University of São Paulo:Waste from the beverage industry is used to produce natural dyes

Nthe Faculty of Animal Science and Food Engineering (FZEA) at USP, in Pirassununga, research used by-products from beverage processing and jabuticaba to produce encapsulated natural dyes. Using techniques already available in the industry, the work used yeasts discarded from the brewery to encapsulate and protect pigments extracted from leftovers, husks and seeds from the production of wine and from the pulping of jabuticaba. The product was tested as a dye for yoghurts, with positive results, such as the addition of proteins, vitamins and other nutrients, in addition to passing sensory tests. The researchers point out that yeasts have the potential to add bioactive compounds to food supplements and other food products, including meat and dairy products.

“The design takes advantage of the yeast cell structure, which resembles a capsule for incorporation and protection of natural pigments extracted from the waste in the wine industry and pulping the blemish” describes the Journal USP to friends Thaís Vieira Rubio researcher who carried out the work during his doctorate at FZEA. “Thus, we sought to meet the appeal of consumers for natural and healthy additives and that of the coloring industry, by expanding the offer of natural, stable, healthy additives that can offer something more to the consumer’s health.”

The residual yeast used in the work was donated by the brewery Hausen Bier, from Araras, after its use in the manufacture of beer. “Two raw materials were used as a source of pigments in this work, grape pomace of the Bordô variety and by-products from the pulping of jabuticaba, consisting of husks and seeds”, points out the researcher. “From these co-products, extracts were produced and mixed with residual yeasts for subsequent encapsulation.”

To encapsulate the pigments, the technique of biosorption followed by atomization or spray-drying was adopted , which consisted of spraying the mixture of extract and yeast in a chamber with hot air. “When it comes into contact with hot air, the mixture is dried instantly and the encapsulate is produced”, emphasizes Fernanda. “After encapsulation, the pigment was protected and had high nutritional value, due to the nutrients present in yeasts, such as proteins, carbohydrates and vitamins of the B complex, and also functional, due to the phenolic compounds present in plant extracts.”

The research tested the use of encapsulated pigments as natural dyes in yogurt, with positive results. Fernanda points out other potential applications of yeast enriched with bioactive compounds. “They can be used in food supplements and as additives in other food products, such as dairy products, meat products and extruded (savory snacks)”, he highlights.

“The spray dryer equipment is already widely known and used in the food industry and atomization is one of the most common drying methods. Therefore, the biggest challenge for the industry would be just the supply of the necessary raw materials.”

According to Fernanda, the sensory evaluation of yogurts enriched with yeast-based pigments was accepted by the Ethics Committee for Research with Human Beings (CEPH) of the FZEA. “For the evaluation, 120 tasters were recruited from students and employees of the Pirassununga campus. The yogurts were evaluated with acceptance rates ranging between 73.9% and 81.4%, which indicates that the samples were well accepted by consumers”, he reports. “The tasters also indicated their intention to purchase the products, if they were to be marketed.”

“We were concerned with developing a simple process, both in the preparation of raw materials and in the production of encapsulates, precisely to facilitate production on an industrial scale,” says the researcher. “The spray dryer equipment is already widely known and used in the food industry and atomization is one of the most common drying methods. Therefore, the biggest challenge for the industry would be just the supply of the necessary raw materials.”

The research is part of Fernanda Thaís Vieira Rubio’s doctorate, with a grant from the Coordination for the Improvement of Higher Education Personnel (Capes), under the supervision of Professor Carmen Sílvia Fávaro Trindade. Graduate student Mayara Martins dos Santos participated in the production of pigments during her scientific initiation, financed by the Foundation for Research Support of the State of São Paulo (Fapesp). Professors Charles Windson Isidoro Haminiuk, Milena Martelli Tosi, Izabel Cristina Freitas Moraes and Marcelo Thomazini, expert technician from the Encapsulation and Functional Food Laboratory, also collaborated with the study. The school-dairy on the Pirassununga campus supplied the yogurt used in the research, and all the rest of the work was carried out on the premises of the FZEA.