1,721,100 research outputs found
SHELF-LIFE INTERNATIONAL MEETING (SLIM 2006) / ITALIAN JOURNAL OF FOOD SCIENCE
No full textIntroduction to SLIM2006 Volume of Proceeding
The role of small-sized tomatoes in carotenoid uptake
No full textThe nutritional value of the tomato owes to the beneficial effects that some of its components have on human health, particularly the prevention of some types of cancer and cardiovascular disease and, in general, contributing to the inhibition of oxidative processes. Among these, beta-carotene and lycopene are the most important, the former represented at levels four to eight times lower than the latter. The tomato is an irreplaceable component of the Mediterranean diet, to which it contributes antioxidants, vitamins, minerals, fibre and carotenoids. The preference of consumers has recently increased towards small-sized tomato varieties, which nowadays represent an emergent product in Italy, where different cultivars are produced and delivered almost entirely for fresh consumption. Many authors have studied the nutritional characteristics of cherry tomatoes, but no study, other than the one presented in this chapter, deals with plum tomatoes, which turn out to be a tomato type even more valuable than the cherry tomato in terms of its carotenoid content. All of the studies, including the one presented hereafter, confirm that small-sized tomatoes, with differences among varieties, are richer in dry matter and in antioxidant compounds, which accumulate especially in the external parts of the fruits and are, therefore, more concentrated in small berries having a higher surface/volume ratio. A literature survey of the tomato's nutritional content points out that if, on one hand, it is difficult to correlate the lycopene content with the tomato size, as some large-sized varieties are rich in this carotenoid, it is more evident that small-sized varieties are characterized by higher beta-carotene levels.
Tomato antioxidanls are relatively stable in the presence of heat treatment. The partial drying of cherry tomatoes represents a novel preservation technology with the ability to increase the opportunity for consumption of tomatoes. Semi-dry cherry tomatoes obtained at higher temperatures with short drying times show a nutritional content, with special regard for beta-carotene, very close to the fresh product. The slight heat damage produced is easily counterbalanced by the concentration of dry matter which, in turn, allows increased consumption of the tomato's nutritive compounds
Susceptibility of plastic packages to insect pests attacks
No full textPackaging represents the ultimate defence of pasta producers against insect pests; even if the product comes out uncontaminated from the production line, this does not guarantee that it will reach the consumer in the same condition. The ability of some pests to pierce different plastic material is well known: insects are attracted by odors, therefore it is necessary to take in consideration the barrier properties to volatile compounds, Pasta packages are characterized by numerous pinholes which are mechanically produced to avoid having swollen bags after sealing: these pre-existing holes are often exploited by most pests as a preferential entrance to packages, and they are detected by insects by following the outflow of attractive odors. Packaging, therefore, represents a critical point in the quality preservation of packed pasta. Insect pests are commonly present in the production and storage environments, and their presence is favoured by unappropriate prevention measures. Common pests that affect pasta and starchy products usually belong to the genera: Tribolium, Sitophilus, Plodia and Rhyzopenha. The aim of the study was to evaluate the resistance to piercing of three plastic materials (polypropylene obtained with different processing techniques) by Tribolium spp>, Sitophilus spp, and Rhyzoperíha Dominica, and the relative ability of each pest to enter the packages. Two tests were carried out, the first one was aimed at evaluating the resistance of the plastic materials, the latter evaluated the ability of the species tested to enter pasta bags. Results confirmed the good resistance of PP to the penetration of insect pests, and highlighted the highest penetration ability of Sitophilus spp. The optimization and suitable design of the packaging system, which should consider the reduction of the hole diameter, would allow to reduce the risk of pests penetration
Electrical conductance of carbon nanotubes with misaligned ends
No full textWhen in a manufacturing processes a straight carbon nanotube is placed on a substrate, e.g. production of transistors, its two ends are often misaligned. Here we investigate the effects of MWCNTs’ outer diameter and chirality on the change in conductance due to misalignment of the two ends. The length of the studied MWCNTs was 120 nm while the diameters ranged between 4 and 7 nm. A mixed finite element-tight-binding approach was carefully designed to realize orders-of-magnitude reduction in computational time in calculating the deformation-induced changes in the electrical transport properties of the nanotubes. Numerical results suggest that armchair MWCNTs of small diameter should work better if used as conductors, while zig-zag MWCNTs of big diameter are more suitable for building sensors
Evaluation of the chemical quality of a new type of small-sized tomato cultivar, the plum tomato (Lycopersicon lycopersicum)
No full textSono stati valutati gli attributi chimici e nutrizionali di un nuovo tipo di pomodoro di piccola pezzatura, chiamato Datterino, recentemente introdotto nel mercato europeo. Sono state considerate sei differenti cultivar (Dasher, Iride, Navidad, Sabor, 292 e 738) e confrontate con una cultivar di pomodoro ciliegino (cv. Cherubino) coltivata nella stessa serra e nelle medesime condizioni. I risultati hanno mostrato alcune differenze significative rispetto alla tipologia ciliegino: un più intenso colore rosso, una minore quantità di acidi ed un maggiore contenuto di licopene. Gli attributi di qualità della cv. 738 sono stati superiori ai valori medi. Il ciliegino, invece, ha mostrato quantità leggermente più elevate di acido ascorbico e di b-carotene.The chemical-nutritional attributes were evaluated in plum tomato, a new type of oblong, small-sized tomato that was recently introduced in the European market. Six different cultivars, namely, Dasher, Iride, Navidad, Sabor, 292 and 738, were tested and compared with a cherry-type tomato (cv. Cherubino) which was grown in the same greenhouse under the same conditions. The plum tomato showed important marked differences with respect to the cherry type: more intense red colour, lower acid content and a higher lycopene content. The quality attribute values for cv. 738 were higher than the average values for the other cultivars. In contrast, the cherry-type variety had slightly higher levels of ascorbic acid and b-carotene than the plum tomatoes
Influence of packaging on the quality maintenance of industrial bread by comparative shelf life testing
No full textThe research focuses on the evaluation of the effects of films with different thickness on the quality of industrial durum wheat bread. A comparative shelf life test was performed taking into consideration textural parameters, instrumental crumb colour parameters, crumb moisture and alkaline water retention capacity, considered as indirect indicators of bread staling. Sliced, durum wheat bread was packed into a system made of a thermoformed bottom, with thickness ranging from 225 to 275. μm, and a lid (121-125. μm), with comparable barrier properties. Results demonstrated that it is possible to reduce packaging by about 20% without affecting shelf life standards. The packaging systems showed comparable barrier performances, maintaining the modified atmosphere during 103 days. Texture profile analysis gave comparable results for packages at reduced thickness compared with conventional ones. Also, colour, alkaline water retention capacity and crumb moisture correlated well with bread ageing and did not significantly vary among packaging types
The influence of lighting on shelf life of extra virgin olive oil packaged in coloured PET bottles
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