Measurements of titratable acidity, soluble solids, firmness, ethylene production and weight loss were made for five apple cultivars held in cold storage for 100 days. Carbosieve G in the traps of the enrichment column, which has only a moderate affinity for light hydrocarbons, was found to meet the requirements for the optimal thermal desorption of ethylene (130°C for 2 minutes) from the enrichment column to the analytical column. ANOVA showed significant differences in all these five parameters between the five cultivars Golden Delicious Reinders, Resista, Topaz, Meteor and Rubinstep, and also in the course of storage. In all cases, the changes in titratable acids measured during storage were especially significant, but the observed changes in sugar levels, as measured by refractometry, were too variable to be useful in this context. High rates of ethylene production impacted probably only indirectly on the loss of firmness and the other parameters which were measured. Discriminant analysis of the measurements of firmness, ethylene production and titratable acid provided the best means of differentiating the cultivars, although Golden Delicious Reinders and Resista still could not be completely separated. Other parameters (soluble solids and loss in weight) did not contribute to the discriminant resolution.Keywords: apple cultivars; composition; ethylene production; firmness; headspace gas analysis tive Magness-Taylor firmness test is still the industry standard for measuring fruit firmness. In term of consumer acceptability appeared to be according to whether a sweet, hard apple or a juicy, but acidic apple was preferred (Daillant-Spinnler et al. 1996).A wide range of factors influence the resistance of apple cultivars to storage diseases (Blažek et al. 2007), particularly the presence of phenolic compounds, skin thickness and its resistance to mechanical damage. This study used discriminant analysis to compare the performance of five different apple cultivars during cold storage, by measuring the production of ethylene and other, non-volatile compounds, changes in firmness of tissues and weight loss. MATERIALS AND METHODS Choice of adsorbent material for trapping ethyleneDetection of ethylene at trace levels (< 10 ppm) is necessary in order to be able to study the influence of this gas on plant development. Gas chromatography (GC) with FID combined with static headspace analysis is limited by the amount gas that can be reliably introduced into the GC inlet. Measurement by dynamic enrichment concentrates analytes to detectable levels and so increases the detection limits. As an adsorbent material for the traps, Carbosieve III has a high affinity for light hydrocarbons such as ethylene and this makes thermal desorption ineffective. However, the Carbosieve G adsorbent (Supelco Inc., Bellefonte, PA) provides optimal thermal desorption of analytes, at 130°C for 2 minutes, from the enrichment column to the analytical column. Determination of ethylene in intact fruitPrior to sampling the apples were place...
ABSTRACT:In ten cultivars of apple fruit, ethylene production expressed in µl/kg/h was determined. The cultivar Resista exhibited a higher ethylene production and can be differentiated from other cultivars. The production ranged from 4.2 ± 0.58 µl/kg/h in the case of Meteor cv. up to 131.6 ± 5.5 µl/kg/h in Resista cv. Infected fruit of Topaz cv. had a lower ethylene production at cold storage temperature (3°C) than some healthy fruit. All examined cultivars can be divided into three clusters. Discriminant analysis and canonical correlation analysis of the examined apple fruit led to the determination of healthy and infected fruit. Values of ethylene production were analyzed on intact fruit by using headspace gas analysis by CGC with thermal desorption technique. Carbosieve G was chosen as the adsorbent material for the traps due to its relatively high affinity for light hydrocarbons such as ethylene. For a full trap of ethylene in the enrichment column the sufficient amount of percolating gas is about 0.3 l.Keywords: Gleosporium rot; apple fruit; ethylene production; headspace gas analysis; cultivars sumers' demand for healthy food products that are free of synthetic chemical residues with resulting improvements in the production and distribution systems (SYLVANDER 1993).However, as organic fruits are not treated with chemical fungicides, they suffer from relatively high rates of decay that develops during the storage and shelf life. There has been an increasing interest in the use of pre-storage heat treatments to control the insect pests, to prevent the fungal decay and to modify the ripening of commodities (LURIE 1998). Gleosporium rot, the most dangerous post-harvest disease of organic apples can lead to over 50% loss during storage. The first appearance of Gleosporium disease can be observed after a few months of cold storage or at the latest when the apples are moved out of the storage room and in market. The reduction of Gleosporium rot under 10% after a storage time (five to six months) could be achieved with a hot water treatment (TRIERWEILER et al. 2003). Alternatives to chemical control, when used alone, are generally less effective than fungicides (LEVERENTZ et al. 2000).Too many bacteria and fungi have the ability to produce gaseous compounds belonging to ethylene and other gaseous metabolites. QADIR et al. (1997) show that B. cinerea demonstrates the capacity to produce ethylene in the presence of methionine. It is not known if the biosynthesis of ethylene in B. cinerea proceeds through the ACC (YANG, HOFFMAN 1984). The volatile profile of M. albus-colonized grain showed that 2-methyl-1-butanol and isobutyric acid were the major volatile compounds found in the headspace, which could be an attractive biological fumigant for controlling post-harvest diseases (MERCIER, JIMÉNEZ 2004).The objectives of this paper were to evaluate the influence of exposure to obvious ethylene concentration during a long-term storage at low temperature on the development of postharvest Gleosporium rot. On selected cultiva...
RŮŽIČKOVÁ, J., LUŽOVÁ, T., NĚMCOVÁ, A., MÝLOVÁ, P., ŠUSTOVÁ, K.: Evaluation of Gloeosporium fungal decay attack in Idared and Golden Delicious Reinders cultivars using NIR spectroscopy. Acta univ. agric. et silvic. Mendel. Brun., 2006, LIV, No. 4, pp. 53-60 The aim of our work was to observe the possibility of application of near-infrared spectroscopy for monitoring of internal changes in stored apples infi cated 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 refl ectance 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 fi rst week from the application of Gloeosporium album. According to spectra, the infection was more evident in Golden Delicious Reinders which was also confi rmed by a stronger visual exposure. Although Idared displays weaker symptoms of the attack, NIR spectroscopy was still able to detect infected fruits. NIR spectroscopy, apples Idared, apples Golden Delicious Reinders, Gloeosporium NIR spektroskopie je metoda využívající k měření oblast infračerveného záření. Jedná se techniku, kterou lze rychle a nedestruktivně zjišťovat chemické a fyzikální vlastnosti zemědělských, zahradnických a potravinářských surovin a produktů.Blízká infračervená spektroskopie je hojně využívá-na v oblasti ovocnářství, kde se aplikuje ke zjišťování kvalitativních znaků (obsah sušiny, obsah cukru, kyselin). Dále se uplatňuje NIR spektroskopie při posuzování fyzikálních vlastností plodů (pevnost dužiny).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.