C. De Pasquale

Isolation of Gram‐positive n‐alkane degraders from a hydrocarbon‐contaminated Mediterranean shoreline

Aims:u2002 To investigate the petroleum hydrocarbon (HC)‐degrading potential of indigenous micro‐organisms in a sandy Mediterranean coast, accidentally contaminated with petroleum‐derived HCs.

A finely tuned strategy adopted by an egg parasitoid to exploit chemical traces from host adults.

SUMMARY Scelionid egg parasitoids can obtain reliable information on the presence of host eggs by discriminating host gender on the basis of chemical footprints of their co-evolved hosts, with a strong preference for the footprint left by host females. Based on the concept of dietary specialization and infochemical use in natural enemies, it could be predicted that host gender discrimination in specialist species belonging to the genus Trissolcus is further tuned to specific cues from distinctive chemical traces left by host females as a consequence of copulation and/or oviposition. To test this hypothesis we used the system Murgantia histrionica – Trissolcus brochymenae. Our results showed that the females of the egg parasitoid search intensely on chemical traces left on the substrate by host females that had mated but had not yet laid host eggs compared with the chemical traces left by virgin or parous host females. This preference for mated females that had not yet laid host eggs was strictly related to the transfer of sperm and associated substances from males to females during copulation. The compounds that mediated the arrestment response of T. brochymenae females are part of the host cuticle, and those that play a role as gender-specific cues seemed to be present in the legs of the host adult. This result represents an interesting new piece of information regarding the exploitation of indirect host-related cues by egg parasitoids. It reveals the existence of a finely tuned strategy that allows the parasitoid to find newly laid host eggs, as chemical traces left by mated host females that have not yet laid eggs are strongly correlated with the moment of oviposition.

Effect of farming system and cheesemaking technology on the physicochemical characteristics, fatty acid profile, and sensory properties of Caciocavallo Palermitano cheese

Caciocavallo Palermitano is a typical stretched-curd cheese that has been produced over the centuries in Sicily according to traditional cheesemaking technology and using raw milk from autochthonous cow breeds reared at pasture. The objective of this experiment was to evaluate the effects of the farming system and processing technology on the characteristics of Caciocavallo Palermitano cheese, with particular regard to the fatty acid profile. The farming system was either extensive, using autochthonous cows fed a pasture-based diet, or intensive, with specialized dairy cow breeds fed mainly hay and concentrate. The cheese-processing technology was either artisanal, using traditional wooden tools and endemic lactic bacteria, or advanced, using modern steel equipment and selected lactic bacteria. Twelve Caciocavallo Palermitano cheeses, 3 from each of the 4 experimental theses (2 farming systems × 2 cheesemaking technologies), were obtained and aged for 1, 30, 60, and 120 d. Milk of origin and cheeses were analyzed for the main chemical and rheological parameters. Fatty acids were methylated in lyophilized cheese and analyzed by gas chromatography. Sensory analysis was carried out by trained panelists. The PROC GLM of SAS 9.1.2 (SAS Institute Inc., Cary, NY) was used for the statistical analysis. The physical, chemical, and sensory characteristics of Caciocavallo Palermitano cheese were influenced more by the farming system than by the cheesemaking technology. Compared with cheese produced through intensive farming, cheese from extensive farming was richer in polyunsaturated, n-3, and odd- and branched-chain fatty acids, as well as in conjugated linoleic acid (cis-9,trans-11 C18:2), with accompanying improved human health benefits. The cheesemaking technology produced variation in the evolution of proteolysis during aging, due presumably to the different active microflora, which influenced the sensory profile of the resulting cheese. Indeed, cheese produced by artisanal manufacturing was described as less bitter and more piquant than cheese produced through the advanced process.

Effects of ewes grazing sulla or ryegrass pasture for different daily durations on forage intake, milk production and fatty acid composition of cheese.

Sulla (Sulla coronarium L.) forage is valued for its positive impact on ruminant production, in part due to its moderate content of condensed tannin (CT). The duration of daily grazing is a factor affecting the feed intake and milk production of ewes. In this study, the effects of grazing sulla pasture compared with annual ryegrass, and the extension of grazing from 8 to 22 h/day, were evaluated with regard to ewe forage intake and milk production, as well as the physicochemical properties and fatty acid (FA) composition of cheese. During 42 days in the spring, 28 ewes of the Comisana breed were divided into four groups (S8, S22, R8 and R22) that grazed sulla (S) or ryegrass (R) for 8 (0800 to 1600 h) or 22 h/day, and received no feeding supplement. In six cheese-making sessions, cheeses were manufactured from the 48 h bulk milk of each group. Compared with ewes grazing ryegrass, those grazing sulla had higher dry matter (DM) intake, intake rate and milk yield, and produced milk that was lower in fat and higher in casein. Ewes grazing for 22 h spent more time eating, which reduced the intake rate, increased DM and nutrient intake and milk yield, and reduced milk fat. Due to the ability of CT to inhibit the complete ruminal biohydrogenation of polyunsaturated fatty acids (PUFA), the FA composition of sulla cheese was more beneficial for consumer health compared with ryegrass cheese, having lower levels of saturated fatty acids and higher levels of PUFA and n-3 FA. The FA profile of S8 cheese was better than that of S22 cheese, as it was higher in branched-chain FA, monounsaturated FA, PUFA, rumenic acid (c9,t11-C18:2), and had a greater health-promoting index. The effect of short grazing time on sulla was attributed to major inhibition of PUFA biohydrogenating ruminal bacteria, presumably stimulated by the higher accumulation of sulla CT in the rumen, which is related to a higher intake rate over a shorter eating time. Thus, grazing sulla improved the performance of ewes, thereby increasing, especially with short grazing time, the nutritional properties of cheese fat.

Influence of the Pressing System on Pomegranate Juice Physical-chemical Properties

Pomegranate juice has many health properties as the fruits contain anticarcinogenic, antimicrobial and antiviral compounds. Its consumption has greatly increased throughout the world in recent years due to the potential of its different components, polyphenols and anthocyanins among all. Many studies have been performed on the pomegranate juice yield demonstrating its influence on the organoleptic and physicochemical properties of the juice. Commercial pomegranate juice production involves pressing fruits procedures. As a consequence, there is a need to investigate the pressing machine types and optimization in order to achieve juice yield and enhance its health properties. The aim of this study was to assess the influence of the pressing systems on pomegranate juice yield and health properties after the extraction. Pomegranate fruits of the Wonderful One variety were manually harvested in November 2014 and mechanically processed to extract juice. Two different pressing systems were used. The first one was an hydraulic pressing machine where the fruits were put after being sliced in half; the second extraction method consisted in using a destemming machine for the entire fruit followed by a pneumatic press, typically applied in grape processing. The juices obtained with the two systems were analyzed and compared in order to identify the extraction performances and quantitatively identify the health care of the juice properties.

Influence of O2 on extra virgin olive oil fatty acids composition during malaxation

Many variables are related to extra virgin olive oil (EVOO) quality and, therefore, to its polyphenols content and fatty acids composition including the steps that lead to EVOO extraction, considering that it is mainly contained in the vacuoles of the fruit mesocarp. The main steps of EVOO production are: harvest, crushing, malaxation, centrifugation, storage and filtration. Considering the olive oil extraction procedures, many studies have been conducted in recent years on oil mill plant and processes for improving EVOO quality. Malaxer is the most studied machine among all; it is responsible for malaxation, which represents a very important and critical step in the EVOO extraction process. Many studies focus on the control of oxygen in the malaxer headspace, with the aim of determining its influence on EVOO quality evaluating volatile and phenolic components. Considering these factors, the main objective of the present study was to evaluate the influence of the malaxer headspace oxygen concentration on EVOO fatty acids composition from cv. Nocellara del Belice olives. The results show that oxygen content in the malaxer headspace, in different time-points and concentrations during the process, influences EVOO fatty acids composition.

Quality Changes of Tropical and Subtropical Fresh-cut Fruits Mix in Modified Atmosphere Packaging

Application of passive modified atmosphere packaging (MAP) for shelf life extension of mixed pineapple slices, mango pieces and orange segments, was evaluated. Fruits of Ananas cv ‘Gold’, Mango cv ‘Keitt’ and Orange cv ‘Washington Navel’ were washed, sanitized, peeled and cut. Minimal processed fruits were packed under 2 different atmospheres, passive (air) and active MAP (70% N2, 10 %O2, 20 %CO2), and stored at 10±1 °C with 85±5% RH for 12 days. Changes in package atmosphere composition, weight loss, color, texture, pH, soluble solids, sensory attributes, were evaluated after cutting and at three subsequent stages of storage (the 3 day, 6d, 9d, and the 12 day). Color parameters L* and b* significantly decreased over time in all packaging conditions and L* variation was directly attributed to the translucency phenomenon in the fruit flesh. The pineapple and orange parameters highlighted the best visual score during the storage period, the lowest values of the browning index and the highest scores of all sensory descriptors at each sampling date. Organoleptic attributes have not been influenced by the storage time and no off-flavors were detected in the treated fruit. We conclude that pineapple slices and orange segments can be maintained in excellent condition for up 9 days at 10±1°C following the treatment with active MAP.