Low phenylalanine breads as an alternative for patients with phenylketonuria

Patients with phenylketonuria (PKU) require a phenylalanine (Phe)-restricted diet due to its toxic effects on such subjects. Considering the low availability of specific foods for these patients, the purpose of this paper is to make breads with low Phe content while also conducting physicochemical and sensory analysis of the samples.

Five bread formulations with a common base were prepared, in which manioc – Manihot esculenta (T1); Baroa potato – Arracacia xanthorrhiza (T2); sweet potatoes – Ipomoea batatas (T3); potatoes – Solanum tuberosum (T4); and, finally, yacon potato – Smallanthus sonchifolius (T5) were added.

The physical analysis showed that the samples had similar weight, height and size values, indicating that the use of different types of vegetables does not compromise the final result of the preparation. The chemical analysis showed that the loaves were low in protein and Phe and, therefore, are considered safe preparations for patients with PKU. In the sensory analysis, all the preparations presented satisfactory characteristics for consumption, specially the one with the addition of potato.

The preparation of breads with low Phe content is a challenging task as it is necessary to exclude formulations with flours that present better technological performance. However, the results in this study showed that it is possible to get around the difficulties and obtain a viable product with easily purchased ingredients. It is known that sensory analysis with PKU patients as judges could have changed these results because their perception can differ from that of general population. The workgroup is continuing this study and we intend to take sensory analysis with PKU patients to future, as they have a pathology, the study needs special care and respectful ethical aspects.

PKU has a direct influence on the daily diet of the patient, interfering with life decisions that go form eating at their home to where and what to eat in environments out of their control. Therefore, creating specific preparations for such patients is a challenge that assists in adherence to dietary therapy.