Production of Probiotic Passion Fruit (Passiflora edulis Sims f. flavicarpa Deg.) Drink Using Lactobacillus reuteri and Microencapsulation via Spray Drying

Abstract

Probiotic foods offer many benefits to human health, causing increased interest in the development of new food products that exploit such benefits. However, traditional dairy foods are being replaced by other non-dairy foods to provide additional sources of benefits provided by bioactive molecules. Therefore, the objective of the present work was to study the production process of a probiotic fruit drink and then microencapsulate the probiotic pulp to stabilize the drink further. Passion fruit pulp (Passiflora edulis Sims f. flavicarpa Deg.) was fermented with Lactobacillus reuteri under different temperature conditions in combination with different pHs to find the best fermentation conditions. Different from dairy sources, the optimal conditions for the growth of Lactobacillus reuteri in the passion fruit pulp were found to be 30 °C at pH 3.18, where phenolic compounds could also be used as a secondary metabolic pathway. Spray-drying was performed using different conditions for microencapsulation. Process yields and Lactobacillus reuteri survival showed the dependency of droplet sizes, whereas phenolic compound retention was increased when higher amounts of gelatin were used. Therefore, the development of a new food product comprising a powdered fruit pulp rich in probiotic and phenolic compounds was possible.

Optimization of the Effects of Different Temperatures and Compositions of Filmogenic Solution on Lactobacillus salivarius Using Predictive Mathematical Models

“…In the present study, Table 2 showed a growth rate variation of 0.27 to 0.54 h −1 in the experiments carried out at temperatures of 35 and 25 °C, respectively. This effect is observed in Figure 2a Under ideal conditions, bacteria are the microorganisms with the highest growth rate and may have a generation time (tg) of less than 1 h [32]. The generation time, which is the parameter that indicates the time required for the duplication of the cell population, ranged from 1.28 to 2.56 h in the present study.…”

“…Reducing sugars are simple sugars, and their presence in filmogenic solutions favors the development of lactic acid bacteria, which use simple sugars as the main source of energy. These values are different from the amount of sugars found in milk (4.49 g of lactose/100 g) [36] and in fruits such as passion fruit (4.86 g of glucose/100 g) [32], which have been studied for the production of probiotic foods. However, inulin is a widely studied prebiotic that acts as a substrate for the development of microorganisms, enabling a favorable environment for the growth of L. salivarius in filmogenic solutions.…”

“…However, the development of probiotic microorganisms in different culture media is influenced by extrinsic and intrinsic factors of the system in which fermentation is carried out. Monteiro et al [32], in a study on the growth of L. reuteri cells in passion fruit pulp, reported an increase in the initial number of cells of 1 LogCFU.mL −1 , when the pulp was fermented at 35 °C. These researchers showed the importance of studying fermentation conditions and the limiting factor of the culture medium composition.…”

“…Monteiro et al [32], when studying the growth of L. reuteri in passion fruit pulp, observed that the maximum rate of cell growth ranged from 0.009 to 0.097 h −1 , according to the influence of passion fruit pulp pH and fermentation temperature. Mestres et al [33], studying the modeling of the mixed fermentation of gowé (Beninese fermented beverage made with malted and non-malted sorghum flour, which is produced by spontaneous fermentation involving mixed cultures of lactic acid bacteria and yeasts), using L. plantarum and Pichia kluyveri strain, observed a maximum growth rate of Pichia kluyveri of 0.73 h −1 , using the logistic model to determine this rate.…”

“…As can be seen in Figure 6, the concentration of reducing carbohydrates has its value stabilized between 2 and 4 h of the process. On the other hand, the decrease in the concentration of these carbohydrates occurs during the fermentation of the filmogenic solution, which is expected because the main metabolic process of lactic bacteria, such as L. salivarius, uses monosaccharides such as fructose, glucose and lactose for the production of energy and, therefore, lactic acid [32].…”