Journal of Food Bioactives, ISSN 2637-8752 print, 2637-8779 online
Journal website www.isnff-jfb.com

Original Research

Volume 6, June 2019, pages 100-109


Bioaccessibility and antioxidant activities of finger millet food phenolics

Tables

Table 1. Phenolic content and antioxidant activities (per g of dry matter) of soluble and insoluble-bound phenolic extracts of finger millet foods
 
TPC* µmol ferulic acid equivTFC* µmol catechin equivTEAC* µmol trolox equivDRSA* µmol trolox equivRP* µmol ascorbic acid equivFICA* µmol EDTA equivFerulic acid µg
*Abbreviations: TPC, Total phenolic content; TFC, Total flavanoid content; TEAC, Trolox equivalent antioxidant capacity; DRSA, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability; RP, Reducing power; FICA, Ferous ion chelating ability; EDTA, Ethylenediaminetetraacetic acid: dm, dry matter. The same letters in each column seperately for soluble and insoluble-bound phenolic extracts are not significantly different (>0.05).
Soluble phenolic extract
Raw flour32.5 ± 0.4a11.0 ± 1.3a1.7 ± 0.1a21.0 ± 0.8a12.4 ± 0.2a8.8 ± 0.0a101.8 ± 1.7a
Rotti31.3 ± 2.3ab8.4 ± 0.9b0.9 ± 0.3b10.3 ± 1.2b27.4 ± 0.4b41.1 ± 0.4b213.3 ± 17.2b
Pittu29.6 ± 0.6b9.6 ± 0.5b1.2 ± 0.1b8.0 ± 0.3c20.4 ± 0.7c40.5 ± 1.5b116.9 ± 3.8c
Halape43.5 ± 1.4c8.1 ± 0.8b1.3 ± 0.4c12.6 ± 1.8d31.9 ± 0.7d99.2 ± 0.8c342.8 ± 37.1d
Thalapa54.4 ± 1.5d17.2 ± 1.3c5.2 ± 0.4d15.4 ± 1.7e32.7 ± 1.0d91.6 ± 2.5d125.1 ± 41.0e
Porridge79.6 ± 1.6e29.6 ± 0.2d5.1 ± 0.3d50.8 ± 0.6f55.6 ± 0.5e170.8 ± 1.5e556.4 ± 14.2f
Bound phenolic extract
Raw flour2.2 ± 0.1a0.1 ± 0.02a0.70 ± 0.03a0.36 ± 0.04a3.37 ± 0.7a1.42 ± 0.01a472.5 ± 0.6a
Rotti4.0 ± 0.3b0.8 ± 0.01b0.12 ± 0.01b1.6 ± 0.2b10.8 ± 1.0b2.4 ± 0.02b0.04 ± 0.01b
Pittu4.2 ± 0.3b0.9 ± 0.01c0.12 ± 0.01b1.0 ± 0.2c9.5 ± 1.4b2.8 ± 0.02b0.02 ± 0.001c
Halape6.2 ± 0.3c1.4 ± 0.06d0.17 ± 0.03c2.3 ± 0.3d16.8 ± 0.6c3.9 ± 0.02c0.03 ± 0.001bc
Thalapa7.2 ± 0.4d2.5 ± 0.01e0.24 ± 0.03d2.8 ± 0.8d24.1 ± 2.6d7.2 ± 0.2d0.02 ± 0.01c
Porridge11.8 ± 0.3e2.8 ± 0.01f0.38 ± 0.03e2.1 ± 0.1d32.5 ± 0.1e8.5 ± 0.07d0.05 ± 0.01b

 

Table 2. Bioaccessible content (µmol/g of dm), absorbable (%) of finger millet food phenolics subjected to in vitro digestion and colonic fermentation
 
Aqueous extractionStatic intestinal digestion bioaccessibilityDynamic intestinal digestionColonic fermentation
Gastric phaseGastric + IntestinalGastricGastric + IntestinalRetentate*Dialysate**Absorbable (%)
*Retentate, non-dialized fraction after intestinal digestion and represent unabsorbed compounds; **Dialysate, dialyzed fraction after intestinal digesation and represent absorbed compounds; dm, dry matter, The same letters in each column are not significantly different (>0.05)
Total phenolic content (TPC) µmol ferulic acid equiv/g of dm
Rotti15.3 ± 1.3a22.1 ± 0.9a39.6 ± 4.0a41.5 ± 3.6a23.2 ± 0.9a24.6 ± 1.0a59.322.1 ± 3.0a
Pittu13.0 ± 1.0a18.7 ± 0.5a30.6 ± 1.2b70.1 ± 1.6b27.6 ± 0.6b40.2 ± 2.8b57.326.8 ± 1.7b
Halape10.6 ± 1.6b24.4 ± 4.1b21.5 ± 2.6c68.1 ± 1.2b45.0 ± 0.1c14.2 ± 1.0c20.924.3 ± 4.1c
Thalapa18.7 ± 1.4c25.7 ± 2.2b23.2 ± 2.5c41.5 ± 1.5a19.7 ± 1.3a20.4 ± 2.4d49.215.8 ± 2.6d
Porridge27.6 ± 1.0d44.7 ± 1.4c27.5 ± 2.9b69.2 ± 4.9b27.9 ± 2.3b39.4 ± 0.1b57.020.0 ± 2.4a
Total flavonoid content (TFC) µmol catechin equiv/g of dm
Rotti4.5 ± 0.9a8.7 ± 0.2a11.7 ± 0.8a13.4 ± 0.7a8.6 ± 0.7a3.4 ± 0.5a25.34.50 ± 0.1a
Pittu8.8 ± 0.3b9.7 ± 0.2b9.9 ± 1.5b27.9 ± 0.4b19.3 ± 0.1b9.1 ± 0.5b32.63.30 ± 0.2b
Halape6.9 ± 0.3c19.2 ± 0.8c8.3 ± 1.7c23.5 ± 1.2c14.7 ± 0.7c8.5 ± 0.2b36.22.01 ± 0.5c
Thalapa8.8 ± 0.1b11.0 ± 0.2d9.3 ± 0.3b23.4 ± 0.3c7.1 ± 0.4d14.2 ± 0.1c60.73.69 ± 0.1d
Porridge10.5 ± 1.0d12.7 ± 0.5e15.2 ± 0.3d18.5 ± 0.7d7.1 ± 1.2d11.0 ± 0.2d59.55.64 ± 0.1e

 

Table 3. Antioxidant activities (µmol equiv/g of dm) of bioaccessible and absorbable (%) finger millet foods subjected to in vitro digestion and colonic fermentation
 
Aqueous extractionStatic intestinal digestion bioaccessiblilityDynamic intestinal digestionAbsorbable***Colonic fermentation
GastricGastric + IntestinalGastricGastric + IntestinalRetentate*Dialysate**
*Retentate, non-dialized fraction after intestinal digestion and represent unabsorbed compounds; **Dialysate, dialyzed fraction after intestinal digesation and represent absorbed compounds; *** Percentage (%) antioxidant activity of absorbable phenolic compounds ; dm, dry matter, The same letters in each column are not significantly different (>0.05).
Trolox equivalent antioxidant capacity (TEAC) µmol trolox equiv/g of dm
Rotti1.6 ± 0.0a7.8 ± 1.7a21 ± 2.0a39.0 ± 2.4a23.0 ± 0.3a11.3 ± 1.8a29.05.14 ± 1.2a
Pittu1.3 ± 0.3a3.4 ± 0.4b9.6 ± 0.6b53.5 ± 2.7b29.3 ± 0.9b25.6 ± 2.3b47.912.63 ± 1.1b
Halape2.2 ± 0.5b15.0 ± 1.3c5.6 ± 0.0c42.7 ± 5.0a25.9 ± 3.6b18.3 ± 3.2c42.93.04 ± 0.5c
Thalapa1.3 ± 0.3a11.8 ± 1.0d6.8 ± 0.2c42.4 ± 0.3a20.0 ± 2.9a17.5 ± 3.3c41.32.29 ± 0.9c
Porridge9.0 ± 0.4c20.8 ± 1.2e17.3 ± 0.8d54.3 ± 0.4b32.7 ± 3.7c22.4 ± 1.2b41.34.86 ± 1.1a
2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability(DRSA) µmol trolox equiv/g of dm
Rotti1.4 ± 0.0a8.4 ± 0.2a10.3 ± 0.5a27.4 ± 1.3a16.0 ± 3.2a7.2 ± 0.1a26.36.07 ± 0.4a
Pittu5.2 ± 0.6b5.4 ± 0.1b7.2 ± 0.4b30.2 ± 1.0b20.2 ± 2.2b10.8 ± 3.0b35.83.66 ± 0.7b
Halape1.3 ± 0.1a6.9 ± 0.3c8.3 ± 0.2c39.7 ± 1.3c19.1 ± 0.6b17.8 ± 0.8c44.83.92 ± 0.8b
Thalapa1.5 ± 0.1a4.2 ± 0.1d1.7 ± 0.2d30.5 ± 1.8b13.3 ± 0.1c13.8 ± 0.6d45.25.36 ± 3.3c
Porridge2.3 ± 0.2c7.2 ± 0.1c6.6 ± 0.4b45.2 ± 1.2d17.6 ± 0.6d25.5 ± 2.5e56.43.01 ± 0.6b
Reducing power (RP) µmol ascorbic acid equiv/g of dm
Rotti14.1 ± 0.7a22.2 ± 0.2a31.8 ± 1.7a36.6 ± 3.0a18.1 ± 0.1a15.5 ± 1.2a42.322.9 ± 5.2a
Pittu9.7 ± 1.0b10.5 ± 0.1b17.4 ± 1.9b58.1 ± 0.7b7.5 ± 0.7b48.6 ± 1.8b83.617.3 ± 1.0b
Halape5.1 ± 0.7c26.9 ± 0.3c17.2 ± 1.8b52.0 ± 1.1c19.3 ± 1.6a31.8 ± 2.8c61.221.3 ± 2.5a
Thalapa12.3 ± 0.2d15.5 ± 0.5d13.3 ± 0.2c47.7 ± 0.1d16.2 ± 1.4c28.6 ± 2.9d59.915.5 ± 4.0b
Porridge17.7 ± 0.7e28.5 ± 0.2e28.0 ± 1.0d53.8 ± 1.9e10.1 ± 0.9d46.3 ± 1.1e79.421.3 ± 3.3a
Ferrous ion chelating ability (FICA) µmol EDTA equiv/g of dm
Rotti56.2 ± 1.2a102.3 ± 1.2a129.5 ± 3.2a187.5 ± 0.5a23.1 ± 2.3a154.2 ± 3.2a82.231.13 ± 2.9a
Pittu54.3 ± 2.0a108.4 ± 1.3a134.4 ± 3.4b175.2 ± 0.4b17.3 ± 2.1b143.5 ± 2.4b81.923.56 ± 0.8b
Halape65.2 ± 1.3b105.3 ± 1.2a120.6 ± 3.0c165.5 ± 0.3c14.5 ± 1.4c140.5 ± 2.1b84.824.24 ± 7.6b
Thalapa45.1 ± 1.4c95.2 ± 1.3b101.2 ± 2.1d190.2 ± 0.1d23.1 ± 1.0a165.2 ± 2.2c86.824.68 ± 4.7b
Porridge40.3 ± 1.0c90.2 ± 0.8b110.1 ± 2.1d183.2 ± 0.4d20.4 ± 1.5a153.4 ± 1.2d83.731.13 ± 3.9a