New insights on the ripening pattern of ‘Blanquilla’ pears: A comparison between on- and off-tree ripened fruit

To better understand the key processes involved in the ripening of attached fruit, we have investigated physico-chemical and biochemical changes occurring in ‘Blanquilla’ pear during on-tree (attached fruit) and off-tree ripening (harvested fruit). Flesh firmness, sugars, acids and the volatile profiles as well as ethylene metabolism, PG and PME enzyme activities and oxidative damage were measured. Firmness loss in detached ‘Blanquilla’ pear (off-tree), was initially mediated by oxidative stress (higher accumulation of malondialdehyde) and then by ethylene in a process in which 1-aminocyclopropene 1-carboxylic acid (ACC) synthase was the limiting factor. In contrast the progressive but slower softening observed during on-tree fruit ripening was not associated to oxidative damage but rather to a delayed production of ethylene limited, in turn, by the activity of ACC oxidase. An interesting association was found between the initiation of the ethylene production and a concomitant increase of sucrose levels during on-tree ripening also accompanied by a decline in hexanal. The putative role of these compounds as a tree-associated factor modulating on-tree pear ripening is discussed.info:eu-repo/semantics/acceptedVersio

Characterization of Fuji Apples from Different Harvest Dates and Storage Conditions from Measurements of Volatiles by Gas Chromatography and Electronic Nose

Volatile compounds in Fuji apples harvested at two different maturities were measured at harvest and after 5 and 7 months of cold storage (1 °C) in four different atmospheres. When the samples were characterized by both chromatographic measurements of volatiles and responses of an electronic nose, the analyses showed a clear separation between fruits from different storage conditions (a normal cold atmosphere and three controlled atmospheres). During poststorage, the apples were left to ripen for 1, 5, and 10 days at 20 °C before analytical measurements were done involving headspace-gas chromatography methods and electronic nose type quartz crystal microbalances. Electronic nose responses registered by seven different sensors were used to classify the apples using principal component analysis. It was possible to identify the samples from different storage periods, days of shelf life, and harvest dates, but it was not possible to differentiate the fruits corresponding to different cold storage atmospheres

New insights on the ripening pattern of ‘Blanquilla’ pears: A comparison between on- and off-tree ripened fruit

To better understand the key processes involved in the ripening of attached fruit, we have investigated physico-chemical and biochemical changes occurring in ‘Blanquilla’ pear during on-tree (attached fruit) and off-tree ripening (harvested fruit). Flesh firmness, sugars, acids and the volatile profiles as well as ethylene metabolism, PG and PME enzyme activities and oxidative damage were measured. Firmness loss in detached ‘Blanquilla’ pear (off-tree), was initially mediated by oxidative stress (higher accumulation of malondialdehyde) and then by ethylene in a process in which 1-aminocyclopropene 1-carboxylic acid (ACC) synthase was the limiting factor. In contrast the progressive but slower softening observed during on-tree fruit ripening was not associated to oxidative damage but rather to a delayed production of ethylene limited, in turn, by the activity of ACC oxidase. An interesting association was found between the initiation of the ethylene production and a concomitant increase of sucrose levels during on-tree ripening also accompanied by a decline in hexanal. The putative role of these compounds as a tree-associated factor modulating on-tree pear ripening is discussed.This work was supported by the CERCA Programme/ Generalitat de Catalunya and by the Ministerio de Economía y Competitividad / MINECO (grant AGL2017-87923-R)

Physiochemical and nutritional characteristics, bioaccessibility and sensory acceptance of baked crackers containing broccoli co‐products

The effects of the inclusion of broccoli co‐products into crackers on the bioaccessibility as well as their overall physical and nutritional quality were evaluated. Crackers were formulated using a 12.5 or 15.0% flour substitution level. Broccoli‐containing crackers presented higher specific volume and spread ratio and lower weight and specific volume than control crackers (P < 0.05). Crackers containing broccoli co‐products showed an increased green hue and a higher colour intensity (P < 0.05). Incorporation of broccoli co‐products into crackers significantly increased the total phenolic content and antioxidant capacity (P < 0.05). A simulated gastrointestinal digestion suggested that the amount of phenolic and antioxidant compounds released during digestion might be higher than what could be expected from common water‐organic extracts. The incorporation of broccoli co‐products into baked crackers would not only reduce the amount of food discarded as waste but also promote health and open novel commercial opportunities to food processors.This work was supported by the CERCA Programme of Generalitat de Catalunya. T. Lafarga is in receipt of Juan de la Cierva contract awarded by the Spanish Ministry of Economy and Competitiveness (FJCI‐2016‐29541). I. Aguiló‐Aguayo thanks the Spanish Ministry of Economy and Competitiveness and to the European Social Fund for the Postdoctoral Senior Grant Ramon y Cajal (RYC‐2016‐19949). Authors thank Congelados de Navarra S.A.U (Navarra, Spain) for providing broccoli processing co‐products and Silvia Villaró for her technical assistance

Aplicación de una nariz electrónica tipo QCM para la medida de aromas emitidos por manzanas cv. Fuji conservadas con diferentes tecnologías

La nariz electrónica (NE) “Libra Nose” se basa en una matriz de 8 sensores del tipo Microbalanzas de Cristal de Cuarzo. Estudios previos muestran que es posible utilizar una NE para hacer un seguimiento de la evolución de la calidad de fruta sometida a diferentes periodos de almacenamiento. En este trabajo se muestra que al analizar la emisión aromática de frutos de manzana cv.Fuji, con NE y cromatografía de gases, es posible por una lado detectar con la NE diferencias significativas en el espacio de cabeza generado por manzanas sometidas a diferentes tiempos de almacenamiento y periodos de vida en estantería, y por otro lado establecer para los frutos almacenados en condiciones de frío normal y atmósfera controlada estándar, una correlación positiva entre la respuesta de los sensores de la NE y la emisión de uno de los compuestos predominantes en el aroma de la variedad Fuji, el acetato de hexilo

Aplicación de una nariz electrónica para la medida de aromas emitidos por manzanas cv. Fuji conservadas con diferentes tecnologías

La nariz electrónica (NE) "Libra Nose" se basa en una matriz de 8sensores del tipo Micro balanzas de Cristal de Cuarzo. Estudios previos muestran que es posible utilizar una NE para hacer un seguimiento de la evolución de la calidad de fruta sometida a diferentes periodos de almacenamiento. En este trabajo se muestra que al analizar la emisión aromática de frutos de manzana cv. Fuji con una NE y un cromatógrafo de gases, es posible por una lado detectar con la NE diferencias significativas en el espacio de cabeza generado por manzanas sometidas a diferentes tiempos de almacenamiento y periodos de vida en estantería, y por otro lado establecer para los frutos almacenados en condiciones de frío normal y atmósfera controlada estándar, una correlación positiva entre la respuesta de los sensores de la NE y la emisión de uno de los compuestos predominantes en el aroma de la variedad Fuji, el acetato de hexílo

Use of a QCM electronic nose to evaluate the aromatic quality in apples

The “Libra Nose” electronic nose has eight Quartz Microbalance Sensors. When gas molecules are adsorbed onto the quartz crystal surface, the oscillation frequency changes in proportion to the amount of mass. The response of sensors depends on numerous factors that may be difficult to control, such as the temperature and the humidity of the carrier gas. All these factors cause changes in the selectivity of sensors which affect the reproducibility of measurements. In this paper additive and multiplicative corrections are proposed to be applied to the raw sensors´s signal in order to eliminate sources of variation. After these corrections, the sensors´ response gives useful information to distinguish between batches of apples with different ripeness stage

Potential of the microalgae Nannochloropsis and Tetraselmis for being used as innovative ingredients in baked goods

The potential use of the microalgae species Tetraselmis and Nannochloropsis was investigated for the production of functional breads and crackers. Optimum flour substitution levels were 2.5% for baked crackers and 1.0 or 2.0% for breads containing Nannochloropsis or Tetraselmis, respectively. No major differences were observed in the physicochemical properties of the end products besides an expected darker and greener colour. Microalgae incorporation led to increased phenolic content and in vitro antioxidant capacity in both matrices. For example, the total phenolic content of crackers increased from 24.6 ± 1.5 mg/100 g in the control to 32.4 ± 0.4 or 34.2 ± 1.0 mg/100 g in crackers containing Tetraselmis or Nannochloropsis, respectively. The amount of bioaccessible polyphenols after a simulated gastrointestinal digestion was also higher in microalgae-containing goods than in the controls. Sensory evaluation showed that microalgae-containing products were competitive with the controls with the added advantage of having an improved nutritional value and a "trendy" ingredient. Moreover, microalgae-containing products showed an increased emission of some volatile compounds such as p-cymene and (Z)-2-heptenal, which are responsible for fresh, citrus, terpenic, woody, and spicy or fatty, oily, and fruity odours, respectively.This work was supported by the CERCA Programme of Generalitat de Catalunya. T. Lafarga (FJCI-2016-29541) and I. Aguiló-Aguayo (RYC-2016-19949) thank the Spanish Ministry of Economy, Industry, and Competitiveness. All authors thank Fundación Cajamar (Almería, Spain) for kindly providing with the microalgal biomass