scholarly journals Between-tree variation in fruit quality and fruit mineral concentrations of Hass avocados

2006 ◽  
Vol 46 (9) ◽  
pp. 1195 ◽  
Author(s):  
J. R. Marques ◽  
P. J. Hofman ◽  
A. H. Wearing

Inconsistent internal fruit quality in Hass avocados affects consumer confidence. To determine the influence of individual trees on fruit quality, Hass avocado fruit were harvested from adjacent trees of similar external appearance in 3 commercial orchards in 1998 and 1 orchard in 1999. The trees in each orchard were grown with similar commercial practices and in similar soil types. Within each location, there were significant (P<0.05) differences in the mean ripe fruit quality between trees with respect to fruit body rot severity (mainly anthracnose) with and without cold storage, internal disorders severity due to diffuse discolouration and vascular browning (after cold storage), days to ripen, percentage dry matter, and the percentage of the skin area with purple-black colour when ripe. These effects were also noted in the same orchard in 1999. There were significant (P<0.05) differences in fruit flesh calcium, magnesium, potassium, boron and zinc concentrations between trees. Significant (P<0.05) correlations were observed between average fruit mineral concentrations in each tree (particularly calcium, magnesium and potassium) and body rot severity, percentage dry matter and fruit mass. There was little conclusive evidence that characteristics such as the growth of the non-suberised roots or the degree of scion under- or overgrowth was involved in these tree effects; however, differences between trees with respect to other rootstock characteristics may be involved. The inconsistency of the correlations across sites and years suggested that other factors apart from tree influences could also affect the relationship between fruit minerals and fruit quality.

1969 ◽  
Vol 95 (1-2) ◽  
pp. 15-23
Author(s):  
Jorge A. Osuna-García ◽  
Gilles Doyon ◽  
Samuel Salazar-García ◽  
Ricardo Goenaga ◽  
Isidro J. L. González-Durán

Mexico is the main 'Hass' avocado exporter in the world. More than 300,0001 are exported every year. The United States of America, Japan, the European Union, and Canada are the main importer countries. Recently, 'Hass'avocado shipments to Canada containing fruit with skin blackening have been rejected since this characteristic is associated with low pulp firmness and short shelf life. The objective of this study was to determine the relationship between skin color of 'Hass' avocado fruit with quality characteristics. Fruit varying in black skin color (from 0 to 100%, categories 1 to 5) were collected from two different packinghouses in Michoacán, Mexico. Treatments were arranged in a split-plot design with five replications. Significant differences were detected between packinghouses for weight, length, skin color ('a', ‘b’, chroma and hue) and pulp firmness but not for width, dry matter content or the Avocado Maturity Index (AMI). As color skin category increased towards more blackened fruit, AMI value increased, firmness decreased but dry matter content did not change. These results provide evidence that fruit skin blackening is not associated with lower fruit quality, but it did lower pulp firmness at fruit packing.


HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 678f-678
Author(s):  
M. L Arpaia ◽  
L. G. Houck ◽  
P. Hartsell ◽  
S. L. Ontai ◽  
J. S. Reints

Postharvest quarantine treatments of methyl bromide fumigation (MB) or a combination of MB and cold storage are allowed for the Mediterranean Fruit Fly (Ceratitis capitata) and other fruit flies. A study was undertaken to address the effect of MB on the fruit quality of `Hass' avocados. Fruit were obtained from two growers at a commercial packinghouse three times during the 1991 season. Fruit were fumigated at 21C or 30 C within 24 hours after harvest or after 1 week of storage. Fruit were evaluated after 0, 1, 2 or 4 weeks of storage at 5 C. Fruit quality was determined by flesh firmness, days to ripe, ease of peeling, weight loss, external discoloration, flesh or vascular discoloration and the presence/absence of decay. There was considerable variability between grower lots, however fruit that were fumigated had higher levels of weight loss, vascular or flesh discoloration and decay after 4 weeks of storage. The timing of fumigation had little effect on fruit quality. Generally, fruit which were fumigated at 30 C had less damage. These results suggest that `Hass' avocado could withstand MB as long as the fruit is marketed within 2 weeks of harvest.


HortScience ◽  
2017 ◽  
Vol 52 (6) ◽  
pp. 880-886 ◽  
Author(s):  
Cristina Pisani ◽  
Mark A. Ritenour ◽  
Ed Stover ◽  
Anne Plotto ◽  
Rocco Alessandro ◽  
...  

Avocado (Persea americana Mill.) is a high-value fruit that continues to increase in consumer demand. A population of ‘Hass’–‘Bacon’ hybrids was planted at USDA-ARS, Fort Pierce, as part of a study to find selections with good horticultural and postharvest quality traits for Florida. Extensive phenotypic data on quality were collected over 3 years. Ten selections were identified in 2014 and 2015 with promising fruit quality and postharvest shelf life characteristics and were tested in sensory panels using store-bought ‘Hass’ as the standard. In general, the selections had fruit quality similar to commercial ‘Hass’. Avocados that were most liked were described as creamy in texture with buttery and nutty flavor. Only one selection (R7T54 in 2014) and one store-bought control (‘Hass’ in 2015) were disliked, which was associated with greater firmness at the time of evaluation, likely relating to insufficient postharvest conditioning. Furthermore, CA ‘Hass’ commercial requirements for minimum dry matter (20.8%) were generally achieved by these selections under Florida conditions, ranging from 18.4% to 25.7%. This study identified 10 selections with composition and sensory quality similar to ‘Hass’ that are suitable for further testing and development in Florida.


HortScience ◽  
2000 ◽  
Vol 35 (4) ◽  
pp. 694-695 ◽  
Author(s):  
Peter J. Hofman ◽  
Marcelle Jobin-Décor ◽  
Janet Giles

The potential to use percentage of dry matter (DM) and/or oil of the flesh of `Hass' avocado as a maturity standard to determine the latest harvest for acceptable fruit quality, was investigated. `Hass' avocado fruit were harvested from early October to mid-January from a commercial orchard in subtropical Queensland. The percentage of DM and oil changed little during the harvest period, and the eating quality of the flesh remained high. However, the incidence of body rots (caused mainly by Colletotrichum sp.) and the flesh disorders grey pulp and vascular browning, increased with harvest. These results indicate that percentage of DM and oil are not reliable late-maturity standards because of the inconsistent change with later harvests, and that disease and internal disorders can be the main determinants of latest acceptable harvest, rather than eating quality.


2018 ◽  
Vol 30 (1) ◽  
pp. 67-78 ◽  
Author(s):  
Ramadan A. Hassanein ◽  
Ehab A. Salem ◽  
Ahmed A. Zahran

AbstractThis study was performed to explore the efficacy of combining more than one postharvest treatment in maintaining some quality attributes and reducing fungal pathogenicity in cold-stored guava fruits. The investigated postharvest treatments included the control, CaCl2(4%), lemongrass oil (2 dm3kg−1), gamma (γ) irradiation (0.2, 0.4 and 0.6 kGy), 0.4 kGy γ irradiation + CaCl2(4%), and 0.4 kGy γ irradiation + lemongrass oil (2 dm3kg−1). The studied physiochemical attributes included weight loss, decay percentage, fruit firmness, total soluble solids (TSS), titratable acidity (TA), and vitamin C content. Different fungal species were also isolated from decayed fruits and were identified asAlternaria alternata,Alternaria solani,Aspergillus niger,Botrytis cinerea,Fusarium solaniandRhizopus stolonifer. The severity of infection for the different fungi was determined, and anin vitroantifungal assay was conducted for lemongrass oil. All the investigated treatments generally reduced decay and water loss percentages, and controlled TSS, TA and vitamin C decrements that occurred during cold storage. On the other hand, higher irradiation doses generally increased fruit softness, and the 0.4 kGy γ dose did not contribute to the overall fruit quality when coupled with CaCl2and lemongrass oil, compared to CaCl2and lemongrass oil treatments alone.


1973 ◽  
Vol 13 (62) ◽  
pp. 245 ◽  
Author(s):  
MN McLeod

The dry matter digestibility measured in vitro and the levels of nitrogen, phosphorus and ash were determined on the leaves from mature trees of twenty-one species growing in two arboreta in southeastern Queensland and known to be grazed by animals. Most of the leaf samples had digestibilities in the lower range (68 per cent samples < 50 per cent D.M.D.) and low ash levels (65 per cent samples < 7 per cent ash). Nitrogen levels were satisfactory (86 per cent samples in range 1.5-3.0 per cent N) but the level of phosphorus tended to be low (84 per cent samples < 0.20 per cent P). Statistically significant variation between individual trees and seasons was found with some species.


2005 ◽  
pp. 481-486
Author(s):  
L. Jarquin-Enriquez ◽  
E. Mercado-Silva ◽  
E. Castaño-Tostado

2014 ◽  
Vol 86 (1) ◽  
pp. 485-494 ◽  
Author(s):  
CRISTIANO ANDRÉ STEFFENS ◽  
CASSANDRO V.T. DO AMARANTE ◽  
ERLANI O. ALVES ◽  
AURI BRACKMANN

The objective of this study was to evaluate the effect of controlled atmosphere (CA) on quality preservation of ‘Laetitia’ plums, mainly on internal breakdown, in order to determine the best CA storage conditions. Two experiments were carried out one in 2010, and another in 2011. In 2010, besides cold storage (CS; 21.0 kPa O2 + 0.03 kPa CO2), the fruits were stored under the following CA conditions (kPa O2+kPa CO2): 1+3, 1+5, 2+5, 2+10, and 11+10. In 2011, the fruits were stored under CS and CA of 1+0, 1+1, 2+1, and 2+2. The fruit stored under different CA conditions had lower respiration and ethylene production, better preservation of flesh firmness, texture and titratable acidity, lower skin red color, and lower incidence of skin cracking than the fruit in CS. In 2010, the fruit under CA with 2+5, 1+5, and 1+3 had a pronounced delay in ripening, although it exhibited a high incidence of internal breakdown. In 2011, the CA conditions with 2+1 and 2+2 provided the best delay in ripening and a reduced incidence of internal breakdown. The best CA condition for cold storage (at 0.5°C) of ‘Laetitia’ plums is 2 kPa O2 + 2 kPa CO2.


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