Microencapsulation of plum (Prunus salicina Lindl.) phenolics by spray drying technology and storage stability

<div><p>Abstract To improve the stability of the phenolic extracts from plum fruit (Prunus salicina Lindl.), the microencapsulation conditions of spray drying were optimized by the response surface method. The Box-Behnken experimental results indicated the optimal conditions involved an inlet air temperature of 142.8 °C, a core material content of 23.7% and a feed solids content of 11.7%. The maximum microencapsulating efficiency was 87.7% at optimal conditions. Further, the physicochemical properties of the microcapsule powders were improved overall due to the addition of the coating agents. There were no statistically significant differences in phenolic content of the obtained microcapsules for the first 40 days of storage at 25 °C in dark condition (p > 0.05), and the retention rate of total phenol remained above 85% after 60 days. Microcapsules can be potentially developed as a source of natural pigment or functional food based on the advantages of rich phenolic compounds and red color.</p></div

Extraction optimization of polyphenols, antioxidant and xanthine oxidase inhibitory activities from Prunus salicina Lindl.

Abstract Optimization of polyphenols extraction from plum (Prunus salicina Lindl.) was evaluated using response surface methodology. The Box-Behnken experimental results showed the optimal conditions involved an extraction temperature of 59 °C, a sonication time of 47 min, and an ethanol concentration of 61% respectively. The maximum extraction yield of total polyphenols was 44.74 mg gallic acid equivalents per gram of dried plum at optimal conditions. Polyphenol extracts exhibited stronger antioxidant activities than Vc by evaluating of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical scavenging activity. Furthermore, polyphenol extracts (IC50 = 179 g/mL) showed obvious inhibitory effects on xanthine oxidase. These findings suggest that polyphenol extracts from P. salicina can be potentially used as natural antioxidant and xanthine oxidase inhibitory agents

Investigating the Respiratory and Energy Metabolism Mechanisms behind ε-Poly-L-lysine Chitosan Coating’s Improved Preservation Effectiveness on <i>Tremella fuciformis</i>

Freshly harvested Tremella fuciformis contains high water content with an unprotected outer surface and exhibits high respiration rates, which renders it prone to moisture and nutrient loss, leading to decay during storage. Our research utilized ε-poly-L-lysine (ε-PL) and chitosan as a composite coating preservative on fresh T. fuciformis. The findings revealed that the ε-PL + chitosan composite coating preservative effectively delayed the development of diseases and reduced weight loss during storage compared to the control group. Furthermore, this treatment significantly decreased the respiration rate of T. fuciformis and the activity of respiratory metabolism-related enzymes, such as alternative oxidase (AOX), cytochrome c oxidase (CCO), succinic dehydrogenase (SDH), 6-phosphogluconate dehydrogenase, and glucose-6-phosphate dehydrogenase (6-PGDH and G-6-PDH). Additionally, the composite coating preservative also delayed the depletion of ATP and ADP and maintained higher levels of the energy charge while preserving low levels of AMP. It also sustained heightened activities of Mg2+-ATPase, Ca2+-ATPase, and H+-ATPase enzymes. These results demonstrate that utilizing the ε-PL + chitosan composite coating preservative can serve as a sufficiently safe and efficient method for prolonging the shelf life of post-harvest fresh T. fuciformis