Microencapsulation of red onion peel polyphenols fractions by freeze drying technicality and its application in cake

Abstract

This work focuses on extraction of biological compounds from red onion peels and its microencapsulation using maltodextrin (MD), soybean protein isolate, and a complex of soybean protein isolate (SPI) and maltodextrin by freeze drying manner. Furthermore, there was a quality evaluation for cake integrated with microencapsulated polyphenols as well as polyphenols stability assessment after baking. Extracts of red onion peel were produced by three methanol concentrations (50, 75, or 100% v/v). A 75% methanolic red onion peel extract (75M) yielded a high total phenolic content, total flavonoid, and antioxidant activity using β‐carotene bleaching and 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging. (SPI + MD) encapsulates had higher encapsulation efficiency (94.30 ± 1.50%). Cake integrated with microcapsules had improved qualitative properties and increased polyphenol content more than other integrated with extract because of encapsulation protective effect pending baking. Comparatively, cake contained SPI microencapsulates showed higher specific volume, moisture absorption, texture, acceptable color, sensory evaluation, and concentration of polyphenols. Practical applications Onion peels are one of the most important onions processing by‐products. The onion peel has a high biological compounds content such as quercetin, phenolics compound, and flavonols. As onion peels extract nature is extremely hygroscopic and sensitive for thermal, it is hard to add them to foodstuffs. The higher polyphenols content of encapsulating incorporated cake were enough to claim for the functionality of polyphenols in the cake. The higher polyphenols content of encapsulating incorporated cake were enough for claiming polyphenols functionality into the cake. (SPI + MD) microcapsules contained high concentrations of red onion peels polyphenols within freeze drying or baking process. Freeze drying is a sufficient technique for add polyphenols into the foodstuffs.

The Physicochemical Properties and Antioxidant Activity of Spirulina (Artrhospira platensis) Chlorophylls Microencapsulated in Different Ratios of Gum Arabic and Whey Protein Isolate

“…In this study, the microcapsule coated with GA:WPI of 3:7 had the lowest moisture content and highest thermal stability, which can play an important role in the chemical stability of CH in microcapsules and can show better antioxidation activity as compared to other microcapsules coated with ratio of GA:WPI. These results were in agreement with previous studies which showed that the suitable carbohydrate and protein ratio of wall materials can present good antioxidant activity [ 46 , 47 ].…”

Value-added salad dressing enriched with red onion skin anthocyanins entrapped in different biopolymers

“…Our reported data are in agreement with other studies. Elsebaie & Essa (2018) reported a high EE of 94.30 ± 1.50 % of ROS extract in SPI and maltodextrin. Additionally, Tao et al (2017) combined various shell materials (whey proteins, gum Arabic, maltodextrin, and β-cyclodextrin) for the encapsulation of blueberry extracts and reported anthocyanins’ EE with values exceeding 82 %.…”

Application of barnûf ( Pluchea dioscoridis ) leaves extract as a natural antioxidant and antimicrobial agent for eggs quality and safety improvement during storage

“…HPLC analysis of barnûf leaves extract (BLE) was performed in the Laboratory of Food Chemistry, Institute of Food Technology Research, National Research Center, Egypt. The quantitative measurement of BLE phenolics content was conducted via the protocol outlined via Elsebaie and Essa (2018) utilizing HPLC instruments (Shimadzu LC-10A; Kyoto; Japan).…”