Background: The refusal of infants to suckle from a breast that is inflamed with mastitis suggests that the taste of the milk has changed. However, the taste of milk from a breast with mastitis has never been empirically determined. The present study compares the taste of milk from breastfeeding mothers with or without mastitis and identifies specific changes in the taste of milk from mothers with mastitis.
Subjects and methods: The intensity of four basic tastes (sourness, saltiness, bitterness, and umami) of breastmilk from 24 healthy mothers at 3-5 days and at 2-3, 4-5, and 8-10 weeks postpartum and from 14 mothers with mastitis was determined objectively using a taste sensor. The intensity of each basic taste and the concentrations of main taste substances in milk were compared between the inflamed breasts and the normal breasts of control mothers or the contralateral asymptomatic breast of mothers with unilateral mastitis.
Results: The transition from colostrum to mature milk was accompanied by changes in the taste of the milk, such as decreased saltiness and umami and increased bitterness and sourness. Umami and saltiness increased in milk from inflamed breasts. Contents of sodium, glutamate, and guanosine monophosphate increased in milk from inflamed breasts.
Conclusions: Tastes that were specifically associated with inflamed breasts appeared to include an increase in umami and saltiness, which might have resulted from an increased content in factors associated with umami and sodium.