...International. 16th Edition, AOAC International, Arlington...

来自 : www.oalib.com/references/20660 发布时间：2021-03-24

ABSTRACT: Elevation of acid degree values (ADV) and peroxidevalue (POV) indicates deterioration of nutritional and sensory qualities ofdairy products during storage. Iron fortification in bovine milk cheeses inrelation to lipolytic parameters and their correlations have been studied,while no such studies have been reported on caprine milk cheeses. Theobjectives of this study were to evaluate levels of ADV and POV of iron fortified[regular ferrous sulfate (RFS) and large microencapsulated ferrous sulfate(LMFS)] goat milk Cheddar cheeses compared to those of non-fortified controlcheese (CC) and their correlations. Three batches of 3 types (CC, RFS and LMFSadded) of goat milk cheeses were manufactured and stored at two temperatures (4 deg;C and -18 deg;C) for 0, 2 and4 months. Iron was supplemented to RFS and LMFS cheeses by 8.23 g and 9.03 gper 9 kg, respectively. ADV and POV were determined using standard methods ofexamining dairy products (Richardson, 1985) and AOCS (1975) procedures. Resultsshowed that ADV values for CC, RFS and LMFS cheeses for 0 and 4 month storageat 4 deg;C were: 0.67, 0.73,0.64; 1.24, 1.78, 1.58, respectively, indicating significant (P 0.05)elevations occurred in ADV for all three cheeses during 4 months storage. The cheesesamples at 4 months storage showed significantly (P 0.05) higher peroxidevalues compared to 0 and 2 month stored ones. The samples stored at refrigerationtemperature (4 deg;C)revealed slightly more lipid oxidation than those stored at frozen temperature(-18 deg;C). Significant (P 0.05) elevations inPOV for all goat cheeses stored for 4 months and slight increases in POV athigher temperature implies that the longer time and higher temperature storagecan elevate the rate of lipid oxidation in goat milk Cheddar cheeses. Correlations(r) between ADV and POV for the pooled data of three types of the caprine cheesesacross storage periods were significant (P 0.01), while r values of CCcheeses alone were negative. It was concluded that significant correlationsexist between extents of lipolysis and lipid oxidation in the caprine milk Cheddarcheeses during 4 months storage.