Vitamin D is a human hormone known mainly for its relevance in bone formation, as it is involved in calcium and phosphorus absorption at intestinal level. However, in recent decades it has been discovered that it also plays a valuable role in strengthening the immune system and in brain development, in addition to having an anti-inflammatory role.
There is, however, a severe vitamin D deficiency problem worldwide, of which Chile is no exception. For example, the 2016-2017 National Health Survey revealed that 84% of women between the ages of 15-49 had some degree of deficiency (16% with severe deficit), while in older adults only 13.4% presented acceptable levels. A 2020 study by the Center for Public Policy of the Catholic University established that vitamin D deficiency is associated with low levels of sun exposure and low dietary intake, which could be considered “ a modern lifestyle epidemic,” since it is associated with the prevalence of sedentary lifestyles, as well as with routine activities.
To reverse this situation, on July 5, 2022, Decree 48 was published, which modifies the Food Sanitary Regulation in favor of vitamin D fortification. The decree was to enter into force 24 months after its publication in the Chilean Official Bulletin, i.e., on July 6, 2024, after the end of a two-year preparation period. However, due to a provision issued by the Ministry of Health, the application of the decree was postponed for another 24 months.
Although vitamin D deficiency can be reversed with clinical intervention (through the prescription of pharmacological supplements), the costs are high, restricting its access to the entire population. An alternative is also to produce good dietary sources of vitamin D. In this direction, the Fondef IDeA I+D 2024 project “Obtaining a yeast strain overproducing ergosterol for its use in the production of bread supplemented with vitamin D” is framed, which was supported by the Vice-Rectory for Research, Innovation and Creation (Vriic).
The director of the initiative and researcher at the Centro de Estudio en Ciencia y Tecnología de Alimentos (Cecta), Dr. Eduardo Kessi Pérez, points out that the general objective “is to obtain a strain of Saccharomyces cerevisiae (a type of yeast used industrially in the manufacture of bread, beer and wine) that overproduces ergosterol (biological precursor of vitamin D) with marketing potential that will enable producing bread supplemented with vitamin D”.
To this end, the proposal will be developed in two stages. “In the first (current phase), we are working in the laboratory with the aim of making a genetic improvement on yeast using a technique known as experimental evolution or laboratory adaptive evolution, in which we speed up the evolutionary process that occurs naturally using a stressor agent. In the second part, we will take the yeast obtained that overproduces ergosterol, make it grow and transform the ergosterol into vitamin D through exposure to UV radiation, to finally have it in a marketable form,” he points out.
Obtaining this baker's strain, assures the doctor in Sciences with mention in Microbiology, “would be an excellent technological solution, as it would facilitate the fortification of bread without the need to add exogenous vitamin D, therefore, without interfering in the bread production process or increasing the production costs for the bakery industry”.
To put this food innovation into practice, the project has an alliance with the Chilean Association of Bakeries and Pastry Shops (Chilepan), with whom the bread production tests will be carried out with the improved yeast. “The purpose is to make at least two types of bread. Probably hallulla and marraqueta, which are the most consumed in Chile. After producing them, we will evaluate chemically if they retain part of the vitamin D and, on the other hand, that the bread produced is similar in terms of flavor and texture to that produced by the unimproved yeast. It should not forfeit the characteristics of a good bread, because if it loses these particularities, the yeast becomes commercially unviable,” he explains.
In this regard, the Cecta researcher emphasizes that since the beginning it was central from the applicability and from the economic point of view, “to have a solution that would not increase costs in a supposed future application. It should not have an impact on the price of the product, because we understand that bread consumption is high in low socioeconomic sectors, making it a good ally in combating this deficit in our country”.
The latter is not irrelevant, since studies show that, unlike the world trend to stop consuming this product, in Chile bread consumption remains high, with an estimated average of 98 kilos per capita per year, making it the second largest consumer after Germany.