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International audience; Sorghum is a potential substitute for corn/wheat in cereal-based extruded products. Despite agronomic advantages and its rich diversity of phenolic compounds, sorghum kafirins group together and form complex with tannins, leading to a low digestibility. Phenolic content/profile by UPLC-ESI-QTOF-MSE and kafirins polymerization by SE-HPLC were evaluated in wholemeal sorghum extrudates; tannin-rich (#SC319) and tannin-free (#BRS330) genotypes with/without turmeric powder. Total phenolic, proantocyanidin and flavonoid contents were strongly correlated with antioxidant capacity (r > 0.9, p < 0.05). Extrusion increased free (+60%) and decreased bound phenolics (−40%) in #SC319, but reduced both (−40%; −90%, respectively) in #BRS330, which presented lower abundance after extrusion. Turmeric addition did not significantly impact antioxidant activity, phenolic content and profile and kafirins profile. Tannins presence/absence impacted phenolic profiles and polymerization of kafirins which appears related to the thermoplastic process. The extrusion improved proteins solubility and can positively enhance their digestibility (phenolic compounds-proteins interactions), making more accessible to proteolysis in sorghum extrudates.

Millet (Pennisetum glaucum) is a small gluten-free cereal originated from Africa that is not currently introduced in the Western diet. It is an interesting source of dietary fiber, vitamins, minerals, proteins and phenolic compounds superior to the most traditional consumed cereals. It is very effective crop adopted in no tilling farming system planted in a vast cultivated area in Brazil. Bread is a food product of high acceptance that is traditionally made from wheat, particularly from refined flours. However, it is known to present a high glycemic index and low levels of dietary fiber and naturally contains gluten proteins. The objective of this work was to develop whole grain bread using blends of raw and extruded flours from millet and to evaluate the physicochemical parameters in comparison to commercial whole bread products with and without gluten. The use of extrusion increased antioxidant capacity (215.2 ± 1.9 μM Trolox/g) and enzymatic inhibition (96.31 ± 0.005) in relation to the product elaborated from raw flour. Millet is presented as potential food interesting for the production of bread considered in the diet of Brazilian population, particularly to those suffering from gluten allergy and diabetes.

The diversity of sorghum grainsis relatedto their intrinsic properties, which include starch type,non-starch components and phenolic compounds. The latter are genotype dependent and affect the pericarp characteristics such as color and presence of a pigmented testa. This diversity can be valuable for developing new food products by thermoplastic extrusion intended for human consumption. Flours from sorghum grains from the genotypes of varied pericarp color: white (CMSXS180; 9010032), red (BRS 310; BRS 308) and light brown (BRS 305; 9929034) were processed in a co-rotating twin-screw extruder. Changes promoted by extrusion cooking were evaluated via specific mechanical energy (SME), die pressure, apparent density, sectional expansion index (SEI), water absorption index (WAI) and water solubility index (WSI). Pericarp color affected diepressure, apparent density and WSI values of extrudates. Light brown genotypes, rich in tannin and fiber content, generated the lowest die pressure and SEI values. Red genotypes presented the lowest SME and the highest WAI values. White genotypes presented intermediate SME and the highest die pressure values. These results reflect differences in starch conversion induced by the pericarp type. These results further suggest the potential use of pigmented sorghum extrudates for human consumption. Made available in DSpace on 2018-05-10T01:03:21Z (GMT). No. of bitstreams: 1 Physicochemicalproperties.pdf: 2413559 bytes, checksum: bbc0c369210dfb5a60600b95befc2684 (MD5) Previous issue date: 2014-01-23

Pereskia aculeata Miller is a native cactus that can be found in Brazil and is called 'ora-pro-nobis' (OPN). Many people from poor communities consume the dark green leaves of OPN as a vegetable. The objective of the present work was to evaluate the nutritional components in terms of proximate composition, minerals, vitamins, protein content and their in vitro protein digestibility. OPN leaves showed remarkable levels of total dietary fiber (39.1% dry basis), minerals (calcium, magnesium, manganese and zinc) and vitamins (vitamin A, vitamin C and folic acid). Among amino acids, tryptophan was the most abundant (20.5% of the total amino acids) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed small peptides, inferior to 6.5 kDa, and four major bands (61 kDa, 53 kDa, 33 kDa, and 15 kDa). The protein digestibility corrected amino acid score showed the lowest value of sulfur-amino acids (Met+Cys). OPN leaves could be considered a good source of minerals, vitamins and amino acids, and may serve as a potential functional ingredient.