Effect of drying technique and feed flow rate on bacterial survival and physicochemical properties of a non-dairy fermented probiotic juice powder

Abstract

Drying of probiotic fruit juice can be a good alternative for new probiotic foodstuff production since most probiotic foods are dairy-based products, which are not suitable for people with galactosemia, lactose intolerance or allergy to milk protein. Thus, the aim of this study was to evaluate the influence of spray and spouted bed drying and feed flow rate on the microorganism survival and physicochemical properties of probiotic orange juice powder. Fermented probiotic orange juice containing Lactobacillus casei NRRL B-442 was spraydried at 140 °C and spouted bed dried at 60 °C, respectively. Three different feed flow rates were studied for each equipment. Maltodextrin and gum Arabic were used as drying agents at 15% (w/w). The low temperature used in the spouted bed drying resulted in better probiotic bacteria viability compared to the product obtained by spray drying. Moisture and glass transition temperature were improved at the lowest feed flow rate (0.2 L/h), and faster rehydration time was achieved using maltodextrin. Thus, the spouted bed drying at low feed flow rates using maltodextrin as drying agent were the best parameters to produce powder fermented probiotic orange juice with high viability levels after drying and with good physicochemical parameters.

Functional Dehydrated Foods for Health Preservation

“…Barbosa et al [118] and Pereira et al [122] when producing orange and cashew apple juice powders, respectively, with lactic acid bacteria (LAB) verified that the powders stored at 4 ∘ C presented higher survival rates than at room temperature. Furthermore, the highest level of probiotic bacteria was observed for the orange juice powders produced at the lowest feed flow rate (0.2 L h −1 ), probably due to their low water contents [117]. However, these results were different to Mestry et al [126], who when preparing Production of chestnut mousse (pilot-scale anhydrous formulation) and sensory analysis [124] 16…”

“…Good results have been obtained with freeze drying, as stated by Vikram Simha et al [113] and Barbosa et al [116], when producing probiotic pomegranate and orange powders, respectively. Spouted bed drying has also been used in some works because lower temperatures are applied [117] when compared to spray drying. Alves et al [117] observed that spouted bed orange juice dried samples presented higher viable microbial cell counts than the spray-dried ones; however, the last ones showed lower values of moisture content and water activity.…”

“…Spouted bed drying has also been used in some works because lower temperatures are applied [117] when compared to spray drying. Alves et al [117] observed that spouted bed orange juice dried samples presented higher viable microbial cell counts than the spray-dried ones; however, the last ones showed lower values of moisture content and water activity. Both samples, spray-dried and spouted bed dried, presented acceptable glass transition temperatures (Tg), which can assure powder quality when stored at temperatures below 30 ∘ C [117].…”

“…9 times) than those obtained with maltodextrin, probably due to its higher solubility in water [122]. This is an important property because the powders with higher rehydration capacity will be easily reconstituted by the consumers [117]. Another important point to raise is that Anekella and Orsat [119] also refer that exposing the probiotics to a sublethal thermal shock before spray drying might increase the subsequent tolerance to near lethal thermal stresses.…”

Synbiotic aerated dessert: diet product development and evaluation of the intake effects in individuals with metabolic syndrome

“…That result probably occurred because the high feed flow rate reduces the microencapsulation process time and the cell exposure to the high air inlet temperature. Thus, the process conditions provide the highest microbial viability using spray drying (Alves et al, 2016). Serantoni et al (2012) also confirmed that high aspiration rate directly positively influenced the contact time of the granulated material with the cyclone hot air in the drying chamber.…”