Toshiya Kobayashi

Serum albumin forms a lactoferrin-like soluble iron-binding complex in presence of hydrogen carbonate ions.

The iron-lactoferrin complex is a common food ingredient because of its iron-solubilizing capability in the presence of hydrogen carbonate ions. However, it is unclear whether the formation of a stable iron-binding complex is limited to lactoferrin. In this study, we investigated the effects of bovine serum albumin (BSA) on iron solubility and iron-catalyzed lipid oxidation in the presence of hydrogen carbonate ions. BSA could solubilize >100-fold molar equivalents of iron at neutral pH, exceeding the specific metal-binding property of BSA. This iron-solubilizing capability of BSA was impaired by thermally denaturing BSA at ≥ 70 °C for 10 min at pH 8.5. The resulting iron-BSA complex inhibited iron-catalyzed oxidation of soybean oil in a water-in-oil emulsion measured using the Rancimat test. Our study is the first to show that BSA, like lactoferrin, forms a soluble iron-binding complex in the presence of hydrogen carbonate ions.

Iron–Lactoferrin Complex Reduces Iron‐Catalyzed Off‐flavor Formation in Powdered Milk with Added Fish Oil

UNLABELLED The iron-lactoferrin complex (FeLf) is useful for dietary iron supplementation. However, the effects of FeLf on iron-catalyzed off-flavors in lipid-containing food products have not been reported. In this study, we investigated the effects of FeLf on off-flavors development during the production and storage of powdered milk with added fish oil. Powdered milk samples were formulated with FeLf or iron (II) sulfate, then stored at 37 °C for 5 mo. A sensory evaluation revealed that FeLf delayed the development of oxidized flavor and reduced metallic taste in the powdered milk compared with iron (II) sulfate. Headspace gas chromatography-mass spectrometry analysis showed that oxidized volatile compounds, such as pentanal, hexanal, heptanal, octanal, 1-penten-3-one, (Z)-4-heptenal, (E, E)-2,4-heptadienal, and (E)-2-octenal, were less developed in the powdered milk containing FeLf than in that containing iron (II) sulfate. Iron and lactoferrin (Lf) were retained in the high-molecular-weight (>10000 Da) fraction of the reconstituted FeLf-containing powdered milk after its manufacture and storage, whereas the antigenicity of Lf was lost after ultrahigh-temperature processing at 120 °C for 5 s. These results suggest that FeLf reduces the iron-catalyzed off-flavors that develop during the production and storage of powdered milk. The stable iron-holding property of FeLf contributes to the inhibition of oxidized and metallic volatile formation, although the loss of Lf antigenicity did not affect the stability of FeLf and the iron-catalyzed formation of off-flavors in the powdered milk. Consequently, FeLf is a suitable candidate for the simultaneous supplementation of a single food with iron and fish oil. PRACTICAL APPLICATION The supplementation of food products with iron and fish oil is a useful approach to redressing their inadequate intake in many populations. The iron-lactoferrin complex can protect food products against the off-flavors caused by iron-catalyzed lipid oxidation. Our results show that the iron-lactoferrin complex is useful for the simultaneous fortification of foods and nutraceuticals with iron and fish oil because this complex also reduces the formation of iron-catalyzed off-flavors in powdered milk enriched with fish oil.

Effects of a Bovine Lactoferrin Formulation from Cow’s Milk on Menstrual Distress in Volunteers: A Randomized, Crossover Study

Dysmenorrhea is a highly prevalent complaint and highly undiagnosed gynecologic condition. Dairy products have a potential in the management of menstrual distress, and bovine lactoferrin can help the subjective dysphoria associated with dysmenorrhea. In the present study, we aimed to investigate the effects of a lactoferrin formulation isolated from cow’s milk on menstrual symptoms in volunteers. A double-blind, randomized, placebo-controlled, crossover study of the iron-lactoferrin complex (FeLf) was performed in thirty-five healthy Japanese women. Participants received the 150 mg FeLf (per day) or placebo from day ten of the luteal phase to day four of the follicular phase. The Moos Menstrual Distress Questionnaire (MDQ) was measured for menstrual distress, and heart rate variability was measured as an index of autonomic nerve balance during menses. A visual analog scale for menstrual pain, and a verbal rating scale for quality of life during the first three days of menstruation were measured. The MDQ score for the automatic nervous system subscale was lower and the parasympathetic nervous system activity was greater in FeLf than in placebo for intention-to-treat or per-protocol populations. The other variables were not different between the groups. No treatment-related side effects were observed during the study. The results indicate that FeLf can provide a beneficial effect on the psychological symptoms in women affected by menstrual distress.