Optimization of antioxidant extraction process from corn meal using pulsed electric field‐subcritical water

Abstract

In this study, response surface method was used to optimize the extraction of antioxidant extract from corn meal using pulsed electric field (PEF)‐subcritical water extraction (SWE) method. Then the extract was used to evaluate its effect on the oxidative stability and fatty acid profile of sesame oil. The corn meal was subjected to different PEF intensities (0.5, 2.5, and 4.5 kV/cm) and then SWE was performed at 110, 130, and 150°C for 30 min. Different properties of the extract including extraction efficiency, phenolic compounds, and 2,2‐diphenyl‐1‐picryl hydrazyl (DPPH) radical scavenging activity and Vitamin C content were measured. The results showed that extraction efficiency, total phenol, and ability to DPPH radical scavenging activity increased at first, but they then decreased by increasing in PEF intensity and subcritical water temperature. In addition, vitamin C content of the extract decreased at higher subcritical water temperature. The optimum processing condition to achieve the highest extraction efficiency and nutritional values was 2.51 kV/cm and 127.91°C. The addition of antioxidants had no effect on changing the profile of fatty acids in sesame oil. The samples containing BHA and 750 ppm of extract showed the same oxidative stability. Finally, PEF‐SWE method is introduced as a suitable method for extracting antioxidants. Novelty impact statement Pulsed electric field (PEF)‐subcritical water method was used to improve the antioxidants extraction from corn meal. The optimum extraction conditions were 2.51 kV/cm and 127.91°C. Addition of antioxidants had no effect on changing the profile of fatty acids in sesame oil, and the antioxidant extract improved the oxidative stability of the oil.

Valorisation of food processing wastes using PEF and its economic advances – recent update

“…However, the SWE temperature above 130°C and PEF field strength above 2.5 kV cm −1 reduced the extraction efficiency due to the destructive nature of both treatments. (Hosseini et al ., 2021).…”

“…76 AE 0.83 mg g −1 dw Hesperidin = 46.96 AE 3.37 mg g −Catechins = 2.0 AE 0.2 mg/100 g Coumaric acid = 0.8 AE 0.2 mg/100 g Chlorogenic acid = 9.8 AE 1.0 mg/100 g Neochlorogenic acid = 16.3 AE 2.6 mg/Caffeic acid = 12.02 AE 1.64 mg/L Kaempferol = 51.21 AE 0.85 mg quercetin/L Cinnamic acid = 8.43 AE 2.36 mg caffeic acid= 204.36 (mg GAE/100 g) Vitamin C = 16 mg/100 g(Hosseini et al, 2021) …”