Browsing by Author "Dzedik, Valentin"
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- Chemical composition and bioactivity of oilseed cake extracts obtained by subcritical and modified subcritical waterPublication . Švarc-Gajić, Jaroslava; Rodrigues, Francisca; Moreira, Manuela M.; Delerue-Matos, Cristina; Morais, Simone; Dorosh, Olena; Silva, Ana Margarida; Bassani, Andrea; Dzedik, Valentin; Spigno, GiorgiaRecovery of bioactive compounds from biowaste is gaining more and more interest in circular economy models. The oilseed cakes are usually insufficiently exploited by most technologies since they represent valuable matrices abundant in proteins, minerals, and phytochemicals, but their use is mostly limited to feed ingredients, fertilizers or biofuel production. This study was thus focused on the exploration of new valorization pathways of oilseed cakes by subcritical water, representing a safe and economic alternative in the creation of value chains. Pumpkin, hemp, and flax seed cakes were treated with subcritical water in nitrogen and carbon-dioxide atmospheres, as well as in nitrogen atmosphere with the addition of acid catalyst. The degradation of carbohydrate fraction was studied by quantifying sugars and sugar degradation products in the obtained extracts. The extracts obtained under different conditions were further compared chemically with respect to total phenols and flavonoids, as well as to the content of individual phenolic compounds. Furthermore, the effects of subcritical water treatment conditions on antioxidant, antiradical and cytotoxic properties of thus obtained extracts were defined and discussed.
- ESG approach in the valorization of cocoa (Theobroma cacao) by-products by subcritical water: Application in the cosmetic industryPublication . Švarc-Gajić, Jaroslava; Brezo-Borjan, Tanja; Dzedik, Valentin; Rodrigues, Francisca; Morais, Simone; Delerue-Matos, CristinaIn this research valorization potentials of cocoa hull extracts in cosmetic industry, following Environmental, Social, and Governance (ESG) criteria, have been investigated and reported, presenting increased value of this biowaste. The extracts of cocoa hull obtained by subcritical water were characterized in respect to chemical composition and certain bioactive properties, and were used to develop functional cosmetic formulation. In this work cocoa hull of cocoa beans originating from different geographical locations (Ivory Coast, Ghana, Togo, Grenada) were extracted by subcritical water to obtain functional extracts rich in valuable compounds. The extracts were characterized in respect to their total proteins (10–27%), total phenols (37–45 mg GAE/g) and total flavonoids (14–21 mg RE/g) contents. In addition, the minerals K (41–60 mg/100 g), Na (0.78–1.17 mg/100 g), and Ca (2.47–5.94 mg/100 g) were also quantified. Antiradical activity against DPPH (IC50 ∼ 11–13 μg/ml) and ABTS (IC50 ∼ 7–9 μg/ml) radicals, as well as total antioxidant activity (∼14–20 mg EAK/100 g DE), were determined and compared for all extracts. The extract with the highest antioxidant and antiradical activity was used for the formulation of a functional cosmetic product – a day cream with sun protective properties and added qualities. The prepared facial cream was analysed in respect to basic quality parameters for cosmetic products, proving the safety of the newly developed product based on subcritical water extracts of cocoa hull. The application of subcritical water extraction, as a green technology, can significantly enhance the ESG development in the cosmetic industry.