http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Inhibitory properties of pepsin digested lactoferrin in apple and carrot juice
Lactoferrin was isolated from raw skim milk and apolactoferrin was prepared from the lactoferrin to test their antimicrobial activity in peptone-yeast-glucose broth. The lactoferrin and the apolactoferrin were digested by pepsin for 4 hr at pH 3.0 and lyophilized to determine the activity of the digests in peptone-yeast-glucose broth, apple juice, and carrot juice using E. coli (ATCC 35343) as the test organism. The minimum inhibitory concentrations of lactoferrin and apolactoferrin in peptone-yeast-glucose broth were 0.4 and 0.2 mg/mL of broth, respectively. Removal of iron from lactoferrin before pepsin digestion caused a slight improvement in the inhibitory action of the peptic hydroxylate. However, the minimum inhibitory concentration of the pepsin digest of lactoferrin was 0.08 mg/mL of broth and was not different from the minimum inhibitory concentration of the pepsin digest of apolactoferrin. The E. coli did not grow in apple juice at pH 4.6. Pepsin digested lactoferrin at 0.7 and 1.5 mg/mL of apple juice did not inhibit growth of the E. coli at pH 4.6 or pH 7.0. The peptic digest of lactoferrin did not have antimicrobial properties in carrot juice at a concentration of 10 mg/mL of juice. The carrot juice was filtered through a membrane with a molecular weight rejection of 10,000 Dalton and the permeate was dialyzed against distilled water. Growth of E. coli was delayed in filtrates of carrot juice by 5 mg but not by l mg of peptic digest of lactoferrin/mL of filtrate. However, after incubation for 24 hr, the bacterial counts of the control and the experimental samples were not different. The peptic digest of lactoferrin at 5 mg of digest/mL. of dialyzate had a bactericidal effect on the E. coli after 24 hr of incubation at 23C̊. The composition of carrot juice, permeate and dialyzate was determined. Dialysis of the permeate caused a percentage reduction in cation concentration in the permeate that ranged from 69.23% (Co) to 99.32% (Na). The data indicated the factor in carrot juice that eliminates the antimicrobial activity of lactoferricin might be cations.
"Major subject: Food Science and Technology".
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Includes bibliographical references (leaves 57-64).