Influence of high-oryzanol rice bran oil on the oxidative stability of whole milk powder.
The effect of high oryzanol rice bran oil (RBO) on the oxidative stability of low-heat and high-heat whole milk powder (WMP) was investigated. Milk (3.6% fat) was fortified with RBO at 0.1 and 0.2% (wt/wt) and was concentrated and dried. Control WMP was made without RBO addition. Thiobarbituric acid reactive substances (TBARS) were used to monitor oxidation during storage at 45 degrees C for 40 d. The oxidation of low-heat WMP was significantly reduced by addition of 0.1% RBO, but there was no significant effect on the oxidation of high-heat WMP. An increase of RBO to 0.2% did not significantly improve the oxidative stability when compared with 0.1% RBO. The TBARS in RBO-fortified, low-heat WMP increased with storage time up to 30 d but decreased with further storage to 40 d. The TBARS in all high-heat WMP and low-heat control WMP increased up to 20 d storage and then decreased with further storage. The most likely reason for this increase was due to the reaction of TBARS with milk proteins. Addition of RBO reduced the L (lightness) value and increased the b (yellowness) value but had no effect on the a (redness) value. When compared with the control milk powder, consumers could not detect any effect on the flavor of the reconstituted 0.1% RBO WMP but could detect a flavor difference in the 0.2% RBO WMP.
Nanua
J N
JN
Dairy Science Department, Louisiana Agricultural Experimental Station, Louisiana State University Agricultural Center, Baton Rouge 70803, USA.
McGregor
J U
JU
Godber
J S
JS
D000818:Animals; D002417:Cattle; D003611:Dairy Products; D005527:Food, Fortified / Q000032:analysis*; D008892:Milk / Q000737:chemistry*; D008894:Milk Proteins / Q000737:chemistry*; D010084:Oxidation-Reduction; D010666:Phenylpropionates / Q000737:chemistry*; D010938:Plant Oils / Q000737:chemistry*; D000073879:Rice Bran Oil; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis
D008894:Milk Proteins; D010666:Phenylpropionates; D010938:Plant Oils; D017392:Thiobarbituric Acid Reactive Substances; D000073879:Rice Bran Oil; C013172:gamma-oryzanol