Modern Techniques in the Production of Table Olives

Abstract

The olive tree (Olea europaea L.) is one of the most important trees in the world, and olive oil and table olives are consumed extensively as a basic ingredient of the Mediterranean diet. Table olives are prepared from the fruit of a variety of cultivated olive trees, and, after removing their bitterness by several methods, they are preserved by natural fermentation or other methods before packing. Currently, scientists and consumers alike are interested in and prefer fresh and healthy table olives that have been minimally and safely processed. The aim of this chapter is to provide information about the modern food-processing techniques that are used to improve the quality characteristics of table olives.

Table olives and health: a review

“…A high consumption of sodium (>2 g/d, equivalent to 5 g salt/d) and low consumption of potassium (<3•5 g/d) contribute to high BP and increase risk of CVD and stroke (152) . It is suggested that a diet rich in potassium and calcium and poor in sodium prevents the development of osteoporosis and/or colon cancer, in addition to their effects on CV health (153,154) . Strategies at individual and governmental levels may be adopted to reduce the intake of NaCl.…”

Technologies and Trends to Improve Table Olive Quality and Safety

“…In industrial applications, chlorinated water (50–200 ppm as free chlorine, 1–2 min, and pH = 6.0–7.5) are used extensively to wash fruits and vegetables. Studies have shown that chlorine dips can reduce the population of microorganisms below 2 log colony forming unit (cfu), but it has the potential to react with organic materials to form harmful by-products, therefore it should not be used in high doses (Degirmencioglu, 2016 ).…”

“…The latter exhibit higher residual levels in food due to their non-solubility in water (Ikeura et al, 2011 ; Iizuka and Shimizu, 2014 ), and most of pesticides residues are retained on fruit and vegetable surface, and may be also absorbed into the flesh (Bajwa and Sandhu, 2014 ). The various food processing methods such as washing (added with strong oxidizing agents, such as ozone, chlorine dioxide), peeling, brushing, blanching, cooking, boiling, etc., can be used to reduce pesticide contamination (González-Rodríguez et al, 2011 ; Bajwa and Sandhu, 2014 ; Misra, 2015 ; Degirmencioglu, 2016 ; Qi et al, 2018 ).…”

“…Results of researches on removal of pesticide residues from olive products documented that pesticides, adsorbed on the dust and adhering to the fruit, may be removed, from no reduction to a 45% decrease, depending on the efficiency of the washing step applied (Cabras et al, 1997 ; Guardia-Rubio et al, 2006a , 2007a , b , c ; García-Reyes et al, 2007 ). At this stage, the effectiveness of the washing process can be improved by cleaning washing machines every day and changing the washing water with fresh water at the starting of the day (Ruiz-Medina and Llorent-Martínez, 2012 ), and it is enhanced by using chemical agents (Degirmencioglu, 2016 ). For that purpose, chlorine based products (10–500 ppm), ozone (1–3 ppm), electrolyzed oxidizing water (EO) alone or with combined chlorine solutions (120 mg/L chlorine, for 15 min), hydrogen peroxide (10–100 ppm), weak and strong acids, potassium permanganate (KMnO 4 , 0.001%), NaCl solution (5–10%), baking soda (NaHCO 3 , 5–10%), vinegar (0.1%) for several minutes, and ultrasonic cleaners (García-Reyes et al, 2007 ; Kaushik et al, 2009 ; Bajwa and Sandhu, 2014 ; Gómez-Almenar and García-Mesa, 2015 ; Qi et al, 2018 ) can be effectively used.…”

“…Most of alternative are scarcely used in the table olives sector (washing olives with organic acids, ozonated water, etc. ), while researchers are studying techniques to improve quality and safety of the material at the pre-fermentation stage (Degirmencioglu et al, 2014 ; Degirmencioglu, 2016 ). Different processing technologies give raise to very distinguishable products.…”