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Spirulina platensis contains several compounds showing nutritional and therapeutic benefits. Recently, a series of peptides able to reduce the blood pressure level and to enhance the endothelial vasorelaxation was isolated from the hydrolyzed highly water-soluble Spirulina extract (HSE). However, HSE shows critical organoleptic characteristics also having poor intestinal permeability, limiting absorption when orally delivered. This research aims to overcome the critical issues through the encapsulation of HSE in Chitosan/Mannitol-(CM)-based microparticles by spray drying. The produced powders (CM-HSE) showed good process yield (≈70%) and encapsulation efficiency (≈100%) also having good derived flow properties as well as stability up to six months storage. The microparticles constituting the spray-dried powder resulted in an amorphous micrometric state (d 50 ≈ 14 µm) able to retain dark colour and unpleasant smell of raw HSE. Moreover, the in vitro permeation study by Franz cell indicated that the engineered microparticles are able to enhance the permeation of HSE through an intestinal biomimetic barrier (551.13 μg/cm 2 CM-HSE vs. 315.46 μg/cm 2 HSE at 270 min).

Strawberries represent a valuable source of bioactive compounds including vitamin C, E, β-carotene, and phenolic compounds, but they are fruits with an extremely short postharvest life. Therefore, the current study was conducted to investigate the effectiveness of an active coating consisting in antifungal microparticles obtained by spray drying of peony extracts ( Paeonia rockii (PPR)) dispersed in chitosan (Ch) and subsequent addition to polysaccharide gels to slow the fungal attack of small highly perishable fruits, such as strawberries. The results of the antimicrobial assays indicate that the peony extracts in chitosan are able to counteract effectively the growth of different fungal isolates from deteriorated strawberries. In conclusion, through the treatment with this antifungal coating, it is possible to prolong the shelf life of delicate fruits, such as strawberries, to about 16 days, slowing down the weight loss, affecting the safeguard of important vitamins and antioxidant capacity during storage, without causing any significant alteration of the nutritional and sensorial properties of the product. [ABSTRACT FROM AUTHOR]

Highlights: [•] Microencapsulation of Paeonia rockii extract (PPR) in a spray dried chitosan (C) matrix. [•] 0.5% w/v C and 1/1 C/PPR ratio led to high process yields (70.1%). [•] The microencapsulation process led to high encapsulation efficiency (82.4%) and low dimensional distribution (5.15μm). [•] The produced powder (C-PPR) showed enhanced water dissolution properties and storage stability with respect to PPR. [•] C-PPR exhibited antioxidant property and enhanced antifungal activity against Candida albicans with respect to PPR. [ABSTRACT FROM AUTHOR]