Ultrasonication and encapsulation of Butcher broom (Ruscus Hyrcanus L.) extract and its bioactive effects on qualitative properties, oxidative stability and shelf life of cake

Abstract

Three solvents of pure-water (PW), 50:50 ethanol-water (EW) and pure-ethanol (PE) were used to obtain phytochemicals of Butcher's broom (Ruscus Hyrcanus L) leaves (BBL) separately with 10% concentrations (w/w) at 20 °C for 48 h. Since the extract yield of EW was higher than other solvents, therefore 100, 300, 500 and 700 mg/L of BBL were macerated separately at similar conditions and ultrasonicated in 37 kHz at 35 °C for 35 min. The yield of ultrasound assisted extraction (UAE) of EW had significantly (P ≤ 0.05) higher DPPH, ferric reducing antioxidant power (FRAP), phenolic, anthocyanin and flavonoids than EW extract before sonication at each BBL concentration. Then the yield of UAE at 700 mg/L was nano-capsulated (NC) with the mixture of (50:50) maltodextrin/gum Arabic (MD/GA). The NC efficiency and the coated-particle sizes were 80.48% and 95.17 nm, respectively. Furthermore, the scanning electron microscopy (SEM) and test of Fourier-transform infrared spectroscopy (FTIR) confirmed successful encapsulation and interactions between the final extract yield and coating layer of MD/GA. The UAE extracts of 700 mg/L with and without encapsulation were separately added into the prepared cake dough at 0.7%. Analysis of baked cakes during 45-day storage at 20 °C showed that thiobarbituric acid, peroxide values, yeast, mold and total viable count of NC-samples were significantly (P ≤ 0.05) lower than non-capsulated UAE-sample and control (cake without any extract). The MD/GA layer of NC-sample could protect the BBL phytochemicals and extend the shelf life of cake significantly longer (without negative quality indictors) due to its stable coating at 150 °C baking temperature.