No abstract

Betalains are vacuolar pigments present in tubers, flowers or fruits. Their use in the food industry is significant because they are considered bioactive completely safe to consume. However, betalains are susceptible to temperature which affects their stability. The most of the available methods that determine stability involve high costs, are destructive and generate waste. In this work was evaluated the thermal degradation of betalain at 75 °C for several intervals of time, by using different techniques. Colorimetry showed a change in the tone angle (h°) from 359.76°to 20.54°after the heat-treatment, suggesting thermal degradation by changing the color from violet to red-orange. High-pressure liquid chromatography, shows the decrease of the concentration of betanin in addition to the formation of neobetanin, the main degradation product in betalains. UV-visible spectrophotometry suggest also thermal degradation of betanin, by the decrease of the absorption at 538 nm caused by the heat treatment. Finally, Fourier transform infrared spectroscopy (FTIR) showed a decrease in the intensity of two absorption bands at 1243 and 879 cm -1 , corresponding to the C-O and C-C vibrations of the carboxylic acid respectively after heat treatment. These results suggest that the main route of degradation corresponds to decarboxylation. We propose the use of FTIR spectroscopy as a practical alternative for the analysis of the degradation of natural dyes during storage, making evident the possible use of this methodology for industrial applications.

In recent decades, the food industry has focused on the search for potential sources of anthocyanins that are able to provide color to replace synthetic dyes and at the same time provide health benefits through food products. Thus, in the present work, we propose the Dahlia pinnata flower as a potential source of anthocyanins. The dahlia is a native, annual flower from Mexico with a wide diversity of shapes and colors. The ancestral use of the flower in several dishes, its abundance, and the intense color of the flowers known as black make the D. pinnata flower a suitable candidate to be considered as a potential source of anthocyanins. Thus, the aim of this research is the determination of its nutritional composition, anthocyanin profile, and antioxidant activity. For this purpose, proximate composition of petals was determined by the AOAC standard methods. Anthocyanins were extracted from the dried petals of the flower with 0.1% HCl in methanol and 70% aqueous acetone solution and purified through Amberlite-XAD7-HP resin. Then, the purified extracts were analyzed for antioxidant activity by the DPPH method and the anthocyanin profile was characterized by HPLC and UPLC-MS/MS. Results showed that D. pinnata flowers have a proximate composition similar to other important edible flowers with a high level of moisture (87%-92%) and fiber (6%-7%). The antioxidant activity of both purified extracts was considerable (2.6-12 g/ml) compared to other sources of anthocyanins. The anthocyanin profile of the purified extracts contains four main anthocyanins: delphinidin-3-glucoside, delphinidin-3-rutinoside, pelargonidin-3-sambubioside-5-glucoside, and peonidin-3-sambubioside-5-glucoside, the last two being uncommon as major anthocyanin components in other plant sources. K E Y W O R D Santhocyanin, anthocyanin profile, antioxidant activity, dahlia flower, UPLC-MS/MS Practical Application: We present a potential and novel source of anthocyanins based on anthocyanin content and antioxidant activity of Dahlia pinnata petals.

Encapsulation of biostimulant metabolites has gained popularity as it increases their shelf life and improves their absorption, being considered a good alternative for the manufacture of products that stimulate plant growth and fruit production. Cell-free supernatants (CFS) were obtained from nine indole-3-acetic acid (IAA) producing bacterial strains. Stenotrophomonas maltophilia (PT53T) produced the highest concentration of IAA (15.88 μg/mL) after 48 h of incubation. CFS from this strain, as well as an IAA standard were separately encapsulated in chitosan microparticles (CS-MP) using the ionic gelation method. The CS-MP were analyzed by Fourier transform infrared spectroscopy (FTIR), showing absorption bands at 1641, 1547, and 1218 cm−1, associated with the vibrations of the carbonyl C=O, the N-H amine, and the bond between chitosan (CHI) and sodium tripolyphosphate (TPP). The effects of unencapsulated CFS, encapsulated CFS (EN-CFS), and encapsulated IAA standard (EN-IAA) on germination and growth of seven-day-old tomato (Solanum lycopersicum) seedlings were studied. Results showed that both EN-CFS and EN-IAA significantly ( p < 0.05 ) increased seed germination rates by 77.5 and 80.8%, respectively. Both CFS and EN-IAA produced the greatest increase in aerial part length and fresh weight with respect to the treatment-free test. Therefore, it was concluded that the application of EN-CFS or EN-IAA could be a good option to improve the germination and growth of tomato seedlings.

The hydrotreating process of vegetable oils (HPVO) involves the transformation of vegetable oil triglycerides into straight chain alkanes, which are carried out by deoxygenation reactions, generating multiple hydrocarbon compounds, cuts similar to heavy vacuum oil. The HPVO is applied to Jatropha curcas oil on USY zeolite supported with gamma alumina and platinum deposition on the catalytic as hydrogenation component. The acid of additional activity of the supports allows the development of catalytic routes that the intervention of catalytic centers of different nature reaches the desired product. The products of the hydrotreating reaction with Jatropha curcas seed oil triglycerides were identified by Fourier transform infrared spectroscopy and by mass spectroscopy to identify and analyze the generated intermediate and final hydrocarbon compounds.