High methoxyl pectin grafted onto gallic acid by one- and two-pot redox-pair procedures.

The aim of this research was to graft gallic acid (GA) onto high methoxyl pectin (HMP) through the redox-pair of ascorbic acid (Aa) and hydrogen peroxide (H2O2) with one- and two-pot procedures. The effectiveness of the both procedures and the chemical, physical and antioxidant properties of the obtained HMP-GA were evaluated. HMP-GAone-pot (23.3 ± 0.21 mg GA Equivalent (GAE)/g) and HMP-GAtwo-pot (32.3 ± 0.52 mg GAE/g) were best obtained at H2O2/Aa molar ratio-HMP/GA weight ratio of 9.0-0.5 and 16.0-0.5, respectively. The UV-Vis and FT-IR spectra and along with their derivative and thermal gravimetric analyses, revealed differences between HMP-GAone-pot and HMP-GAtwo-pot. The latter exhibited a greater antioxidant capacity than the former in single electron transfer (ET), hydrogen atom transfer (HAT), and ET-HAT mixed assays. The chemical differences can be attributed to side reactions that may have interfered with the grafting reaction. Consequently, HMP-GA, possessing unique antioxidant and prebiotic properties, can be synthesized through redox-pair procedures.

Flavonoid diversity in bitter and debittered seeds of Andean lupin (Lupinus mutabilis Sweet).

Seeds of ten Andean lupin (Lupinus mutabilis Sweet) ecotypes were collected from different regions of Peru and treated with an aqueous debittering method. Both untreated and treated seeds were analyzed by using LC-MS to investigate flavonoid profiles of different ecotypes and impact of debittering process on these compounds. Thirteen isoflavones (mainly as glycosides of genistein and methoxy-genistein) and eight flavones (glycosylated apigenins and methyl-luteolins) were characterized as the main flavonoids in the seed samples. The untreated lupin seeds contained 187-252 mg/100 g (dry weight) of flavonoids. The main difference among lupin ecotypes was observed in the levels of genistein-malonylhexoside, methoxy-genistein-malonylhexoside, and methyl-luteolin-malonylhexoside. After the debittering treatment, the total flavonoid content in the seeds was decreased to 125-203 mg/100 g dry weight, the aglycones of genistein, methoxy-genistein, and methyl-luteolin being the key distinguishing compounds of ecotypes. The aqueous treatment was effective in degrading flavonoid glycosides and releasing the corresponding aglycones.

Structural, chemical and technofunctional properties pectin modification by green and novel intermediate frequency ultrasound procedure.

The impact of intermediate frequency ultrasound (IFUS, 582, 864 and 1144 kHz), mode of operation (continue and pulsed) and ascorbic acid (Aa) addition on the structural, chemical and technofunctional properties of commercial citrus high methoxyl-grade pectin (HMP) was investigated. The chemical dosimetry of IFUS, monitored by the triiodide formation rate (I3-), demonstrated that the pulsed ratio (1900 ms on/100 ms off) at the three frequencies was similar to that of continue mode but IFUS1144 kHz produced more acoustic streaming demonstrated by the height liquid measured using image analysis. In presence of Aa, HMP presented higher fragmentation than in its absence. IFUS did not give rise any changes in the main functional groups of the HMP. In general, a reduction in molecular weight was observed, being the presence of Aa the most influencing factor. Regarding monosaccharides, IFUS modified the structure of homogalacturonan and rhamnogalacturonan-I and increased of GalA contents of the HMP in presence of Aa at the above three frequencies. A reducing of the consistency index (k) and increasing of the flow index (n) of HMP were showed by IFUS frequency and Aa addition. The emulsifying activity and stability index were increased for HMP treated by IFUS in continue mode at all frequencies and in presence of Aa. The results presented in this research shown the effectiveness of IFUS as tool to modify pectin into different structures with different functionalities.

Efecto del germinado sobre las características nutricionales, propiedades bioactivas y funcionales de basul (Erythrina edulis) / Effect of sprouting on the nutritional characteristics, bioactive and functional properties of basul (Erythrina edulis)

El basul es el fruto de la planta Erythrina edulis que posee un alto contenido de proteínas, fibra dietética y antioxidantes, pero también con contenido de antinutrientes. Objetivo. El objetivo del estudio fue evaluar el efecto del germinado sobre las características nutricionales, propiedades bioactivas y funcionales de las semillas de basul. Materiales y métodos. Mediante un diseño aleatorizado con arreglo factorial de 2x2x2 (tiempo de remojo, tiempo de germinado, presencia o ausencia de luz), las semillas de basul fueron germinadas y convertidas en harina (HBG) para determinar la composición proximal y la digestibilidad in vitro de la proteína. Además, se ha determinado los fenoles totales (CFT), la capacidad antioxidante (métodos ABTS y DPPH) y las propiedades de hidratación y adsorción de aceite. Resultados. Las diferentes condiciones de germinado no han modificado la composición proximal de la HBG; sin embargo, la digestibilidad in vitro de la proteína incrementó hasta en 6,25% en uno de los tratamientos respecto a la muestra no germinada. El CFT, también ha incrementado de 241,49 mg AGE/100g (sin germinar) a 267,15 mg AGE/100g (germinado); al igual que la capacidad antioxidante (ABTS) de 173,04 µmolTE/g (sin germinar) a 195,67 µmolTE/g (germinado). También se tuvo incrementos en la solubilidad, la capacidad de absorción de agua y la capacidad de hinchamiento. Conclusión. La calidad de la proteína, el contenido de fenoles totales, la capacidad antioxidante y propiedades funcionales de interacción con el agua de la semilla de basul mejora con el germinado(AU)

Basul is the fruit of the Erythrina edulis plant. It has a high content of proteins, dietary fiber, and antioxidants, but it also contains antinutrients. Objective. The study objective was to evaluate the effect of sprouting on the nutritional characteristics, bioactive and functional properties of basul seeds. Materials and methods. Basul seeds were germinated to produce flour (HBG) and determine its proximal composition and in vitro digestibility of the protein through a randomized design with a 2x2x2 factorial arrangement (soaking time, germination time, and presence or absence of light). Total phenols (CFT), antioxidant capacity (ABTS and DPPH methods), and hydration and oil adsorption properties were also determined. Results. The different germination conditions did not modify the proximal composition of HBG. However, the in vitro digestibility of the protein increased up to 6.25% in one of the treatments compared to the non-germinated sample. The CFT also increased from 241.49 mg AGE/100g (without germination) to 267.15 mg AGE/100g (germinated) and the antioxidant capacity (ABTS) from 173.04 µmolTE/g (without germination) to 195.67 µmolTE/g (germinated). Solubility, water absorption capacity, and swelling capacity also increased. Conclusion. The quality of the protein, the content of total phenols, the antioxidant capacity, and the functional properties of interaction with the water of the basul seed improved with germination(AU)

Profile and Content of Residual Alkaloids in Ten Ecotypes of Lupinus mutabilis Sweet after Aqueous Debittering Process.

The evaluation of the level of alkaloids in edible Lupinus species is crucial from a food safety point of view. Debittering of lupin seeds has a long history; however, the control of the level of alkaloids after processing the seeds is typically only evaluated by changes in the bitter taste. The aim of this study was to evaluate the profile and residual levels of quinolizidine alkaloids (QA) in (Lupinus mutabilis Sweet) after aqueous debittering process. Samples from 10 ecotypes from different areas of Peru were analyzed before and after the process. Based on results obtained by gas chromatography and mass spectrometry, from eight alkaloids identified before the debittering process, only small amounts of lupanine (avg. 0.0012 g/100 g DM) and sparteine (avg. 0.0014 g/100 g DM) remained in the seeds after the debittering process, and no other alkaloids were identified. The aqueous debittering process reduced the content of alkaloids to levels far below the maximal level allowed by international regulations (≤ 0.2 g/kg DM).