• Food Science and Biotechnology
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• v.27 no.6
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• pp.1871-1875
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• 2018

Preventive and curative activity of postharvest treatments with chitosan nanoparticles (CS) and chitosan biocomposites loaded with pepper tree essential oil (CS-PEO) against anthracnose were evaluated on Avocado (Persea americana) cv. Hass artificially inoculated in rind wounds. After 10 days of storage significant preventive and curative activity against Colletotrichum gloeosporioides was observed with the absence of internal damage by applying CS and CS-PEO. Quality parameters like water losses and firmness changes were assessed on fruit treated. CS and CS-PEO were effective to reduce water losses and firmness losses.

• Preventive Nutrition and Food Science
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• v.2 no.4
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• pp.333-337
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• 1997

Trans-cinnamic acid-4-hydroxylase(tC4H) is the first cytochrome P450-dependent monooxygenase of the phenylpropanoid pathway. The roots of avocado seedlings were wounded and examined to determine whether the tC4H would be activated in response to wounding and/or whether tC4H activity be modulated by the application of exogenous p-coumarate. At the specified length of times, the wounded and treated roots were either frozen in liquid nitrogen or used immediately to extract microsomal proteins. The microsomal proteins were subjected to immunoblot analysis using polyclonal antibodies against CYP73 of tC4H gene. In this study, tC4H was induced in wounded roots sealed in bags within 6 hours, and in low level({TEX}$10^{-8}${/TEX}M) of p-coumarate solution within 24 hours, whereas the olution without p-coumarate and high levels of p-coumarate solution repressed tC4H induction in wounded roots. These results indicate that tC4H is induced by wounding in the root of avocado, and is inhibited by the application of exogenous p-coumarate.

• Preventive Nutrition and Food Science
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• v.2 no.4
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• pp.328-332
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• 1997

The ripe fruit of Hass avocado contains one of the highest elvels of cytochrome P-450 protein found in the plant kingdom. To determine whether wounded roots of avocado contain P-450 protein, the roots of avocado were wounded by slicing, and then allowed to incubate in sealed plastic bags, in 0.4M mannitol, and in the solution to make protoplast preparation containing cellulysin and macerase during the specified times. The microsomal proteins were extracted from the samples, separated by SDS-PAGE, and then subjected to Western blot analysis using polyclonal antibodies which are generated against the CYP71A1 protein. wounded roots in sealed bags produced CYP71A1 within 6 hours after cutting, and those in 0.4M mannitol did not produce CYP71A1 even after 72 hours, but those in the protoplast preparation by cellulysin and macerase induced and produced CYP71A was induced in only 24 hours. These results indicate that CYP 71A1 plays a role for wound healing for root tissue o avocado, and would-inducible P-450 protein was not detected in the mannitol solution by preventing a synthesis of ethylene in a liquid state, but the softening of tissues by cellulysin and macerase to make protoplast preparation was involved in an activation of CYP 71A1 even in the liquid state.

• Journal of the Korean Wood Science and Technology
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• v.47 no.2
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• pp.239-248
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• 2019

This research presents an improvement of the physical and mechanical properties of composite board (com-ply) made of Oriented Strand Board (OSB) coated with wood veneer of Pine (Pinus merkusii), Avocado (Persea Americana) and Mahogany (Swietenia mahogany). 1.5 mm thick veneers of those three wood types were adhered to the surface of OSB using two adhesive types: epoxy and isocyanate. The adhesive with the glue spread of $250g\;m^{-2}$ applied using single glue line was spread and then cold pressed with the pressure of $15kg\;cm^{-2}$ for 3 hours. The research result showed an improving dimension stability of com-ply, but not found on all parameters of physical property test. The moisture content seemed to be influenced by the com-ply type, yet not related to its thickness swelling, water absorption and linear expansion. The exception took place in the parallel linear expansion when immersed for 2 hours. The highest to the lowest increases of MOE and MOR were consecutively found on OSB coated with wood veneer of Pine, Mahogany and Avocado. However, the increases were statistically insignificant. The highest increasing screw hold power was found at the com-ply type AE (avocado veneer and epoxy adhesive) that was by 28%.

• Mycobiology
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• v.46 no.2
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• pp.92-100
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• 2018

The filamentous Ascomycota Colletotrichum gloeosporioides sensu lato is a fungus that has been reported worldwide as a causal agent of anthracnose disease in avocado and other crops. In Mexico, this species affects fruits from an early stage of development in the orchard until the post-harvest stage. Although fungicides are continuously applied to control Colletotrichum species, pericarp cankers and soft rot mesocarp in fruits are still frequently observed. Considering the lack of a precise description of the causative agent, the aim of the current study was to determine the pathogens involved in this symptomatology. Twenty-four isolates were consistently obtained from the pericarp of avocado fruits cv. "Hass" collected in the central avocado-producing area of Mexico. Morphological features such as colony growth, conidia size, and mycelial appressorium were assessed. Bayesian multilocus phylogenetic analyses were performed using amplified sequences of the internal transcribed spacer region of the nuclear ribosomal DNA; actin, chitin synthase, glyceraldehyde-3-phosphate dehydrogenase partial genes; and APn2-Mat1-2 intergenic spacer and mating type Mat1-2 partial gene from the nine selected isolates. In addition, fruits were inoculated with a conidial suspension and reproducible symptoms confirmed the presence of Colletotrichum fructicola in this area. This pathogenic species can now be added to those previously reported in the country, such as C. acutatum, C. boninense, C. godetiae, C. gloeosporioides, and C. karstii. Disease management programs to reduce the incidence of anthracnose should include C. fructicola to determine its response to fungicides that are routinely applied, considering that the appearance of new species is affecting the commercial quality of the fruits and shifting the original population structure.

• Journal of the Korean Wood Science and Technology
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• v.48 no.6
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• pp.907-916
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• 2020

This research was conducted to investigate the linear expansion and resistance properties of a composite board (com-ply). This board was made of medium-density fiberboard (MDF) laminated using avocado (Persea americana), mahogany (Swietenia mahogani), and pine (Pinus merkusii) veneers. These three types of veneers were laminated on both surfaces of the MDF using adhesives, namely, epoxy and isocyanate. Glue (250 g·m^-2) was spread on the surface, followed by cold press for 3 h with an applied pressure of 15 kg·cm^-2. The research result revealed that com-ply exhibited an increased dimensional stability compared with MDF, indicated by reduction in water absorption, thickness swelling, and linear expansion. The com-ply made of the pine veneer and isocyanate adhesive exhibited high density, water absorption, thickness swelling, and screw withdrawal load. The com-ply that exhibited the strongest resistance to drywood termite attacks was the one made of the mahogany veneer and isocyanate adhesive. Moreover, the com-ply that exhibited the biggest weight loss (3.6 %) was made of the pine veneer and epoxy adhesive. The results of this research may facilitate in manufacturing com-ply using the selected veneer and adhesive without the application of hot press.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.7
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• pp.919-927
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• 2011

Avocado (Persea americana Mill., Family Lauraceae) is an important subtropical crop in the Americas where it has been cultivated for several thousand years. To investigate the bioactivities of avocado, which acts on bone formation, we prepared methanol extracts from the sarcocarp, peels, and seeds of avocado. The methanol extracts of peels and seeds showed higher bone-forming activity than avocado sarcocarp extracts accompanied by MC3T3-E1 osteoblast proliferation and alkaline phosphatase (ALP) activity. Additionally, the extracts of sarcocarp and peel from avocado also decreased tartrate-resistant acid phosphatase (TRAP) activity against differentiation of osteoclasts, derived from mouse bone marrow macrophages. The hexane fraction from avocado peels showed strong bone-forming activity accompanied by osteoblast proliferation and ALP activity (170.7${\pm}$8.4%), and the ethyl acetate fraction from avocado peel decreased TRAP activity (5.2${\pm}$0.3%) and differentiated osteoclasts at 50 ${\mu}g$/mL. Therefore, avocado is expected to be a natural source for developing medicinal agents to prevent bone-related diseases, such as osteoporosis, by increasing osteoblast differentiation and reducing osteoclast activity.