Introduction. The avocado (Persea americana Mill.) fruit is sensitive to chilling injury (CI) when exposed to low temperatures. High lipid content in avocado pulp makes it prone to oxidation, resulting in rancidity and subsequent production of undesirable flavours and quality loss during storage. Materials and methods. Avocado fruit (cv. Becon) were treated with 1 μL.L-1 1-MCP for 24 h at 20 °C, and thereafter stored at 4 °C for 21 d under low oxygen atmosphere (3.5% O2), followed by transferring to 20 °C for 14 d to simulate the shelf life. The CI index, firmness, peel colour, relative electrical conductivity (EC), respiration, ethylene evolution, malondialdehyde (MDA) content, peroxidase (POD) activity, peroxide value and iodine value were measured throughout the storage period. Results and discussion. The CI incidence and severity of fruit treated with a combination of 1-MCP and low oxygen were significantly lower and delayed compared with the other treatments. The combined application of 1-MCP and low oxygen treatment was effective and delayed the onset of climacteric peaks of respiration and ethylene production. The delay was associated with reductions in fruit softening and cell membrane permeability as expressed by EC. The results of MDA content and POD activity of fruit treated with a combination of 1-MCP and low oxygen were significantly reduced. Moreover, significantly lower peroxide values and higher iodine values suggested that a combination of 1-MCP and low oxygen treatment effectively controlled the lipid oxidation in avocado fruit pulp. Conclusion. Overall, the results support the hypothesis that combined treatment (as compared with either 1-MCP or low oxygen treatment) was the most effective for alleviation of CI, lipid oxidation stability and extending the shelf life of avocado fruit under low temperature storage

In order to limit the thermal gradient of plates during quenching and limit flatness issues, it is necessary to control the cooling. This control requires the knowledge of the cooling performances of the cooling device. This paper describes the equipments and procedure we developed for the on-line characterization of quenching. We illustrate the application of this methodology to the quench of Burns Harbor. After the austenitzing furnace, this quench is equipped with 3 cooling sections that have been characterized for several flow rates, for several speeds of plates and for the top and bottom sides of plates. Thanks to the collected data, heat fluxes have been calculated and correlations describing the cooling performances of the equipment have been built. These correlations have been implemented in a thermal model that gives the thermal state of a plate during cooling according to parameters like thickness of the plate, flow rates of the cooling sections, speed of the plate, and temperature after heating. Experimental and numerical results are discussed.