RESUMO
Driven by the modern lifestyle, the consumers are interested in healthier and balanced diets, including both probiotics and natural antioxidants. The beneficial health effects of probiotics are mainly due to their capacity of modulating the human intestinal microbiota, although achieving at least a 6 log of viable cells at the targeted site is still challenging. Therefore, in this study, an attempt to improve the bioaccessibility of Lacticaseibacillus casei (L. casei) 431® through a co-microencapsulation by complex coacervation and freeze-drying, using an extract from Cornelian cherry and two biopolymeric matrices, whey protein isolates and casein (WPI-CN) and inulin (WPI-I), was studied. The powders showed a comparable anthocyanin content of around 32.00 mg cyanidin-3-rutinoside (C3R)/g dry matter (DM) and a microbial load of about 10 Log CFU/g DM. A high stability of the lactic acid bacteria was assessed throughout 90 days of storage, whereas the anthocyanins' degradation during storage followed a first order kinetic model, allowing the estimation of a half-time of 66.88 ± 1.67 days for WPI-CN and 83.60 ± 2.46 days for WPI-I. The in vitro digestion showed a high stability of anthocyanins in the simulated gastric juice, whereas the release in the simulated intestinal juice was favored in the variant with inulin (up to 38%). The use of casein permitted to obtain finer spherosomes, with smaller diameters, whereas a double encapsulation was obvious in both variants, thus explaining the high resistance in the gastric environment. The anti-proliferative effect against the human colon cancer cell line (HT-29) was also demonstrated. No cytotoxicity has been found for the concentrations between 1 and 25 µg/mL for the WPI-I variant, whereas a cell proliferation effect was observed at low concentrations of 1-5 µg/mL.
Assuntos
Cornus , Lactobacillales , Antocianinas/farmacologia , Antioxidantes/farmacologia , Caseínas , Frutas , Humanos , Inulina/farmacologia , PósRESUMO
Cornus mas was used in this study as a rich source of health-promoting bioactives. The cornelian cherries were used to extract the polyphenols and anthocyanins. The chromatographic profile of the Cornus mas fruit extract revealed the presence of several anthocyanins, mainly delphinidin, cyanidin and pelargonidin glycosides. The extract was co-microencapsulated with Lactobacillus casei ssp. paracasei in a unique combination of whey protein isolates, inulin and chitosan by freeze-drying, with an encapsulation efficiency of 89.16 ± 1.23% for anthocyanins and 80.33 ± 0.44% for lactic acid bacteria. The pink-red colored powder showed a total anthocyanins content of 19.86 ± 1.18 mg cyanidin-3-glucoside/g dry weight (DW), yielding an antioxidant activity of 54.43 ± 0.73 mMol Trolox/g DW. The viable cells were 9.39 × 109 colony forming units (CFU)/g DW. The confocal microscopy analysis revealed the microencapsulated powder as a complex one, with several large formations containing smaller aggregates, consisting of the lactic acid bacteria cells, the cornelian cherries' bioactive compounds and the biopolymers. The powder was tested for stability over 90 days, showing a decrease of 50% in anthocyanins and 37% in flavonoids content, with no significant changes in antioxidant activity and CFU. The powder showed a significant inhibitory effect against the α-amylase of 89.72 ± 1.35% and of 24.13 ± 0.01% for α-glucosidase. In vitro digestibility studies showed a significant release of anthocyanins in gastric juice, followed by a decrease in intestinal simulated conditions. The functional properties of the powder were tested by addition into a yogurt, highlighting a higher and more stable antioxidant activity at storage when compared to the control.
RESUMO
Anthocyanins from black currant extract and lactic acid bacteria were co-microencapsulated using a gastro-intestinal-resistant biocomposite of whey protein isolate, inulin, and chitosan, with an encapsulation efficiency of 95.46% ± 1.30% and 87.38% ± 0.48%, respectively. The applied freeze-drying allowed a dark purple stable powder to be obtained, with a satisfactory content of phytochemicals and 11 log colony forming units (CFU)/g dry weight of powder (DW). Confocal laser microscopy displayed a complex system, with several large formations and smaller aggregates inside, consisting of biologically active compounds, lactic acid bacteria cells, and biopolymers. The powder showed good storage stability, with no significant changes in phytochemicals and viable cells over 3 months. An antioxidant activity of 63.64 ± 0.75 mMol Trolox/g DW and an inhibitory effect on α-amylase and α-glucosidase of 87.10% ± 2.08% and 36.96% ± 3.98%, respectively, highlighted the potential biological activities of the co-microencapsulated powder. Significantly, the in vitro digestibility profile showed remarkable protection in the gastric environment, with controlled release in the intestinal simulated environment. The powder was tested by addition into a complex food matrix (yogurt), and the results showed satisfactory stability of biologically active compounds when stored for 21 d at 4 °C. The obtained results confirm the important role of microencapsulation in ensuring a high degree of protection, thus allowing new approaches in developing food ingredients and nutraceuticals, with enhanced functionalities.