RESUMEN

Postharvest wounding stress in carrots induces the accumulation of phenolics, whereas extrusion generates modifications in the nutritional profiles of food matrixes. In the present study, the sequential application of wounding stress and extrusion on total free and bound phenolics as well as on carotenoid profiles of carrots was evaluated. Wounding was applied by shredding carrots and storing the tissue (48 h, 15 °C). The stressed-tissue was dehydrated and extruded at 63 °C or 109 °C and at continuous or expansion screw configurations. Extrudates were milled and sieved before phytochemical analysis. Wounding increased total free (288.1%) and bound (407.6%) phenolic content, whereas the carotenoid content was unaltered. The free and bound phenolics that showed the highest increase due to wounding were the chlorogenic (579.8%) and p-coumaric (390.9%) acids. Extrusion, at 109 °C under expansion screw configuration, further increased the wound-induced accumulation of total free (296.6%) and bound (22.1%) phenolics and induced trans-cis isomerization of ß-carotene.

Asunto(s)

Daucus carota/química , Fenoles/análisis , Carotenoides/análisis , Fitoquímicos/análisis , Estrés Fisiológico

RESUMEN

The phenolic-profiling of seven different wheat (Triticum aestivum) genotypes was investigated for the first time during different stages of grain development (milky, softy, physiological maturity and mature). Free and bound phenolic compounds were extracted separately and analyzed by UPLC-QTOF-MSE. Total phenolic content significantly decreased, up to 50% depending on the genotype, towards the maturation of grain. The highest content (free and bound) was observed in the most immature grains, while the lowest level was found in mature grains (408.0 and 165.0 GAE mg/100 g, respectively). Globally, 237 phenolic compounds were identified, divided into 5 classes: flavonoids (85), phenolic acids (77), other polyphenols (51), lignans (16) and stilbenes (8). UPLC-MS results showed a progressively decrease of the number of phenolic identification (ID) all along grain development, milky (213), softy (192), physiological maturity (169) and mature (144). The proportion bound to free phenolic progressively increased, reaching the maximum at physiological maturity, indicating a possible enzymatic reactions and complexation during grain growth. Ferulic acid, diphyllin, 4-hydroxybenzoic acid, ferulic acid isomer, apigenin 7-O-apiosyl-glucoside isomer and myricetin isomer were the most abundant compounds. Chemometric tools showed a clear separation between immature and mature grain for all genotypes. Phenolic profile varied significantly among genotypes, this result can help the selection of varieties towards a higher retention of bioactive compounds. Noteworthy, immature wheat grains can be considered a rich source of phenolic compounds and as an attractive ingredient to incorporate to functional foods.

Asunto(s)

Metabolómica/métodos , Fenoles/análisis , Fenoles/metabolismo , Triticum/química , Triticum/metabolismo , Ácidos Cafeicos/análisis , Ácidos Cafeicos/metabolismo , Cromatografía Líquida de Alta Presión , Cinamatos/análisis , Cinamatos/metabolismo , Ácidos Cumáricos/análisis , Ácidos Cumáricos/metabolismo , Genotipo , Hidroxibenzoatos/análisis , Hidroxibenzoatos/metabolismo , Espectrometría de Masas en Tándem , Triticum/genética , Triticum/crecimiento & desarrollo

RESUMEN

Prosopis alba (algarrobo) flours are traditional food resources from Argentina. The aim of this work was to determine the effect of particle sizes of Prosopis flour on its chemical composition and functional properties. Flours were obtained by mechanical methods (F1 to F4, >840, 840 to 500, 500 to 149 and <149 µm, respectively). F1 and F2 contain 40% mesocarp while F3 and F4 show 80 and 90%, respectively. Mesocarp reserve parenchyma is rich in free and bound phenolic compounds, carbohydrates and fibers of the vascular system, CaCO3 crystals, and minerals (Fe, Ca, Mg, K). Apigenin C-glycosides and phenylpropanoids acids were identified in all fractions whereas F4 showed the highest level. All fractions showed functional properties. F3 and F4 showed the highest activity as H2O2 and HO• scavenger. F1 and F2 showed the highest activity as reductor agents and lipoperoxidation inhibitors. Flours with different granulometry may be suitable as functional ingredient or nutraceutical whereas flours with a smaller particle size (F3 and F4) are more interesting as functional ingredients because of their high content of bound phenolic compounds and particle homogeneity and could be used either alone or together.

Asunto(s)

Harina/análisis , Tamaño de la Partícula , Prosopis/química , Apigenina/análisis , Apigenina/química , Peróxido de Hidrógeno/química , Fenoles/análisis , Fenoles/química , Prosopis/citología

RESUMEN

This work is part of the search in native food matrices from arid regions of Argentina of interest to improve human health. Prosopis species are ethnic food resources in South America capable of growing in arid and semi-arid environments. This work was focused to determine the nutritional and phytochemical composition of Prosopis nigra fine flour and to evaluate its biological properties. Flour showed a high level of sucrose (30.35 g/100 g flour), fiber (6.34 g/100 g flour), polyphenols (0.45 g GAE/100 g flour), and minerals (potassium, calcium, and magnesium). Apigenin C glycosides and phenylpropanoid acids were identified in free and bound phenolic enriched extracts, respectively. Polyphenols (especially free polyphenols) were able to inhibit enzymes associated with the metabolic syndrome, including α-amylase (IC50 30.1 µg GAE/mL), α-glucosidase (IC50 22.5 µg GAE/mL), while bound phenolics may control lipase activity (IC50 33.5 µg GAE/mL) and exhibit antioxidant activity by different action mechanisms (SC50 between 16 and 93 µg GAE/mL). Both extracts were more effective to inhibit cyclooxygenase-2 than phospholipase A2 and lipoxygenase, proinflammatory enzymes. Polyphenolic extracts did not show any mutagenic effect. Our studies add value to this non-conventional flour as a promising food resource that could be used as a functional food or functional ingredient in formulations to reduce the risk of the development of obesity. These studies revalue our native resources by promoting their conservation, their use and their propagation. PRACTICAL APPLICATION: Pods of P. nigra are traditional food resources in South America. The non-conventional flour obtained from them is a food that inhibits enzymes linked to carbohydrates metabolism and lipids metabolism, show antioxidant activity and anti-inflamatory activity, principally on COX-2. This natural product is a promising resource that could be used as a functional food or as functional ingredient in food formulations for reduce the risk of the development of obesity. Our studies are relevant to stimulate a sustainable management of this specie and for its development as potential new crops.

Asunto(s)

Harina/análisis , Síndrome Metabólico/dietoterapia , Estrés Oxidativo , Fitoquímicos/farmacología , Prosopis/química , Alcaloides/análisis , Aminoácidos/análisis , Antocianinas/análisis , Antiinflamatorios/farmacología , Antioxidantes/farmacología , Ácido Ascórbico/análisis , Proteínas Sanguíneas/análisis , Inhibidores de la Ciclooxigenasa 2/análisis , Grasas de la Dieta/análisis , Fibras de la Dieta/análisis , Proteínas en la Dieta/análisis , Inhibidores de Glicósido Hidrolasas/análisis , Inflamación , Inhibidores de la Lipooxigenasa/análisis , Valor Nutritivo , Polifenoles/análisis , alfa-Amilasas/antagonistas & inhibidores , alfa-Amilasas/metabolismo

RESUMEN

Jatropha curcas seed shells are the by-product obtained during oil extraction process. Recently, its chemical composition has gained attention since its potential applications. The aim of this study was to identify phenolic compounds profile from a non-toxic J. curcas shell from Mexico, besides, evaluate J. curcas shell methanolic extract (JcSME) antioxidant activity. Free, conjugate and bound phenolics were fractionated and quantified (606.7, 193.32 and 909.59 µg/g shell, respectively) and 13 individual phenolic compounds were detected by HPLC. The radical-scavenging activity of JcSME was similar to Trolox and ascorbic acid by DPPH assay while by ABTS assay it was similar to BHT. Effective antioxidant capacity by ORAC was found (426.44 ± 53.39 µmol Trolox equivalents/g shell). The Mexican non-toxic J. curcas shell is rich in phenolic compounds with high antioxidant activity; hence, it could be considerate as a good source of natural antioxidants.

Asunto(s)

Antioxidantes/farmacología , Jatropha/química , Fenoles/análisis , Extractos Vegetales/análisis , Extractos Vegetales/farmacología

RESUMEN

The effects of the type of solvolytic solution and number of extraction steps on the recovery of free phenolics, anthocyanins and proanthocyanidins from different rice samples were evaluated. Moreover, bound phenolic acids were determined as a function of enzymatic and/or alkaline hydrolysis treatment of the rice residue obtained after the extraction of free phenolics. The Acetone/Water (70:30 v/v) was the most effective solvolytic solution for extracting free phenolics from pigmented rice, as well as anthocyanins from black and wild rice, and proanthocyanidins from red rice. The application of three extraction steps increased the recovery of free phenolics up to 10%. The adoption of an enzymatic treatment, with α-amylase in order to reduce the paste viscosity of the residue, increased the extractability of bound phenolics. α-Amylase at 37°C during 15min followed by an alkaline hydrolysis at 37°C was the best treatment for the recovery of bound phenolics.

Asunto(s)

Hidroxibenzoatos/análisis , Oryza/química , Fenoles/análisis , Extractos Vegetales/química , Antocianinas/análisis , Hidrólisis , Proantocianidinas/análisis

RESUMEN

Among phytochemicals, phenolic compounds have been extensively researched due to their diverse health benefits. Phenolic compounds occur mostly as soluble conjugates and insoluble forms, covalently bound to sugar moieties or cell wall structural components. Absorption mechanisms for bound phenolic compounds in the gastrointestinal tract greatly depend on the liberation of sugar moieties. Food processes such as fermentation, malting, thermoplastic extrusion or enzymatic, alkaline and acid hydrolyses occasionally assisted with microwave or ultrasound have potential to release phenolics associated to cell walls. Different kinds of wet chemistry methodologies to release and detect bound phenolic have been developed. These include harsh heat treatments, chemical modifications or biocatalysis. New protocols for processing and determining phenolics in food matrices must be devised in order to release bound phenolics and for quality control in the growing functional food industry.

Asunto(s)

Análisis de los Alimentos , Fenoles/química , Pared Celular/química , Manipulación de Alimentos