Ultrasound Technology Parameters: Effects on Phenolics in Olive Paste and Oil in Relation to Enzymatic Activity

Abstract

In this paper, the occurrence of secoiridoid aglycones via degradation of phenolic glucosides which have strong effects on commercial, nutritional, and sensory properties of olive oil is studied. The experiment consists in the sonication treatment of Chemlali and Memecik cvs. olive paste three times for 4, 8, and 10 min. This kind of approach has never been used in determining the partition and degradation of phenolics during extraction. Concerning phenolic content present in Chemlali olive oil extracted from whole olives, no significant differences are found after 10 min of treatment using ultrasound apparatus, whereas a rise of more than 60% is detected if olive paste without stones is used. On the other hand, the total phenolic content of Memecik cv. increases positively with the increasing time of treatment. Throughout this report, it is noted that enzymatic activities are affected by ultrasound treatment. Practical Applications: The results of this study will be useful in modification of present processes or development of new processes with the aim of protecting and improving the phenolic composition of olive oil. To the best of the authors’ knowledge, this kind of systematic approach has never been used in determining the partition and degradation of phenolics during extraction. It is believed that describing the effects of high‐power ultrasound applications on olive paste before malaxation will exhibit possible benefits for the future of olive processing technology. The optimization of olive oil extraction parameters with proper adjustments in such a way that the quality of the product is highly increased is an important issue. The effect of ultrasound technology parameters is investigated from the point of phenolic compounds by searching their relation to enzymes in Chemlali and Memecik cvs. olive paste. In addition, the effects of stone removal during extraction are also studied in terms of enzymes in Chemlali and Memecik cvs. olive paste and phenols in olive oil.

The ultrasound application does not affect to the thermal properties and chemical composition of virgin olive oils

“…Among them, the US technology seems to be a promising application in the field of VOOs industry, due to its mechanical and thermal effects when applied on olive paste [12] , [13] , [14] , [15] , [19] , [20] , [34] . Besides, according to several studies, the olive oils obtained from treated olive paste with US in the malaxation step did not present changes in the quality indices, fatty acid composition and volatile aromatic compounds of the VOO, however controversial results on phenols content have been reported by different authors [12] , [14] , [20] , [21] , [23] , [34] , [35] .…”

Impact of Emerging Technologies on Virgin Olive Oil Processing, Consumer Acceptance, and the Valorization of Olive Mill Wastes

“…However, in a subsequent study by the same laboratory, a significant increase in polyphenols was observed in the sonicated oils, which was attributed to the effect of US on polyphenol oxidase activity [ 30 ]. In a recent research on the effects of US on the phenolic content of oil, the concentration of secoiridoids increased by 60% when using depitted olives, and this positive effect was enhanced when applying longer US treatment [ 32 ].…”

Fatty acids profile (GC-FID) and analytical evaluation of Chemlali olive oil according to a combined laboratory scale ultrasounds and microwave extraction

“…In recent years, numerous alternative techniques to overcome these problems have been developed. Among them, there are emerging microwaves, supercritical fluids, ultrasound or the addition of a co-adjuvant, [1][2][3][4][5] as well as pulsed electric field, [6][7][8] Therefore, ultrasound and microwave have many applications not only in our homes but also in industry. In order to increase the oxidative stability capacities of virgin olive oil (VOO), by reducing the extraction time and increasing the olive oil quality, many researchers teams proposed many studies to improve olive oil performance.…”

“…Therefore, Malheiro et al 10 studied the influence of introducing microwaves and ultrasounds on the extraction of olive oil in point of view: oil yields and quality. For example, Yahyaoui et al 4 studied the phenolic compounds present in Chemlali and Memlick olive pastes and oils obtained after ultrasound treatment of depitted olive paste and whole olive samples 4 . They found that the first one were the most affected.…”