1,721,044 research outputs found
Prevention of enzymatic browning during freezing, storage and thawing of cherimoya (Annona Cherimola, Mill.) derivatives
No full textStrong Solvent and pH Dependence in the Photolysis of Diphenylmethaneimine
No full textBenzophenone imine photolysis shows a strong product solvent pH dependence: diphenylmethane is by far the dominating outcome in methanol
Prevention of enzymatic browning during freezing, storage and thawing of cherimola (Cherimoya cherimola, mill) derivatives
No full textThe objective of this research was to obtain frozen derivatives (puree and slices) from Cherimoya fruit and verify the effectiveness of some substances, individually or combined, on the prevention of enzymatic browning (EB) during freezing, storage and thawing of these products. Results showed that the addition of 0.2% ascorbic acid plus 0.2% citric acid with or without 0.1% sodium chloride to Cherimoya puree and, in the case of slices, dipping for 15 min in solutions containing the same substances, allowed complete control of browning to be obtained during freezing, storage and thawing
Revisitation of Formaldehyde Aniline Condensation. VIII - Monomeric N-Methylene Anilines
No full textA convenient, high yield "dry" method pf the synthesis of monomeric N-methyleneanilines and the characterization of the products by MS, 1H and 13C-NMR and IR are reported, improving previous procedures and describing new compounds. It appeared that the existence of monomeric N-methyleneanilines is strictly related to the presence of enough steric hindrance to oligomerization by substituents in ortho positions
Control of browning in frozen puree of cherimoya (Annona cherimola, mill.) fruit
No full textThe extensive polymorphism and the small size of the fruits of Cherimoya (Annona cherimola, Mill.), known in Italy under the name of "annona", influence the marketability of this product. Further more annona derivatives are very sensitive to enzymatic browning even during storage in the frozen state. The objective of this research was to verify the effectiveness of combined pretreatments on the prevention of enzymatic browning during freezing and thawing of annona puree. In particular the combination of two or more "mild pretreatments", which separately are incapable of obtaining complete control of browning in vegetal tissue, was studied. Results showed that the addition of 2 g . kg(-1) ascorbic acid plus 2 g . kg(-1) citric acid with or without 1 g . kg(-1) sodium chloride to annona puree allowed complete browning control during freezing, storage and thawing
Espresso Coffee (EC) by POD: study of thermal profile during extraction process and influence of water temperature on chemical-physical and sensorial properties
No full textIn this work the thermal profiles of five coffee pods (pure Arabica, pure Robusta, and Arabica Robusta
blends: A20R80, A80R20, and A40R60) at 90, 100 and 110°C are reported. Moreover the chemical–physical
and sensorial properties of espresso coffee (EC) obtained from five different coffee pods were investigated.
The analysis of the thermal profiles highlighted that the extraction process can be considered as
an isothermal process because, after a starting phase, the recorded temperatures stayed around a mean
temperature (Tm). In addition the Tm recorded for each extraction temperature was significantly lower
than those set up by the controller. The chemical–physical parameters of EC samples increased proportionally with extraction temperature highlighting that the effectiveness of extraction process scales up
with percolation temperature. The solid and caffeine contents of the EC samples extracted at 110°C
are related to an over extraction process. Principal Component Analysis (PCA) was applied to identify
relationships and differences among EC samples. Pure Arabica and A80R20 EC samples at 100 and
110°C have shown sensorial attributes typical for a fine espresso coffee
Alcoholic extracts composition from lemon fruits of the Amalfi-Sorrento peninsula
Full text linkThe composition of alcoholic extracts of lemons coming from the Amalfi and Sorrento areas were studied, namely samplings of the cultivars “Sfusato di Amalfi” and “Limone di Sorrento.” Lemons were taken monthly from six orchards in the Amalfi area and eight orchards in the Sorrento area. Lemon peels were submitted to alcoholic infusion similar to that used for the production of the “limoncello” drink. The extracts were analyzed by GC/MS and the volatile fractions were characterized. The compositions observed were similar to those reported for cold-pressed
lemon essential oils, hydroalcoholic extracts and commercial “limoncello” drinks. The evolution during the season has underlined defined courses for some classes of components. The carbonyl-to oxygenated compound ratio, alcohols-to-oxygenated compounds ratio and esters-to-oxygenated compounds ratio are indices of flavoring quality. These showed a similar trend for both lemon types. In comparison to other lemon productions a higher amount of minor classes of components were exhibited
Cyclic gamma-Iminolactone Intermediates in the Photolysis of 2,4,5,6-Tetrachloro-1,3-dicyanobenzene
No full textCyclic gamma-iminolactones can be identified among the more abundant products of the fast photolysis of 2,4,5,6-tetrachloro-1,3-dicyanobenzene (1) in absolute ethanol with an unfiltered UV high pressure lamp. A number of other photolytes accounted for the material balance of the experiment. The preliminary identification of the products was secured by mass spectrometry after separation by capillary gaschromatography and also on a comparative basis with the mass spectra of their oxo-analogs. A rationale is offered for some discrepances of comparison of individual photolites and in some departures from a close correlation with end products of previous findings from the present experiments
Valorizzazione delle risorse frutticole locali mediante tecniche di essiccazione delicate
No full textKetimines from Ketones and Ammonia
No full textThe direct synthesis of ketimines from ammonia and ketones catalyzed by ammonium chloride is described
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