66 research outputs found
Why do millets have slower starch and protein digestibility than other cereals?
Background
Millet and millet based products are known to have lower starch and protein digestibility rates when compared to other cereals. Understanding, why millets are slowly digestible and how they are affected by processing is important in maintaining their lower starch and protein digestibilities when processed.
Scope and approach
This review explores the factors that contribute to the lower starch and protein digestibilities of millets and their underlying mechanisms. The effects of different processing methods on millet starch and protein digestibility rates are also discussed.
Key findings and conclusions
Factors such as starch structural characteristics, starch-protein-lipid interactions, fiber and polyphenols present in millets play significant roles in their hypoglycemic property. The amount and type of fatty acids present in millets significantly affect their starch hydrolysis rates. Unsaturated fatty acids are more effective in reducing starch hydrolysis rates than their saturated counterparts. In-vitro protein digestibility (IVPD) of millets appears to be mostly affected by polyphenols and processing. Simple processing steps such as decortication, germination and fermentation which are mostly applied to millets significantly affect both starch digestibility and IVPD of millets. The adoption of processes that maintain low starch hydrolysis rates and increases protein digestibility in millets should be encouraged
Genetic variability among sorghum accessions for seed starch and stalk total sugar content
Sorghum (Sorghum bicolor (L.) Moench) is a staple food grain in many semi-arid and tropical areas of the world, notably in sub-Saharan Africa because of its adaptation to harsh environments. Among important biochemical components for sorghum for processors are the levels of starch (amylose and amylopectin) and total sugar contents. The aim of this study was to determine the genetic variation for total starch in the seed, its components and total sugar in the stalks of the sorghum accessions from Ethiopia and South Africa. Samples of 22 sorghum accessions were evaluated. Significant variations were observed in total starch (31.01 to 64.88 %), amylose (14.05 to 18.91 %), the amylose/amylopectin ratio (0.31 to 0.73) and total stalk sugar content (9.36 to 16.84 %). Multivariate analysis showed a wide genetic variation within and among germplasm accessions which could be used in the selection of parental lines for the improvement of traits of interest through breeding. The variation found among the sorghum accessions shows that an improved total starch and starch components and stalk sugar contents can be achieved through crossing these selected genotypes
Development of new microalgae-based sourdough "crostini": functional aspects of Arthrospira platensis (spirulina) addition
The aim of this work was to evaluate the influence of Arthrospira platensis F&M-C256 (spirulina)
incorporation on the nutritional and functional properties of “crostini”, a leavened bakery product
largely consumed in Italy and Europe. Sourdough was used as leavening and fermentation agent and
three concentrations of A. platensis F&M-C256 were tested: 2%, 6% and 10% (w/w). Despite a lower
volume increase compared to the control, the A. platensis F&M-C256 “crostini” doughs reached a
technological appropriate volume after fermentation. At the end of fermentation, no significant
differences in microorganisms concentrations were observed. A. platensis F&M-C256 “crostini” showed
higher protein content compared to the control. Considering the European Commission Regulation on
nutritional claims, “crostini” incorporated with 6% and 10% biomass can be claimed to be a “source
of protein”. Six and ten percent A. platensis “crostini” also presented significantly higher antioxidant
capacity and phenolics. A significantly lower value of in vitro dry matter and protein digestibility
between A. platensis F&M-C256 “crostini” and the control was found. The overall acceptability
decreased with increasing A. platensis F&M-C256 addition. The combination of spirulina biomass
addition and the sourdough technology led to the development of a novel microalgae-based bakery
product with nutritional and functional featuresinfo:eu-repo/semantics/publishedVersio
Lactic acid fermentation as a tool to enhance the antioxidant properties of Myrtus communis berries
Background: Myrtle (Myrtus communis L.) is a medicinal and aromatic plant belonging to Myrtaceae family, which
is largely diffused in the Mediterranean areas and mainly cultivated in Tunisia and Italy. To the best of our knowledge, no
studies have already considered the use of the lactic acid fermentation to enhance the functional features of M.
communis. This study aimed at using a selected lactic acid bacterium for increasing the antioxidant features of myrtle
berries, with the perspective of producing a functional ingredient, dietary supplement or pharmaceutical preparation.
The antioxidant activity was preliminarily evaluated through in vitro assays, further confirmed through ex vivo analysis on
murine fibroblasts, and the profile of phenol compounds was characterized.
Results: Myrtle berries homogenate, containing yeast extract (0.4%, wt/vol), was fermented with Lactobacillus plantarum
C2, previously selected from plant matrix. Chemically acidified homogenate, without bacterial inoculum and incubated
under the same conditions, was used as the control. Compared to the control, fermented myrtle homogenate exhibited
a marked antioxidant activity in vitro. The radical scavenging activity towards DPPH increased by 30%, and the
inhibition of linoleic acid peroxidation was twice. The increased antioxidant activity was confirmed using Balb 3 T3
mouse fibroblasts, after inducing oxidative stress, and determining cell viability and radical scavenging activity
through MTT and DCFH-DA assays, respectively. The lactic acid fermentation allowed increased concentrations of total
phenols, flavonoids and anthocyanins, which were 5–10 times higher than those found for the non-fermented and
chemically acidified control. As shown by HPLC analysis, the main increases were found for gallic and ellagic acids, and
flavonols (myricetin and quercetin). The release of these antioxidant compounds would be strictly related to the
esterase activities of L. plantarum.
Conclusions: The lactic acid fermentation of myrtle berries is a suitable tool for novel applications as functional
food dietary supplements or pharmaceutical preparations
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