Preservation of bioactive compounds of a green vegetable smoothie using short time–high temperature mild thermal treatment

• Autores: Noelia Castillejo, Ginés Benito Martínez Hernández, Kamila Monaco, Perla Gómez, Encarnación Aguayo Giménez, Francisco Artés Calero, Francisco Artés Hernández
• Localización: Food science and technology international = Ciencia y tecnología de alimentos internacional, ISSN-e 1532-1738, ISSN 1082-0132, Vol. 23, Nº 1, 2017, págs. 46-60
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • Smoothies represent an excellent and convenient alternative to promote the daily consumption of fruit and vegetables in order to obtain their health-promoting benefits. Accordingly, a green fresh vegetables smoothie (77.2% cucumber, 12% broccoli and 6% spinach) rich in health-promoting compounds was developed. Soluble solids content, pH and titratable acidity of the smoothie were 4.3 ± 0.4°Bx, 4.49 ± 0.01 and 0.22 ± 0.02 mg citric acid 100−1 g fw, respectively. Two thermal treatments to reduce microbial loads and preserve quality were assayed: T1 (3 min at 80 ℃) and T2 (45 s at 90 ℃). Fresh blended unheated samples were used as control (CTRL). The smoothie presented a viscoelastic behaviour. T1 and T2 treatments reduced initial microbial loads by 1.3–2.4 and 1.4–3.1 log units, respectively. Samples were stored in darkness at 5 and 15 ℃. Colour and physicochemical changes were reduced in thermal-treated samples throughout storage, which were better preserved at 5 ℃ rather than at 15 ℃. Vitamin C changes during storage were fitted with a Weibullian distribution. Total vitamin C losses of T1 and T2 samples during storage at 15 ℃ were greatly reduced when they were stored at 5 ℃. Initial total phenolic content (151.1 ± 4.04 mg kg−1 fw) was 44 and 36% increased after T1 and T2 treatments, respectively. The 3-p-coumaroyl quinic and chlorogenic acids accounted the 84.7 and 7.1% relative abundance, respectively. Total antioxidant capacity (234.2 ± 20.3 mg Trolox equivalent kg−1 fw) remained constant after the thermal treatments and was better maintained during storage in thermal-treated samples. Glucobrassicin accounted the 81% of the initial total glucosinolates content (117.8 ± 22.2 mg kg−1 fw) of the smoothie. No glucosinolates losses were observed after T2 treatment being better preserved in thermal-treated samples. Conclusively, a short time–high temperature mild thermal treatment (T2) showed better quality and bioactive compounds retention in a green fresh vegetable smoothie during low temperature storage.