Table 4 Various processing methods for removing antinutrients from flaxseed cake and flaxseed (whole)

Physical

Flaxseed Cake

Heated at 90 °C for 1 h which was stirred continuously.

94.3% reduction due to either heat.

Deactivation of glycoside or

evaporation of HCN (which is

formed after hydrolysis) or both takes place.

Safdar et al. (2020)

Boiling for 15–30 min at intervals of 5 min.

94.3% removal of HCN

Soaking for 12–48 h at intervals of 12 h.

48.2% removal of HCN

Autoclaving at 120 °C for 5–20 min at interval of 5 min.

62.6% reduction of HCN

Flaxseed (whole)

Pelleting under high pressure and temperature

Repeated pelleting (with or without other ingredients decreased HCN content.

Feng et al. (2003)

Autoclaving to sterilize at 16.5 kg cm⁻² at 120 °C for 15 min

High temperature inactivates glycosidase, decreased HCN to negligible levels.

Steaming-

Reduction in tannins by2.86%2.39%2.06%

Damayanti and Sjofjan (2022)

Treatment time for tannin-10 min20 min30 min

Reduction in phytic acid by38.39%33.88%29.73%

Treatment time for phytic acid-10 min20 min30 min

Removal of HCN upto detectable limit

Microwave-400 W power for 4 min 50 s

80.72% and 50.87% reduction of cyanogenic glycosides and phytic acid respectively.

Dusica et al. (2012)

Germination-Incubation at 42 °C

70% reduction in cyanogenic glycosides.

Kajla et al. (2017)

Sprouting in dark for 4 days at 20 ± 2 °C

70% reduction in cyanogenic glycoside content.

Hady & Elsorady (2020)

Soaking done for 12 h followed by germination

39.72% reduction in trypsin inhibitor activity

Khare et al. (2021)

Fermentation

Flaxseed cake

Aspergillus niger and Candida utilis (1:1 ml inoculum incubated at 30 °C

for 72 h)

The lowest HCN was observed after 60 h fermentation.

Zhai et al. (2019)

Flaxseed (whole)

Fermentation using consortium of Lactobacilli (incubated at 30 °C for 72 h)

Reduced the cyanogenic glycosides to undetectable limits.

Huang et al. (2023)

Enzymatic treatment

Flaxseed cake

Incubation with 0.1 M sodium citrate

buffer at 30 °C for 18 h.

100% removal of cyanogenic compounds

Yamashita et al. (2007)

Flaxseed (whole)

12.5% beta-glucosidase and 8.9% cyanide hydratase (no use of steam to evaporate HCN which prevents environmental pollution and low energy consumption) followed by fermentation

Up to 99.3% reduction in cyanogenic glycosides after 48 h of fermentation.

Wu et al. (2012)

Extrusion

Flaxseed cake

Extrusion conditions-

screw speed- 96.8 rpm,

barrel temperature-80 °C

40% moisture level

Reduction of tannin by 61.27%

Mukhopadhyay et al. (2007)

Multi-stage solvent treatment

Flaxseed cake

Increasing the volume of solvent and duration of extraction.

Multistage extraction using methanol-ammonia-water or hexane as solvents

80% removal of linustatin and neolinustatin.

Up to 90% removal of cyanogenic glycosides.

Among the solvents used, methanol was found to be the most efficient solvent for removal of CGs.

Wanasundara et al. (1993)