Physico-chemical study of steroids from different matureness corn silk material

Abstract

This study shows an ultrasonic assisted extraction procedure of steroids from corn silk (CS). The total steroids contents were positively correlated with the ultrasonic assisted extraction time. The extracted steroids contents varied according to the different maturity stages of CS. There were three tested CS maturity stages: silking stage (CS-S), milky stage (CS-M) and mature stage (CS-MS). The β - sitosterol standardization method with 530 nm wavelength colorimetric measurements were applied to determine the content of extracted steroids. Measured steroids concentrations range were from 38.3 × 10-3 mg.mL-1 to 368.9 × 10-3 mg.mL-1 in different extraction time and CS maturity stages. The highest concentration of steroids, 368.9 × 10-3 mg.mL-1 was found in CS-MS sample with the 75 minutes ultrasonic extraction time. The fluorescence mapping techniques were used to confirm the existence of steroids. The thermal analysis illustrated a typical multistep decomposition process for the CS-S, CS-M and CS-MS samples. Two endothermic peaks were found: The first one was 54.3 °C for CS-S and CS-MS, 60.2 °C for CS-M, the second one, 397 °C (CS-MS), 415.1 °C (CS-M) and 419.7 °C (CS-S) attributed to the total thermal decomposition. The observed exotheric process found at 524 °C corresponded to CS-MS sample decomposition. The optimal ultrasonic-assisted extraction time for all samples under study CS-S, CS-M and CS-MS was about 75 minutes and the optimal steroids extraction contents obtained were 92.8 × 10-3 mg.mL-1 (CS-S), 124.2 × 10-3 mg.mL-1 (CS-M) and 368.9 × 10-3 mg.mL-1 (CS-MS) respectively.

A Physicochemical Study of the Antioxidant Activity of Corn Silk Extracts

“…In the range of 60-75 min, a slight increase in steroids content was detected. Therefore, 75 min of ultrasonication at laboratory temperature may be defined as the optimal extraction time to gain the maximum steroids content for all CS maturity stages under study, as also confirmed in our previous study [38]. The CS-MS sample yielded the highest steroid concentration (0.37 mg/mL) accompanied with the increased extraction rate via ultrasonic treatment compared to the CS-M sample (0.12 mg/mL) and CS-S (0.09 mg/mL).…”

“…Steroids extraction kinetics was characterized as a non-linear third-order polynomial dependency [38]. However, there was a proportional trend between corn silk steroid concentration and ultrasonic processing time from 15 to 60 min.…”

“…Compared to hot water extraction, the yield of CSP increased, and the enzyme-ultrasonic assisted extracts showed higher antioxidant activities, due to the conformation changes in CSP. In our previous studies, we focused on optimal extraction conditions and extraction yield of corn silk flavonoids [9] and steroids [38].…”

The influence of beet pectin concentrate and whole-ground corn flour on the quality and safety of hardtacks

“…Analysing the vitamin composition of whole-ground corn flour in comparison with first-grade wheat flour, it can be concluded that corn flour is rich in vitamins [47], [48], [49]. In particular, the content of niacin (vitamin PP) in corn flour is 1.54 times higher than in wheat flour.…”