Influencia del riego deficitario controlado precosecha sobre la calidad de la cereza ´Prime Giant`

El uso de redes de sensores para el manejo del riego deficitario controlado (RDC) en cerezo puede incidir en la mejora de la productividad del agua, calidad de la fruta y en su comportamiento poscosecha, al permitir el conocimiento y control del estado hídrico del suelo y árbol en todo momento. En el primer año de ensayo, el riego deficitario aplicado en precosecha para satisfacer el 85% de las necesidades máximas del cultivo (ETcg) permitió un ahorro de agua del 17% (380 m3 ha-1) respecto al tratamiento control, que se regó al 110% de la ETcg. Este déficit hídrico ligero no afectó a la producción (16,13 t ha-1) e incluso mejoró la calidad del fruto. Así, en el momento de la cosecha (t0) los frutos bajo déficit ligero presentaron matices más rojos y mayor acidez que los de riego completo. Esta mayor acidez no afectó al índice de madurez debido a la compensación por sólidos solubles totales (SST). El carácter de mayor acidez perduró tras 30 días de conservación en frio (t1) y 5 días de simulación de las condiciones de comercialización (t2). Igualmente, los frutos bajo déficit hídrico presentaron una tendencia a menores pérdidas de peso por deshidratación a finales de los periodos de conservación en frio y de simulación de la comercialización.Ministerio de Economía y Competitividad AGL2013-49047-C2-1

Quality changes and shelf-life prediction of a fresh fruit and vegetables purple smoothie

The sensory, microbial and bioactive quality changes of untreated (CTRL) and mild heat−treated (HT; 90 ºC/45 s) smoothies were studied and modelled throughout storage (5, 15 and 25 ºC). The overall acceptability was better preserved in HT samples being highly correlated (hierarchical clustering) with the flavour. The sensory quality data estimated smoothie shelf−life (CTRL/HT) of 18/55 (at 5 ºC), 4.5/12 (at 15 ºC), 2.4/5.8 (at 25 ºC) days. The yeast and moulds growth rate was lower in HT compared to CTRL while a lag phase for mesophiles/psychrophiles was observed in HT−5/15 ºC. HT and 5 ºC−storage stabilized the phenolics content. FRAP reported the best correlation (R2=0.94) with the studied bioactive compounds, followed by ABTS (R2=0.81) while DPPH was the total antioxidant capacity method with the lowest adjustment (R2=0.49). Conclusively, modelling was used to estimate the shelf−life of a smoothie based on quality retention after a short time−high temperature heat treatment that better preserved microbial and nutritional quality during storage.The financial support of this research was provided by the Ministerio Español de Economía y Competitividad MINECO (Projects AGL2013−48830−C2−1−R and AGL2013−48993−C2−1−R) and by FEDER funds. G.A. González−Tejedor thanks to Panamá Government for the scholarship to carry out his PhD Thesis. A. Garre (BES−2014−070946) is grateful to the MINECO for awarding him a pre−doctoral grant. We are also grateful to E. Esposito and N. Castillejo for their skilful technical assistance

Shelf-life of rocket leaves stored in argon enriched atmospheres

The aim of this work was to monitor the effect of storage in non-conventional modified atmospheres on sensory, nutritional, and microbiological quality of rocket leaves during refrigerated storage. Rocket leaves (Diplotaxis tenuifolia) processed according to industry procedures were stored for 10 days in a humidified flow of air (as a control), and of the following atmosphere mixtures: 97% Ar + 3% O2, 50% Ar + 3% O2 (in nitrogen), and 3% O2 (in nitrogen). The effect of atmosphere composition on respiration rate was evident only at 6 days of storage when both Ar-enriched atmospheres were more effective than air and 3% O2 in nitrogen in slowing down respiration rate. Moreover, Ar-enriched atmospheres were more effective in controlling color changes of the leaves, as resulted by a lower hue angle variation at 10 days of storage, compared to 3% O2, whereas samples stored in air showed intermediate variation. The gas mix 50% Ar + 3% O2 induced an increase of phenolic compounds, which was higher than in those stored in 97% Ar + 3% O2, the latter also showing a sensible decrease after 10 days of storage. As for microbial control, the atmospheres with 50% Ar + 3% O2 and 3% O2 (in nitrogen) showed lowest microbial counts, after 10 days of storage. Moreover, samples stored in 50% Ar + 3% O2 showed the lowest yeast and mould growth rate after 10 days. There was no significant difference for quality parameters such as texture, antioxidant capacity and ascorbic acid. In conclusion, results obtained indicated a slight benefit induced by the atmosphere with 50% Ar + 3% O2 compared to conventional modified atmosphere with 3% O2 in nitrogen, although further investigations are needed to confirm these findings

UV-C and hyperoxia abiotic stresses to improve healthiness of carrots: study of combined effects

Phenolic compounds are phytochemicals with high health-promoting properties. Carrot is a vegetable highly worldwide consumed although its phenolic content is low compared to other plant products. The aim of this work was to evaluate changes in phenolic compounds in carrots caused by abiotic stresses. The phenylalanine ammonia-lyase (PAL) activity, phenolic compounds and total antioxidant capacity (TAC) changes during storage up to 72 h at 15 °C after wounding (shredding), 9 kJ UV-C m−2 pretreatment and hyperoxia (80 kPa) conditions of carrots were studied. Shredding and hyperoxia storage induced the highest phenolic compounds and TAC enhancements. Accumulation of phenolic compounds in shredded carrots could be structured in the following phases: 1st phase (<24 h): unchanged phenolic compounds levels with minimum PAL activity; 2nd phase (24–48 h): moderate phenolic increases (≈600–700 mg CAE kg−1 accumulated in 24 h) concurring with the greatest increase of PAL activity; 3nd phase (48–72 h): high phenolic increases (≈1600–2700 mg CAE kg−1, accumulated in 24 h) while a moderate increment of PAL activity was registered. Although UV-C pretreatment of shreds reduced phenolic accumulation, 600 % increments were still registered in those samples stored under hyperoxia conditions for 72 h. However, the contents of chlorogenic acid at 72 h were 1.4-fold higher in irradiated shreds under hyperoxia compared to the same samples under air conditions.Authors are grateful to the Spanish Ministry Economy and Competitiveness (Project AGL2013-48830-C2-1-R) and FEDER for financial support. We are grateful to V. Díaz-López for his skillful technical assistance