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1.
Juan Chirinos Jose Arévalo Tamara Rajmankina Angel Morillo Darmenia Ibarra Ali Bahsas Alvaro Parada 《Polymer Bulletin》2004,51(5-6):381-387
Summary The complex
5-(C5H5)2Ti
(1-OC(O)C6H5)2
was synthesized and activated with MA0 for ethylene
polymerization. The resultant polymer is UHMW-PE with a
viscosimetric molecular weight of Mv = 6.8 x
106 to 0.7 x
106 g/mol dependent on the
temperature of the reaction. The effects of the Al/Ti molar
ratio and temperature of the reaction on the catalytic activity
and polymer properties were studied. 相似文献
2.
Sacha inchi (Plukenetia volubilis L.) shell: an alternative source of phenolic compounds and antioxidants 下载免费PDF全文
Rosana Chirinos Ornella Necochea Romina Pedreschi David Campos 《International Journal of Food Science & Technology》2016,51(4):986-993
Sacha inchi seed (SI) is known as a rich source of oil with high content of polyunsaturared fatty acids of the ω‐3 and ω‐6 type (~85% of total fatty acids). However, few studies have focused on the use of by‐products from the seed. The aim of this study was to characterise the main phenolic families present in SI shell and to evaluate the best extraction solvent for the extraction of phenolic compounds (PC) and antioxidant capacity (AOXC). The PC content corresponded to 74.5 ± 5.1 mg g?1 of which 93.1% were condensed tannins and the remaining compounds corresponded to free and bound phenolic acids, hydrolyzable tannins, flavonoids and flavanoids. Protocatechic and p‐coumaric acids but also hydroxycinammic acid derivatives of ferulic and o‐coumaric type and lignan derivatives were identified. Acetone containing solvents favoured the extraction of higher amounts of total PC and AOXC. This study highlights the potential use of SI shell as a novel and alternative source of PC antioxidants for the nutraceutical and/or functional food industries. 相似文献
3.
María?D.?GuillénEmail author Ainhoa?Ruiz Nerea?Cabo Rosana?Chirinos Gloria?Pascual 《Journal of the American Oil Chemists' Society》2003,80(8):755-762
Three oil samples obtained from sacha inchi (Plukenetia volubilis L.) seeds were studied by means of FTIR and 1H NMR. Frequency data of the most significant bands of the IR spectrum of this oil are given. These data show that sacha inchi
oil has a high degree of unsaturation. The same fact is deduced from the ratio between the absorbance of the bands due to
the stretching vibrations of the cis olefinic CH double bonds at 3010.5 cm−1 and to the methylene symmetrical stretching vibrations at 2855.1 cm−1. The proportions of monounsaturated, polyunsaturated, and saturated acyl groups were predicted from the frequency of some
IR bands, and these were in satisfactory agreement with the values obtained through FAME generation and their quantification
by GC. Likewise, simple observation of the 1H NMR spectra provided a great deal of information about sacha inchi oil, with regard not only to the relative proportions
of the different acyl groups but also to their nature. Thus, the presence of γ-linolenic acyl groups was discounted. Furthermore,
the area of some 1H NMR signals was used to determine the proportion of saturated and mono-, di-, and triunsaturated acyl groups, which also
were in satisfactory agreement with the values obtained by classical methods. IR and 1H NMR determinations take very little time in comparison with classical methods and do not require chemical manipulation or
transformation of the sample. A comparison was also made between the compositions of sacha inchi and linseed oil. Both oils
are important sources of the healthful n−3 linolenic acyl groups, and sacha inchi also contains high proportions of the n−6
linoleic acyl groups. 相似文献
4.
Reina A. Mejía-Águila Ana Aguilar-Galvez Rosana Chirinos Romina Pedreschi David Campos 《International Journal of Food Science & Technology》2021,56(1):392-401
This work aimed to incorporate prebiotic FOS from yacon in apple slices using vacuum impregnation (VI). Three FOS concentrations (10.3, 14.1 and 18.9 g per 100 g of dry matter (DM)), two temperatures (25 and 35 °C), reuse of extracts and stability of the impregnated slices were evaluated. The highest impregnation level (30.5 g per 100 g DM) was obtained at 35 °C with 14.1% FOS extract while levels of common sugars were reduced. Total phenolics and ABTS antioxidant capacity (AC) slightly decreased while ORAC AC was reduced by 55%. Reuse of the impregnation solution in successive cycles after restoring the FOS level maintained the FOS concentration and profile (GF2–GF7), sugars and phenolic antioxidants. FOS in apple slices remained stable during 4 week storage, while aw, colour and fracture point changed during storage. This work demonstrated the feasibility of yacon FOS to improve the functional properties of dehydrated apple slices. 相似文献
5.
Cinthya Huaman-Alvino Rosana Chirinos Fernando Gonzales-Pariona Romina Pedreschi David Campos 《International Journal of Food Science & Technology》2021,56(10):5040-5049
This work aimed evaluating some physicochemical compounds, hydrophilic (H-AC) and lipophilic (L-AC) antioxidant capacity of eleven avocado genotypes grown in the Andes. The results show great variability in physical and chemical properties, dry matter (DM) and lipid contents with ranges of 18.4–39.3% and 10.1–23.2%, respectively. All genotypes had high oleic acid content (50.4–69.9%) and a high unsaturated fatty acid/saturated fatty acid ratio (UFA/SFA, from 3.05 to 6.05), while the unsaponifiable fraction contained mainly β-sitosterol (140.83–235.51 mg/100 g DM) and α-tocopherol (17.44–71.29 µg/g DM). Total phenolic compounds (TPC), H-AC and L-AC ranged from 0.48 to 0.88 mg EAG/g DM, 5.37 to 14.00 and 1.87 to 6.71 μmol ET/g DM, respectively. Although the genotype influences avocado characteristics, climatic conditions in the Andean region seem to be important for the biosynthesis of metabolites of interest and should be considered in future studies. 相似文献
6.
Enhanced antioxidant properties of tara (Caesalpinia spinosa) gallotannins by thermal hydrolysis and its synergistic effects with α‐tocopherol,ascorbyl palmitate,and citric acid on sacha inchi (Plukenetia volubilis) oil 下载免费PDF全文
7.
Stability of Betacyanin Pigments and Antioxidants in Ayrampo (Opuntia soehrensii Britton and Rose) Seed Extracts and as a Yogurt Natural Colorant 下载免费PDF全文
8.
Rosana Chirinos David Campos Carlos Arbizu Hervé Rogez Jean‐François Rees Yvan Larondelle Giuliana Noratto Luis Cisneros‐Zevallos 《Journal of the science of food and agriculture》2007,87(3):437-446
The total phenolics, anthocyanins, flavan 3‐ols, carotenoids and antioxidant capacity of mashua (Tropaeolum tuberosum Ruiz & Pavón) tubers from 10 yellow and purple cultivars were determined at different maturity stages (5–7.5 months after planting) and sunning post‐harvest storage periods (7–35 days). Both the antioxidant capacity (ORAC and ABTS assays) and the content of the bioactive compounds tested varied markedly between cultivars. Purple varieties reached the highest antioxidant capacity during tuber development (271–446 µmol Trolox equiv g?1 DM, ORAC assay). The kinetics of accumulation or disappearance of the bioactive compounds tested during maturation was dependent both on the cultivar and on the compound considered. For anthocyanins, there was a marked increase during maturation in all the purple cultivars. During the sunning post‐harvest storage, the changes in antioxidant capacity (ABTS assay) and content of the bioactive compounds tested also varied between cultivars. A marked decrease in anthocyanins was observed for the anthocyanin‐containing cultivars. In general, the correlation between antioxidant capacity and the content of bioactive compounds varied markedly between cultivars. Antioxidant capacity in purple varieties correlated with total phenolics or flavan 3‐ols while only in some yellow varieties antioxidant capacity correlated with total phenolics. Copyright © 2007 Society of Chemical Industry 相似文献
9.
Summary Magnesium dichloride supported titanium catalysts were prepared by dissolving anhydrous MgCl2 in 1-hexanol/isooctane. Then recrystallization took place through different techniques such as evaporation of the solvent, quick cooling, precipitation with silicon tetrachloride and precipitation with titanium tetrachloride. The FT-IR analysis showed that several degrees of dealcoholation took place as a result of the adducts of MgCl2· XROH. Moreover, it was found that the most active catalysts in the polymerization of ethylene were those obtained recrystallizing MgCl2 by precipitation with SiCl4. On the other hand, those directly recrystallized with TiCl4 were the least reactive and the ones that produced polyethylenes with the highest molecular weights and the lowest degrees of crystallinity. Received: 14 December 1998/Revised version: 17 August 1999/Accepted: 17 August 1999 相似文献
10.
David Campos Felix Teran-Hilares Rosana Chirinos Ana Aguilar-Galvez Diego García-Ríos Alejandro Pacheco-Avalos Romina Pedreschi 《International Journal of Food Science & Technology》2020,55(5):2208-2218
The influence of regular air cold storage (7 °C and 85 ± 5% RH) followed by ripening at shelf-life conditions (19–21 °C and 65 ± 5% RH), on bioactive compounds of Hass avocados was investigated. Results showed that the content of mannoheptulose and perseitol decreased significantly already during cold storage and ripening period. The fatty acid profile and contents of tocopherols (α- and β-tocopherol) and phytosterols (β-sitosterol, stigmasterol, campesterol) remained unchanged from day 0 to edible ripeness. Total phenolics, hydrophilic and lipophilic antioxidant capacity remained unchanged during cold storage and increased during the ripening period. At edible ripeness, significant amounts of phenolic acids, p-coumaric and caffeic and their derivatives were synthesised. Our results demonstrated that regular air cold storage for up to 37 days followed by ripening at shelf-life conditions enhances the phenolic compounds and mainly the hydrophilic antioxidant capacity without affecting the remaining bioactive compounds in Hass avocado. 相似文献