Evaluation of peanut skin subcritical extract as a natural antioxidant for preserving a high-fat food product

RODRIGUEZ CAROLINA; MARTINEZ MARCELA; DAMIAN MAESTRI; VELEZ ALEXIS; BODOIRA ROMINA

Buenos Aires

Congreso; 11th World Congress of chemical engineering; 2023

Asociación Argentina de Ingenieros Químicos (AAIQ)

Preservation proceduresare commonly used in the food industry to guarantee a product's quality. One ofthese procedures consists in adding components that prevent or retard thedegradation processes, prolonging their shelf life. The decrease of quality inproducts with high-fat content, such as mayonnaise, is mainly caused byoxidative processes. Currently, the antioxidants (AOs) used for foodapplications are mainly synthetic substances (TBHQ, BHT, BHA), which have beenquestioned for their safety. In this regard, the need of using innocuousnatural AOs obtained through the application of clean technologies with lowenvironmental impact is increasing. Peanut skin (PS) is a by-product of lowadded value that has abundant bioactive phenolic substances with a highantioxidant capacity, both in vitro and applied to certain foods. Subcriticalextraction uses water or ethanol + water mixtures at temperatures between 100 -374 °C, and pressures above atmospheric to keep it in a liquid state. It is agreen, environmentally friendly, safe, and fast extraction technique thatachieves high extraction yields of medium and high polarity compounds from asolid matrix.  Considering thisbackground and the antioxidant effectiveness of a PS extract observed in an O/Wmodel emulsion [1], a storage test with mayonnaise was carried out using thisextract as a natural antioxidant to retard lipid degradation processes. The PS extract wasobtained with ethanol-water (40:60) under subcritical conditions (200°C, 7 MPa,and a solvent flow of 7 g/min) using semi-continuous extraction equipment. Theextract was processed until obtaining a dry extract (PSE). The mayonnaise wasmade with refined soybean oil without additives (65%). The PSE was incorporatedinto the aqueous phase in concentrations of 1 and 2 mg PSE/g fat matter,mayonnaise without any antioxidant was used as a negative control, and theaddition of BHT-EDTA at the concentrations allowed by the Argentinian Food Codewas used as a positive control. The color and other physical parameters weremeasured for all treatments (four in total). For the storage test,30 g of mayonnaise from each treatment (in duplicate) were placed in 50 mLamber bottles, covered with film, and stored at shelf temperature (25°C) forsix months. A sample was taken without replacement every month. The oil wasextracted by stirring at room temperature using 30 mL of chloroform: methanol(1:1). Subsequently, the evolution in the peroxide index (PI) and acidity index(AI) was measured by volumetric analysis. The control mayonnaise presented a pHof 5,10 and water activity of 0,914 at 24,7°C. The color parameters, accordingto the CIELAB system, showed differences between the treatments. Previous testsunder accelerated conditions (40°C) allow considering the PSE as a replacementfor synthetic antioxidants in commercial high-fat products.