Table 2 Changes in the raw material (natural starch) after treating with microwave radiation

Maize

Moisture content up to 30% (w/w)

2450 MHz microwave oven

Output power 1.2 kW

The content of amylopectin decreased, relative crystallinity increased initially then decrease, granules were completed, the degree of gelatinization, and digestibility increased

[64]

Chickpeas

2450 MHz microwave oven

Power of 565 W (90% maximum power)

Temperature 105 °C

Mineral content decreased slightly, starch gelatinized, slow digesting starch decreased, fast digesting starch increased

[40]

Lycoris

Heated for 120 s at a power level of 200 W, followed by heating at 50 °C in a convection oven until the moisture content was approximately 8%

Granules collapsed and developed the characteristics of a massive, rough or irregular surface; the tendency to aggregate was strong and retrogradation was poor

[67]

Rice

Power values of 4, 8, or 10 W/g for 3 min

The number of microcrystalline and periodic amorphous structures increased and digestibility decreased

[68]

Taro

The moisture content was adjusted to 25%, heated for 5 min at power level 180 W

Amylose content increase, the swelling and solubility of the modified starch increased, the water retention, and final viscosity increased

[66]

Indian Horse chestnut

Moisture content tempered to 22% ± 3% Exposure to microwave radiation for 15, 30 and 45 s

The morphology of starch granules was round and ellipse, the surface was smooth, the water absorption and light transmittance increased, the apparent amylose content decreased, and the antioxidant activity increased

[69]

Potato

Heated for 5 min in a laboratory microwave oven (2450 MHz) at 440 or 800 W

Viscosity decreases, heat treatment temperature is low, free radicals increase

[70]

Millet

Duration of exposure to microwave radiation was 60 s

The power level was 700 W, and the moisture content was adjusted to 30%, 35%, 40%, 45%, and 50%

The peak viscosity decreased, the swelling force decreased, the molecular order decreased, the digestibility of amylose increased, and starches gelatinized

[49]

Yam

Operated at 2450 MHz and full power of 700 W (130–140 °C) for 5 min, then at 100 W for 2 h (60–70 °C)

The moisture content decreased, the total starch content decreased, the amylose content increased, the slow digesting starch content was high, and the swelling power decreased

[71]

Fritillaria

Thunbergia,

Miq

Operated at 2450 MHz

and full power (700 W) for 5 min (130–140 °C), and then at 100 W for 30 min (60–70°C)

The total starch content was low, the swelling force was reduced, the surface of the grain was not uniform, there were a lot of lamellar bands, the crystal structure was destroyed, and the digestible starch was increased

[72]