Investigation of phenolic compounds and antioxidant activity in red and yellow onions and a synergistic utilization of skin extract in modified atmosphere packaging of salmon (Salmo salar)

Abstract

This study investigated potentially synergetic effects of red onion skin extract and modified atmosphere packaging (MAP) on lipid oxidation of salmon. The skin and flesh of red and yellow onions were extracted with water at 25 C, 45 C, 65 C and 90 C, ethanol and acetone in water solutions. Total anthocyanin and polyphenol levels and antioxidant capacity were determined after extraction. Minced salmon samples were mixed with red onion skin extract (ROSE) and packaged under MAP at different O 2 concentrations (0%, 5%, 10% and 15% of total package gas composition) with 40% CO 2 and balance N 2 . Polyphenol recovery and antioxidant capacity increased for each sample as the extraction temperature increased with hot water use. Water extraction at 90 C provided higher extraction yields than ethanol and acetone in water solutions. The ROSE treatment of fish with MAP reduced lipid oxidation rates as evidenced by a decrease in peroxide value (43%) and thiobarbituric acid reactive substance (TBARS) (30%). The ROSE might effectively suppress the free radicals in a MAP system. A skin extract and MAP application might increase the shelf life of salmon.

Some Physicochemical Properties and Fatty Acid Compositions of Different Originated Anatolian Water Buffaloes Milk Samples

“…The extraction of milk fat was conducted according to Güner et al (2021) with some modifications. The 20 ml of milk was mixed with the 40 ml of methanolchloroform solution (1:1, v/v).…”

“…The mixture was shaken vigorously for a min and then kept at ambient temperature for 1 h. The lower phase was collected and dried under vacuum using a rotary evaporator. The obtained milk fat samples were stored at 4⁰C until further use (Güner et al 2021).…”

“…The fatty acid compositions of the milk fat samples were obtained using fatty acid methyl esters (FAME) analysis (Güner et al 2021). For the FAME analysis, the milk fat samples were diluted using hexane and following that mixed with potassium hydroxide.…”

Preparation and Performance Characterization of a Composite Film Based on Corn Starch, κ-Carrageenan, and Ethanol Extract of Onion Skin

“…Onion waste is mainly made up of onion skins, which are rich in bioactive phenolic compounds. Polyphenols are a kind of natural antioxidant, and their groups include flavonoids and anthocyanins [ 16 ]. Purple onions obtain their color from anthocyanins in their epidermal cells.…”

“…Although onion skins are rich in fiber and flavonoids, the dry, outer layer of onion skin is considered waste and is discarded, resulting in a significant loss of phenolic compounds [ 18 ]. Phenolic compounds can act as free radical scavengers and metal ion chelators to inhibit lipid oxidation [ 16 ]. Therefore, onion skin extract can be added to films as antioxidant material to prepare food-active packaging and to develop a biodegradable antioxidant film.…”