1,721,037 research outputs found
Application of different thermal analysis techniques to characterize oxidized olive oils
No full textThe deep changes caused by oxidation on virgin olive oil (VOO), which is a high-quality product, not
subjected to ameliorative refining, make this phenomenon one of the most studied. Among the
techniques used to study oxidation in olive oil, thermal analysis (TA) provides useful information about
the thermal behavior of the samples as affected by oxidation. Thermogravimetry (TG), measuring the
changes in the sample mass, can monitor the kinetics of oil mass loss in decomposition processes or
oxidation and has been found particularly useful, especially when operating simultaneously with
Differential Thermal Analysis (DTA) or Differential Scanning Calorimetry (DSC). The DSC thermal
curves of olive oil, both on cooling and heating, has been found to be largely influenced by the oxidative
status of the samples and different statistical approaches have been successfully proposed to correlate the
thermal parameters with the conventional chemical indicators of oxidation. DSC can be also used to
study the kinetics of phase transition phenomena as affected by oxidation. This review provides an
exhaustive survey about the application of the thermoanalytical techniques on this topic proposing them
as as a fast and green alternative to conventional chemical methods
Chestnut flour addition in commercial gluten-free bread: A shelf-life study
No full textTwo commercial gluten-free mixtures (F1gf, and F2gf) were enriched with 20 g/100 g and 10 g/100 g of chestnut flour, respectively, to produce technologically and nutritionally improved breads (M1C, M2C) to be compared to gluten-free breads (M1 and M2). Physicochemical (proximate composition, colour, texture, crumb grain characteristics) and nutritional (antioxidant capacity, in vitro digestion) indices were monitored during three days storage. The addition of chestnut flour led to colour browning, lower bulk volume with larger crumb holes and faster staling resulting from crumb cohesiveness and resilience decrease. M2C presented harder crumb and smaller holes compared to M1C, probably due to the lupine proteins in M2C. During storage, the crust hardness decreased (M1C) or increased (M2C) depending on mixture components, as consequence of different water migration. Higher antioxidant activity was observed for both the enriched breads while no variations resulted in starch digestibility. Finally, only breads with 20 g/100 g of enrichment showed a significant increase in total as well as soluble and insoluble fibres
Chestnut peels and wheat bran at different water level influence the physical properties of pan bread.
Full text linkSourdough Fermentation and Chestnut Flour in Gluten-free Bread: a shelf-life evaluation
Full text linkThe effect of sourdough fermentation combined with chestnut flour was investigated for improving technological
and nutritional quality of gluten-free bread during 5 day shelf life by means of chemicophysical
and nutritional properties.
Sourdough fermentation by itself and with chestnut flour reduced volume of loaves and heterogeneity
in crumb grain. Sourdough technology allowed increasing crumb moisture content with no significant
variations during shelf-life. Chestnut flour darkened crumb and crust while no effects on colour were
observed for sourdough.
Sourdough and/or chestnut flour addition caused a significant increase in crumb hardness at time 0
while a significant reduction of staling was observed only at 5 days, even if a decrease in amylopectin
fusion enthalpy was observed. The percentage of hydrolysed starch during in vitro digestion was significantly
reduced by sourdough fermentation with a presumable lower glycaemic index
- …
