Alessandra Fratianni

Effects of fatty acids, nucleotides and reactive oxygen species on durum wheat mitochondria.

Linoleic acid (LA) and other fatty acids added to respiring durum wheat mitochondria (DWM) were found to cause a remarkable membrane potential (ΔΨ) decrease, as monitored by measuring safranin fluorescence. The rate of ΔΨ decrease showed (i) saturation dependence on LA concentration; (ii) fatty acid specificity; (iii) inhibition by externally added ATP, GDP, GTP and Mg2+ and (iv) sigmoid dependence upon initial ΔΨ, thus suggesting the existence of an active plant mitochondrial uncoupling protein (PUMP) in mitochondria from monocotyledonous species (durum wheat, Triticum durum Desf.). Surprisingly, the rate of the linoleate dependent ΔΨ decrease was found to be activated by reactive oxygen species (ROS) (hydrogen peroxide and superoxide anion) and, moreover, linoleate proved to lower the mitochondrial generation of superoxide anion. These results suggest that ROS can activate PUMP, thus protecting the cell against mitochondrial ROS production.

Response of Carotenoids and Tocols of Durum Wheat in Relation to Water Stress and Sulfur Fertilization

Lipophilic antioxidants are essential components of plant defense against stressful conditions. The response of carotenoids and tocols to water deficit and sulfur fertilization was investigated in durum wheat cultivars. The amounts of tocols and carotenoids were evaluated in both whole meal and semolina samples. Differences among cultivars were observed. Simeto cultivar showed a significant effect of water regime on whole meal and semolina carotenoids, with about 20% and 15% increase, respectively. Also tocols and tocotrienols of Simeto were positively affected by water stress (about 10% increase and 15% increase in whole meals and semolinas). Sulfur fertilization positively impacted mainly Ofanto whole-grain and semolina carotenoids, semolina tocols, and tocotrienols. In conclusion, water deficit occurring under a Mediterranean environment was responsible for an improvement of lipophilic antioxidant content in durum wheat; in contrast sulfur supplementation did not improve the response of the antioxidant pool under water deficit.

Innovative Caciocavallo cheeses made from a mixture of cow milk with ewe or goat milk

This study assessed and compared the physicochemical, microbiological, and sensorial characteristics of Caciocavallo cheeses, made from cow milk and a mixture of cow with ewe or goat milk, during ripening. Different cheese-making trials were carried out on an industrial scale following the standard procedure of pasta filata cheeses, with some modifications. The percentage of the different added milk to cow milk influenced compositional and nutritional characteristics of the innovative products, leading to a satisfactory microbiological and sensorial quality.

Determination of lutein from fruit and vegetables through an alkaline hydrolysis extraction method and HPLC analysis

A simple and rapid analytical method for the determination of lutein content, successfully used for cereal matrices, was evaluated in fruit and vegetables. The method involved the determination of lutein after an alkaline hydrolysis of the sample matrix, followed by extraction with solvents and analysis by normal phase HPLC. The optimized method was simple, precise, and accurate and it was characterized by few steps that could prevent loss of lutein and its degradation. The optimized method was used to evaluate the lutein amounts in several fruit and vegetables. Rich sources of lutein were confirmed to be green vegetables such as parsley, spinach, chicory, chard, broccoli, courgette, and peas, even if in a range of variability. Taking into account the suggested reference values these vegetables can be stated as good sources of lutein.

Influence of microorganisms on retinol isomerization in milk

In order to have a deeper insight into the retinol isomerization phenomenon, in this work different milk samples have been analysed for their content of trans retinol and its cis-isomers, by means of reliable HPLC techniques. Levels of the different isomers and the degree of retinol isomerization (13-cis/all-trans ratio, %) have been monitored during milk storage at different temperatures and after addition of specific microorganisms. In raw milk stored at 4 degrees C for 96 h the degree of retinol isomerization shifted from 1.1 to 2.3%, while in raw milk stored at 22 degrees C for 24 h it increased from 1.1 to 12.7%. Among microorganisms tested in pasteurized milk, the most active in causing an increment in the 13-cis/all-trans ratio (%), from 3.4 to 33.4% in 8 h, was Streptococcus thermophilus. The results obtained demonstrated a relationship between microbial evolution and retinol isomerization. Therefore, the determination of retinol isomers is of importance not only for a more precise evaluation of vitamin A activity but also for the evaluation of the microbiological quality of milk.

Kinetics of carotenoids degradation and furosine formation in dried apricots (Prunus armeniaca L.)

The kinetics of carotenoid and color degradation, as well as furosine formation, were investigated in apricot fruits during convective heating at 50, 60 and 70°C. Degradation of carotenoids and color, expressed as total color difference (TCD), followed a first and zero order kinetic, respectively. The activation energy (Ea) for carotenoids degradation ranged from 73.7kJ/mol for 13-cis-β-carotene to 120.7kJ/mol for lutein, being about 91kJ/mol for all-trans-β-carotene. Violaxanthin and anteraxanthin were the most susceptible to thermal treatment. The furosine evolution was fitted at zero order kinetic model. The Ea for furosine formation was found to be 83.3kJ/mol and the Q10 (temperature coefficient) varied from 1.59 to 4.14 at the temperature ranges 50-60°C and 60-70°C, respectively.

Patulin Degradation by the Biocontrol Yeast Sporobolomyces sp. Is an Inducible Process

Patulin is a mycotoxin produced by Penicillium expansum and a common contaminant of pome fruits and their derived products worldwide. It is considered to be mutagenic, genotoxic, immunotoxic, teratogenic and cytotoxic, and the development of strategies to reduce this contamination is an active field of research. We previously reported that Sporobolomyces sp. is able to degrade patulin and convert it into the breakdown products desoxypatulinic acid and ascladiol, both of which were found to be less toxic than patulin. The specific aim of this study was the evaluation of the triggering of the mechanisms involved in patulin resistance and degradation by Sporobolomyces sp. Cells pre-incubated in the presence of a low patulin concentration showed a higher resistance to patulin toxicity and a faster kinetics of degradation. Similarly, patulin degradation was faster when crude intracellular protein extracts of Sporobolomyces sp. were prepared from cells pre-treated with the mycotoxin, indicating the induction of the mechanisms involved in the resistance and degradation of the mycotoxin by Sporobolomyces sp. This study contributes to the understanding of the mechanisms of patulin resistance and degradation by Sporobolomyces sp., which is an essential prerequisite for developing an industrial approach aiming at the production of patulin-free products.

Evolution of free amino acids during ripening of Caciocavallo cheeses made with different milks

The evolution of free amino acids (FAA) in Caciocavallo cheeses, made with cow milk (CC) and cow milk mixed with ewe (CE) and goat (CG) milk, was studied throughout ripening. In all Caciocavallo cheeses produced, the total free amino acid (TFAA) content increased during ripening. In general, the highest TFAA content was found in cow cheeses, and the lowest in CG cheeses, whereas CE cheeses ranged over an intermediate level. In all the analyzed samples, during ripening, the content of the individual FAA increased with the exception of arginine. Tyrosine and histidine were found only in CE samples from the middle to the end of ripening. The major FAA found throughout the whole ripening period, in all types of cheese, were leucine, phenylalanine, lysine, valine, asparagine, γ-aminobutyric acid, and ornithine. The TFAA and several AA showed significant differences in ripening time, whereas tyrosine and histidine showed significant differences in kinds of milk.

Variability in chemical and microbiological profiles of long-ripened Caciocavallo cheeses

Five protected designation of origin (PDO) Caciocavallo Silano and 6 non-PDO Caciocavallo cheeses, ripened for 6mo and collected in the 5 Italian regions of the PDO area (Apulia, Basilicata, Calabria, Campania, and Molise, Italy), were studied to assess their physico-chemical (pH, acidity, moisture, fat, ash, protein, and free amino acid composition) and microbiological profiles. Analyses evidenced a certain fluctuation of previous parameters among samples regardless of the kind of cheese evaluated (PDO and non-PDO). The PCR-denaturing gradient gel electrophoresis analysis performed on the DNA directly extracted from cheeses gave different results, but a low number of bands was always observed. Only one band, corresponding to the species Streptococcus thermophilus, was detectable in 1 PDO and in 2 non-PDO cheese samples, whose free amino acid content was the lowest. Analyses were repeated on experimental Caciocavallo cheeses. Specifically, 2 productions were made, one mimicking the industrial technology (pasteurized milk and selected starter culture) and one the artisanal technology (raw milk and natural whey starter). Results obtained on experimental cheeses at 6mo of ripening showed that industrial samples had lower amounts of total free amino acids then the artisanal ones (1,188.2 vs. 7,523.67mg/100 g of dry matter). Moreover, the PCR-denaturing gradient gel electrophoresis analysis evidenced the sole presence of S. thermophilus in the case of the industrial technology. These data sustain the hypothesis that, out of 11 cheeses analyzed previously, 1 PDO Caciocavallo Silano and 2 non-PDO Caciocavallo cheeses were obtained with the industrial technology. These results could be of help in the discrimination of PDO products, taking into account that the PDO production regulation does not allow the milk pasteurization, nor the use of selected starters.

Technological use of donkey milk in cheesemaking

The efficacy of donkey milk as an alternative to hens egg white lysozyme in preventing cheese blowing during ripening of Italian Grana cheeses was tested. Indices of proteolysis and lipolysis did not differ between the different cheesemaking processes. All tested products showed good microbiological and sensorial quality.