Tullia Gallina Toschi

Characterization of olive mill wastewater fractions treatment by integrated membrane process

BACKGROUNDnUp to now, the management of olive mill wastewaters, a three-phase mill by-product, remains an unsolved problem, in particular for those regions where huge quantities of vegetable water are produced. Olive mill wastewaters were therefore treated to evaluate the characteristics of permeate and retentate fractions produced by an integrated membrane system working at two different volume concentration factors.nnnRESULTSnThe effect of two membrane-based filtration steps (microfiltration and nanofiltration) on the content of chemical oxygen demand, dry matter, sensory quality, phenolic compounds and antioxidant activity of permeate and retentate samples was evaluated. Furthermore, the effect of two different volume concentration factors (VCF), in the nanofiltration step, were investigated. At high VCF values, the total phenolic content in the retentate fraction was found to be 3.7-fold higher than the starting one, while the reduction of chemical oxygen demand in the permeate fraction was greater than 97% also at lower VCF values.nnnCONCLUSIONnEach filtration step has provided useful information concerning the utility and appropriateness of the processes chosen, suggesting a sustainable hypothesis of normal industrial practice that can be included in current processes of oil extraction, in order to purify water and recover phenolic compounds with high added value.

Chemical and Sensory Analysis of Commercial Tomato Juices Present on the Italian and Spanish Markets

A quantitative descriptive analysis was developed to characterize the sensory quality of a set of 12 organic and conventional tomato juices sold in Spanish and Italian markets. The volatile compounds of tomato juices were also studied. Twelve sensory descriptors, selected by a trained panel, evaluated the sensory profile of the samples. Some tomato juices were characterized by dominant positive notes typical of tomatoes (tomato paste, vegetable notes), whereas others by negative sensory attributes (off-flavors, high intensity of acidity, and sweetness). The volatile pattern of the samples, studied by SPME/GC-MS, was correlated with the sensory results: basically, organic tomato juices were characterized by vegetable notes and higher volatile compounds than conventional samples, regardless of their geographical origin. Conventional tomato juices were grouped in a closer cluster, whereas organic tomato juices were more diversified. Moreover, defective samples showed higher amounts of 3-methyl-1-butanol.

Olive oil enriched in lycopene from tomato by-product through a co-milling process

Abstract The aim of this investigation was to produce an olive oil (OO) naturally enriched with antioxidants, recovering carotenoids, in particular lycopene, using an industrial by-product of tomato seeds and skin. For this purpose, a technological process in a low-scale industrial plant to co-mill olives and tomato by-product in de-frosted or freeze-dried forms was applied and studied with respect to control samples. Preliminary results obtained from two different experiments were carried out by 40u2009kg of cultivar Correggiolo olives and 60u2009kg of olive blends from different cultivars. In both the experiments, the co-milling showed significant enrichment in carotenoids, especially in lycopene (mean values of 5.4 and 7.2u2009mg/kg oil from defrosted and freeze-dried by-products, respectively). The experimental results demonstrated the possibility to obtain a new functional food naturally enriched in antioxidant compounds, which might be marketed as “OO dressing enriched in lycopene” or “condiment produced using olives and tomato by-product”.

A New Patented System to Filter Cloudy Extra Virgin Olive Oil

The aim of this investigation was to evaluate the chemical and sensory quality of three extra virgin olive oils (EV1-3) subjected to a new patented system to clarify cloudy oils through the insertion of an inert flow gas (argon) in olive oil mass. For this purpose, several quality parameters were determined on the three clarified (EVC1-3) and untreated (EVNC1-3) samples. In particular, the system patented by the University of Bologna and Sapio (a private company that supplies gas for industrial and research sectors) was applied to a 50 L batch of each oil after its production by a low-scale mill. The EV samples were bottled and stored at room temperature and kept in darkness before analysis. Basic quality indices including free acidity, peroxide value, specific absorption in the conjugated triene region and sensory analysis, as well as the composition of the major (fatty acids) and minor (tocopherols, polar phenols, volatiles, water) compounds were determined after three months of storage. The oxidative stability under stress conditions was also assessed. The main results concern the higher overall quality of the EV samples clarified by the patented system compared to untreated ones. The quantity of water significantly decreased in all clarified samples. Above all, the non-clarified oils showed a tendency to quickly develop off-flavors over time and to decrease their oxidative stability.

A novel electrochemical method for olive oil acidity determination

Olive oil is a very important product due to its nutritional value, sensory and antioxidant properties. National and international regulations define basic quality parameters (such as acidity and peroxide index) to discriminate high quality oils (extra virgin olive oil) from those of lower quality. The procedures to measure acidity and peroxide index are manual titration techniques requiring a laboratory environment and trained personnel. In this paper a novel technique, based on electrical impedance spectroscopy, is presented to be suitable for the realization of a simple, low-cost, mobile instrument allowing such measurements to be carried out everywhere and by anybody, with substantial improvements of the current quality control of oil producers of any dimension. The presented method has been validated on 39 olive oil samples, featuring different levels of acidity, peroxide index and total phenolic content. The results show that the emulsion conductance is the electrical parameter best suited to discriminate the oil acidity. Moreover, since the emulsion conductance is also affected by the oil storage conditions (i.e. peroxide index), the presented technique can also be proposed, in a second time, to evaluate product ageing.