The biodiversity of the Brazilian Amazon has a large number of underexploited native and exotic fruits. Among them are Jambolan and Camu-camu fruits, with are fruits rich in anthocyanins and ascorbic acid, respectively, which can be used in development of a fruit juice blend, with a high content of bioactive compounds. During the production of fruit juices, the pasteurization process is of great importance, as it guarantees stability and food safety to the product. On the other hand, in order to improve the stability and increase the shelf life of this type product, spray drying is a widely used process to obtain powdered fruit juices. Thus, this work aimed to evaluate the stability of the bioactive compounds from jambolan and camu-camu mixture; establish a formulation for the juice blend, based on sensory properties; determine the best temperature and time for the pasteurization of jambolan and camu-camu juice blend; to evaluate the stability of the pasteurized juice blend at room temperature (25 °C); establish the best temperature, maltodextrin:gum arabic (MD:GA) concentration and feed flow rate, for spray drying jambolan and camu-camu juice blend. The stability of three juice formulations with jambolan:camu-camu:water (m:m:m): 37.5:12.5:50 (JB); 12.5:0:87:5 (JJ) and 0:37.5:62.5 (JC). To determine the formulation of the juice blend, analyzes of bioactive compounds and sensory acceptance test were performed in six jambolan/camu-camu juices: 37.5:12.5 (F1); 32.5:17.5 (F2); 27.5:22.5 (F3); 22.5:27.5 (F4); 17.5:32.5 (F5) and 12.5:37.5 (F6). The best pasteurization condition was determined based on the enzymatic activity (peroxidase, polyphenoloxidase and pectin methylesterase), the content of bioactive compounds (anthocyanins, total phenolic compounds and ascorbic acid) and the microbial count (aerobic mesophilic bacteria, fungi and thermotolerant coliforms). The stability of the pasteurized juice blend at room temperature (25 °C) was monitored for 35 days. Drying by spray drying was established based on the characteristics of the obtained powder (moisture, water activity (aw), hygroscopicity, water solubility index (WSI), yield and total color difference (∆E*)) and efficiency of microencapsulation of bioactive compounds (ascorbic acid (AA), total monomeric anthocyanins (TMA) and total phenolic compounds (TPC)). The stability of anthocyanins in the JB formulation was ensured for up to five days of storage at 25°C. Pseudo-first order reaction kinetics accurately described the degradation of anthocyanins during storage. The internal preference map analysis showed the existence of two groups: one formed by the formulations F1 and F2 and the other by formulations F3, F4, F5 and F6. The formulation with the lowest concentration of camu-camu (12.5%) had the best sensory acceptance rate (80.4%), and anthocyanin contents of 23.04 mg.100 mL-1 , ascorbic acid of 353.32 mg.100 mL-1 , total phenolic compounds of 892.06 mg.100 mL-1 and antioxidant capacity of 3668.78 mM ET.100 mL-1 . The response surface methodology and desirability function defined the best conditions for the pasteurization of JB, being 75 °C and 90 s. The product pasteurized under these conditions showed safe microbial counts, all spoilage enzymes inactivated, 24.18 mg anthocyanins.100 mL-1 , 325 83 mg of total phenolic compounds.100 mL-1 and 1862.4 mg of ascorbic acid.100 mL-1 . The stability of the pasteurized juice blend showed pseudo-first order kinetics for the degradation of anthocyanins and ascorbic acid, with half-times of 18 and 126 days, respectively, during storage at room temperature. The response surface methodology and the desirability function were also used to define 145 °C, 34% MD:GA and 8 mL/min as the best conditions for spray drying the jambolan and camu-camu juice blend powder, with 3.47% moisture, 0.18 aw, 35.97% hygroscopicity, WSI of 85.67%, 33.46% yield, ∆E* of 24.17 and microencapsulation efficiency of 24.95% for AA, 50.34% for TMA and 33.93% for TPC. The product obtained in the optimal condition presented in its composition 50.4 g of AA, 263.98 mg of TMA and 1307.94 mg of TPC, per 100 g of powder. Thus, the juice blend of jambolan and camu-camu (F1), selected by the tasters, can be considered a promising source of bioactive compounds. The effectiveness of the heat treatment applied in the retention of bioactive compounds of the juice blend studied, was evidenced by the half-time during storage at 25 °C. The high levels of bioactive compounds in the juice blend powder, indicate that the product has potential for application in industry and food, as they promote beneficial health effects.
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