title: By-product from decoction process of Hibiscus sabdariffa L. calyces as a source of polyphenols and dietary fiber.
abstract: BACKGROUND
  Dietary fiber (DF) and antioxidant compounds are widely used as functional ingredients. The market in this field is competitive and the search for new types of quality ingredients for the food industry is intensifying. The aim of this study was to evaluate the composition and antioxidant activity of by-products generated during the decoction of calyces of four Mexican Hibiscus sabdariffa L. cultivars ('Criolla', 'China', 'Rosalis' and 'Tecoanapa') in order to assess them as a source of functional ingredients.
  
  
  RESULTS
  Some calyx components were partially transferred to the beverage during the decoction process, while most were retained in the decoction residues. These by-products proved to be a good source of DF (407.4-457.0 g kg⁻¹ dry matter) and natural antioxidants (50.7-121.8 µmol Trolox equivalent g⁻¹ dry matter).
  
  
  CONCLUSIONS
  The decoction process extracted some soluble carbohydrates, ash and some extractable polyphenols. The DF content changed in the dried residues, which could be considered as high-DF materials with a high proportion of soluble DF (∼20% of total DF) and considerable antioxidant capacity. These by-products could be used as an antioxidant DF source.
authors.affiliation: Laboratorio Integral de Investigación en Alimentos, División de Estudios de Posgrado, Instituto Tecnológico de Tepic, Av. Tecnológico 2595, CP 63175, Tepic, Nayarit, Mexico.
authors.forename: Sonia G
authors.initials: SG
authors.lastname: Sáyago-Ayerdi
authors.forename: Carolina
authors.initials: C
authors.lastname: Velázquez-López
authors.forename: Efigenia
authors.initials: E
authors.lastname: Montalvo-González
authors.forename: Isabel
authors.initials: I
authors.lastname: Goñi
mesh_terms: D000975:Antioxidants / Q000032:analysis / Q000737:chemistry / Q000191:economics / Q000302:isolation & purification*; D001628:Beverages / Q000032:analysis / Q000191:economics; D004040:Dietary Carbohydrates / Q000032:analysis / Q000191:economics / Q000302:isolation & purification; D004043:Dietary Fiber / Q000032:analysis* / Q000191:economics; D035264:Flowers / Q000737:chemistry*; D005527:Food, Fortified / Q000191:economics; D005525:Food-Processing Industry / Q000191:economics; D031584:Hibiscus / Q000737:chemistry*; D007220:Industrial Waste / Q000032:analysis* / Q000191:economics; D008800:Mexico; D010936:Plant Extracts / Q000737:chemistry; D059808:Polyphenols / Q000032:analysis / Q000737:chemistry / Q000191:economics / Q000302:isolation & purification*; D011134:Polysaccharides / Q000032:analysis / Q000737:chemistry / Q000191:economics / Q000302:isolation & purification; D012995:Solubility
chemical_list: D000975:Antioxidants; D004040:Dietary Carbohydrates; D004043:Dietary Fiber; D007220:Industrial Waste; D010936:Plant Extracts; D059808:Polyphenols; D011134:Polysaccharides
keywords: Hibiscus sabdariffa L; antioxidant dietary fiber; by-products; polyphenols