Effect of the storage time and temperature on phenolic compounds of sorghum grain and flour

• After 180 days there was effect of the storage time on the all compounds.
• There was no effect of storage temperature on the most compounds contents and color.
• After 180 days the retentions of the total anthocyanin and phenols were almost 90%.
• The retentions of tannins and all 3-deoxyanthocyanidins were above 50%.
• The color remained stable during 120 days of storage in all temperatures evaluated.

This study evaluated the effect of storage temperature (4, 25 and 40 °C) and time on the color and contents of 3-deoxyanthocyanins, total anthocyanins, total phenols and tannins of sorghum stored for 180 days. Two genotypes SC319 (grain and flour) and TX430 (bran and flour) were analyzed. The SC319 flour showed luteolinidin and apigeninidin contents higher than the grain and the TX430 bran had the levels of all compounds higher than the flour. The storage temperature did not affect most of the analyzed variables. The content of most of the compounds reduced during the first 60 days when they became stable. At day 180, the retention of the compounds in the genotypes SC319 and TX430 ranged from 56.1–77.9% and 67.3–80.1% (3-deoxyanthocyanins), 88.4–93.8% and 84.6–96.8% (total anthocyanins) and 86.7–86.8 and 89.4–100% (phenols) respectively. The retention of tannins ranged from 56.6 to 85.3%. The color of samples remained stable for 120 days.