Foods that are commonly consumed in the diet are considered to provide more than 40 different carotenoids. However, the content in carotenoids varies considerably in both qualitative and quantitative ...terms as a consequence of different genotypes, climatic conditions of the production area, and agronomic factors, among others. In this paper, analytical data, obtained by HPLC or UHPLC, of carotenoids in fruits and vegetables produced in Ibero-America have been compiled from peer-reviewed journals, organized in food categories, and documented in relation to the sampling and analytical quality system used. In addition to common products of the diet of the Ibero-American countries, other wild or little used fruit and vegetables have been included with the aim of contributing to promote and to value species and local varieties. The importance of the commodities containing carotenoids in food, health, agriculture, and biodiversity, and the need of their preservation, was evidenced in this work namely by the large differences in carotenoid content related to the locals of production and varieties, and the high levels of carotenoids in native fruits and vegetables. The contribution of these compounds to meet the needs of vitamin A as well as the necessity of establishing recommendation for the daily intakes of theses bioactive compounds were also discussed.
A scalable, high yielding, rapid route to access an array of nitriles from aldehydes mediated by an oxoammonium salt (4‐acetylamino‐2,2,6,6‐tetramethylpiperidine‐1‐oxoammonium tetrafluoroborate) and ...hexamethyldisilazane (HMDS) as an ammonia surrogate has been developed. The reaction likely involves two distinct chemical transformations: reversible silyl‐imine formation between HMDS and an aldehyde, followed by oxidation mediated by the oxoammonium salt and desilylation to furnish a nitrile. The spent oxidant can be easily recovered and used to regenerate the oxoammonium salt oxidant.
A serendipitous find: The scalable and high yielding title reaction is mediated by 4‐acetylamino‐2,2,6,6‐tetramethylpiperidine‐1‐oxoammonium tetrafluoroborate and hexamethyldisilazane (HMDS). The reaction likely involves reversible silyl‐imine formation between HMDS and an aldehyde, and subsequent oxidation and desilylation. The spent oxidant can be easily recycled.
A simple, high yielding, rapid route for the oxidative esterification of a wide range aldehydes to hexafluoroisopropyl (HFIP) esters using the oxoammonium salt ...4-acetylamino-2,2,6,6-tetramethylpiperidine-1-oxoammonium tetrafluoroborate (1a) is reported. These esters can be readily transformed into a variety of other functional groups. The spent oxidant (1b) can be recovered and conveniently reoxidized to regenerate the oxoammonium salt, 1a.
Camu–camu (
Myrciaria dubia) is a small berry, native to the Amazon, known as a rich source of ascorbic acid. The carotenoid composition of this fruit was determined using high performance liquid ...chromatography-diode array detection on C
18 and C
30 columns. Fruits produced in two different regions of São Paulo State, Iguape and Mirandópolis, were analysed. All-
trans-lutein was the major carotenoid in camu–camu fruits from both regions, ranging from 45% to 55% of the total carotenoid content (160.5
±
93.1
μg/100
g for Iguape and 601.9
±
75.6
μg/100
g for Mirandópolis fruits), followed by β-carotene, violaxanthin and luteoxanthin. The levels of lutein, β-carotene, violaxanthin, luteoxanthin and other minor carotenoids were significantly higher in the camu–camu produced in Mirandópolis region, most probably due to the higher temperature and light exposure found in this region, in comparison to those from Iguape. Maturation was also an important feature affecting batches from the same region.
Bixin was encapsulated by spray-drying with gum arabic or maltodextrin, and the stability was evaluated in aqueous solution both under illumination or in the dark at 21 °C. The microcapsules ...containing emulsifier, such as gum arabic or maltodextrin
+
Tween 80, showed the highest encapsulation efficiency, respectively 86% and 75%, less superficial imperfections and higher stability than bixin encapsulated with maltodextrin alone or blended with sucrose. The kinetic behavior of bixin photodegradation in all encapsulated systems was composed by two first-order decays, due to the presence of bixin outside and inside the microcapsules. Bixin encapsulated with gum arabic was 3 to 4 times more stable than that encapsulated with maltodextrin. In all systems, greater bixin stability (<two orders of magnitude) was observed in the dark than under illuminated conditions. In addition, 10 times greater bixin stability was observed for encapsulated solutions as compared to the non-encapsulated systems in the absence of light.
The objective was to use natural pigments to replace sodium erythorbate (NaEry), a synthetic compound used as an antioxidant in sausage formulations, and to evaluate the oxidative stability of the ...samples. Six assays were prepared in which sodium erythorbate (ERY) at 0.05
g/100
g was substituted by norbixin (NOR), lycopene (LYC), zeaxanthin (ZEA), β-carotene (CAR) or dextrose (used as a control (CON)). Physical, chemical, color, texture and sensory parameters were measured on the first day and after 45
days of storage at 4
°C. All pigments used in the sausage formulations were able to maintain the oxidative stability of the sausages (MDA equivalents <0.38
mg/kg). Zeaxanthin and norbixin were the most efficient antioxidants of those tested. This antioxidant effect might be associated with the intermediate polarities of these two compounds, which would allow them to concentrate in the membrane lipids or emulsion interface, where lipid oxidation is most prevalent. Other volatile secondary products of oxidation besides MDA should be evaluated in further studies involving natural pigments and sensory oxidative stability.
The propensity of oxoammonium cations to facilitate the oxidative ring-opening of cyclic ethers to their corresponding distal hydroxy ketones is investigated. The reaction has been evaluated using ...experimental and computational methods to gain deeper insight into trends in reactivity.
Thermus filiformis
is an aerobic thermophilic bacterium isolated from a hot spring in New Zealand. The experimental study of the mechanisms of thermal adaptation is important to unveil response ...strategies of the microorganism to stress. In this study, the main pathways involved on
T. filiformis
thermoadaptation, as well as, thermozymes with potential biotechnological applications were revealed based on omics approaches. The strategy adopted in this study disclosed that pathways related to the carbohydrate metabolism were affected in response to thermoadaptation. High temperatures triggered oxidative stress, leading to repression of genes involved in glycolysis and the tricarboxylic acid cycle. During heat stress, the glucose metabolism occurred predominantly via the pentose phosphate pathway instead of the glycolysis pathway. Other processes, such as protein degradation, stringent response, and duplication of aminoacyl-tRNA synthetases, were also related to
T. filiformis
thermoadaptation. The heat-shock response influenced the carotenoid profile of
T. filiformis,
favoring the synthesis of thermozeaxanthins and thermobiszeaxanthins, which are related to membrane stabilization at high temperatures. Furthermore, antioxidant enzymes correlated with free radical scavenging, including superoxide dismutase, catalase and peroxidase, and metabolites, such as oxaloacetate and α-ketoglutarate, were accumulated at 77 °C.
Trifluoromethyl ketones (TFMKs) are exceedingly valuable synthetic targets in their own right and as synthons in the construction of fluorinated pharmacons. This Feature Article provides an overview ...of the properties of TFMKs, an in-depth discussion of the methods available for their synthesis, and two illustrative examples of their application as key intermediates in medicinal chemistry.
Trifluoromethyl ketones are valuable synthetic targets in their own right as well as reagents in the construction of other important fluorinated compounds.
Carotenoids are pigments responsible for the yellow-reddish color of many foods and are related to important functions and physiological actions, preventing several chronic-degenerative diseases. The ...objective of this study was to confirm the carotenoid composition of jackfruit by high-performance liquid chromatography connected to photodiode array and mass spectrometry detectors (HPLC-PDA-MS/MS). The main carotenoids were all-trans-lutein (24-44%), all-trans-β-carotene (24-30%), all-trans-neoxanthin (4-19%), 9-cis-neoxanthin (4-9%) and 9-cis-violaxanthin (4-10%). Either qualitative or quantitative differences, mainly related to the lutein proportion, were found among three batches of jackfruit. Since the fruits from batch A showed significantly lower contents for almost all carotenoids, it also had the lowest total carotenoid content (34.1 μg/100 g) and provitamin A value, whereas the total carotenoid ranged from 129.0 to 150.3 μg/100 g in the other batches. The provitamin A values from batches B and C were 3.3 and 4.3 μg RAE/100 g, respectively. The carotenoid composition of jackfruit was successfully determined, where 14 of the 18 identified carotenoids were reported for first time. Differences among batches may be due to genetic and/or agricultural factors.
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