We report on the application of the Photoacoustic Spectroscopy and the phase-resolved technique to analyze the presence and contribution of the photosensitive pigments to the photoacoustic signal of ...the peel in Golden Delicious Apple (
Malus domestica
), as well as the changes in the photoacoustic signal with maturation time. Unlike optical absorption spectra reported with conventional methods, the application of phase-resolved technique on the data of amplitude and phase measured with Photoacoustic Spectroscopy provides the spectral separation of absorption centers of the photosensitive pigments in the layers of the peel. The results obtained show a clear definition of the contributions to the photoacoustic signal associated with each one of the isolated absorption centers of the surface layers of the apple samples. A remarkable decrease in amplitude of the photoacoustic signal and its isolated contributions was observed with maturation time, showing the usefulness of the photoacoustic spectroscopy and phase-resolved technique to monitor the degradation of the photosensitive pigments in apple fruit peel with the maturation time.
The rosy apple aphid, Dysaphis plantaginea (Passerini) (Hemiptera: Aphididae), is one of the major pests of European apple orchards, commonly controlled by the use of synthetic insecticides. In the ...present work, the non‐protein amino acid DL‐β‐aminobutyric acid (BABA), known to induce plant resistance against a wide range of abiotic and biotic stresses, has been tested for its protective effect against this pest on apple. We first verified the lack of any contact effect of BABA on the insect itself. Next we applied BABA as a soil drench to apple and monitored its effect on the population development of aphids after artificial infestation. We demonstrated that BABA strongly reduced the population growth and that this compound severely affected various life‐history characteristics of the aphid such as female longevity and fecundity, nymph mortality, and larval development.
The effects of an antioxidant dipping treatment (in an aqueous solution of 1% ascorbic acid (AA) and 1% citric acid for 3
min) and of modified atmosphere (90% N
2O, 5% O
2 and 5% CO
2) packaging ...(MAP) on some functional properties of minimally processed apples have been investigated. In particular, AA and total polyphenol (TP) contents and the overall antioxidant power of the product were monitored during 8 days of low temperature storage. Colour, texture and some chemical indices associated with the ripening stage of the product (titrable acidity and soluble solids content) were also evaluated. As a consequence of the anti-browning treatment, the AA content of dipped samples was about 20-fold higher than not treated samples at the beginning of storage and remained higher until the sixth day of refrigeration. Moreover, the dipping treatment resulted in an increase in the apple slice antioxidant activity, while MA had a negative effect on AA levels. As shown by the positive correlation between the AA and TP results, TP levels were higher for treated samples compared to those not treated over the whole storage period, because of the reducing action of AA that prevented a high level of TP degradation. Results of the other physico-chemical parameters investigated confirmed the synergistic preservative effect on the colour of MA, together with the dipping treatment, while structural decay of fruit tissue was evident due to the anti-browning chemical agents used.
Firmness, soluble solids content and acidity are important factors determining eating quality of apples. Tests with consumers confirmed that acceptance can be predicted by instrumental measurements ...of total soluble solids (refractometer), titratable acidity and firmness measurements for some apple varieties. ‘Golden Delicious’ of acceptable eating quality should attain a minimum of 12° Brix for total soluble solids, a minimum acidity of 3.2 g/l (malate) and a minimum reading of 44 N for firmness. For Elstar firmness should exceed 46 N and soluble solids should be above 12° Brix. Elstar with acidity less than 4.0 g/l or high acidity (>6.5 g/l) were not liked by consumers. Firmness readings of ‘Gala’ should attain 56 N. However, acceptance by consumers of ‘Gala’ and ‘Elstar’ seemed less dependent on firmness, soluble solids content and acidity but dependent on aroma quality and juiciness. In this respect, future optimisation of storage should take aroma aspects into account.
Global warming is a strongly felt reality in recent years in Algeria. The fruit trees crop is particularly exposed to the impact of this warming, especially apple trees. A comparative study has been ...realized between a chronological daily temperature series from 1980 to 2016, and phenological data series (budburst and flowering) from 2000 to 2016, regarding the apple tree variety of Golden Delicious in two zones of Northern Algeria, Sidi Lakhdar (town of Ain Defla, in an altitude of 211 m) and Benchicao (town of Médéa, in an altitude of 1133 m). Some contrasting tendencies according to sites and periods have been demonstrated: very significant warming at Sidi Lakhdar site in autumn and spring, in particular in October and April, disturbing thus the entrance of the buds in the endodormancy and ecodormancy. The result is a late action of the cold until February, which proved to be insufficient. However, no average warming has been demonstrated at the Benchicao site, where the temperatures between November and January were cold enough to satisfy the need of cold units and raise the endodormancy. It seems that the failure to fulfill the need of cold units at Sidi Lakhdar site has strongly affected the goodness of fit of the classic phenological models, confirming indirectly the existence of more complex physiological processes (not taken in consideration by models), which manifest themselves in limited zones such as Sidi Lakhdar site.
10th Anniversary of Plants—Recent Advances and Perspectives is a scientific paper collection specially published on the anniversary of Plants. Covering all major areas of plant science, it is a ...valuable guide through current achievements and future discoveries in this scientific field.
10th Anniversary of Plants—Recent Advances and Perspectives is a scientific paper collection specially published on the anniversary of Plants. Covering all major areas of plant science, it is a ...valuable guide through current achievements and future discoveries in this scientific field.
The aim of our work was to observe the possibility of application of near-infrared spectroscopy for monitoring of internal changes in stored apples inficated by Gloeosporium album (Osterw) Pezicula ...malicorticis (H. S. Jackson). The cultivars Idared and Golden Delicious Reinders were used in this work. Two groups of infected and non-infected apples of both cultivars each containing twenty pieces and stored in cold-storage room (± 3 °C) were observed for seven weeks. The apples were measured in reflectance mode with resolution 8 and number of scans 100. Each fruit was analysed 4 times and the average spectrum was used for evaluation. The discriminate analysis was applied to separate into clusters. This method was used for distinguishing infected and non-infected apples of both cultivars during the first week from the application of Gloeosporium album. According to spectra, the infection was more evident in Golden Delicious Reinders which was also confirmed by a stronger visual exposure. Although Idared displays weaker symptoms of the attack, NIR spectroscopy was still able to detect infected fruits.
Studies were conducted to observe the effect of pre-harvest fruit bagging on Golden Delicious apples. For this, Golden Delicious apples were bagged on 60, 75 and 90 days after full bloom (DAFB), and ...bags were removed five days before harvesting. Our results revealed that apples bagged on 60, 75 and 90 DAFB matured 15, 10 and 3 days earlier than non-bagged apples. The incidence of Sanjose scale (2.6 ± 0.2 %), scab (6.3 ± 0.4 %), sooty mold (0 ± 0%) and fly speck (2.8 ± 0.2 %) was the least in apples bagged on 60 DAFB than non-bagged apples. Apples bagged on 60 DAFB, developed appealing golden colour (Hunter ‘b’ value = 58 ± 2.2) than those bagged on later dates or non-bagged ones (Hunter ‘b’ value = 28 ± 1.5). Similarly, apples bagged on 60 DAFB were less firm (32.4 ± 1.6 N) but had higher levels of anthocyanins and exhibited high antioxidant activity (14.6 ± 0.4 μmol Trolox/g FW)than apples bagged on later dates or non-bagged apples with slight improvement in quality attributes. Thus, it can be concluded that pre-harvest fruit bagging in Golden Delicious apple on 60 days after full bloom is the best practice to get attractive golden coloured fruits with least incidence of insects and diseases and improved fruit quality.
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