Effects of adding fumaric acid on phytochemical antioxidation and antimicrobial stabilities in baked corn products

Abstract

The objectives of this study were: (1) to investigate the effects of adding fumaric acid supplementation on the total phenolics (TPN), total anthocyanins (ACN), 2,2-Diphenyl-1-picrylhydrazyl radical scavenging ability (DPPH-RSA), 2,22-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging ability (ABTS-RSA), Ferrous chelating ability (FCA), total plate count (TPC) and total fungi count (TFC) stabilities in baked corn products, and (2) to investigate the effects of storage condition of baked corn products on TPC and TFC. Purple corn contained higher DPPH-RSA ABTS-RSA and FCA (2.3, 6.9 mg Trolox equivalents (TE)/g and 77 g EDTA/g) than white corn (2.0, 6.2 mg TE/g & 36 g EDTA/g), however the TPN content (1.9 mg GE/g) was lower than that of white corn (2.1 mg GE/g). Amounts of ACN was not detected in White corns while purple corn kernels contained 270 g CE/g. Heating corn kernels in alkaline solution had the greatest negative impact on the stability of TPN, ACN, DPPH-RSA, ABTS-RSA and FCA. However, the dough acidification of white and purple corn could reduce TPN, DPPH-RSA, ABTS-RSA and FCA losses (5 and 9%, 4 and 4%, 5 and 2%, 5 and 6% and 6 and 12%, respectively). Similarly, ACN losses were also reduced when processed into dough (16%) and bake purple corn product (13%). In addition, acidified treatment of baked corn products also signicicantly reduced the microbial growth. Acidified baked purple corn product contained lower amount of TPC and TFC (1,030 and 25 CFU/g) than acidified baked white corn product (3,100 and 26 CFU/g). Storage condition of products at -18 ฐC could reduced the growth of microbial than storage conditions at room temperature and 4 ฐC. This study confimed that dough acidification could reduce the phytochemical and antioxidation losses as well as microbial growth.