Enrico Valli

Characterization of virgin olive oils produced with autochthonous Galician varieties

The interest of Galician oil producers (NW Spain) in recovering the ancient autochthonous olive varieties Brava and Mansa has increased substantially in recent years. Virgin olive oils produced by co-crushing both varieties in two different proportions, reflecting the usual and most common practice adopted in this region, have gradually emerged for the production of virgin olive oils. Herein, the sensory and chemical characteristics of such oils were characterized by quality and genuineness-related parameters. The results of chemical analysis are discussed in terms of their effective contribution to the sensory profile, which suggests useful recommendations for olive oil producers to improve the quality of oils. Antioxidant compounds, together with aromas and coloured pigments were determined, and their contribution in determining the functional value and the sensory properties of oils was investigated. In general, given the high levels of phenolic compounds (ranging between 254 and 375mg/kg oil), tocopherols (about 165mg/kg oil) and carotenoids (10-12mg/kg oil); these are oils with long stability, especially under dark storage conditions, because stability is reinforced with the contribution of chlorophylls (15-22mg/kg oil). A major content of phenolic compounds, as well as a predominance of trans-2-hexen-1-al within odor-active compounds (from 897 to 1645μg/kg oil), responsible for bitter sensory notes. This characterization allows to developing new antioxidant-rich and flavour-rich VOOs, when co-crushing with a higher proportion of Brava olives, satisfying the consumers demand in having access to more healthy dishes and peculiar sensory attributes.

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”.

Italian and Spanish commercial tomato sauces for pasta dressing: Study of sensory and head-space profiles by Flash Profiling and solid-phase microextraction-gas chomatography-mass spectrometry

BACKGROUNDnThe sensory and head-space profiles of Italian and Spanish commercial tomato sauces were investigated. The Flash Profiling method was used to evaluate sensory characteristics. Samples within each set were ranked according to selected descriptors. One hundred volatile compounds were identified by solid-phase microextraction-gas chomatography-mass spectrometry.nnnRESULTSnFor Italian samples, the sensory notes of basil/aromatic herbs, acid and cooked tomato were among those perceived most by the assessors, whereas, in Spanish samples, the sensory attributes of garlic/onion and onion/sweet pepper and, in Italian samples, cooked tomato were among those found most frequently. Data were elaborated using multivariate statistical approaches and interesting correlations were observed among the different sensory attributes and related volatile compounds.nnnCONCLUSIONnSpanish samples were characterized by the highest content of volatiles linked to the thermal treatment of tomatoes and to raw and sautéed garlic and onion, whereas the Italian samples were characterized by terpenic compounds typical of basil and volatile molecules derived from fresh tomato. These results confirm the influence of both formulation and production processes on the aromatic profile (sensory attributes and volatile compounds) of tomato products, which is probably related to the different eating habits and culinary traditions in Italy and Spain.

EFFECTS OF ARCHAIC OLIVE AND OIL STORAGE METHODS STILL USED IN SOUTHERN TUNISIA ON OLIVE OIL QUALITY

The present paper investigated how virgin olive oil quality is influenced by two different storage conditions that residents of Gabes (Southern Tunisia) usually apply to fruits of the Zarazi cultivar: long conservation as oil in glass bottles or traditional storage of olives as sun-dried fruits before processing for oil production. Even if both storage conditions are associated with strong losses in the qualitative characteristics of olive oil, the changes observed were more accentuated for oil stored for two years after its production compared to the oil obtained from olives stored by traditional methods.