title: Preservation of bioactive compounds of a green vegetable smoothie using short time-high temperature mild thermal treatment.
abstract: 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 100-1g 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-1fw) 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-1fw) 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-1fw) 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.
authors.affiliation: Postharvest and Refrigeration Group, Department of Food Engineering, Universidad Politécnica de Cartagena, Cartagena, Spain.
authors.forename: Noelia
authors.initials: N
authors.lastname: Castillejo
authors.affiliation: Postharvest and Refrigeration Group, Department of Food Engineering, Universidad Politécnica de Cartagena, Cartagena, Spain.|Institute of Plant Biotechnology, Universidad Politécnica de Cartagena, Cartagena, Spain.
authors.forename: Ginés Benito
authors.initials: GB
authors.lastname: Martínez-Hernández
authors.affiliation: Department of Chemistry and Biochemistry, São Paulo State University, Botucatu, Brazil.
authors.forename: Kamila
authors.initials: K
authors.lastname: Monaco
authors.affiliation: Institute of Plant Biotechnology, Universidad Politécnica de Cartagena, Cartagena, Spain.
authors.forename: Perla A
authors.initials: PA
authors.lastname: Gómez
authors.affiliation: Postharvest and Refrigeration Group, Department of Food Engineering, Universidad Politécnica de Cartagena, Cartagena, Spain.|Institute of Plant Biotechnology, Universidad Politécnica de Cartagena, Cartagena, Spain.
authors.forename: Encarna
authors.initials: E
authors.lastname: Aguayo
authors.affiliation: Postharvest and Refrigeration Group, Department of Food Engineering, Universidad Politécnica de Cartagena, Cartagena, Spain.|Institute of Plant Biotechnology, Universidad Politécnica de Cartagena, Cartagena, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Artés
authors.affiliation: Postharvest and Refrigeration Group, Department of Food Engineering, Universidad Politécnica de Cartagena, Cartagena, Spain fr.artes-hdez@upct.es.|Institute of Plant Biotechnology, Universidad Politécnica de Cartagena, Cartagena, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Artés-Hernández
mesh_terms: D000975:Antioxidants / Q000032:analysis; D001205:Ascorbic Acid / Q000032:analysis; D001628:Beverages / Q000032:analysis / Q000382:microbiology; D002338:Carotenoids / Q000032:analysis; D002734:Chlorophyll / Q000032:analysis; D003080:Cold Temperature; D003116:Color; D004043:Dietary Fiber / Q000032:analysis; D005504:Food Analysis; D005506:Food Contamination / Q000032:analysis; D005511:Food Handling; D005516:Food Microbiology; D005519:Food Preservation; D061353:Food Storage; D005638:Fruit / Q000737:chemistry / Q000382:microbiology; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D009753:Nutritive Value; D010636:Phenols / Q000032:analysis; D064209:Phytochemicals / Q000032:analysis*; D012212:Rheology; D013649:Taste; D014675:Vegetables / Q000737:chemistry* / Q000382:microbiology
chemical_list: D000975:Antioxidants; D004043:Dietary Fiber; D010636:Phenols; D064209:Phytochemicals; D002734:Chlorophyll; D002338:Carotenoids; D001205:Ascorbic Acid
keywords: Phenolic compounds; antioxidants; beverages; glucosinolates; quality; vitamin C