Effect of Emblica Polyphenols on the Processing Quality of Fried Instant Noodles

Macroporous adsorption resin LSA-10 was used to purify emblica polyphenol (EP), while the purified polyphenols were added into flour to make fried instant noodles and the major phenolic compounds were measured by high performance liquid chromatography. The effects of EP on cooking characteristics, texture properties and oil oxidation of fried instant noodles were investigated. The results showed that ellagic acid (EA), corilagin and gallic acid were major phenolic compounds in the EP extracts. The contents of three phenolic compounds (EA, corilagin and gallic acid) were (45.2±0.1), (16.6±0.5) and (22.1±0.7) mg/g extract, respectively. The retention rates of the three polyphenols in fried instant noodles were all above 30%. The addition of EP could reduce the rehydration time of fried instant noodles. When the addition amount increased to 1%, the rehydration time of instant noodles decreased significantly (P<0.05), from (125±3.5) s to (108±2.2) s. However, with the increase of EP, the cooking loss and water absorption increased significantly compared to the control sample (P<0.05). The results of texture analysis showed that EP had a significant effect on the texture characteristics of instant noodles. The hardness, elasticity, adhesiveness and chewiness of noodles increased significantly with the addition of 0.5% to 1% (P<0.05). However, the hardness, stickiness and chewiness of noodles decreased significantly when the addition amount was more than 1.5% (P<0.05). The peroxide value (POV) and acid value (AV) of fried instant noodles were significantly decreased by adding more than 1% EP (P<0.05). During the 10 day experiment period, POV and AV were lower than 0.25 g/100 g and 1.8 mg/g of national standard, respectively. The antioxidant activity of EP was closely related to the content of three polyphenols, and the antioxidant capacity was positively related to the phenolic hydroxyl number of polyphenols. Therefore, the addition of EP can improve the processing of fried instant noodles, and inhibit the oil oxidation.