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Respiration kinetic of mango Mangifera indica L. Universidad de Antioquia. Calle 67 No. Carrera 50G No. Received: March 7, ; Accepted: July 13,

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Respiration kinetic of mango Mangifera indica L. Universidad de Antioquia. Calle 67 No. Carrera 50G No. Received: March 7, ; Accepted: July 13, Two models were used to estimate the gas concentration, which were adjusted through non-lineal regression algorisms using Matlab Ra software. Three mathematic models, a model based on Michaelis-Menten's enzymatic kinetics, and two models based on regression analysis, in one of which a saturation equation was included as a new proposal in this field, were set to predict the substrate respiration rate.

Results made evident the positive effect of temperature on mango respiration rate. The model with the best adjustment to mango respiration rate was Michaelis-Menten's with an adjusted correlation coefficient of 0. Key words: Shelf life , Ripeness , Respiratory process. Mango M. Furthermore mango is a rich source of carotenoids and provides high contents of ascorbic acid and phenolic compounds Shahnawaz et al.

In general, fruits and vegetables stay metabolically active after harvest, period during which anabolic processes such as photosynthesis, flavor synthesis, fermentation and other cell wall degraders happen Heydari et al. Respiration rate is an indicator of the metabolic level, as high rate respiration is associated with short shelf life Lurie and Crisosto, , and its control may be an effective mean to regulate the metabolism in general, this is why it is important to extend these products shelf life Kan et al.

On the other hand, respiration rate may be reduced by changing the atmosphere around the food, which may also delay associated deterioration reactions, extending fruit and vegetable product shelf life Luo et al. Oxygen negative effects occur because reactive oxygen accumulation damages the integrity of mitochondrial membrane, resulting at the end in an irreversible mitochondrial dysfunction, which is believed to be the main cause of ageing in different kinds of organisms among which postharvest fruits are Qin et al.

Respiratory process modeling is an important step in designing and selecting packaging and storing systems of fruit and vegetable products as it is the case of modified atmosphere packaging Ravindra and Goswami, Then again, works oriented to assess this kind of parameters in fruit and vegetables, and in particular cut products, are rare.

Accepting respiratory process modeling with all implicated factors in enzyme reaction would be highly complex and little practical, the usual strategy has been to develop empiric models for each product with controlled variable functions such as temperature or gas concentration Guevara et al. Nevertheless, the popularity of tropical fruits in the most important world markets, is an excellent opportunity for the introduction of fresh-cut mango Siddiq et al.

Yet, fresh-cut processing induces chemical and biochemical changes as well as increases product respiration rate leading to a reduction of shelf life Azarakhsh et al.

Therefore, the current work goal is to assess different models to predict respiration rate and gas concentrations of cut mango cv. Tommy Atkins variety at three different temperatures in a closed system. Raw material preparation Mango Mangifera indica L. They were washed with alkaline detergent and disinfected with a solution at ppm of sodium hypochlorite Ngarmsak et al. They were cut in 0. Respiration experimental calculation Respiration rate was determined to the mango in a closed system Ravindra and Goswami, , which consisted in subjecting g of the product deposited in a 4, mL capacity airtight recipient to atmospheric conditions of Each assay was performed twice.

Models for the gas behavior The following models were used to estimate the gas concentration by a regression made with Matlab Ra software, finding the model coefficients for all treatments.

Model 1. A model is proposed to estimate the experimental data of the O 2 and CO 2 concentrations by a growing reason expression or saturation equation Chapra and Canale, , as indicated in equations 3 and 4 , adjusting them to CO 2 kinetic production and O 2 consumption, respectively.

Where a and b are model parameters, and t is time h. Model 2. The model used by Bhande et al. Amrapali, was also assessed. Equations 5 and 6 are used in this one adjusting O 2 and CO 2 concentrations in time function. Where a' and b' are model parameters and t is time h. Equations 3 , 4 , 5 and 6 were derived, as derivatives of model 1and model 2, respectively. Respiration rate was calculated with model 1 and model 2 derivatives, replacing them in equations 7 and 8 , as follows:.

Equation 9 expresses this mechanism for the respiration process in terms of O 2 consumption and CO 2 production rate. This kind of model presented a significant adjustment in the calculation of mango Ravindra and Goswami, , banana Bhande et al. Arrhenius's equation Temperature effect on O 2 consumption and CO 2 production rate was assessed by Arrhenius's equation Iqbal et al. Relative standard deviation Respiration rates predicted from the different models were contrasted with the experimental respiration rate, equations 1 and 2 by relative standard deviation, equation The physicochemical parameters to fresh mango were pH 3.

Experimental data of the O 2 consumption and CO 2 production at different temperatures are shown in figure 1. The nonlinear drop on O 2 concentration in the conditions of the current work matches the pattern expected from other climacteric products kept in sealed containers Ravindra and Goswami, ; Hagger et al.

It is observed that a rise in temperature also raises the gradient of the graph for the gas behavior, consequently the respiration rate increases as it happens with the papaya Zapata et al. Amrapali Ravindra and Goswami, This is due to that the rate of the enzymatic reactions grows exponentially with the rise of the temperature Lee et al.

Low temperatures reduce respiration rate, O 2 consumption, CO 2 and ethylene production. As the tissues react to the latter Mendoza et al. Models 1 and 2 parameters Table 1 shows the values of the coefficients a and b for equations 3 , 4 , 5 and 6 with their respective correlation coefficients R 2 , obtained for the three temperatures assessed in the closed system.

Model 2 coefficients presented a high variability with temperature compared with model 1; it can be seen that parameter b is more influenced with temperature than coefficient a in both.

Respiration kinetics Table 2 presents Michaelis-Menten's model parameters, with their corresponding adjusted correlation coefficient R2. Table 2 data analysis based on the form of equation 9 , allows to observe the effect gases have on the rate of CO 2 production and O 2 consumption. Km and Ki values indicate CO 2 production rate is more sensible to the concentration of both gases than O 2 consumption rate, due to both constants are lower for the CO 2 production than O 2 consumption expressions.

On the other hand, low Km values indicate the significant effect of O 2 concentration on respiration rates in terms of CO 2 as well as O 2.

While relatively high Ki values indicate that CO 2 concentration does not have such as significant effect on respiration rates. Nevertheless, the effect this gas has on respiration rate, given the adjust the model shows, cannot be denied. Reduction of temperature not only reduces ethylene production, but also the response rate of tissues to such gas; therefore, the more the temperature drops, the higher exposure time required by the metabolic cycle to start at a certain ethylene concentration is Mendoza et al.

Associated to this the temperature affect R O2 , as can be seen in figure 3. Table 3 shows the R CO2 and R O2 average value predicted for the three temperatures with Michaelis-Menten's equation, models 1 and 2, being noncompetitive inhibition Michaelis-Menten's equation the best model.

Figures 2 and 3 show graphic behavior of experimental respiration and the one predicted by the models in terms of R CO2 and R O2. A cell change due to the incapacity of the enzymes associated to mitochondrial membranes to metabolize glycolysis products may happen at these low temperatures Kader, therefore, model 2 may not give a good adjustment.

Relative standard deviation values of each one of the models are shown in table 4. Model 2, reported by Bhande et al. Table 5 shows Arrhenius type equation parameters, activation energy and pre-exponential factor for O 2 consumption and CO 2 production rates of the experimental data, proposed model 1 and Michaelis-Menten's equation.

Certain effects could be observed in some cut mango pieces due to cold sensitive reactions generating a brown color, beginning around the vascular bundles, because of the polyphenol-oxidase action on the phenolics released out of the vacuole after freezing Lee et al. The descending form of the gradient in figures 2 and 3 indicates an inverse relationship between respiration rate and shelf life, which is due to O 2 reduces and CO 2 increases in an airtight container, consequently with what is observed in figure 1.

It is also known that respiration rate decreases with CO 2 rising and O 2 dropping due to the first is a product of the reaction and the second is a reactive in it, as can be seen in the general reaction for respiration Devanesan et al. Consequently and accordingly to Le Chatelier's principle, when increasing the concentration of a product or reducing the concentration of a reactive, the chemical reaction rate reduces.

Noncompetitive inhibition Michaelis-Menten's kinetic equation presented better results in the prediction of the respiration rate in contrast with others two models. Models 1 and 2 are useful to predict gas concentration but do not predict the respiration rates.

Postharvest Biology and Technology 48 3 : Lemongrass essential oil incorporated into alginate-based edible coating for shelf-life extension and quality retention of freshcut pineapple. Postharvest Biology and Technology Minimally fresh processed pepper under different kind of cuts.

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Effect of storage temperatures, O2 concentrations and variety on respiration of mangoes. Journal of Agrobiology 28 2 : Modelling respiration rate of fresh fruits and vegetables for modified atmosphere packages: a review. Journal of Food Engineering 52 2 : Modeling the influence of temperature and relative humidity on respiration rate of prickly pear cactus cladodes. Postharvest Biology and Technology 41 3 : Application of an enzyme kinetics based respiration model to closed system experiments for fresh produce.

Journal of Food Process Engineering 15 2 : Studies on the respiration rate of banana fruit based on enzyme kinetics. International Journal of Agriculture and Biology 12 1 : Variedades mejoradas. Mathematical modelling of the influence of temperature and gas composition on the respiration rate of shredded carrots. Journal of Food Engineering Validation of a systematic approach to design equilibrium modified atmosphere packages for fresh-cut produce.

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