A simple model of the diffusion phenomena taking place during the debittering process of green table olives

The Desalting Process for Table Olives and Its Effect on Their Physicochemical Characteristics and Nutrient Mineral Content

The desalting process is critical for packaging table olives in brine with reduced NaCl or fortified mineral nutrients. In this study, the effect of desalting on the physicochemical characteristics and mineral content of green Manzanilla Spanish-style (plain and stuffed with pepper paste) and DOP Aloreña de Málaga table olives was investigated for the first time. The surface colour of the fruits turned slightly brownish, and the olives became somewhat softer. The lactic acid, the mineral macronutrients (mainly) and micronutrient contents decreased, while flesh moisture increased. The kinetic parameters of the minerals' losses depended on the presentation, with the estimated values for plain olives being the lowest (slowest desalting). Overall, the desalting process resulted in slight quality damage and a moderated decrease in the mineral concentration in the flesh, leading to some product degradation. This study provides quantitative information on these changes that may affect the commercial value of the final products and offers information for viable designs.

NaOH-free debittering of table olives using power ultrasound

A major drawback to the extension of NaOH-free olive debittering is its lengthy processing. In this research, the power ultrasound efficacy was investigated in a laboratory scale to accelerate this process. Olive fruits were sonicated in water or brine (15% NaCl). The effects of ultrasound-assisted debittering (UAD) were evaluated on olives physicochemical and textural properties in comparison with conventional debittering (CD). In UAD, however, the removal rate of phenolic compounds, which cause olives natural bitterness, increased significantly and as a result, the processing time decreased by 37.8% and 38.6% when debittering was done in water and brine, respectively. The chemical compositions, fatty acids profile, total color differences, Firmness and other textural parameters of UAD-treated samples remained unchanged and their antioxidant activity was significantly higher in comparison with CD-treated samples. Remarkably, UAD was able to speed up and promote NaOH-free olive debittering, without causing any undesirable changes.