Exploring the Use of Bryophyllum as Natural Source of Bioactive Compounds with Antioxidant Activity to Prevent Lipid Oxidation of Fish Oil-In-Water Emulsions

Abstract

The current industrial requirements for food naturalness are forcing the development of new strategies to achieve the production of healthier foods by replacing the use of synthetic additives with bioactive compounds from natural sources. Here, we investigate the use of plant tissue culture as a biotechnological solution to produce plant-derived bioactive compounds with antioxidant activity and their application to protect fish oil-in-water emulsions against lipid peroxidation. The total phenolic content of Bryophyllum plant extracts ranges from 3.4 to 5.9 mM, expressed as gallic acid equivalents (GAE). The addition of Bryophyllum extracts to 4:6 fish oil-in-water emulsions results in a sharp (eight-fold) increase in the antioxidant efficiency due to the incorporation of polyphenols to the interfacial region. In the emulsions, the antioxidant efficiency of extracts increased linearly with concentration and levelled off at 500 μM GAE, reaching a plateau region. The antioxidant efficiency increases modestly (12%) upon increasing the pH from 3.0 to 5.0, while an increase in temperature from 10 to 30 °C causes a six-fold decrease in the antioxidant efficiency. Overall, results show that Bryophyllum plant-derived extracts are promising sources of bioactive compounds with antioxidant activity that can be eventually be used to control lipid oxidation in food emulsions containing (poly)unsaturated fatty acids.

From Ethnomedicine to Plant Biotechnology and Machine Learning: The Valorization of the Medicinal Plant Bryophyllum sp.

“…Additionally, they also prevent lipid peroxidation [99] (by decomposing lipid peroxides and scavenging harmful free-radicals) and develop an effective metal chelation activity [100]. The free-radical scavenging [62,101,102] and lipid oxidation preventing activities [64] of Bryophyllum-derived extracts rich in flavonoids have already been reported. Other bioactivities, such as antibacterial [103], antiviral [104], cytotoxic [105], anti-inflammatory [106], cardioprotective [107], sedative and anti-diabetic activities [108] have been associated to flavonoids.…”

“…The inhibition of lipid peroxidation by hydromethanolic extracts from aerial parts of B. daigremontianum, B. tubiflorum, and B. × houghtonii, cultured in vitro was also determined [64]. Moreover, cell-based in vitro antioxidant assays have been performed for the inhibition of lipid peroxidation of root extracts from B. daigremontianum [24].…”

“…The antioxidant activity of Bryophyllum phenolic compounds, focused on the free-radical scavenging activity, has been largely determined [63,79]. Recently, the antioxidant capacity of Bryophyllum extracts for preventing the lipid oxidation of omega-3 enriched fish oil emulsions was reported, thus conferring a valuable approach for the application of Bryophyllum-derived by-products in the food and pharmacological industries [64]. In the same way, the polyphenols from Bryophyllum-derived extracts may be efficiently purified using environmental-friendly procedures, like the use of activated carbon [80].…”

“…The great diversity of bioactivities described for these compounds places the phenolic compounds of Bryophyllum sp. as one of the main families of plant secondary metabolites that boost the phytochemical potential of this subgenus [62,64,81].…”

“…In particular, our research group has developed a simple and reliable method for the disinfection of epiphyllous buds of the adult plants of B. daigremontianum, B. × houghtonii and B. tubiflorum species grown in greenhouse, which involves the use of common, safe and environmental-friendly disinfectant agents [62,64,80,101,137]. The protocol includes an initial tap water wash of the buds overnight, followed by a two-step stage, where the buds are rinsed in 70% ethanol (v/v) for 1 min, washed with sterile distilled water and then rinsed in 0.4% (v/v) sodium hypochlorite with a few drops of Tween ® -20 for 10 min.…”