Modeling of volatile and phenolic compounds and optimization of the process conditions for obtaining balanced extra virgin olive oils

Abstract

SUMMARY:The main objective of this paper is to obtain extra virgin olive oils (EVOOs) which are balanced in volatile and phenolic compounds. An experimental design was performed and response surface methodology was applied. The factors for malaxation were: temperature 20-40 °C, time 30-90 min, and hole diameter of hammer-crusher 4.5-6.5 mm. The results show that high temperatures and small hole diameter must be used in order to obtain a higher content in phenolic compounds, while for volatile compounds a low temperature and large hole diameter must be used. The models predict that the best and more balanced EVOO are obtained with the hole diameter of greater size and a medium-low temperature. Thus, for a hammer-crusher hole diameter of 6.5 mm 337 and 356 mg/kg total HPLC phenols were obtained for malaxation temperature of 20 and 25 °C, respectively and, likewise, 12.7 and 11.5 mg/kg total LOX volatiles. KEYWORDS: Balanced olive oils; Oil mill; Phenolic compounds; Response Surface Methodology; Volatile compounds RESUMEN:Modelado de compuestos volátiles y fenólicos y optimización de las condiciones de operación para obtener aceites de oliva virgen extra equilibrados. El principal objetivo es obtener aceites de oliva vírgenes extra (AOVEs) equilibrados en compuestos volátiles y fenólicos. Se ha realizado un diseño experimental y aplicado metodología de superficie de respuesta. El rango de los factores de batido fue, temperatura 20-40 ºC y tiempo 30-90 min, y diámetro de orificio del molino de martillos 4,5-6,5 mm. Los resultados muestran que a altas temperaturas y pequeño diámetro de orificio se obtienen elevados contenidos en compuestos fenólicos, mientras que para volátiles se debe usar temperatura baja y orificio de gran diámetro. Los modelos predicen que el mejor y más equilibrado EVOO se obtiene con el orificio de mayor tamaño y temperatura media-baja. Así, para diá-metro de orificio de 6,5 mm se obtienen 337 y 356 mg/kg de fenoles totales HPLC, para temperaturas de batido de 20 y 25 °C respectivamente y, asimismo, 12,7 y 11,5 mg/kg de volátiles totales LOX.

The Chemistry Behind the Folin–Ciocalteu Method for the Estimation of (Poly)phenol Content in Food: Total Phenolic Intake in a Mediterranean Dietary Pattern

“…Although gallic acid is now routinely used as a standard for calibration curves, equivalents of catechin, 23 , 24 tannic acid, 25 chlorogenic acid, 26 caffeic acid, 27 and ferulic acid 28 have also occasionally been used, requiring standardization of the reported results. 29 Caffeic acid, 30 gallic acid, 31 and hydroxytyrosol (HTyr) 32 calibration curves were utilized to measure phenolic compounds in virgin olive oil extracts. Twelve different extra virgin olive oils were analyzed using various methods, and their phenolic content was statistically compared using two-tailed paired t tests.…”

Virgin Olive Oil Volatile Compounds: Composition, Sensory Characteristics, Analytical Approaches, Quality Control, and Authentication

“…As for malaxation, higher temperatures lead to decreases of positive sensory attributes and to increases of branched short chain alcohols and aldehydes due to the amino acid conversion pathway . The effect of malaxation time and temperature on the LOX VOCs was hypothesized to be cv-dependent. ,,, The use of innovative technologies such as microwave and ultrasound during malaxation only slightly affected the VOC profile of the obtained oils, as for example the sono-heat-exchanger, a flexible machine able to shorten the processing time, save energy, and increase oil yield up to 5.5% . The use of the two-phase decanter was reported to produce oils with higher levels of LOX VOCs than the three-phase one, while vertical centrifugation led to a reduction of approximately 10% of the total content of LOX VOCs and of 53.3% of the EtOH content .…”

Fresh and Aromatic Virgin Olive Oil Obtained from Arbequina, Koroneiki, and Arbosana Cultivars

“…Consumers demand EVOO with a balanced composition. To achieve a balanced final product, several studies to optimize the extraction conditions and agronomic factors have been conducted [3,4,5].…”