ABSTRACT
The objective of this work was to evaluate the potential of whey protein concentrate (WPC), native agave fructans (NAF), and their mixture (WPC-NAF, 1:1 w/w) as wall materials and evaluate the physicochemical properties and stability of encapsulated Enterococcus faecium during the spray drying, storage, and passage through the simulated gastrointestinal tests. The encapsulated microorganisms with WPC-NAF by spray drying showed greater viability (9.26 log CFU/g) and a higher microencapsulation yield (88.43%). They also had a smaller reduction in the cell count (0.61 log cycles), while the microcapsules produced with NAF had the greatest reduction in viability during the simulated gastrointestinal tests. Similarly, probiotics encapsulated with WPC-NAF revealed a higher survival rate (> 8 log CFU/g) when stored at a water activity of 0.328. The thermal analysis showed that the addition of NAF to the WPC produced a slight shift in the Tg towards temperatures higher than that shown by NAF. Therefore, this study provides evidence that the spray drying process was appropriate to encapsulate the probiotic strain Enterococcus faecium and that the mixture WPC-NAF protected it from adverse drying conditions and improved the viability of Enterococcus faecium during storage and simulated gastrointestinal tests, demonstrating that the combination of NAF and WPC as encapsulating material is adequate in the production of more stable microcapsules with potential application in various foods.Key Points⢠E. faecium was successfully encapsulated in WPC and NAF.⢠WPC-NAF offered protection to E. faecium in the gastrointestinal tests and during storage.⢠Aw around 0.328 positively influenced the viability of the microorganism during storage. Graphical abstract.
Subject(s)
Enterococcus faecium , Probiotics , Spray Drying , Capsules , Desiccation , Probiotics/analysisABSTRACT
The objective of this study was to evaluate the physicochemical, textural, sensory and microbiological stability of cupcakes during storage after the addition of different proportions of quinoa protein isolate modified by heat denaturation (QPI-HD) and freezing-lyophilization (QPI-FL). The cupcakes containing modified quinoa protein exhibited greater firmness and water activity than the control cupcake. The texture profile analysis (TPA) revealed that the cupcakes with modified quinoa protein were statistically different from those with unmodified protein isolate and the control cupcake. Moreover, cupcakes with quinoa protein modified by either heat or freezing had greater acceptance and preference on the part of consumers. In addition to this, these cupcakes showed lesser growth of molds after 10 days of storage; this indicated that the abovementioned additive could extend the shelf life of cupcakes. These results showed that the addition of modified quinoa protein led to cupcakes with better sensory and textural properties and greater stability during storage.
Subject(s)
Bread/analysis , Chenopodium quinoa/chemistry , Food Analysis , Plant Proteins/chemistry , Plant Proteins/isolation & purification , Antifungal Agents , Bread/microbiology , Cooking , Flour , Food Microbiology , Freeze Drying , Freezing , Hot Temperature , Protein Denaturation , Protein Stability , Seeds/chemistry , Taste , Water/chemistryABSTRACT
Blackberry (Rubus fruticosus) juice possesses compounds with antioxidant activity, which can be protected by different biopolymers used in the microencapsulation. Therefore, the effects of cell wall material including maltodextrin (MD), Arabic gum (GA) and whey protein concentrate (WPC) were evaluated on the physicochemical and antioxidant properties of encapsulated blackberries using a spray-drying technique. Anthocyanin concentration, polymeric colour, total polyphenols, radical scavenging activity of the 1,1-diphenyl-2-picrilhydrazil radical, reducing power and the stability at different storage conditions were evaluated. GA and MD conferred a similar protection to the antioxidant compounds when the microcapsules were stored at low water activities (aw < 0.515) in contrast to at a high moisture content (aw > 0.902), whereas WPC presented a high protection. Therefore, the selection of the best wall material for blackberry juice encapsulation depends of the conditions of storage of the powder.
Subject(s)
Anthocyanins/administration & dosage , Antioxidants/administration & dosage , Beverages , Gum Arabic/chemistry , Polysaccharides/chemistry , Rubus , Anthocyanins/chemistry , Anthocyanins/pharmacology , Antioxidants/chemistry , Antioxidants/pharmacology , Beverages/analysis , Capsules/chemistry , Desiccation , Drug Compounding , Drug Stability , Drug Storage , Oxidation-Reduction/drug effects , Rubus/chemistryABSTRACT
Se preparó jarabe de sacarosa a 70 grados Brix, concentrado hasta alcanzar una concentración mayor a 95 grados Brix. Se estudió el efecto de la concentración de pepino (20, 25 y 30 grados Brix) sobre las propriedades físicas de los gránulos de pepino (Cucumis sativa L.), determinando; humedad, solubilidad y densidad. Los mejores resultados fueron para la concentración de 30 grados Brix. Se adicionó jugo de limón a ésta última para disminuir el pH de 5.5 a 4.0 para mejorar el sabor do concentrado y evitar el crecimiento de hongos y levaduras, encontrando que no hubo diferencia significativa entre los pHs, de acuerdo a los resultados obtenidos en la determinación de higroscopicidad. También se determinó de acuerdo a la evaluación sensorial, que 30 panelistas de los 45 que participaron prefirieron la bebida preparada con cocristalizado al cual se le añadió jugo de limón.
