359 research outputs found
Exploitation of lettuce waste flour to increase bread functionality: effect on physical, nutritional, sensory properties and on consumer response
n/
Recommended from our members
Valorization of sweet corn (Zea mays) cob by extraction of valuable compounds
The main objective of this study was to investigate the proximate, mineral and phytochemical compositions of sweet corn cob (SCC), often neglected and regarded as agricultural waste. Compositional analysis showed that more than 60% of SCC was composed of insoluble dietary fibre, with cellulose being the major constituent. Results also showed that SCC can be a good source of non-essential protein and minerals (phosphorus,potassium and manganese). SCC had a total phenolic content of 6.74 g GAE kg-1 dry weight DW), of which bound phenolics were predominant. The bound phenolics fraction showed the highest antioxidant capacity in all three antioxidant capacity assays (TEAC, FRAP and
DPPH) and contained the highest amount of ferulic and p-coumaric acid. The main carotenoids present in SCC were β-carotene, zeaxanthin and lutein. This investigation shows
that SCC can be a potential source of natural colorant (carotenoids), antioxidants (phenolics)and nutritional supplements (proteins and phytochemicals)
Cricket Flour-Laden Millet Flour Blends' Physical and Chemical Composition and Adaptation in Dried Pasta Products
Increasing the protein and antioxidant content of food products is a constant challenge amongst researchers. Dried pasta products are popular amongst all groups of society. The most important factor in pasta processing is the quality of the flour. Millet (Panicum miliaceum) flour has high nutritional value, enriching it with cricket (Gryllus bimaculatus) flour is good choice to increase the quality of protein composition and antioxidant properties of products. Flour mixtures of millet and insect flours (5% and 10%) were analysed after mixing and pasta processing. Addition of wheat gluten improved both texture and nutrition value of pasta products. Total polyphenol content, antioxidant capacity, total protein content, free and total amino acid composition were studied. Quality analysis of dried pasta products were carried out according to Hungarian standards. Data was analysed with Kruskal-Wallis test, Dunn's pair-wise post hoc test was used with Bonferroni correction. The correlation was determined by Spearman's rank. Addition of cricket flour modified the pH, acid value, moisture content, and colour of the samples, these changes lasted during storage. Enrichment could increase the total phenol content significantly even at the low level of 10%. Heat treatment during pasta processing had negative effect on the antioxidant capacity except at higher cricket flour contents. Cricket flour's high protein content proportionately increased millet flour's, thus pasta products'. Dried pasta products passed all quality norms. Enrichment of millet flour with cricket flour is favourable from both nutritional and quality aspects
Preliminary characterization of a Moroccan honey with a predominance of Bupleurum spinosum pollen
Honey with Bupleurum spinosum (zandaz) as a main pollen source has not been the subject of previous detailed study. Therefore, twelve Moroccan samples of this honey were subjected to melissopalynological, physicochemical and microbiological quality characterization, as well as antioxidant activity assessment. From a quality point of view, almost all samples were within the limits established by Codex Alimentarius, and/or the European legislation. All samples presented predominance of B. spinosum pollen (more than 48%). Relatively high levels of trehalose (1.3-4.0 g/100 g) and melezitose (1.5-2.8 g/100 g) were detected. Those sugars, not common in monofloral honeys, could be used as an important factor to discriminate zandaz honey. Flavonoid content correlated positively with the honey color, melanoidin and polyphenol content, and negatively with the IC50 values of scavenging ABTS (2,2' - azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) free radicals, while proline amount correlated negatively with IC50 values of nitric oxide scavenging activity and chelating power. This correlation supports the use of anti-oxidant activities as important variables for PCA (principal component analysis). Both components explained 70% from the given data, and showed certain homogeneity upon analyzed samples independent of the region, suggesting the importance of B. spinosum nectar in the resulting honey characteristics.Fundacao para a Ciencia e Tecnologia for Research Center [UID/BIM/04773/2013 CBMR 1334, UID/AGR/00239/2013, UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569)]; ERDF through the COMPETE - Programa Operacional Competitividade e Internacionalizacao (POCI
Global volatile signature and polyphenols patterns in Vespolina wines according to vintage
The global volatile signature of Vespolina wines from different vintages was established using solid-phase
microextraction combined with gas chromatography–mass spectrometry (HS-SPME/GC-qMS). Wines
were also characterised in terms of bioactive compounds (such as individual polyphenols, biogenic amines
and their precursors) by high-performance liquid chromatography (RP-HPLC). In addition, some physic ochemical parameters, such as the total phenolic content, total tannins and antioxidant capacity, were
evaluated. Seventy-one volatile compounds and thirty-three bioactive compounds were identified in Ves polina wines. The application of multivariate analysis to the obtained data revealed that 2-phenylethyl
acetate, ethyl nonanoate, 2-hexanol, isoamyl octanoate and ethyl 2-hydroxymethylbutanoate were the pri mary compounds responsible for Vespolina wines classification, mainly indicative for wines of 2015 and
2013 vintages. Conversely, wines from 2008 and 2009 vintages showed highest values of procyanidin B1,
catechin, gallic acid, trans-piceid and trans-resveratrol.info:eu-repo/semantics/publishedVersio
The effect of yeast on the anthocyanin characteristics of fermented model solutions
The sensory quality of red wines is basically determined by the colour, which depends on the amount and on the evolution of anthocyanins and other phenolic compounds extracting from the berries into the wine during wine-making. The anthocyanin-monomers are responsible for the development of the red colour, and their acylated derivatives provide stability for the colour of the wines. The anthocyanin profile of wines is affected by several factors: the grape variety, the conditions during wine-making, and also the yeast culture used for the fermentation. In our experiments a self-compiled model solution was fermented by spontaneous fermentation, as well as by four commercial yeasts under laboratory conditions. After fermentation total polyphenolics, anthocyanins, anthocyanin monomer profile, colour intensity, hue, and the ratio of polymeric anthocyanins were studied. Our results show that the spontaneous yeast fermentation resulted in a higher anthocyanin concentration in the fermented model solution, but the commercial yeast strains provided a more advantageous colour characteristic compared to the spontaneous fermentation. After the spontaneous fermentation less sediment was left than in the commercial yeast fermented samples
Antioxidant capacity and toxicological evaluation of pterospartum tridentatum flower extracts
Pterospartum tridentatum Willk. (prickled broom) is an autochthonous plant, common
in Portuguese territory.
The yellow flowers are used in traditional medicine, as a potential cure for all body
illnesses, mainly for throat irritation treatment or for diabetes, hypertension and
hypercholesterolemia therapy.Despite its traditional use, no toxicological assessment has been performed as we know.
A high antioxidant activity of P. tridentatum flower water extract was acessed in good
agreement with its ESI-MS spectrum that revealed the presence of several flavonoids, as
luteolin-O-(O-acetyl)-glucuronide, luteolin-O- glucuronide or isorhamnetin-O-hexoside.
Mitocondrial respiratory rates (state 4, state 3 and FCCP-stimulated respiration) and
respiratory indexes (respiratory control and P/O ratios) showed no consistent decrease
of respiratory and phosphorylative efficiencies for the concentrations tested (up to 500
μg.mL-1). Cytotoxicity evaluation, using MTT assay, was reliable with the previous
results. In conclusion, for the concentration range commonly used P. tridentatum
flowers usage can be regarded as harmless and trustworthy
Distribution of antioxidant components in roots of different red beets (Beta vulgaris L.) cultivars
The beetroot is typically on the table in winter in form of pickles or juice, but for its nutritional values it would deserve more common consumption. Its curative effect in great part is due to the several vitamins, minerals, and compounds with antioxidant activity. But the division of biological active compounds is very different in the parts of the root. Based on our results, we could compare the differences between the morphology and some inner contents (soluble solid content, colour, betacyanin, betaxanthin, and polyphenol contents, antioxidant activity, and some flavonoids) of two beetroot cultivars. The results of the morphological investigations showed that the ‘Cylindre’ cultivar had more favourable crop parameters than the ‘Alto F1’ cultivar. In the ‘Cylindre’ cultivar the polyphenol content and the antioxidant capacity were significantly higher than in the ‘Alto F1’ cultivar. By determination of the betanin contents of the investigated beetroots, our results showed both betacyanin and betaxanthin contents were higher in the ‘Cylindre’ cultivar. The chlorogenic acid, gallic acid, the cumaric acid have been identified based on the peaks of HPLC in the studied beetroot cultivars
Effect of harvest time on physicochemical quality parameters, oxidation stability, and volatile compounds of extra virgin olive oil
The aim of this study was to determine the changes in some physicochemical properties of olives (fruit weight, water content and oil content) and olive oils (total chlorophyll, carotenoid, pheophytin a, peroxide value and free acidity), and in the chemical properties (fatty acids, tocopherols, phenolics, oxidation stability and volatile profiles) of oils during ripening.Ripening indices (RI) of olive samples were 1.93 (unripe), 4.28 (ripe) and 5.89 (overripe). Most of the mentioned features changed with ripening. During ripening there was a sharp decrease in total chlorophyll, carotenoid and pheophytin a contents. An increase in oleic and linoleic acids and a decrease in palmitic acid were found in the fatty acid composition. Olive oils showed strong relations among oxidation stability, tocopherol content, total phenols content, and antiradical actvity of phenol extracts and these parameters decreased with maturation. Nevertheless, higher amounts of trans-2-hexenal were found in the oil from ripe olives than from unripe and overripe olives. On the other hand, the highest concentration of hexanal was found in the oil from overripe olives.In general, significant differences were observed in fruit weight, pigments, free acidity, fatty acid, tocopherol, and total phenolics contents, radical scavenger activity, oxidation stability, phenolic profile and volatile profile between the olive oils from the Gemlik cultivar at different stages of maturation
Anthocyanins, phenols, and antioxidant activity in blackberry juice with plant extracts addition during heating
In this work the influence of addition of different plant extracts (olive leaf, green tea, pine bark PE 95%, pine bark PE 5:1, red wine PE 30%, red wine PE 4:1, and bioflavonoids) to blackberry juice during heating (at 30, 50, 70 and 90 °C) on the anthocyanin and phenol contents, polymeric colour, and antioxidant activity was investigated. Also, reaction rate constant, half-lives of degradation, and activation energy were calculated. Control sample was juice without addition of extracts. The highest anthocyanin content at 30 °C was in samples with the addition of olive leaf and green tea. At 90 °C the highest anthocyanin content was measured in samples with the addition of extract of red wine and bioflavonoides. Samples supplemented with the extracts had much higher antioxidant activity in comparison to the control sample. Results showed that at 90 °C the sample with green tea supplementation had the lowest reaction rate constant and the highest half-life. Activation energy ranged from 29 to 44 kJ mol−1
- …