effect of pH on flavor formation and antioxidant activity of amino acid and sugars interaction products

ABSTRACT

Flavor is the crucial part of eating quality. In the preparation of natural identical flavor in different model systems like cysteine- ribose [cys-rib], cysteine-glucose [cys- glu] and cysteine-beef fat [cys-BF] affected at different pH [4.5, 7 and 10] a wide range of flavors was obtained. The proteins as glutamine, glutamic acid and the sugars as D- ribose and D-glucose,l,l-diphenyl-2-picrylhydrazyl [DPPH] and beta-Carotene and all the lab grade chemical as Linoleic acid, Polyoxyethylene sorbitan monopalmitate [Tween-80], Chloroform [99%], Anhydrous sodium sulfate, Dichloromethane [99.8%], 0.1 N HC1 and 0.1N NaOH, Gallic acid, Sodium carbonate, Folin-Ciocalteu reagent were used to conduct research. In sugar and amino acid model system, roasted and burnt meat flavor was obvious while in beef fat model system boiled meat flavor was dominated which was strongly supported by sensory evaluation. In rib-cys and glu-cys model systems total phenolic contents [TPC] were highest at pH 7 and pH 4.5, respectively along with browning, leading to strong antioxidant activity. In beef fat-cys model system it was found that as pH increases TPC, browning increases and antioxidant activity becomes maximum at basic pH. All the results indicated that, there is a positive relationship between the TPC, browning and antioxidant activity of all model systems