Effect of quality of milk on maillard reaction and protein oxidation during preparation of cow and buffalo milk khoa

Abstract

The browning indicators (Lactulose, HMF and Furosine) and protein bound carbonyls were used to assess the effect of developed acidity and subsequent neutralization of milk at various stages of khoa (heat desiccated milk product) preparation. Available lysine was also analyzed in raw milk and final product i.e. khoa. Available lysine decreased as milk progressed to khoa preparation. Present study indicated that increase in heating intensity resulted in increased concentration of browning indicators and protein bound carbonyls (PC) in boiled milk and khoa. Concentration of browning indicators was found to be significantly higher in buffalo milk and khoa samples whereas, PCconc. was higher in cow milk and khoa samples. Neutralization of milk significantly affected Maillard reaction by elevating concentration of browning indicators and PC in both milk and khoa.

Keywords: Furosine; HMF; Khoa; Lactulose; Protein bound carbonyls.

Fig. 1

Lactulose, HMF and Furosine concentration of milk during preparation of khoa at raw milk, boiled milk and khoa stage. a Lactulose concentration in Buffalo milk. b Lactulose concentration in Cow milk. c HMF concentration in Buffalo milk. d HMF concentration in Cow milk. e Furosine concentration in Buffalo milk. f Furosine concentration in Cow milk. ^a–c Different lowercase letters denote significant difference (p < 0.05) between groups (raw milk, boiled milk and khoa). Error bars show the variations of three determinations in terms of standard error of mean. ^A–C Different uppercase letters denote significant difference (p < 0.05) across sub-groups [(FBM, ABM and NBM) and (FCM, ACM and NCM)]. FBM Fresh buffalo milk, ABM Acidic buffalo milk, NBM Neutralized buffalo milk and FCM Fresh cow milk, ACM Acidic cow milk, NCM Neutralized cow milk)