Study of physiopathologies and post-harvest shelf life of fruits.

Benefit description

Storage of fruits after harvest The main limiting factor for  shelf life of fresh plant products is their metabolic activity which continues after harvest processes such as respiration, transpiration and production of ethylene. The service is a pioneer in the use of low impact physical treatments postharvest which achieved significant reductions in the percentage of fruits affected by bitter pit in apples, corky spot and chilling injury in peach, and other physiological alterations in other fruit species. The processes of respiration, transpiration and ethylene production should be monitored thoroughly to extend the optimum ripeness of these foods to consumption. If these reactions progress too, fruits ripen in excess, soften and wilt tissues, and significantly reduces their quality, while promoting the development of physiological disorders. Current technologies for storage of plant products, allowing long-term preservation of pome fruits such as apples are widely used. However, the occurrence of physiological disorders during storage causes important quality losses and therefore economic occur. The parameters necessary to determine the goodness of storage and shelf life of fruits are: - Fruit  Periodic counts of physiopathies in fruits stored will be used. - Fruit  At poststorage chamber output, macroscopic assessment of surface and internal damage will be used. - Respiratory activity and ethylene production: Determination of the respiratory activity is carried out using a closed system. The samples are placed inside an airtight container and the accumulation of CO2 is measured and / or the consumption of O2 after a certain time will be used. If the CO2 and ethylene have effect on respiration of the product, its accumulation can be prevented by using KOH, which absorbs CO2 and / or KMnO4 oxidizing ethylene. This system is efficient to measure the respiration rate as a function of gas concentration. Is often started with air and the gas composition inside the container is changing. Knowing the sample weight and the free volume of the container can be calculated respiration ratewill be used. To calculate the ethylene production and O2 consumption and CO2 production, it is necessary to know the free volume in the container and weight. The free volume is calculated by difference between the capacity of the flask and the volume occupied by the sample. For quantification of ethylene gas chromatograph Hewlett Packard 4890 equipped with a Flame ionization detector (FID), which will be injected 1mL sample taken from the headspace of the jars, using a Hamilton syringe 1001RN gastight be used. To determine the concentration O2 and CO2 inside the bottles, an automatic gas analyzer is used Dansensor GDPwill be used. - Production of ethanol and acetaldehyde: by following the method described by Gorny et al (1999): From 100 g of fruit, 5 mL of juice obtained are decanted and 5mL transferred to a 10mL tube volume and resealable septum to facilitate sampling headspace will be used. The tubes were incubated in a water bath at 60 ° C for one hour. After that time is taken with a syringe Hamilton Gastight 1001RN, 1 mL sample of the headspace of the vials and analyzed by gas chromatography. The determination is performed on a Hewlett Packard 4890 chromatograph equipped with a flame ionization detectorwill be used. The analysis time is 10 minutes under isothermal conditions, with the 50 ° C oven, the detector and injector at 125 ° C at 50 ° Cwill be used.