Effect of Drying Process, Encapsulation, and Storage on the Survival Rates and Gastrointestinal Resistance of L. salivarius spp. salivarius Included into a Fruit Matrix

• Published in: Microorganisms (Basel) Vol. 8; no. 5; p. 654
• Main Authors: Betoret, Ester, Betoret, Noelia, Calabuig-Jiménez, Laura, Barrera, Cristina, Dalla Rosa, Marco
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 30-04-2020; MDPI
• Subjects: Air drying; Digestion; Digestive system; Encapsulation; Food; Food matrix; Food preservation; Food processing; Food products; Freeze drying; Fruits; Functional foods & nutraceuticals; gastrointestinal simulation; Gastrointestinal system; Gastrointestinal tract; Health aspects; Homogenization; hot air drying; microencapsulation; Microorganisms; Moisture content; Molecular modelling; Physicochemical properties; Physiological effects; probiotic; Probiotics; Stress response; Survival; Spain; United States > US; Germany; gastrointestinal simulation; probiotic; freeze drying; hot air drying; microencapsulation
• ISSN: 2076-2607; 2076-2607
• DOI: 10.3390/microorganisms8050654

In a new probiotic food, besides adequate physicochemical properties, it is necessary to ensure a minimum probiotic content after processing, storage, and throughout gastrointestinal (GI) digestion. The aim of this work was to study the effect of hot air drying/freeze drying processes, encapsulation, and storage on the probiotic survival and in vitro digestion resistance of
spp.
included into an apple matrix. The physicochemical properties of the food products developed were also evaluated. Although freeze drying processing provided samples with better texture and color, the probiotic content and its resistance to gastrointestinal digestion and storage were higher in hot air dried samples. Non-encapsulated microorganisms in hot air dried apples showed a 79.7% of survival rate versus 40% of the other samples after 28 days of storage. The resistance of encapsulated microorganisms to in vitro digestion was significantly higher (
≤ 0.05) in hot air dried samples, showing survival rates of 50-89% at the last stage of digestion depending on storage time. In freeze dried samples, encapsulated microorganisms showed a survival rate of 16-47% at the end of digestion. The different characteristics of the food matrix after both processes had a significant effect on the probiotic survival after the GI digestion. Documented physiological and molecular mechanisms involved in the stress response of probiotic cells would explain these results.