title: Incorporation of strawberries preparation in yoghurt: impact on phytochemicals and milk proteins.
abstract: An immediate decrease in the total antioxidant activity (23%) and total phenolic content (14%) was observed after addition of strawberry preparations to yoghurt. The total anthocyanin content did not change immediately, but decreased 24% throughout the yoghurt shelf-life. The individual compounds, (+)-catechin (60%), (-)-epicatechin (60%), kaempferol (33%) and quercetin-3-rutinoside (29%) decreased after 24h in the yoghurt made with the strawberry preparation. During the remaining period of storage these compounds increased by 47%, 6%, 4% and 18%, respectively. Pelargonidin-3-glucoside decreased 49% after 28 d. Immediately after the addition of the strawberry preparation to yoghurt, β-lactoglobulin decreased to values lower than the limit of detection and α-lactalbumin by approximately 34%, and was reduced further slowly throughout yoghurt self-life. An immediate interaction between the carrageenan present in the strawberry preparation and β-LG was observed. The variations of both polyphenols and protein in the presence of carrageenan and the potential interactions were discussed.
authors.affiliation: Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Dr. António Bernardino Almeida, 4200-072 Porto, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Oliveira
authors.affiliation: Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Dr. António Bernardino Almeida, 4200-072 Porto, Portugal.
authors.forename: Elisabete M C
authors.initials: EM
authors.lastname: Alexandre
authors.affiliation: Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Dr. António Bernardino Almeida, 4200-072 Porto, Portugal.
authors.forename: Marta
authors.initials: M
authors.lastname: Coelho
authors.affiliation: Frulact. S.A., Rua do Outeiro, 589, 4475-150 Gemunde, Maia, Portugal.
authors.forename: Cláudia
authors.initials: C
authors.lastname: Lopes
authors.affiliation: Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal.
authors.forename: Domingos P F
authors.initials: DP
authors.lastname: Almeida
authors.affiliation: Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Universidade Católica Portuguesa/Porto, Rua Dr. António Bernardino Almeida, 4200-072 Porto, Portugal. Electronic address: mpintado@porto.ucp.pt.
authors.forename: Manuela
authors.initials: M
authors.lastname: Pintado
mesh_terms: D000872:Anthocyanins / Q000032:analysis*; D000975:Antioxidants / Q000032:analysis; D031985:Fragaria / Q000737:chemistry*; D007768:Lactalbumin / Q000032:analysis; D007782:Lactoglobulins / Q000032:analysis; D008894:Milk Proteins / Q000032:analysis*; D010084:Oxidation-Reduction; D010636:Phenols / Q000032:analysis*; D064209:Phytochemicals / Q000032:analysis*; D010936:Plant Extracts / Q000737:chemistry; D059808:Polyphenols / Q000032:analysis; D013997:Time Factors; D015014:Yogurt / Q000032:analysis*
chemical_list: D000872:Anthocyanins; D000975:Antioxidants; D007782:Lactoglobulins; D008894:Milk Proteins; D010636:Phenols; D064209:Phytochemicals; D010936:Plant Extracts; D059808:Polyphenols; D007768:Lactalbumin
keywords: Carrageenan; Milk proteins; Polyphenols; Strawberry; Yoghurt