Secagem em leito fluidizado de snacks de maçã incorporados com probiótico

• Autor(a) principal: Galvão, Andrêssa Maria Medeiros Theóphilo
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Ceará (UFC)
• Texto Completo: http://www.repositorio.ufc.br/handle/riufc/50655
• topic: Engenharia química; Ultrassom; Probióticos; Frutas - Desidratação; Fluidized bed dryer; Apple snacks

Apple snacks incorporated with probiotic are an alternative for people who can not consume dairy food, whereas they are not derived from milk, as well as dismiss refrigeration in their storage and being a convenient food. The drying technology used for this product in this work is performed in the fluidized bed, due to the highest heat transfer caused by the contact between the drying air and the snacks. Aiming to improve this drying process, ultrasound was used as a pretreatment, due to its mechanical and cavitation properties reported to improve the transport of water inside and in the surface of the fruit. Furthermore, it decreases the energy consumption by reducing the drying time at low temperature (30 °C) preserving the quality of the dried product. Another technique is the application of a probiotic coating (Bacillus coagulans spores), which prolongs the shelf life of this food and makes it functional due to the health benefits of its consumption. The water activity (aw), moisture (U), water diffusivity, water gain and loss of solids in the ultrasonic bath, viability of the probiotic after drying, the enzymes polyphenoloxidase (PPO) and peroxidase (POD), total phenolics, antioxidant activity with DPPH and vitamin E were analyzed. The results of water diffusivity were higher in the procedures at 50 °C, being chosen for the drying processing optimization of this work, besides displaying values of aw and U to 0.4 and 9%, respectively. The viability of this probiotic in the snacks after drying is above the minimum values for a food probiotic (8.0 log CFU/mL). The PPO and POD rates decreased after drying, however, 71.56% of PPO and 72.37% of POD were maintained in samples related to fresh apple. The relative quantities of total phenolics up to 35 days of storage at room temperature had similar result as the control with 90.58 ± 0.28% and this may be related to the protective effect of probiotic coating on these phenolic compounds combined with reduction of the water activity in the dehydrated apples. This same explanation is given for the increase of antioxidant activity (up to 117.40 ± 2.20% related to the control) during 21 days of storage at room temperature. Thereby, this work shows the potential of these fluidized bed dryer probiotic apple snacks to be marketed.