Table 2.
Thermal, chemical, and combination processing of millets relating to the starch digestibility and its action
| SI no | Millet | Processing | RDS (%) | SDS (%) | RS (%) | PGI | Action | References |
|---|---|---|---|---|---|---|---|---|
| Thermal treatments | ||||||||
| 1 | Foxtail millet flour | Heat moisture | 12.46 | 8.65 | 19.25 | – | Increase in SDS and RS, reduced glycaemic response | Amadou et al. (2014) |
| 2 | Barnyard millet grain | Microwave treatment | 15.56 | – | High RS content due to microwave drying | Kanagaraj et al. (2019) | ||
| 3 | Foxtail millet Starch | Annealing | 41.53 | 16.15 | 42.32 | – | The annealing promoted the interaction of amylose with amylose and amylopectin which increased the RS | Babu et al. (2019) |
| 4 | Pearl millet starch | Heat moisture | 36.6–42.2 | 39.1–40.2 | 18.1–23.8 | – | SDS and RS increased restricted the activity of alpha amylases | Sandhu et al. (2020) |
| 5 | Sorghum grain | Infra-red treatment with 30% moisture | 12.64–30.87 | 40.07–51.85 | 48 | Starch kafrin complex might have increased the RS and reduced GI | Semwal and Meera (2021) | |
| 6 | Sorghum starch | Infra-red treatment with 30% moisture | 4.57–14.27 | 37.55–47.92 | 61 | Starch protein interaction with infra-red treatment increased the RS and reduced GI | Semwal and Meera (2021) | |
| 7 | Pearl millet flour | Heat moisture | 52.61 | 7.68 | 1.75 | – | Crystalline disruption by heat moisture treatment and increased accessibility of enzymes | Vinutha et al. (2022) |
| 8 | Pearl millet flour | Infra-red | 51.13 | 9.46 | 1.77 | – | Crystalline disruption by infra-red treatment and increased accessibility of enzymes | Vinutha et al. (2022) |
| Chemical treatments | ||||||||
| 9 | Pearl millet starch | Cross-linking | 46.1–50.6 | 34.5–36.1 | 13.6–19.4 | – | Increase in RS reduced the activity of alpha amylase | Siroha and Sandhu (2018) |
| 10 | Pearl millet starch | Acetylation (5.0%) | 45.4 | 27.3 | 27.3 | – | Increase in RS restricted the activity of digestive enzyme | Siroha et al. (2019) |
| 11 | Foxtail millet starch | Succinilayation | 76.31 | 15.39 | 8.29 | – | Reduced in RDS with increase in SDS and RS | Babu and Mohan (2019) |
| Combination of treatments | ||||||||
| 12 | Foxtail millet flour | Heat moisture and fermentation | 15.92 | 18.42 | 22.68 | – | Combination has promoted increase RDS and RS due to proteolysis of starch | Amadou et al. (2014) |
| 13 | Foxtail millet starch | Acid treated and succinilayted | 69.58 | 12.22 | 18.19 | – | Acid hydrolysis increased amylopectin regions which increased RS | Babu and Mohan (2019) |
| 14 | Foxtail millet | Ultrasonication and annealing | 40.57 | 13.84 | 45.59 | – | The combination treatment promoted the interactions of amylose with amylose and lipid which lead to increase in crystallinity and increase in RS | Babu et al. (2019) |
| 15 | Pearl millet flour | Heat moisture and infra-red | 49.23 | 12.34 | 1.75 | – | SDS increased | Vinutha et al. 2022) |
RDS Rapidly digestible starch; SDS Slowly digestible starch; RS Resistant starch; PGI Predicted glycaemic index