Improvement of the polyphenol extraction from avocado peel by assisted ultrasound and microwaves

Abstract

AbstractUltrasound (UAE) and microwave (MAE) are green technologies to assist in the extraction of polyphenols. The goals were to study the application of sonication temperature (40–60°C), time (15–60 min), microwave power (250–750 W) at 30–120 s; and to combine the principal factors of each method for the maximum recovery of total phenolics from avocado peel employing a response surface methodology. The phytochemical, biological, and feasibility characteristics of the hydroethanolic extracts were analyzed. The combination of 15 min of sonication followed by 95.1 s of microwaving were the optimal parameters to recover 166.3 ± 4.9 mg GAE/g dry matter, which was 1.3, 1.2, and 1.1 times higher than UAE, MAE, and maceration, respectively. Likewise, the U‐MAE was upper in yield (25.3 ± 0.6%), TPC (281.4 ± 0.2 mg GAE), TFC (62.0 ± 0.4 mg QuE), and TAC (4.8 ± 0.1 mg cyanidin‐3‐O‐glucoside) and DPPH, FRAP and LPO (779.1 ± 0.6, 167.0 ± 2.3 μg TEAC, 70.03 ± 0.62%, respectively) per gram of dry extract. All the extracts displayed antibacterial activity. The economic feasibility analysis indicated MAE to be highly effective when energy is less affordable, whereas, if the cost associated with the raw material is high, the U‐MAE is suitable.Practical ApplicationsThe extraction industry is moving fast into sustainable processes based on the implementation of ecologically friendly methods of extraction and the utilization of by‐products to obtain bioactive metabolites to be used in the food and pharmaceutical industries. The results here presented were meant to design efficiently extracting procedures. Hence, the correct selection of factors that affect the extraction such as sonication temperature as well as microwave power is vital to reduce the resource consumption; especially raw material and time. Moreover, the exploitation of by‐products as the avocado peel will reduce the negative impact on the environment and enhance the value chain of avocado production.