Effect of Maltodextrin and Soy Protein Isolate on the Physicochemical and Flow Properties of Button Mushroom Powder

Design of an antioxidant powder additive based on carvacrol encapsulated into a multilayer chitosan-alginate-maltodextrin emulsion

Carvacrol has demonstrated antioxidant activity; however, its high volatility and low water solubility limit its direct application in food matrices. Then, an effective encapsulation system is required to protect it. This study aimed to design and characterize a carvacrol-based additive encapsulated in a spray-dried multilayer emulsion based on chitosan/sodium alginate/maltodextrin. Spray-drying temperature of 120 °C and 3 %(w/w) maltodextrin content maximized both encapsulation efficiency (~97 %) and loading capacity (~53 %). The powder's antioxidant properties were evaluated in two food simulant media: water (SiW) and water-ethanol (SiD). The highest antioxidant activity was observed in SiW for both ABTS•+ (8.2 ± 0.3mgEAG/g) and FRAP (4.1 ± 0.2mgEAG/g) methods because of the reduced release of carvacrol in SiD vs. SiW, as supported by micro- and macrostructural observations by SAXS and microscopy, respectively. An increase from 143 to 157 °C attributable to carvacrol protection and Tg = 44.4 °C (> ambient) were obtained by TGA and DSC, respectively. FT-IR confirmed intermolecular interactions (e.g. -COO- and -NH3+) as well as H-bonding formation. High water solubility (81 ± 3 %), low hygroscopicity (8.8 ± 0.2 %(w/w), poor flowability (CI:45 ± 4), and high cohesiveness (HR:1.8 ± 0.1) between particles were achieved, leading to a powdered antioxidant additive with high potential for applications which required avoiding/reducing oxidation on hydrophilic and hydrophobic food products.

Microencapsulation of riboflavin-producing Lactiplantibacillus Plantarum MTCC 25,432 and Evaluation of its Survival in Simulated Gastric and Intestinal Fluid

Microencapsulation is an optimistic method for the delivery of live microbial cells through different food products. In this study, riboflavin-producing probiotic strain Lactiplantibacillus plantarum MTCC 25,432 was encapsulated using a spray drying technique with different wall materials including Inulin, maltodextrin (MD), and MD + Inulin (1:1). The obtained spray dried powder was investigated for probiotic viability, encapsulation efficiency, particle size, water activity, moisture content, hygroscopicity, bulk and tapped densities, storage stabilities, Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Besides this, the viability of the free and encapsulated probiotic cells was tested under simulated gastric and intestinal fluid conditions. In the results, microcapsules produced with the combination of MD + Inulin showed higher dry powder yield (36.5%) and viability of L. plantarum MTCC 25,432 (7.4 log CFU / g) as compared with individual coating materials. Further characterization revealed that MD + Inulin microcapsules are spherical (3.50 ± 1.61 μm in diameter) in shape with concavities, showed the highest encapsulation efficiency (82%), low water activity (0.307), moisture content (3.67%) and good survival ability at low pH (pH 2.0 and 3.0), high bile salt concentrations (1.0% and 2.0%), and long storage conditions. No differences in FTIR spectra were observed among the tested samples. However, TGA showed enhanced thermal stability of probiotic-loaded microcapsules when MD + Inulin was used together. In conclusion, MD + Inulin could be a potential encapsulation material for riboflavin-producing probiotic bacteria L. plantarum MTCC 25,432.

Stability and expression of K-ras mimotopes in freeze-dried recombinant Lactococcus lactis NZ3900-fermented milk powder during storage in vacuum packaging

AIMS

This study aims to evaluate the storage stability of the freeze-dried recombinant Lactococcus lactis NZ3900-fermented milk powder expressing K-ras (Kristen rat sarcoma viral oncogene homolog) mimotopes targeting colorectal cancer in vacuum packaging.

METHODS AND RESULTS

The freeze-dried L. lactis-fermented milk powder stored in 4-ply retortable polypropylene (RCPP)-polyamide (PA)-aluminium (AL)-polyethylene terephthalate (PET) and aluminium polyethylene (ALPE) was evaluated throughout 49 days of accelerated storage (38°C and 90% relative humidity). The fermented milk powder stored in 4-ply packaging remained above 6 log10 CFU g-1 viability, displayed lower moisture content (6.1%), higher flowability (43° angle of repose), water solubility (62%), and survivability of L. lactis after simulated gastric and intestinal digestion (>82%) than ALPE packaging after 42 days of accelerated storage. K-ras mimotope expression was detected intracellularly and extracellularly in the freeze-dried L. lactis-fermented milk powder upon storage.

CONCLUSIONS

This suggests that fermented milk powder is a suitable food carrier for this live oral vaccine.

Effects of Tremella aurantialba on physical properties, in vitro glucose release, digesta rheology, and microstructure of bread

In this study, the functional properties of a mixture consisting of Tremella aurantialba powder (TAP) and wheat flour were investigated. Further, the effects of adding 0%, 1%, 3%, 5%, and 10% TAP on the physical properties of bread, as well as its glucose release, microstructure, and rheology during in vitro simulated digestion were studied. The water-holding, oil-holding, and swelling capacities of wheat flour were significantly enhanced (p < 0.05) with the increase of TAP. The addition of TAP increased the hardness, chewiness, gumminess, and moisture content and darkened the color of the bread. Sensory evaluation showed that adding the 3% of TAP could produce bread that satisfies the requirements of consumers. Furthermore, adding TAP could inhibit the release of glucose from the digesta into the dialysis solution, especially the addition of 10% TAP reduced the release of bread glucose by 23.81%. This phenomenon might be related to the increased viscosity of the digesta and the smooth physical barrier on the surface of starch granules during simulated in vitro digestion of bread. Therefore, as a natural food, T. aurantialba has great potential in improving the functional properties of bread and the application of starch matrix products.