Characterization and Quantification of the Major Bioactive Compounds in Mexican Purple Tomatoes

The present work carries out a quantitative analysis of the major bioactive compounds found in the native Mexican purple tomatoes. Total phenolic content ranged from 7.54 to 57.79 mg TPC/g DM, total flavonoid content ranged from 1.89 to 16.93 mg TFC/g DM, total anthocyanin content ranged from 0.29 to 2.56 mg TAC/g DM, and total carotenoid content ranged from 0.11 to 0.75 mg TCC/ g DM. In addition, 14 phenolic acids were identified, among which caffeoylquinic acid derivatives were the most abundant compounds with chlorogenic acid concentration up to 9.680 mg/g DM, together with flavonoids, such as rutin and quercetin-hexoxide. The qualitative analysis also showed the presence of 9 acylated anthocyanins and 2 carotenoids with significant functional features. As for anthocyanins, their chemical structures disclosed special structural features: glycosylated anthocyanins exhibited cis-trans hydroxycinnamic moieties and petunidin-3-(trans-p-coumaroyl)-rutinoside-5-glucoside was reported to be the main anthocyanin, whitin the range of concentrations between 0.160 and 1.143 mg/g DM.

Chemical characterization of yellow-orange and purple varieties of Opuntia ficus-indica fruits and thermal stability of their betalains

Betalains are plant pigments with biological properties and can be used instead of synthetic colorants to confer color and functional properties to foods. The objective of this work was to carry out the chemical characterization of two varieties of prickly pear of Opuntia ficus-indica, one of yellow-orange coloration (Mandarina) and the other of purple coloration (Vigor), through measurements of chemical parameters and color in pulp, antioxidant activity, total phenolic compounds, and betalain content. Considering the thermolability of betalains and their potential applications in food, the thermal stability and activation energy of betacyanins from Vigor variety and betaxanthins from the Mandarina variety were also evaluated and compared with those from beetroot, the main source of betalains. Results for chemical characterization agreed with previous prickly pear reports of other regions, while the thermal degradation kinetics of betalains showed a first-order degradation pattern with respect to time and temperature treatment. Betacyanins from Vigor prickly pear showed similar thermal stability to those from beetroot, which was reflected in similar values of activation energy, while betaxanthins from Mandarina prickly pear showed a higher stability, and therefore a higher activation energy, than those from beetroot. Based on the results, the prickly pear varieties used in this study can be considered as a good source of betalains with potential applications in food and, in addition, the methodology for the evaluation of thermostability can be used to compare the stability of betalains from different sources in a temperature range of 50-90°C. PRACTICAL APPLICATION: The varieties of prickly pear used in this study can be considered a good source of red-purple and yellow-orange easily extractable pigments. In addition, we report a methodology that can be used for the evaluation of the thermal stability of these pigments and to compare this stability between different plant sources. Gaining knowledge on betalain thermal stability will make it possible to propose specific applications, for example, in processed foods requiring different pigment stabilities.

Betalain plant sources, biosynthesis, extraction, stability enhancement methods, bioactivity, and applications

Betalains are plant pigments with functional properties used mainly as food dyes. However, they have been shown to be unstable to different environmental factors. This paper provides a review of (1) Betalain plant sources within several plant families such as Amaranthaceae, Basellaceae, Cactaceae, Portulacaceae, and Nyctaginaceae, (2) The biosynthesis pathway of betalains for both betacyanins and betaxanthins, (3) Betalain extraction process, including non-conventional technologies like microwave-assisted, ultrasound-assisted, and pulsed electrical field extraction, (4) Factors affecting their stability, mainly temperature, water activity, light incidence, as well as oxygen concentration, metals, and the presence of antioxidants, as well as activation energy as a mean to assess stability, and novel food-processing technologies able to prevent betalain degradation, (5) Methods to increase shelf life, mainly encapsulation by spray drying, freeze-drying, double emulsions, ionic gelation, nanoliposomes, hydrogels, co-crystallization, and unexplored methods such as complex coacervation and electrospraying, (6) Biological properties of betalains such as their antioxidant, hepatoprotective, antitumoral, and anti-inflammatory activities, among others, and (7) Applications in foods and other products such as cosmetics, textiles and solar cells, among others. Additionally, study perspectives for further research are provided for each section.

Environmentally friendly achiote seed extracts with higher δ-tocotrienol content have higher in vitro and in vivo antioxidant activity than the conventional extract

Achiote (Bixa orellana) is highly appreciated as a condiment and as the main source of bixin and tocotrienols, both having antioxidant properties. To explore the possibility of maximizing the antioxidant activity of achiote seed extracts using clean methodologies, the use of sonication and green solvents were tested. Ethyl lactate, isopropyl acetate, and ethanol combined with probe sonication produced the best results, obtaining similar bixin contents but higher δ-tocotrienol contents, as well as significantly higher in vitro and in vivo antioxidant activity compared with the maceration method extract, requiring low energy and saving time and solvents. The probe-sonicated achiote extract with the highest δ-tocotrienol content was better at increasing the Caenorhabditis elegans resistance to oxidative stress than the extract obtained through maceration. This is the first report about the effect of sonication combined with green solvents on the bixin and δ-tocotrienol content in achiote seed extracts and its relevance on the in vitro and in vivo antioxidant activity.

Achiote (Bixa orellana) Lipophilic Extract, Bixin, and δ-tocotrienol Effects on Lifespan and Stress Resistance in Caenorhabditis elegans

The onset of many degenerative diseases related to aging has been associated with a decrease in the activity of antistress systems, and pharmacological interventions increasing stress resistance could be effective to prevent the development of such diseases. Achiote is a valuable source of carotenoid and tocotrienols, which have antioxidant activity. In this work, we explore the capacity of an achiote seed extract and its main compounds to modulate the lifespan and antistress responses on Caenorhabditis elegans, as well as the mechanisms involved in these effects. Achiote lipophilic extract, bixin, and δ-tocotrienol were applied on nematodes to carry out lifespan, stress resistance, and fertility assays. The achiote seed extract increased the median and maximum lifespan up to 35% and 27% and increased resistance against oxidative and thermal stresses without adverse effects on fertility. The beneficial effects were mimicked by a bixin+δ-tocotrienol mixture. All the effects on lifespan and stress resistance were independent of caloric restriction but dependent on the insulin/insulin growth factor-1 pathway. This study could provide insights for further research on a new beneficial use of this important crop in health and nutraceutical applications beyond its use as a source of natural pigments.

Achiote (Bixa orellana L.): a natural source of pigment and vitamin E

Commercialization of agricultural products, including seeds and its derived products, represents an important economic source for developing countries. Natural colorants obtained from the seeds of achiote plant (annatto) have been used since pre-Hispanic times. Also, production of this crop has been important for Mayan cuisine. Annual world production of achiote seeds is approximately 14,500 tons (dry weight). Two thirds of the production is commercialized as dried seeds and the rest as colorant. Latin America produces 60% of the total world production, followed by Africa (27%) and Asia (12%). The main producers in Latin America are Peru, Brazil and Mexico. The purpose of the present paper is to review the most recent literature on Bixa orellana L. focusing on bixin, norbixin, tocotrienols and tocopherols biosynthesis, use and industrial applications of annatto extracts, as well as its nutraceutical potential and its benefits for human health.

Regulation of ribosome biogenesis in maize embryonic axes during germination

Ribosome biogenesis is a pre-requisite for cell growth and proliferation; it is however, a highly regulated process that consumes a great quantity of energy. It requires the coordinated production of rRNA, ribosomal proteins and non-ribosomal factors which participate in the processing and mobilization of the new ribosomes. Ribosome biogenesis has been studied in yeast and animals; however, there is little information about this process in plants. The objective of the present work was to study ribosome biogenesis in maize seeds during germination, a stage characterized for its fast growth, and the effect of insulin in this process. Insulin has been reported to accelerate germination and to induce seedling growth. It was observed that among the first events reactivated just after 3 h of imbibition are the rDNA transcription and the pre-rRNA processing and that insulin stimulates both of them (40-230%). The transcript of nucleolin, a protein which regulates rDNA transcription and pre-rRNA processing, is among the messages stored in quiescent dry seeds and it is mobilized into the polysomal fraction during the first hours of imbibition (6 h). In contrast, de novo ribosomal protein synthesis was low during the first hours of imbibition (3 and 6 h) increasing by 60 times in later stages (24 h). Insulin increased this synthesis (75%) at 24 h of imbibition; however, not all ribosomal proteins were similarly regulated. In this regard, an increase in RPS6 and RPL7 protein levels was observed, whereas RPL3 protein levels did not change even though its transcription was induced. Results show that ribosome biogenesis in the first stages of imbibition is carried out with newly synthesized rRNA and ribosomal proteins translated from stored mRNA.

Contaminated soil phytoremediation by Cyperus laxus Lam. cytochrome p450 EROD-activity induced by hydrocarbons in roots

Laboratory and greenhouse experiments with Cyperus laxus Lam were conducted to determine the rate and extent of phytoremediation and the effect of hydrocarbons on the cytochrome P450 EROD (7-ethoxyresorufin-O-deethylase) enzymatic activity in roots. Plants were cultivated on hydrocarbon-contaminated soil (HCS) and spiked perlite. Phytoremediation was evaluated using 6.5 kg HCS (173 +/- 15 mg total petroleum hydrocarbons [TPH] g(-1) of dry soil) pots at different moisture contents; the average removal rate was 3.46-0.25 mg TPH g(-1) dry soil month(-1) and 48% was removed when moisture was kept at 60%. The aromatic hydrocarbon fraction was the mostly removed, 60%; aliphatic, 51%; and polar 24% after 24-month experiments. In unplanted pots, TPH concentration did not exhibit significant differences with respect to the initial concentration. We confirmed that the presence of hydrocarbons induced ERODactivity up to 6.5-fold. Moreover, short-term experiments (up to 13 d) with spiked perlite demonstrated that two EROD activities in roots contributed to the total detected; 60% was found in the cytosolic and 40% in the microsomal fraction. To our knowledge, this is the first work that tries to build links between the hydrocarbon-inducible character of ERODactivity in roots and the phytoremediation ability of C. laxus in highly contaminated soils.