In Vitro Antioxidant Activity, Bioaccessibility, and Thermal Stability of Encapsulated Strawberry Fruit (Fragaria × ananassa) Polyphenols

Abstract

Bioactive compounds in red fruits, such as strawberries, are vulnerable to digestion, and encapsulation has become an alternative for their protection. This study aims at encapsulating strawberry juice (SJ) by freeze-drying with pea protein and okra mucilage (SJPO), pea protein and psyllium mucilage (SJPP), and pea protein, psyllium mucilage, and okra mucilage (SJPPO) and investigating the in vitro release. The highest encapsulation efficiency was observed in capsule SJPPO (95.38%) and the lowest efficiency in SJPO (82.45%). Scanning electron microscopy revealed an amorphous glassy structure for the structure of the strawberry microcapsules, and X-ray diffraction confirmed that observation. However, X-ray diffraction further showed that SJPPO was crystalline, indicating a tighter crosslinking density than the other microcapsules. Fourier transform infrared spectroscopy showed peaks at 3390 and 1650 cm−1, confirming the presence of polyphenols and polysaccharides in the strawberry microcapsules. Thermal stability was higher for SJPPO, and the observed thermal transitions were due to the bonds formed between the polymers and polyphenols. Pelargonidin 3-glucoside, cyanidin 3-glucoside, cyanidin, delphinidin, malvidin 3-glucoside, ellagic acid, chlorogenic acid, catechin, and kaempferol were identified in the strawberry microcapsules. Digestion affected the compounds’ content; the bioaccessibility for SJ was 39.26% and 45.43% for TPC and TAC, respectively. However, encapsulation improved the bioaccessibility of both TPC (SJPP, 51.54%; SJPO, 48.52%; and SJPPO, 54.39%) and TAC (SJPP, 61.08%; SJPO, 55.03%; and SJPPO, 71.93%). Thus, encapsulating pea protein isolate, psyllium mucilage, and okra mucilage is an effective method to facilitate targeted release and preserve the biological activities of fruits.

Preparation and Physicochemical Analysis of Camellia sinensis cv. ‘Ziyan’ Anthocyanin Microcapsules

“…[8], carbohydrates (maltodextrins and cellulose derivatives) [9], or lipids (waxes, emulsifiers) [10]. Seke et al [11] found that the stability and bioavailability of bioactive components in red fruits (such as strawberries) can effectively be improved by microencapsulation. According to Berg et al [12], microcapsules with the addition of highly esterified citrus pectin and beet pectin based on maltodextrin-encapsulated blueberry anthocyanin resulted in higher hydration capacity and better retarding of anthocyanin.…”

Valorization of Agricultural By-Products (Fragaria vesca) through the Production of Value-Added Micro/Nanostructures Using Electrohydrodynamic Techniques

“…Wild strawberry, scientifically known as Fragaria vesca, is a member of the Rosacea family and is usually found in Europe, Asia West of the Urals, and North America [12][13][14]. This plant species has a rich history in traditional medicine, where it has been widely recognized for its anti-inflammatory properties and its potential in the treatment of gastrointestinal disorders [4,11,12,15].…”