The video explains methods to determine moisture content, water activity, and probiotic viability in dried products. It details the use of Karl Fisher Equipment and hygrometers for moisture tests, along with serial dilutions and agar plating for probiotic counts. Results indicate that higher spray drying temperatures reduce probiotic viability but maintain powder yield.

powder characterization and probiotic viability

Optimizing Spray-Dried Probiotic Product Quality Through Process Development

To be defined as probiotics, microorganisms added to foods (or supplements) have to be consumed alive, be able to survive during passage in the gastrointestinal tract of the host, and reach the site of action in adequate amounts to exert beneficial effects1,2,7.
The growing interest in probiotics is due to the several benefits to human health they confer, such as the stimulation of the immune system, the reduction of serum cholesterol levels, and the enhancement of gut barrier function by acting against harmful microbes, as well as their beneficial effects in the treatment of the irritable bowel syndrome, among others2,3. In addition, several studies have demonstrated that probiotics can positively affect other parts of the human body where unbalanced microbial communities can cause infectious diseases3,4,5.
For probiotics to be therapeutically effective, the product should contain between 106-107 CFU/g of bacteria at the time of consumption6. On the other hand, the Italian Ministry of Health and Health Canada have established that the minimum level of probiotics in food should be 109 CFU/g of viable cells per day or per serving, respectively7. Considering high loads of probiotics are needed to guarantee they will have beneficial effects, it is essential to guarantee their survival during processing, shelf storage, and passage through the gastrointestinal (GI) tract. Several studies have demonstrated that microencapsulation is an effective method to improve the overall viability of probiotics8,9,10,11.
In this context, several methods have been developed for the microencapsulation of probiotics, such as spray-drying, freeze-drying, spray-chilling, emulsion, extrusion, coacervation, and, more recently, fluidized beds11,12,13,14. Microencapsulation by spray-drying (SD) is widely used in the food industry because it is a simple, fast, and reproducible process. It is easy to scale up, and it has a high production yield at low energy requirements11,12,13,14. Nonetheless, the exposure to high temperatures and low moisture content can affect the survival and viability of the probiotic cells15. Both parameters can be improved for a given strain by determining the effects of culture age and conditions to pre-adapt the culture and optimize the spray-drying conditions (inlet and outlet temperatures, atomization process) and the encapsulating composition8,14,16,17,18.
The composition of the encapsulating solution is also an important factor during SD as it can define the level of protection against adverse environmental conditions. Inulin, Arabic gum, maltodextrins, and skim milk are widely used as encapsulating agents for probiotic drying5,17,18,19. Inulin is a fructooligosaccharide that presents a strong prebiotic activity and promotes intestinal health19. Skim milk is very effective in maintaining the viability of dried bacterial cells and generates a powder with good reconstitution properties17.
Lactiplantibacillus paraplantarum FT-259 is a lactic acid bacterium that produces bacteriocin and presents antilisterial activity, besides probiotic traits20,21. It is a facultative heterofermentative rod-shaped Gram-positive bacterium that grows from 15 &#176;C to 37 &#176;C20 and is compatible with the homeostatic body temperature. This study aimed to present all the steps involved in the production and physicochemical characterization of a spray-dried probiotic (L. paraplantarum FT-259) and evaluate the influence of the protectants and drying temperatures.

Author Spotlight: Process Development for the Spray-Drying of Probiotic Bacteria and Evaluation of the Product Quality  

Process Development for the Spray-Drying of Probiotic Bacteria and Evaluation of the Product Quality

In our laboratory, we do research on beneficial microbes, including probiotics, which are live microorganisms that can be added to food to improve the health of consumers, Usually by competing with pathogenic bacteria in the gut to exclude them and relieve symptoms, like diarrhea or other gastrointestinal disorders. Nowadays, many techniques have been applied to guarantee that the probiotics will survive in food during the shelf life. And also, they needed to tolerate the harsh conditions of the gastrointestinal tract to exert their beneficial effects inside the gut.We studied many technologies that can enhance the survival of probiotics, either in food or in the human host. Among the techniques, microencapsulation by spray drying is of great interest because it's simple, fast, and reproducible, providing high yields at low energy requirements. It's challenging, however, to determine the right conditions to obtain dried probiotics.And for that, suitable protectants must be chosen. Skim milk, maltodextrin, or other like probiotic inulin have been used with different probiotic strains. The area of microencapsulation is a happily evolving field of research that has the potential to impact the food industry by providing new products to be used as functional ingredients.In this study, we demonstrate how to obtain a microencapsulated preparation of a potential probiotic culture using the spray drying technique. We also show how to determine the main parameters to characterize the powder, obtain it, and how to evaluate the survival rate of the probiotic.

Watch this Scientific Journal Video about Powder Characterization and Probiotic Viability at JoVE.com

Powder Characterization and Probiotic Viability  

To determine product moisture content, precisely weigh 100 milligrams of the dried product and place it in the titration vessel of Karl Fisher Equipment. Initiate the biamperometric titration of water present in the sample by pressing the initiation button. To determine water activity, weigh 0.6 grams of dried product in the sample compartment of the hygrometer at 25 degrees Celsius and close the equipment cover.For determining probiotic viability, dilute bacterial culture in nine milliliters of peptide water and vortex until complete dispersion. Perform serial decimal dilutions with diluted bacterial culture in nine milliliters of saline solution. Seed the dilutions onto De Man, Rogosa and Sharpe agar plates and incubate at 37 degrees Celsius for 24 to 48 hours.After incubation, count the colony forming units or CFU using a colony counter with magnifying lens. Calculate the probiotic viability in the dried product using the given equation to express the number of viable cells in CFU per gram of product dispersion. The results of the spray drying of the probiotics at 80 degree Celsius showed that the distinct drying aids promoted efficient protection of the probiotic cells.The increase in spray drying temperature tended to decrease the probiotic viability and reached nearly 80%at 160 degrees Celsius. However, the powder yield remained around 50%throughout all the temperatures. The powder's moisture content and water activity decreased conversely with the spray drying temperature.

powder-characterization-and-probiotic-viability

Research

JoVE Journal

Biology

212 vistas.  Universidade de São Paulo. Para determinar el contenido de humedad del producto, pese con precisión 100 miligramos del producto seco y colóquelo en el recipiente de valoración de Karl Fisher Equipment. Iniciar la valoración biamperométrica del agua presente en la muestra pulsando el botón de iniciación. Para determinar la actividad del agua, pese 0,6 gramos de producto seco en el compartimiento de muestras del higrómetro a 25 grados centígrados y cierre la cubierta del equipo.Para determinar la viabilid...