1,721,049 research outputs found
Antioxidants, reactive oxygen species and nutrition
No full textFree radicals and other oxygen-derived species (ROS) are constantly generated in vivo, both by "accidents of chemistry" and for specific metabolic purpose. The reactivity of different free radicals varies, but some can cause severe damage to biological molecules, especially to DNA, lipids and proteins. Oxidative damage to these molecules has been implicated in a wide variety of degenerative diseases such as atherosclerosis and cancer. The human body has powerful mechanisms for defence against free radicals and other reactive oxygen species. Components of both endogenous and exogenous origins contribute to protection, and new data suggests that the various defences are complementary to one another, so, they interact to spare or replace each other. Nevertheless the antioxidant defence systems are not 100% effective, the result is a condition called oxidative stress, that is an imbalance between pro-oxidant factors and antioxidants. Hence, diet-derived antioxidants may be particularly important in slackening cumulative oxidative damage and helping the human body to stay healthier for longer. Vitamin C is an effective scavenger of many oxyradicals in body's aqueous compartments such as blood plasma end cell cytosol. Vitamin E provides antioxidant protection in body's lipid phases, especially by protecting the unsaturated fatty acids of cell membranes and plasma lipoproteins. Carotenoids are also believed to provide antioxidant protection to lipid rich tissues. A variety of minor plant constituents (phytochemicals), such as flavonoids, exhibit antioxidant and free radical scavenging properties in vitro, suggesting a possible protective role in the human body. However, the mechanisms through which these compounds act in vivo are still incompletely understood and many uncertainties persist relative to their bioavailability and metabolic fate in human body. The progress of the studies in this particularly topic will have important repercussions both in the preventive medicine and in clear pathology. The possibility to taking protective components with foods is very important for health human body and even more for ill person. With respect to this, the enteral and parenteral nutrition, as specialized nutrition support during critical illness, will evolve in response to the results of studies regarding to the different antioxidants (exogenous and endogenous) interactions and synergisms. Moreover, will be investigated possible sinergisms and antagonisms between natural antioxidants and dietary components, as well as, other substances such as drugs or farmacological active molecules
CONJUGATED LINOLEIC ACID. A natural anticarcinogenic substance from animal food
No full textConjugated linoleic acid (CLA) is a natural component of animal food derived from linoleic acid. It is present mainly in dairy products and bovine meat and the amount of these unusual essential fatty acids in animal food depends on seasonal conditions, feeding conditions and rumen microflora. This short review provides an update on in vivo and in vitro studies which demonstrate anticarcinogenic activity of CLA in various animal organs and in different stages of carcinogenesis. These compounds exhibit a protective effect also in atherosclerotic disease at a concentration similar to that found in food. Studies are being carried out to assess the health protecting effect of CLA in humans
Nuove frontiere nella valutazione della qualità degli alimenti
No full textLa globalizzazione del mercato che introduce nuovi prodotti e nuove preparazione gastronomiche provenienti da Paesi quali India, Cina, Sud America, insieme allo sviluppo di avanzate tecniche agronomiche, di allevamento e di conservazione hanno contribuito in maniera determinante all'e¬norme disponibilità e diffusione dei prodotti alimentari sulle nostre tavole, tanto che sono ormai eliminati i vincoli della stagionalità per molti prodot¬ti, specie per gli ortofrutticoli. Nello scenario attuale definire il concetto di qualità degli alimenti (Food Quality, FQ) solo in termini di salubrità e sicurezza igienica non e più suffi¬ciente. La norma UNI EN ISO 8402 definisce la qualità come « l'insieme delle proprietà e caratteristiche di un prodotto o servizio che gli conferiscono l'attitudine a soddisfare bisogni espressi o impliciti». ». La qualità di un prodot¬to alimentare diviene un concetto complesso da definire: si tratta di una no¬zione in parte soggettiva (caratteristiche organolettiche del prodotto), in parte oggettiva (qualità nutrizionali, sicurezza d’uso, proprietà salutistiche fattori psicologici ecc). Sulla base di tutti questi fattori la tendenza attuale e quella di riferirsi alla qualita con un nuovo concetto, ovvero quello della Total Food Quality (TFQ)
Photoacustic techniques applied to non-destructive analysis of phytochemicals in typical foods of the Mediterranean diet
No full textFruits and vegetable have long been regarded as having considerable beneficial effects on health due in part, to the presence of bioactive compounds or phytochemicals. Some of these molecules, such as chlorophylls, carotenoids and anthocyanins are responsible for the organoleptic qualities of fruit and vegetables. In addition, they are implicated in numerous physiological processes of the plants, being produced in response to different types of abiotic and biotic stress. In particular, chlorophylls and carotenoids, widely found in the skins of fruits like apples, are involved in the photosynthesis process, while anthocyanins together with carotenoids, play an important role in protecting the fruits from photo-damage induced by UV irradiation. Thanks to these properties, the mentioned pigments play an important role as biomarkers of nutritional, healthy and commercial quality, so in this respect they receive great interest not only from nutritionists, but also from the agro-food industry.
In apples, chlorophylls, carotenoids and anthocyanins undergo to the changes during ripening and storage of fruits and their direct determination by a non-destructive analytical approach make it possible to correlate the content of these pigments with the degree of ripeness, freshness and shelf life of fruits. Eventually, non-destructive analysis could allow to standardize the quality parameters to meet the needs of both consumers and market.
In recent years, the photoacustic non-destructive technique (PA) have had a great acceleration in food analysis, since is not affected by scattering of light in turbid media, as occur for traditional spectroscopic techniques. Moreover, PA require little or no manipulation of the sample, nor require extraction procedures, so it can be employed for the direct optotermic characterization of the molecules contained in complex matrices such foods.
PA measurement were carried out on the apple peels of two cultivars: Golden Delicious and Royal Gala. The results revealed that PA signals were in agreement with the presence of chlorophylls (a and b), carotenoids and anthocyanins in different side of apple according to the different colour of the portion of apple peel analysed.
The quantitative standardization of the system will allow to correlate the concentration and the proportion of chlorophylls, carotenoids and anthocyanins with ripening state of the fruits in order to provide indication on optimum harvest date of apple fruits
Exploring new frontiers in total food quality definition and assessment: from chemical to neurochemical properties
No full textAbstract In order to understand the concept of “Total Food Quality” (TFQ) and how it has evolved, we give a brief historic outline from Pasteur to the recent rise of the globalized market. Nowadays, “total food quality” is clearly a partially objective concept, in the sense that it can be defined according to scientific and technological criteria, and partly subjective since consumers’ judgments, mainly based on their appraisal, may equally concur in its definition. Food properties contributing to “total food quality” definition and assessment, include: 1) organoleptic and sensory attributes, 2) food safety, 3) nutritional value, 4) functionality, 5) service and stability, 6) wholesomeness and 7) psychological factors. Many technological and gastronomic treatments may alter food components, e.g. fats, proteins and vitamins (the most sensitive to physico-chemical changes in the environment), thus negatively affecting any one of the aspects of quality in the above list. Specific analytical strategies and sensitive appliances can be utilized both to assess and protect food quality and to correctly conduct and monitor food production. Among the so-called “psychological factors”, however, there are some molecular aspects that are still elusive, although of enormously great interest. In fact, food can have some psycho-active effects on the consumer, thus influencing his or her behaviour during either pre-ingestive or post-ingestive phases. As studies of psycho-active substances in food seem to be opening up a new scenario in "Total Food Quality" research, the gathering together in a single chart, of all the information on the effects of food on its journey, from sight to ingestion, would seem like a good basis for a more rational and thorough discussion of the topic
Stili di vita e prevenzione della malattie cronico-degenerative
No full textAlla base della maggior parte delle patologie croniche, quali le malattie cardiovascolari, i tumori ed il diabete, ci sono fattori di rischio intermedi ormai ben noti rappresentati da obesità, dislipidemia, iperglicemia e ipertensione, responsabili della maggior parte dei decessi soprattutto nei paesi industrializzati. La presenza di questi fattori di rischio intermedi si può spesso ricondurre a quattro stili di vita non corretti in termini di salute, quali l’abitudine al fumo di tabacco, un’alimentazione non sana, la sedentarietà e l’abuso di alcolici. Per questo agire in modo coordinato e integrato sui principali fattori di rischio modificabili diventa una priorità non solo dei programmi sanitari, ma anche di ogni medico, per migliorare la salute, la qualità della vita e il benessere del singolo e della società in generale
Alimentazione all'inizio del terzo millennio
No full textLa sicurezza alimentare (food safety) garantisce la salubrità o meglio la non tossicità degli alimenti. La contaminazione degli alimenti è di diversa origine: biologica, chimica e fisica; sono necessari controlli lungo tutta la “catena alimentare” per contenere il rischio entro livelli accettabili. La food security, cioè la garanzia di accesso fisico ed economico al cibo per tutti, in ogni momento, è un obiettivo da perseguire per sconfiggere la fame nel mondo che l’umanità, all’inizio del III millennio non può più trascurare. La food security, cioè la garanzia di accesso fisico ed economico al cibo per tutti, in ogni momento, è un obiettivo da perseguire per sconfiggere la fame nel mondo che l’umanità, all’inizio del III millennio non può più trascurare. La sicurezza nutrizionale si raggiunge se vengono utilizzati in modo corretto gli alimenti (porzioni) per fornire a ciascun organismo le quantità di nutrienti necessari per la realizzazione del patrimonio genetico. Per il raggi..
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