"Ready to eat": maduración controlada de fruta de hueso en cámara

El desarrollo de un protocolo para controlar la maduracion poscosecha de fruta de hueso, ha permitido a los productores californianos el envio de frutos a los puntos venta en condiciones optimas para el consumo ("lista para comer") mejorando el precio final y preci

New quality index based on dry matter and acidity proposed for Hayward kiwifruit

Researchers from various countries have proposed using dry matter at harvest as a worldwide quality index for Hay-ward kiwifruit, because it includes both soluble (sugars and acids) and insoluble (structural carbohydrates and starch) solids and doesn't change during post-harvest handling. Our consumer tests in 1999 and 2008 indicated that dry matter and ripe titratable acidity are related to in-store consumer acceptance of kiwifruit. In most California seasons, when ripe titratable acidity was less than 1.2%, only a dry matter greater than or equal to 15.1% was required for consumer acceptability. Our 6-year quality attribute survey of California kiwifruit at harvest and from cold storage demonstrated that dry matter and ripe soluble solids concentration were highly variable among vineyards and seasons, but ripe titratable acidity values varied more among seasons than between vineyards. Our results provide strong evidence that dry matter would be a reliable quality index candidate for California kiwifruit, especially if ripe titratable acidity were factored in

Relationship between nondestructive firmness measurements and commercially important ripening fruit stages for peaches, nectarines and plums

Fruit firmness measurement is a good way to monitor fruit softening and to predict bruising damage during harvest and postharvest handling. Ripening protocols traditionally utilize a destructive penetrometer-type fruit firmness measure to monitor ripening. Until recently, methods of assessing fruit texture properties nondestructively were not commercially available. The nondestructive Sinclair iQ™ firmness tester was investigated to monitor ripening and predict bruising susceptibility in stone fruit. This work was carried out on four peach, three plum, and five nectarine cultivars over two seasons. The correlations between destructive and nondestructive firmness measurements were significant (p-value = 0.0001), although too low for commercial applications as they varied from r2 = 0.60–0.71 according to fruit type. Using a different approach, the relationship between destructive and nondestructive firmness measures was characterized in terms of segregating these fruit according to their stages of ripening. This was done by using discriminant analysis (66–90% agreement in ripeness stage classification was observed in validation tests). Discriminant analysis consistently segregated nondestructive firmness measured fruit into commercially important classes (“ready to eat”, “ready to buy”, “mature and immature”). These represented key ripening stages with different bruising potentials and consumer acceptance. This work points out the importance to relate nondestructive measurements directly to important commercial physiological stages rather than to correlate them with the current standard penetrometer values. Thus, destructive and nondestructive firmness measurements can be directly used to identify the stage of ripeness and potential susceptibility to bruising during postharvest changes. Further work is recommended to evaluate the performance of this nondestructive sensor in segregating fruit according to their stage of ripeness under packinghouse or processing plant conditions

Evaluación del funcionamiento de un sensor comercial de firmeza en pera. Estudio metrológico

Non-destructive firmness estimation of fruits has recently become available for packers, although they demand more information on their performance and reliability. A commercial device based on low mass impact has been tested in this work, and it has been applied on pears. Correlation between the firmness Índex gíven by the device and Magness-Taylor forcé was low (r=0.896). Classifications modeled with discrlmínant analysis showed that it is feasible sort samples into two firmness groups 96 to 91 % of correct classification for pear). Classification into three classes yields lower scores. A study searching for sources of variation ¡n the measurement showed that the distance sensor-fruit, the displacement from the center, and the operating pressure affect the reading ¡n a significant way

Evaluation of a Kiwifruit non-destructive firmness sensor

Non-deslructive firmness sensors have recently become available for packers and f r u í handlers although they derrand more ¡nforrratbn on their performance and reliability. A corrmerdal sensor based on low rrass irrpact has been tested on kiwifruit. Correlatton betweer the firrmess Índex given by the device and Magness-Taybr foro» was low (r3 = 0.594). Classiftoatbns modeled with dbcrirrinant analysls showed that it Is feasible to sort samples Into two firnness groups (96 to 91%), but dassiflcatbn into three dasses yields lower scores

Predicting pitting damage during processing in California clingstone peaches using color and firmness measurements

Nondestructive and destructive measures of color and firmness were studied to determine the feasibility of predicting the level of damage to clingstone peaches during mechanical pitting. Nondestructive and destructive measures of firmness were equally variable when measuring the firmness at three equatorial cheek locations (coefficient of variation of about 17%), both had inverse relationships with the level of pitting damage (r2 ranged from 0.70 to 0.83), and could classify peaches into two categories (those subject to and those not subject to pitting damage) with classification accuracies of 75.2% and 81.7%, respectively. Destructive firmness was not a good predictor of nondestructive firmness in clingstone peaches. Skin color was not a good predictor of flesh color in clingstone peaches, and flesh color was not a good predictor of potential for damage to clingstone peaches during mechanical pitting

Genome-wide DNA-(de)methylation is associated with Noninfectious Bud-failure exhibition in Almond (Prunus dulcis [Mill.] D.A.Webb).

Noninfectious bud-failure (BF) remains a major threat to almond production in California, particularly with the recent rapid expansion of acreage and as more intensive cultural practices and modern cultivars are adopted. BF has been shown to be inherited in both vegetative and sexual progeny, with exhibition related to the age and propagation history of scion clonal sources. These characteristics suggest an epigenetic influence, such as the loss of juvenility mediated by DNA-(de)methylation. Various degrees of BF have been reported among cultivars as well as within sources of clonal propagation of the same cultivar. Genome-wide methylation profiles for different clones within almond genotypes were developed to examine their association with BF levels and association with the chronological time from initial propagation. The degree of BF exhibition was found to be associated with DNA-(de)methylation and clonal age, which suggests that epigenetic changes associated with ageing may be involved in the differential exhibition of BF within and among almond clones. Research is needed to investigate the potential of DNA-(de)methylation status as a predictor for BF as well as for effective strategies to improve clonal selection against age related deterioration. This is the first report of an epigenetic-related disorder threatening a major tree crop

Tecnología postcosecha del melocotón en California

Los melocotones se caracterizan por ser frutos altamente perecederos y de consistencia blanda por lo que su vida poscosecha es en general muy corta. Existe un creciente interés en profundizar en el conocimiento de la fisiología de los frutos para poder prolongar su vida poscosecha y extender así el periodo de oferta, especialmente en el caso de las variedades tardías por las posibilidades de exportación que ofrecen. Trabajos recientes indican que los melocotones son una buena fuente de antioxidantes, entre los que incluyen el ácido ascórbico (vitamina C), carotenoides (provitamina A) y compuestos fenólicos

Developing critical pitter thresholds for canning peaches using the nondestructive Sinclair firmness sensor

The rclationship bctwccn mechanical pitting damage using ihe Alias piner (Atlas Pacific Engineering Ca, l»c > Pueblo, Colorado) over a range of nondestmetive and destruciive firmness measuremems for 'Andross*, Car$on\ and *Ros$* clingsíone peaches was studied, During the two years of woifc, (he percentage of 'Aodiosa1, *Car$on\ and 'Rou' fmit wiih pitung damage increased sharply as nondestmetive firmness sensor Sinclair firmness index valúes fell below 7 0 (SFI) and \\hcn dostructive penelromeief readings fell bdow 3 S pounds (17 N) Even ihough ihere was a low correlation between nondesiruciive and desinictive firmness measuremems. nondestmetive mcasuremcnte appcar to be wcll lelated lo (he piíüng damage These preliminary results encourage ihat further research to ímprove the relationship belween an automatic nondestmetive systcm could give processors ihe opüon to segiegate peaches susceptible lo pitting prior lo processin