Ultrasound-Assisted Aqueous Extraction of Biocompounds from Orange Byproduct: Experimental Kinetics and Modeling.

Esperanza Dalmau,Carmen Rosselló,Cristina Ratti,Valeria Eim,Susana Simal

doi:10.3390/antiox9040352

Esperanza Dalmau, Carmen Rosselló + Show 3 more

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https://doi.org/10.3390/antiox9040352

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Abstract

Orange byproduct (flavedo and albedo) from juice extraction, was used as raw material for this study. Kinetics of total phenolic and total flavonoid contents and antioxidant activity was experimentally determined during both conventional (agitation at 80 rpm) and ultrasound assisted (at 520 and 790 W/L) aqueous extraction from orange byproduct at 5, 15, and 25 °C. An extraction mathematical model was also developed. Significant increase of biocompounds extraction yields was observed as temperature and acoustic power density increased. Ultrasound assistance allowed higher yields at lower temperatures and shorter times. Yields of total phenolic and total flavonoid contents and antioxidant activity obtained with ultrasound extraction (790 W/L, 25 °C, 3 min) were 29%, 39%, and 197% higher, respectively, than those obtained by conventional extraction. The extraction kinetics curves were properly represented by the Weibull model for both conventional and acoustic extraction (mean relative error lower than 5%). Naringin, neohesperidin, and hesperidin were the main phenolic compounds found in the extracts, followed by ferulic, sinapic, and cuomaric acids. Neohesperidin, hesperidin, coumaric acid, and sinapic acid presented the highest yields, especially when extraction was assisted by ultrasound. Meanwhile, naringin and ferulic acid were extracted in a lesser extent, most likely due to their lipophilic character.

Highlights

Spain produces more than one million tons/year of oranges, being the largest producer of this fruit worldwide
The extraction yields after ultrasound was applied ca 11% (UAE1) and UAE2 at 25 ◦ C for 3 min, were significantly higher than those by conventional extraction at 25 ◦ C for 10 min. These results showed that ultrasound assisted extraction (UAE) promoted higher extraction efficiencies compared to conventional extraction
The experimental data discussed above clearly suggest that orange byproduct constitutes an important source of biocompounds, which could be extracted with high yields in water at low/moderate temperature (5–25 ◦ C) when the extraction is assisted by ultrasound

Summary

Introduction

Spain produces more than one million tons/year of oranges, being the largest producer of this fruit worldwide. The industrial use of a part of these oranges, especially for the production of juice, results in the accumulation of high amounts of byproducts (37,800 tons/year [1]), consisting mainly of peel and flesh, which account for about half of the fruit weight. In Spain, the waste from orange juice production is typically used as animal feed or discarded. This byproduct is rich in numerous biologically active compounds such as phenolic acids and flavonoids [2]. The extraction of these bioactive compounds from the orange byproducts has had considerable scientific interest to use them as natural source of antioxidants, especially for food formulation to prevent the oxidation of lipids [2]. In recent years, a lot of research has focused on plants and their by-products to extract natural and low-cost antioxidants that can replace synthetic additives such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), which might be liver-damaging, carcinogenic, and more toxic in general [3]

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