Phenolic profile and content of sorghum grains under different irrigation managements.

TL;DR: Findings will be valuable for the selection of sorghum genotypes for grain production as human food under water deficit conditions, since polyphenol levels can affect the grain's nutritional value and health properties.

About: This article is published in Food Research International.The article was published on 2017-07-01 and is currently open access. It has received 28 citations till now. The article focuses on the topics: Deficit irrigation & Sorghum.

Summary

1. INTRODUCTION

• Polysaccharides are widely used in biomaterials development.
• Starch is a very versatile raw material that can be processed by extrusion, injection molding, and thermomolding into either porous or dense thermoplastic materials.
• The mechanical properties, and particularly the rigidity of starchbased materials, can be modulated by the addition of plasticizers such as glycerol or sorbitol, which decrease the glass transition temperature of the material.
• Due to its biocompatibility and biodegradability, starch is also introduced in formulations suitable for biomedical applications.

2. MATERIALS AND METHODS

• Potato starch was purchased from Roquette (Lestrem, France).
• The initial moisture content was approximately 13% of the wet basis weight (wb) or 15% dry basis (db).
• Glycerol (99% purity) was purchased from Sigma-Aldrich Chemie GmbH (Steinheim, Germany).
• Prior to extrusion, water was added to adjust the starch moisture content to 27% wb (37% db).
• For the samples containing glycerol, the glycerol content was adjusted to 20% wb (27% db).

3. RESULTS AND DISCUSSION

• Figure 2 presents the cross sections of the conservation rate XC for each type of sample at various relevant immersion times.
• Because the kinetics are not the same depending on the sample observed, the relevant immersion times displayed on the figures can vary.
• As a side note, the S-GLY20 sample appears asymmetric, most probably because it was not cut as straightly flat (it is a very sensitive procedure) and therefore one side was slightly thicker than the other.

4. CONCLUSION

• The in-depth observations of the structural evolutions of starchy samples upon immersion in water were made possible by the use of synchrotron radiation (wide-angle scattering), which gives very high resolution measurements on small samples, and of magnetic resonance microimaging, which gives high-resolution images, two powerful nondestructive techniques.
• They are complementary and together allow a multiscale study of the phenomena, from crystal structure changes (a few Å) to water transfer (several millimeters).
• These methods enabled a better understanding of the water uptake mechanisms in these materials, which have a lot of potential as biosourced, biocompatible, and biodegradable polymers for use in the biomedical field, for example, or for food packaging.
• Using the method described in this Article, one would also be able to follow the enzymatic degradation of samples (simply by replacing water with an enzyme solution) which is of uttermost importance for the applications mentioned above.
• Another perspective for the use of this unique setup is to follow changes at a different scale by changing the scattering angle (small-angle instead of wide-angle) and investigate the fate of starch granules or the creation of supramolecular structures upon immersion, or during biodegradation.

Figures

Table 3. Free, bound and total individual flavonoid content (µg /g, dry basis) of six genotypes of sorghum grain grown in three irrigation treatments.

Figure 3

Table 1. Identification of individual polyphenols in sorghum grains by HPLC-DAD-ESIMS fragmentation and in comparison with respective standards.

Figure 1

Figure 2

Table 2. Free, bound and total contents of hydroxycinnamic acids (µg/g dry basis) of six genotypes of sorghum grain grown under three irrigation treatments.

Frequently asked questions

Q1. What have the authors contributed in "Phenolic profile and content of sorghum grains under different irrigation managements" ?

Wu et al. this paper investigated the effect of irrigation treatment on the levels of polyphenols in sorghum grain. 

Q2. How many polyphenols were identified in the sorghum extracts?

A total of eight 193 individual polyphenols, including ferulic acid, caffeic acid, luteolin, apigenin, 194 luteolinidin, apigeninidin, taxifolin and naringenin, were unequivocally identified and 195 another 17 tentatively identified. 

Q3. Why is the number of people consuming sorghum growing in developed countries increasing?

the number of people consuming sorghum grain 40 is slowly but steadily increasing in developed countries mainly due to sorghum’s 41 gluten-free property and antioxidant potential from polyphenolic phytochemicals 42 (Taylor et al., 2006). 

Q4. What is the effect of the high temperature on the biosynthesis of polyphenols in s?

As the sorghum was unable to regulate the severe water 335 stress, the high temperature might also have decreased the biosynthesis of 336 polyphenols, flavonoids and some individual polyphenols on the sorghum grain under 337 the SDI regime. 

Q5. How many ethyl acetate fractions were added to the hydrolys?

The 138 hydrolysate was re-extracted with the 15 mL ethyl acetate four times more, and all 139 ethyl acetate fractions were combined and evaporated to dryness. 

Q6. What is the valuable cereal crop in the world?

Sorghum (Sorghum bicolor (L.) Moench) is the fifth most valuable global cereal crop, 34 widely grown in semi-arid and arid regions of the world because of its tolerance to 35 drought and high temperatures (Taylor, Schober, & Bean, 2006). 

Q7. What enzymes were shown to be catalysed by CHS and F3'H?

Synthesis of 308 3-deoxyanthocyanidin has been previously shown to be catalysed by CHS and F3'H 309 enzymes, and the synthesis of these two enzymes was reported to be enhanced under 310 biotic stress in sorghum, which led to increased 3-deoxyanthocyanidin concentration 311 (Boddu et al., 2004; Lo et al., 1999). 

Q8. What is the effect of the reduced irrigation level on the synthesis of polyphenols?

it is proposed that more CHS and F3'H enzymes might 314 be synthesized when irrigation level was reduced from FI to DI. 

Q9. What is the lowest level of luteolin and apigenin in Shawaya Short?

Group C (Liberty) has a low level 289 of individual polyphenols, while a high level of some individual flavonoids is found 290 in Group B (Shawaya Short Black 1) or Group D (IS1311C). 

Q10. How many methanol residues were extracted from sorghum?

The 129 residue was extracted with 20 mL 80% (v/v) aqueous methanol two times more, and 130 all supernatants were combined after centrifuging. 

Q11. What is the effect of irrigation on the concentration of polyphenols in sorghum?

The HPLC chromatograms illustrated that across all 218 genotypes, irrigation treatments did not differ in the polyphenolic species present 219 rather only altered their concentrations. 

Q12. what is the effect of sorghum flour on the antioxidant capacity of a durum?

Acute effect of 458 sorghum flour-containing pasta on plasma total polyphenols, antioxidant 459 capacity and oxidative stress markers in healthy subjects: A randomised 460 controlled trial. 

Q13. How many peaks were identified by authentic standards?

196 Peaks, 8, 9, 13, 16, 17, 21, 24 and 25 were identified by authentic standards based 197 on their chromatographic comparisons.