximum intensity and increased the decline of the gradient resulting in a rotation of the intensity profiles. The measured backscattering profiles for Golden Delicious apples responded to bruising (p<0.05) already after one day storage.
Authors:Bodor Péter, Baranyai László, Szekszárdi Andrea, Bisztray György Dénes, and Bálo Borbála
Leaf morphology of the grapevine (Vitis vinifera L.) cv. ‘Kövidinka’ was evaluated based on 32 landmarks. The aim of this study was to reveal leaf morphological diversity along the shoot axis. For this purpose 10 shoots were collected with 26 to 35 leaves. Altogether 304 leaf samples were digitised and analysed with the GRA.LE.D 2.04. raster graphic software. Leaf damage was estimated based on the missing landmarks on the lamina. Our results showed that the leaves on the 11th and 13th nodes are the most intact, without missing landmarks. Lowest variability (cv = 0,126) of the investigated 54 morphological characteristics were observed among the leaves on the 11th nodes of the shoots, in accordance with the literature. Based on the results length of the veins, angles between the veins and further features such as size of the serrations show high diversity along the shoot axis. These results underline the need of careful sampling during the ampelometric investigations.
Authors:Tamás Zsom, Viktória Zsom-Muha, Lien Phuong Le Nguyen, Dávid Nagy, Géza Hitka, Petra Polgári, and László Baranyai
Application of cold storage temperatures below optimum induces a high risk and threat of chilling injury (CI) in the case of sensitive commodities. Sweet pepper belongs to this group of vegetables, so our main objective was to investigate and monitor the effect of non-optimal temperatures (2.5 and 5 °C) induced stress (chilling injury) on kápia type sweet pepper (Capsicum annuum L.) during its postharvest storage by nondestructive quality measuring methods. Fresh, semi-matured (reddish-green colored) samples of ‘Kapitány F1’ cultivar were stored at 2.5, 5 and 10 °C for 7 d followed by 7 d shelf-life. Nondestructive texture measurements were carried out by a purpose built tabletop acoustic stiffness device. Surface color and chlorophyll content related quality indices were evaluated by a chroma meter, a DA-meter® and a chlorophyll fluorescence imaging system. High resolution digital pictures were captured and analyzed for possible CI defects by means of surface color values (normalized RGB, hue and saturation). According to our results, the evaluated quality indices (DA-index®, acoustic stiffness coefficient, surface color parameters; F0, Fm, Fv and Fv/Fm chlorophyll fluorescence parameters) clearly represented the temperature dependent quality changes during low temperature storage, subsequently followed by ambient shelf-life. Samples stored under and at 5 °C showed the chilling temperature stressed symptoms of delayed and partly retarded postharvest ripening, even under simulated shelf-life conditions, but without the onset and manifestation of the characteristic visible symptoms of chilling injury. This may raise doubts and suggest possible future research areas regarding the role of non-optimal cold storage temperatures induced stress, the effect of chilling injury contributing factors and consequences.