A large increase in demand for high-quality virgin olive oil during the past few years can be attributed not only to its potential health benefits, but also to its particular organoleptic properties. The aim of increasing the quality standards for virgin olive oil is continuously stimulating the search for new technologies. All operations carried out during the oil extraction process aim to obtain the highest quality of oil from fruits. Malaxation is one of the most important critical points of the olive oil mechanical extraction process. The employment of wrong mixing conditions (time, temperature and atmosphere) compromise the healthy and organoleptic properties of the product. A new malaxer was projected and tested to improve thermal exchange reducing the malaxation time and enhancing the virgin olive oil quality. The experimental data showed that resistance to oxidation, total phenols and pleasant volatile compounds were higher in the extracted olive oils employing the innovative malaxer than in the extracted oils utilizing the traditional one.

The entire virgin olive oil (VOO) process has changed very little over the last 20 years. One of the essential challenges of VOO industrial plant manufacturing is to design and build advanced machines in order to improve the working capacity of the industrial plants and create more sustainable engineering solutions. Ultrasound (US) and microwave (MW) are emerging technologies that have already found application in the food industry. Yet, application in the VOO sector has been scarcely investigated. In order to ascertain if the mentioned emerging technologies are able to increase the environmental sustainability improving VOO extraction yields, two different treatments (US and MW) of olive paste were adopted in the VOO extraction process on a pilot scale plant. In these experimental conditions, the main parameters legally established (acidity, peroxide value, and specific extinction coefficients (K232 and K270)) to evaluate VOO quality were not affected by the US and MW treatments. Moreover US and MW processes reduced significantly the length of the malaxation and improved the extraction yield as compared with the control when the oils were extracted from the paste without malaxation. Results also prove that US technology was more sustainable than MW which appears as an energy consuming method in a pilot scale plant. Therefore the industrial application of these technologies could represent the first step toward the development of continuous new devices.

This paper deals with an extensive analytical approach, which uses two complementary tandem mass spectrometry techniques, to characterize the chlorogenic acids (CGAs) present in a typical Italian sweet cherry variety (cv Ferrovia). Sixteen monoacyl-quinic acids and esters, five diacyl-quinic acids, three caffeoyl-quinic acids glycosides, and two caffeic acid hexoses were detected by HPLC-MSn analyses (MSn up to MS4), among which four methyl coumaroyl quinate and three methyl caffeoyl quinate isomers were tentatively identified in sweet cherries for the first time. HPLC-MS/MS analyses through multiple reaction monitoring (MRM) experiments showed that trans-3-O-caffeoylquinic acid, cis-3-O-coumaroylquinic acid, trans-3-O-coumaroylquinic acid, trans-5-O-caffeoylquinic acid, and methyl-3-O-caffeoyl quinate were the main CGAs in the mature berries of cv Ferrovia. Considering that CGAs can have several health benefits depending on their amount but also on their structural features, the results of this study provide new insight into the knowledge of the quali-quantitative profile of these phytochemicals in a widespread fruit such as sweet cherry. © 2018 Elsevier Inc.

The objective of this work was to verify the effect of cold storage and controlled atmosphere (CA) on long term storage of olives in relation to quality parameters of the extracted oil. ‘Coratina’, ‘Leccino’ and ‘Ogliarola leccese’ olives were stored in air at ambient temperatures (approximately 15 to 20°C), air at 5°C, and 2% O2 in nitrogen at 5°C, in two replicates for treatment. Initially, and after 15 and 30 day samples were taken, oil was extracted with a laboratory scale milling plant. Before milling, respiration rate was measured with the static system. The following quality attributes were measured on oil samples: acidity (related to the presence of free fatty acid), peroxide value (peroxides are the first products of oxidation), coefficients of specific extinction at 232 nm (related to the presence of products of primary oxidation) and 270 nm (related to the presence of products of secondary oxidation), and oil stability (Rancimat test). ‘Leccino’ and ‘Ogliarola leccese’ olives showed a high incidence of decay after 30 days of storage in room conditions. Cold storage and controlled atmosphere had a significant effect on slowing down the respiration rate, and therefore, the metabolic activity of the drupes for all cultivars. Results on oil samples show a strong effect of low temperature storage on quality attributes. Results show a good potential for application in the olive oil industry in order to preserve quality of the product and to lengthen the processing season, while not many additional benefits can be attributed to the use of low oxygen. The implementation of cold storage of the fruit in the olive oil industry may lead to a general increment of oil quality and to the decrease of the incidence of capital costs due to the extension of the extraction season.

Agro-biomass residues can play a crucial role in promoting the fossil-fuel replacement in agro-food farms. Apulia, a region in Southern Italy, concentrates 22% of farms and 57% of total national olive and olive oil production, resulting the leader producer of the Country. So that, a high quantity of biomass (olive pomace) can be recovered from the milling process. This study investigates the biogas production that occurs during the anaerobic digestion of olive pomace by means of an ultrasound pre-treatment or by means of green synthesis of ZnO Nanoparticles mixed with olive pomace, in order to facilitate its digestion or co-digestion. Measurement of dry matter and biogas produced volume during the anaerobic process were investigated starting from 3-phase and 2-phase olive pomace by means of high specific energy and low frequency ultrasound values. The results highlight a promising influence of ultrasound pre-treatment useful at increasing the biogas yield of olive pomace. © 2018 The Authors. Published by Elsevier Ltd.

A large increase in the demand for high-quality virgin olive oil continuously stimulating the search for new technologies. In olive oil extraction process, is known that to extract greater oil amount longer kneading time at optimal temperature is needed or, alternatively, higher process temperature. However, both high temperature and longtime of malaxation goes in damage of oil quality, oxidation processes are enhanced and losses in sensory characteristics take place. The malaxer is a heat exchanger characterized by a low overall heat transfer coefficient. At industry scale, extra malaxation time is required to reach the optimal paste temperature, usually around 15- 20 minutes for 30°C. The aim of this work is to show the results obtained from experiments carried out, at laboratory scale, applying high-power ultrasounds during the malaxation step and its effect on oil characteristics. High-power ultrasound application on olive paste has shown a positive effect on length of malaxation step. It provides a quick-heating of olive paste without alteration of olive oil composition. Two main mechanisms are involved in the ultrasonic treatment on olives and on olive paste: a thermal effect and a mechanical effect. The thermal effect was due to the attenuation characteristics of the medium. The mechanical effect is due to cavitation or particulate streaming which cause violent movement of the particles of the medium. Sound waves, which have frequencies higher than 20 kHz, are mechanical vibrations in a solid, liquid and gas. Unlike electromagnetic waves, sound waves must travel in a matter and they involve expansion and compression cycles during travel in the medium. Expansion pulls molecules apart and compression pushes them together. The expansion can create bubbles in a liquid and produce negative pressure. The bubbles form, grow and finally collapse. Close to a solid boundary, cavity collapse is asymmetric and produces high-speed jets of liquid that have strong impact on the solid surface and can disrupt biological cell walls. The mechanical effect of ultrasounds promotes the release of soluble compounds from the plant body by disrupting cell walls and improves mass transfer also in the olive tissues. The ultrasound technology provides a reduction of malaxing time improving extractability of oil and its antioxidant content both of Coratina and Paranzana variety.

The main goal of this study was to investigate the effects of moderate saline water irrigation in the "Chemlali" olive cultivar grown in Sfax, an arid region of Tunisia, on the composition and quality of the resultant virgin olive oil in comparison to a control plot grown under rain-fed conditions. Free acidity, peroxide value, specific ultraviolet absorbance (K(232), K(270)), fatty acid composition, induction time, total polyphenol and total chlorophyll contents were determined and reported. The irrigation did not affect free acidity and peroxide value. Whereas, specific ultraviolet absorbance (K(232), K(770)), fatty acid composition, induction time, total polyphenol and total chlorophyll contents were affected by irrigation. Rain-fed virgin olive oils showed a statistically significant higher content of oleic and linoleic acids. Virgin olive oils extracted from moderate saline water irrigated trees had higher contents of palmitic, palmitoleic, stearic and linolenic acids and a longer shelf-life. A positive correlation was noted between polyphenol content and oxidative stability.

Winemaking techniques are well-known to influence extraction and evolution of phenolics and volatile compounds, affecting in turn on the wine quality. The influence of several technological variables (cold pre-fermentative maceration, addition of tannins, long maceration) on the vinification of Apulian Aglianico, Uva di Troia, and Montepulciano grapes was studied. The main results regarding volatile compounds as affected by the several vinification parameters were here reported. Numerous compounds were determined, including alcohols, acids, esters, aldehydes, ketones, volatile phenols, which constitute the main components of flavour of young wines contributing with typical fruity notes. For all wines, especially the one obtained from Uva di Troia, cold pre-fermentative maceration with the use of dry ice was the technology which caused the most enrichment of alcohols and esters, at a concentration higher than the sensory thresholds.

The malaxation, a basic step of the mechanical olive oil extraction process, was studied by several authors, but a comprehensive investigation of its effects on the oil composition has not been accomplished yet. An effective olive paste malaxing is crucial in producing virgin olive oil (VOO) of exceptional quality. It is important to extract the optimum amount of oil, with the right quantities of antioxidants and the best possible flavour. The aim of this work is to present the state-of-the-art about malaxing technology and its influence on analytical parameters related to VOO quality, healthy and organoleptic characteristics of the product. Machinery evolution has been reported from the most traditional to the newest designs. Recent advances and future trends applied to the olive oil extraction technology are also reported.

This monograph is a critical review of the biological activities that occur during virgin olive oil (VOO) extraction process. Strategic choices of plant engineering systems and of processing technologies should be made to condition the enzymatic activities, in order to modulate the nutritional and the sensory quality of the product toward the consumer expectations. “Modulation” of the product quality properties has the main aim to predetermine the quantity and the quality of 2 classes of substances: polyphenols and volatile compounds responsible of VOO nutritional and sensory characteristics. In the 1st section, a systematic analysis of the literature has been carried out to investigate the main olive enzymatic activities involved in the complex biotransformation that occurs during the mechanical extraction process. In the 2nd section, a critical and interpretative discussion of the influence of each step of the extraction process on the polyphenols and the volatile compounds has been performed. The effect of the different mechanical devices that are part of the extraction process is analyzed and recommendations, strategies, and possible avenues for future researches are suggested. Practical Application In the field of virgin olive oil industry, time and energy should be spent on developing innovative processing plants and equipment able to better modulate the physical parameters that influence endogenous olive enzyme activities, such as temperature, time, amounts of processing water and oxygen. This review paper can be a useful resource to design and develop innovative equipment by offering an exhaustive analysis of mechanical effects of industrial devices and biological effects of endogenous enzymes on the sensory and nutritional properties of virgin olive oil.

The olive oil extraction process is a combination between a mechanical eparation of lipid fraction from the olive paste and a complex enzymatic transformation of same compounds. The enzymes are released after the disruption and smashing of the olive cell structure due to the crushing process. The fruit enzymes catalyze both desirable and undesirable reactions during the olive paste mixing. The oxygen plays a primary role in both circumstances. In order to produce an excellent extra virgin olive oil correct strategies have to be used to optimize the oxygen employment during the extraction process. The control of this parameter, coupled to the right choice of crushing machine, is able to emphasize the organoleptic and healthy properties of product. Experimental tests were carried out in order to verify the influence of oxygen on olive oil quality. Virgin olive oil samples were extracted employing an industrial plant equipped with an innovative mixer instead of a traditional type. The mixer was made with a hermetically sealed cap, and valve for inert gas. Oxygen measurement were carried out employing an oximeter. The experimental data showed that resistance to the oxidation and total phenols were higher in the olive oils extracted employing inert gas in the head space of the malaxer, while pleasant volatile compounds were higher in the olive oils extracted utilizing low concentration of oxygen in the composition of atmosphere in contact with olive paste.

A high quality raw material is well known to be required for premium winemaking. Therefore, the advancement in technology for must treatment is a key factor for progress in high quality wine production. When the vintage is poor, grape generally undergoes to different treatments to enhance sugar and acid contents and colour. Many concentration techniques can be used, including evaporative concentration, freeze concentration, and membrane processes. The membrane filtration works at a low temperature, preserving must components from degradation. The aim of the present work was to tailor the use of reverse osmosis and nanofiltration technology to different varieties from Southern Italy. Several membranes for reverse osmosis and nanofiltration were tested for several varieties. The main oenological parameters including sugar content, acidity, pH, colour and total phenol content, were evaluated in comparison with the addition of rectified concentrated must. Quality characteristics of all musts showed to be improved by means of membrane processes, which could be successfully implemented in the cases of premature harvest carried out for obtaining wines with enhanced acidity.

When the vintage is poor, different must concentration techniques are used for overcoming grape compositional deficiency, such as evaporative or freeze concentration, and membrane processes. The membrane filtration works at low temperature, preserving must components from degradation. The aim of the present work was to tailor reverse osmosis and nanofiltration technologies applied to grape juice testing several membranes for different grape varieties from southern Italy. The main oenological parameters, including sugar content, acidity, pH, color and total phenol content, were evaluated in comparison with the addition of rectified concentrated must. Quality characteristics of all musts showed to be improved by means of membrane processes, which could be successfully implemented in the cases of premature harvest carried out for obtaining wines with enhanced acidity

Malaxation is a basic step in the mechanical olive oil extraction process that may affect yield, quality and health properties of virgin olive oil (VOO). The operative conditions of malaxation, such as temperature and time, are fundamental to favour the oil coalescence process and, consequently, the duration of the VOO extraction process. The aim of this study was to improve the extraction process efficiency by using an ultrasound treatment of olive paste before the malaxation step. The ultrasonic treatment was applied to Coratina and Peranzana, which are two of the most popular Southern Italian olive varieties characterized by extremely different technological performance. Different times of ultrasound treatments were tested (0, 2, 4, 6, 8, 10 min) and free acidity, peroxide value, K232, K270, sensory analysis, tocopherols, total carotenoids, chlorophyll and total polyphenols were determined. Results showed that the ultrasound treatment caused a quick heating of the olive paste as a function of the ultrasound treatment time. Times of treatment of 8 and 10 min allowed the reduction of the malaxation phase from 60 to about 40 min. The ultrasound technique improved antioxidant content in both VVOs, except for polyphenols that decreased. However, the reduction of polyphenol concentration in Coratina VOO improved its taste by reducing the bitter and pungent notes, which are not always accepted by consumers.

The aim of virgin olive oil elaboration process is to obtain the highest recovery of the best quality oil from the fruits. The aim of the researchers is to understand the key elements that allow to modulate the complex series of physical, physico-chemical, chemical and biochemical transformations in order to develop innovative and sustainable plant solutions able to increase simultaneously both yield and quality of product. The basic principles applied also in the newest olive oil industrial plants still follow the technical knowledge which have been empirically learned by humans thousands of years ago. In fact, it is well known that three factors, mixing, water adding and warming, are the three macroscopic driving forces able to favour the separation of the oily phase from the mass of crushed olives. In this consolidated scenario, can new elements emerge? The whole process should be considered more than a simple extraction of the oil present in fruit cells, but a complex elaboration of a product, which is depleted and enriched of both constitutive and neo-synthesised compounds through complex phenomena only in part discovered. In fact, while it is evident that numerous studies have been conducted to elucidate the behaviour of olive paste during virgin olive oil extraction process, a key conclusion is that the current level of understanding can be improved further by means the development of more rigorous researches with more focused targets aimed to understand the rheological changes, the coalescence phenomena, the changes in hydrophobic and hydrophilic phenomena, the partition equilibrium of minor compounds between aqueous and oily phases and, last but not least, the favourable and unfavourable enzymatic reactions. This paper provides an analysis of the present research field and its strengths and weaknesses are discussed. Potentially important future directions for research are also proposed.

Malaxation has been recognized as one of the most critical points in the mechanical extraction process for virgin olive oil (VOO). It is a low and continuous kneading of olive paste at a carefully monitored temperature. Through this essential technological operation the small droplets of the oil formed during the milling merge into large drops that can be easily separated with a decanter centrifuge. During this technological phase, a complex and necessary bioprocess takes place in order to determine the quality and composition of the final product. The malaxer is a heat exchanger characterized by a low overall heat transfer coefficient because the ratio of surface area to volume is disadvantageous, so it is important to find an innovative technology to improve heat-exchange. As matter of fact, the malaxing step is the only discontinuous phase in a continuous extraction process. In the next future, the essential challenge of VOO industrial plant manufacturing sector is to design and build advanced machines in order to transform the discontinuous malaxing step in a continuous phase and improve the working capacity of the industrial plants. In order to reduce the malaxing time enhancing the quality of the product, two ultrasound-assisted virgin olive oil extraction processes were tested against the traditional method. The sonication treatment was applied on olives submerged in a water bath (before the crushing) and on olive paste (after the crushing). The ultrasound technology provides a reduction of the malaxing duration improving VOO yields and its minor compounds content. Better extractibility and higher minor compounds contents were obtained by sonicating the olives submerged in a water bath than olive paste. After experimental trials the results were employed to suggest innovative scaling up solutions of the process and new applications of ultrasounds in the VOO industry.

The present invention lies in the field of the treating and transforming of olives or other oleaginous fruits in processes for extracting virgin oils. In particular, it refers to a method and an apparatus for thermal treatment of olives or other oleaginous fruits, for crushing in controlled or modified atmosphere and for kneading in controlled or modified atmosphere, allowing to reduce the kneading times, improving the working capacity of the line, concomitantly preserving the quality of the product.