Extra virgin olive oil bitterness evaluation by sensory and chemical analysis

An experimental investigation was performed on blend extra virgin olive oils (EVOO) from different cultivars and EVOO from different olive monovarieties (Coratina, Leccino, Maiatica, Ogliarola) with the aim to evaluate the possibility of estimating the perceived bitterness intensity by using chemical indexes, such as the total phenol content and the compounds responsible of oil bitterness measured spectrophotometrically at 225 nm (K225 value) as bitterness predictors in different EVOO. Therefore, a bitterness predictive model, based on the relationship between the perceived bitterness intensity of the selected stimuli and the chosen chemicals parameters has been built and validated. The results indicated that the oil bitterness intensity could be satisfactorily predicted by using the K225 values of oil samples

Quality Traits of Some Cauliflower Cultivars Grown in the “Valle dell’Ofanto” Area (Italy) as Affected by Post-Harvest Storage

Some quality characteristics of the “Valle dell’Ofanto” cauliflower, that has been recently appointed the certification of collective brand, were investigated at Gaudiano (41°03’N; 15°42’E, Southern Italy, Basilicata Region). Six white head cauli-flower cultivars, characterized by a different length of the crop cycle (2 early, 2 medium and 2 late), were studied. The above cultivars were transplanted in open field at the middle of August 2004 and harvested from the middle of October 2004 to the end of March 2005. At harvest time, yield traits and head sizes of cauliflowers were measured. Among the qualitative traits, color, weight loss, total soluble solids, nitrate and vitamin C content were assessed on the fresh florets and after a storage period lasting 15 days at 0°C and 95% R.H. The “Valle dell’Ofanto” cauliflower was charac¬terized by a high content in sugars and vitamin C, even if significant differences in some qualitative parameters (e.g., vitamin C and nitrate content) were affected by cultivars and crop cycle length. On the other hand, the storage at controlled tempera¬ture and R.H. did not substantially change the qualitative characteristics of the heads, but caused only a slight increase of dry matter and soluble solids levels, especially in those cultivars more susceptible to weight loss

Effects of anti-UV film and protective atmosphere on fresh-cut iceberg lettuce preservation

The aim of this research was to study the shelf-life of fresh-cut iceberg lettuce, testing a packaging film manufactured with and without addition of anti-UV compounds, and using two different protective atmospheres (N2/CO2 70/30% and Ar/CO2 80/20%). In order to simulate the most common retail storage conditions, the samples were stored at 6 °C under artificial light by using real supermarket refrigerated exposition stands. The data obtained showed that the use of an anti-UV film always causes a lower quality decay of the product; in any case, the best results were obtained when the anti-UV film was utilized in association with the packaging atmosphere consisting of Ar and CO2 (80/20%) gas mixture

Application of ozone in fresh-cut iceberg lettuce refrigeration

Recently, technological innovations have been geared to supporting environmental sustainability, also in the fruit and vegetable industry. The application of ozone in the cold storage of fruits and vegetables is a sustainable technology used to improve product quality and its antimicrobial effect, simple use, and characteristic of not leaving any residue, makes this treatment suitable for many applications in this field. The aim of this work was to evaluate the effect of refrigeration at 4°C, associated with ozonization treatment at a concentration of 0.2 ppm on the shelf life of fresh-cut lettuce, compared to a lettuce control stored only at 4°C. Lettuce quality throughout the storage period (7 days) was determined by means of color and microbiological indexes, such as total bacterial count, total coliforms, Escherichia coli, Pseudomonadaceae, yeasts and molds. The lettuce used in the experiment was found to have a low microbiological load. Microbiological results obtained at different storage times have shown that the use of ozone is effective in containing microbial growth during chilling storage of the raw material compared to the refrigerated control. In particular, the positive effects of ozonation were appreciable after the third day of storage. Furthermore, the ozone treatment did not affect the color of the product

Effect of sucrose replacement and resistant starch addition on textural properties of gluten-free doughs and biscuits

There is a need to develop low-sugar healthy products. The aim of this research was to evaluate the effect of maltitol and inulin as sucrose replacement alongside resistant starch (RS) and green banana flour (GBF) on the texture and physical properties of gluten-free doughs and biscuits formulated with buckwheat, sorghum and lentil flours. These properties are important to predict the dough workability, how easy the biscuits could be mass-produced and determine consumers’ acceptability. Results showed that partial and complete substitution of sucrose could be achieved and appropriate concentration of resistant starch or green banana flour contributed to better dough and biscuit texture. RS content showed the biggest influence on dough stickiness and biscuit hardness and could be used to correct the negative effect of sucrose replacement and to maximise both the dough processability and biscuit acceptability

Influence of indigenous starter coltures on the free fatty acids release during ripening in artisan sausages produced in the Basilicata region.

The influence of indigenous starter cultures on the free fatty acids content during ripening of \ubbsalsiccia\uab, a typical dry fermented sausage produced in the Basilicata region, was studied. Three batches of \ubbsalsiccia\uab were produced using different starter mixtures (Lactobacillus sakei G20 and Staphylococcus xylosus S81; L. sakei G20 and S. xylosus S142; L. sakei G20 and S. xylosus S206), while the control batch was produced without a starter. The amounts of free fatty acids present in the samples at the end of the ripening period were not significantly different, suggesting that the lipolytic enzymes naturally occurring in meat could play a predominant role in the free fatty acids release. Oleic and linoleic acids were present in the highest concentrations, while only small quantities of short chain fatty acids were detected, with acetic acid being the most representative one

Discrete Convex Functions on Graphs and Their Algorithmic Applications

The present article is an exposition of a theory of discrete convex functions on certain graph structures, developed by the author in recent years. This theory is a spin-off of discrete convex analysis by Murota, and is motivated by combinatorial dualities in multiflow problems and the complexity classification of facility location problems on graphs. We outline the theory and algorithmic applications in combinatorial optimization problems

Personality in the Cockroach (Diploptera punctate): Evidence for Stability Across Developmental Stages Despite Age Effects on Boldness

Despite a recent surge in the popularity of animal personality studies and their wide-ranging associations with various aspects of behavioural ecology, our understanding of the development of personality over ontogeny remains poorly understood. Stability over time is a central tenet of personality; ecological pressures experienced by an individual at different life stages may, however, vary considerably, which may have a significant effect on behavioural traits. Invertebrates often go through numerous discrete developmental stages and therefore provide a useful model for such research. Here we test for both differential consistency and age effects upon behavioural traits in the gregarious cockroach Diploptera punctata by testing the same behavioural traits in both juveniles and adults. In our sample, we find consistency in boldness, exploration and sociality within adults whilst only boldness was consistent in juveniles. Both boldness and exploration measures, representative of risk-taking behaviour, show significant consistency across discrete juvenile and adult stages. Age effects are, however, apparent in our data; juveniles are significantly bolder than adults, most likely due to differences in the ecological requirements of these life stages. Size also affects risk-taking behaviour since smaller adults are both bolder and more highly explorative. Whilst a behavioural syndrome linking boldness and exploration is evident in nymphs, this disappears by the adult stage, where links between other behavioural traits become apparent. Our results therefore indicate that differential consistency in personality can be maintained across life stages despite age effects on its magnitude, with links between some personality traits changing over ontogeny, demonstrating plasticity in behavioural syndromes