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Actual trends and improvements in olive oil extraction technology
No full textOlive oil is one of the most important oils for human consumption due to its peculiar sensorial characteristics and its beneficial effects on human health. Starting from the Olea europaea fruits, the technological aspects of the whole extraction process may affect both the overall yield and quality of the recovered oil. Over the years in order to produce high quality Extra Virgin Olive Oil (EVOO) there have been several innovation and changes in the various technical phases (milling, malaxation, extraction) involved in the olive oil recovery. However, while the EVOO quality should be of the utmost importance, producers have also to face other complementary issues, such as the need for increasing extraction yields, improving the level of automatization and reducing the overall extraction costs, including the disposal of the generated by-products. In this paper the technological evolution related to the EVOO production is reported, taking into account the actual trends and innovations involving the extraction process
Biogenic Amines in Wines: A Review.
No full textBiogenic amines are basic nitrogen compounds that can have toxicological effects on human health when present in foods and beverages at significant levels. These compounds in small amounts are produced in all living organisms and have an important role in cell growth and development and in protection of stressed cells, but their presence in foods at dangerous levels is principally attributed to microbial decarboxylation of the corresponding amino acids. Therefore, the occurrence of biogenic amines can be related to both food safety and food spoilage, becoming a useful index for the assessment of food quality and of the related manufacturing practices.
Nowadays an increasing attention is given to the presence in wine of biogenic amines, whose level and the possible synergic effect with ethanol may represent a significant risk for some consumers. The major toxicological implications are related to aromatic amines, such as histamine, tyramine, and 2-phenylethylamine; nevertheless, for these amines it is quite difficult to establish the exact threshold toxicity, which depends on the efficiency of the detoxification mechanisms of different individuals. However, some countries have set limits for histamine in wine ranging from 2 to 10 mg/L, while for tyramine levels exceeding 10 mg/L in beverages should be considered unsafe. Several other amines may be found in wine, among them polyamines which result able to enhance the adverse effect of aromatic amines or to cause negative consequences on wine aroma. Moreover, spermine and spermidine, that have secondary group, are involved in nitrosamine formation, compounds with a known cancerous action. Volatile amines, such as methylamine and ethylamine, come from amination of non-nitrogen compounds, such as aldehydes and ketones. They have not a toxic action, but can have a negative effect on wine aroma.
Biogenic amines usually found in wines are cadaverine, histamine, 2-phenylethylamine, putrescine and tyramine; agmatine and ethanolamine can be abundant in wines, but they are generally little investigated. Low biogenic amine amounts, as normal constituents of the raw materials, can be released in must from grape and pulp during the winemaking process, and the biogenic amine concentration may increase as consequence of alcoholic fermentation, yeast autolysis, MLF and wine aging, usually being red wines richer in amines than white wines.
In this work an overview of the presence of biogenic amines in wines is given, with a focus on the factors (i.e. microorganisms, raw materials, and processing techniques) affecting their presence and concentration in this alcoholic beverage
Extra virgin olive oil bitterness evaluation by sensory and chemical analysis
Full text linkAn 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
Nutritional quality of vegetables: effect of chilling on the ascorbic acid content of fennel
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Nutritional quality of vegetables: effects of chilling on the ascorbic acid content of fennel.
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