Recently, the media reported that some Mainland brands of infant formula were found to contain trans fats. Indeed what are trans fats and why do they appear in infant formulae?

Trans fats are unsaturated fats with at least a double bond in trans configuration. Trans fats in foods originate from three main sources: (i) bacterial transformation of unsaturated fats in the stomach of ruminants (e.g. cattle, sheep, goats); (ii) industrial hydrogenation (used to produce semi-solid and solid fats) and deodorisation (a necessary step in refining) of vegetable oils high in polyunsaturated fats; and (iii) during heating and frying of oils at extreme high temperatures.

Bacteria in the stomach of ruminants biohydrogenate some of the ingested unsaturated fats to trans fats. Therefore, trans fats can be present naturally in milk, cheese, butter, meat/meat products of ruminants, etc.. Overseas literature shows that dairy and beef fat typically contains around 3-6% trans fats (% of total fat).

The Codex Alimentarius Commission* (Codex) has stated that trans fats are endogenous components of milk fat. According to the Codex standard for infant formula, the content of trans fats in an infant formula shall not exceed 3% of total fatty acids.

To better protect the health of infants and young children, the Administration is currently drafting legislative proposals on formula products and foods intended for infants and young children under the age of 36 months. The legislative proposals comprise requirements on nutritional composition of infant formulae and nutrition labelling of infant formulae, follow-up formulae and other foods for infant and young children.

* The Codex Alimentarius Commission (Codex) was established in 1963 by the Food and Agriculture Organization of the United Nations and World Health Organization as an international authority to set food-related standards and guidelines.