Development of functional breads with dry flour from residues and lyophilized extracts of the husk and apple by-product (Malus domestica Borkh)

Food waste generated today due to industrial processing has a great impact on the environment, and these losses are noticed in all the processes of the productive chain for the generation of food products. Apple residues are a rich source of phenolics compounds which are associated with health benefits.
The present project studied the elaboration of bread with functional properties using lyophilized apple peels and an industrial residue from apple juice production, consisting of a dried apple bagasse, to replace part of the wheat flour used in traditional recipes. Additionally, extracts from dried materials were also used. Different breads were produced with 1 to 5% of these additives (lyophilized and oven dried peels and extracts) in substitution of wheat flour
The extracts from the apple peels and bagasse were obtained by a sequential extraction with hydroalcoholic solvents. The extract was concentrated on a rotatory evaporator, frozen and freeze-dried.
The breads were prepared separately and baked in a laboratory oven. Samples of the breads were extracted with methanol and evaporated with nitrogen. The analyzes were performed on Total Phenolic, FRAP, ABTS and Liquid Chromatography (HPLC). The aim of the study was to identify losses after thermal processing and whether this addition would be interesting from an antioxidant point of view in the production of functional loaves. We also performed the centesimal analysis of water, moisture, ash, lipid, protein and carbohydrate activity by difference. In the centesimal analysis, the flour of the lyophilized apple peel, the flour of the residue, and the baked loaves (white and 5% of each substitution) were analyzed, and the values found were adequate.
In the results it was found that the extract of the residue had the highest concentration of total phenolics (7,17mg / g GAE) and antioxidant activity and the apple peel flour had the lowest amount of total phenolics (1.36mg / g GAE). In relation to the loaves, the ones that had the substitution by extract of the residue were those that presented higher concentrations of phenolic compounds, being in the raw 0.218mg / g GAE and in the roast 0,159mg / g GAE. The data found in the HPLC analysis also showed that the loaves with extract of the residue presented greater functional property when compared to the other formulations, demonstrating that the residue and extract of the residue present a higher concentration of Gallic Acid. All the loaves in the different formulations showed phenolic losses of up to 30% after thermal processing, both in the Total Phenolic and in the Liquid Chromatography (HPLC) analysis, which is advantageous as a substitution
In this way, it can be concluded that it is possible to add functional and antioxidant aspects to the reuse of the apple residue, generating positive industrial impacts, adding value in the loaves and reducing the impact of this by-product to the environment, as it presents a purpose for its use.