Efeito da desidratação osmótica nas características físico-químicas, nos compostos bioativos e perfil volátil de caqui (Diospyros kaki) submetido a diferentes métodos de secagem

Abstract

Persimmon (Diospyros Kaki) is a fruit native to eastern Asia, more precisely to China. Because it is a fruit that adapts to the subtropical and temperate climate, Brazil gets used to it very well. Given that most native Brazilian fruits grow at specific times during the year, this seasonality ends up making their consumption very low. Admitting this reality, processing techniques are increasingly studied, with the use of making the products consumed in these fruits available. In this way, this work aims to use osmotic pre-treatment to evaluate the same reduction of possible undesirable physical-chemical and chemical effects in drying processes by hot air and freeze drying. An evaluation was made through chemical analysis, quantification of bioactive compounds and extraction of volatile compounds, and all analyzes were performed on fresh fruit and dehydrated fruit. One egg pulp contains 270 mg GA / 100g of phenolic compounds, 212.97 mg QE / 100g of flavonoids and 3.87 μg / g of carotenoids. It also showed good antioxidant activity with 32003 μmol TE / 100g for the ABTS method and 702 μmol Fe2 + / 100g for the FRAP method. When dehydrating by greenhouse or freeze drying as persimmon clothes that are not used for osmotic pretreatment and tests that recover, it is not like those sold by the pretreatment experienced better results in antioxidant activity and in the quantification of bioactives. The predictive model of the Desirability function generated in the drying processes, which is the best concentration of the sucrose solution and the immersion time is 29.5% for 60 minutes for drying by hot air, and for drying by freeze drying is 38% sucrose for 29 min immersion. A volatile composition of khaki pulp in nature and its dehydrated products, shown that the aldehyde class has the highest percentage of compounds. The concomitant volatile compounds in the studied samples were: non-anal, decanal, β-cyclocitral and dodecanal. Therefore, it is evident that the osmotic pre-treatment is an ally in the protection of the physicochemical and chemical characteristics of fruit when it goes through a drying process, mainly in bioactive and volatile compounds.