Olive Biophenols as New Antioxidant Additives in Food and Beverage

Antioxidant food and beverage additives are widely used by industry to prolong shelf-life by inhibiting the oxidation of fat (oxidative rancidity), vitamins and various amino acids molecules, ensuring also retention of taste and colour. In the food industry, the purpose of adding one ore more antioxidants is twofold, namely i) to suppress lipid oxidation and free radicals in foodstuff under conditions of long storage or of cooking, and ii) to reduce the concentration of free radicals in vivo after food ingestion. For over 70 years, the most commonly used antioxidant food additives have included BHA (butylated hydroxyanisole), BHT (butylated hydroxytoluene), PG (propyl gallate) and TBHQ (tert-butyl hydroquinone), namely phenolic compounds, often used in combination, to stabilize fat in baked and fried products, vegetable oils and margarine. It has been at least two decades since consumer safety concerns are driving a major trend in the food industry, namely the shift from the use of synthetic to natural ingredients in food products. A range of natural antioxidants are nowadays increasingly used in industry as food and beverage antioxidant additives, including ascorbic acid (vitamin C, contained in many citrus fruits) to protect soft drinks, jams, condensed milk and meat, and tocopherols (vitamin E family) for preserving vegetable oils, margarine and cocoa products. Arguing that natural antioxidants are preferred over synthetic antioxidants by most consumers “for emotional reasons”, Pokorny and Parkányiová emphasized the poor stability and carry through properties of natural antioxidants, suggesting that their optimal utilization consists in direct addition as food ingredients without any fractionation, such as in the case of rosemary resins (see below). Other major changes driven by consumer changing lifestyles are the increasing demand of precooked meals, the progressive elimination of hydrogenated fats, and the incorporation of oxidatively unstable nutritional ingredients such as polyunsaturated fatty acids (omega-3) and vitamins in today’s complex foods. All this will require better ways for controlling oxidation. involving “blends of antioxidants that operate on different components of the oxidation mechanism and act synergistically”. One suitable replacement for synthetic antioxidants for preventing rancidity in meat, fish, baked and dairy products, might be olive biophenols due to their antioxidant, antimicrobial and anti-inflammatory properties. Obtained from olive fruits and also from its by-products (olive tree leaves, olive pomace and olive mill waste water) these phenolics have exceptionally high antioxidant activity, and generally show no adverse health effects. Besides extended shelf life, they would impart new health benefits to foodstuffs. In other words, olive biophenols may act as antioxidant food additives and as food supplements endowing new and relevant properties to foodstuffs and also to beverages. The most interesting biophenols are found in the olive mill waste water (OMWW, containing >50 % of the total olive biophenols), in the pomace and in the leaves from which they are increasingly extracted. The aim of this study is not to provide a complete overview on food applications of olive biophenols, but rather to provide a critical answer to the question: Are olive biophenols suitable for large-scale replacement of synthetic antioxidants and preservatives?