Extração e utilização do amido do endocarpo da pitomba na elaboração de catchup e no desenvolvimento de revestimentos comestíveis.

Abstract

The pitomba endocarp (Talisia esculenta) makes up half of the total weight of this Brazilian exotic fruit that is very appreciated in the North and Northeast of the country. The extraction of starch from this seed is an alternative of using unconventional starches; so this study was carried out with the objective of extracting the starch from the endocarp of the pitomba and evaluating its potential as a food thickener and stabilizer and in the development of edible coating. The fruits of the pitomba were analyzed for the physical properties and their endocarp as the physical-chemical characteristics. The extraction was carried out by two methods: immersion in sodium metabisulfite and immersion in sodium hydroxide, followed by physical and physicochemical characterization of the starch to choose the best extraction method. The selected starch was subjected to toxicological, chemical, functional, differential scanning calorimetry, viscosity profile, morphology, rheology and moisture adsorption isotherm. To test the thickening and stabilizing capacity of pitomba starch and to compare with commercial starch, 0.5% and 1% of commercial and pitomic starch catchups were formulated, stored under temperatures of 7 and 25 ° C, following evolution of syneresis and viscosity of these samples. Ketchup formulations were analyzed for sensory acceptance and purchase intent. Pitomba starch was used as an edible coating on Tommy Atkins mangoes from gelatinization in water at concentrations of 1 and 3%. The results of the characterization showed that the starch extracted in sodium metabisulfite showed superiority in its composition with yield of 44.20%, low content of protein and lipid, purity of 77.78% and amylose of 19.25% indicating small index of retrogradation after gelatinization. The water and oil absorption capacity was 89.49 and 85.07, respectively. The gelatinization temperature was 66.92øC, maximum temperature was 72.84øC, transition enthalpy of 4.70 J / g, viscosity peak of 2531 cps, final viscosity of 1607 cps, viscosity of retrogradation of 551 cp, besides presenting smooth surface granules with predominance of semioval format, showing the potential of use of this starch in the food industry. The rheology of starch pastes showed the ability to form viscous gels that behaved as pseudoplastic fluid, tending to decrease apparent viscosity as a function of increasing shear stress and temperature rise, suggesting applications of these in the increase of fluid flow. The Power Law model was considered the most suitable for describing the rheological parameters of starch pastes. The model that best fit the experimental data of the adsorption isotherms of the starches was that of Peleg, classifying the isotherms as type III. The catchups formulated with addition of the pitomba starch showed decrease of the syneresis during the storage, being the concentration of 1% of starch able to decelerate the sinérese of the sauce in the temperatures of 7 and 25 ° C, resembling the stabilizing capacity of the starch of corn. The ketch viscosity was increased with the addition of the pitomba starch which during the first days of storage presented progressive increase of viscosity, followed by decrease after the 30 days of storage. The sensorial evaluation of ketch formulated with the addition of pitomba starch showed good acceptance of the sensorial parameters, and no significant differences were observed between the sensorial characteristics of catchups formulated with corn starch. The development of the edible coating with pitomba starch was effective in minimizing the post-harvest changes of the Tommy Atkins mango stored at 5 and 25ºC, resembling the maize starch coating.