Detección del ahuecado interno en sandía sin semillas usando métodos acústicos.

Hollow heart is a problem quite specific to seedless watermelon, affecting to all varieties. Percentage of fruits affected range from nil to up to more than 50% of the fruits. The acoustic impulse response of 158 watermelons was measured using a prepolarized free-field microphone. After carrying out a fast Fourier transformation on the time signal of the generated sound several acoustic parameters were evaluated. Values of spectral density were significantly different between 'good watermelons' and 'hollow heart watermelons'

Monitoring of firmness evolution of peaches during storage by combining acoustic and impact methods

Firmness is a very important quality property in peach. The storage of peach affects its subsequent softening process and shelf life. The temperature and duration of storage mainly influence the firmness of stored fruit, and monitoring the evolution of fruits enables producers to manage its commercial life. The objective of the present study was to use non-destructive acoustic and impact tests to estimate firmness of peaches and to elucidate the influence of storage temperature and of time on the softening process of peach. Continuous and classification models based on variables obtained from non-destructive methods were developed. Parameters obtained from non-destructive methods were compared to destructive reference tests. The maximum force in ball compression correlated well with the maximum acceleration from impact test (r2 = 0.75), and with a band magnitude parameter from acoustic test (r2 = −0.71). Combining impact and acoustic parameters, the multiple correlation coefficient increases up to 0.91 (adjusted R2 = 0.82) in the prediction of the maximum force in ball compression. Classification models based on both non-destructive parameters and sorting peaches into two classes of firmness, showed scores of well classified higher than 90%

Métodos no destructivos para la determinación de firmeza. Sensores de Aceleración. Impactadores.

Impact techniques can be used to evaluate firmness on fruit. Chen and Ruiz-Altisent developed and used a 50,4 g impactor with a 19 mm diameter spherical tip, dropping from different heights onto the fruit. Another impactor device is a semispherical impacting tip attached to the end of a pivoting arm. In both devices a small accelerometer is mounted behind the impacting tip. Prototype lateral impactor on-line sorting system for high-speed firmness sorting of fruits has been developed and tested. Preliminary results shows that is possible its use on-line. The last version of an impact device has new elements that improve the data resolution, the signal-noise ratio and the precision

Medida instrumental de la textura de la yema de huevos cocidos enriquecidos con ácido linoleico conjugado

There is increased interest in enhancing the conjugated linoleic acid (CLA) content of food products because of its potential health benefits. Inclusion of CLA in the diets of laying hens has led to the incorporation of CLA into eggs, changes in yolk fatty acid (FA) composition and non-acceptable greater firmness of hard-boiled egg yolks. This study was designed to develop instrumental tests to determine the texture characteristics of hard-boiled egg yolks obtained from hens fed diets supplemented with different levels of CLA and other fat sources. Two compression tests have established relationship between some FA levels added to diets and the firmness of boiled egg yolks. There were significant differences in the compression parameters among egg yolks from laying hens fed diets supplemented with 3 and 5 g/kg of CLA (without other fats in diet) and commercial egg yolks. Supplementations with 30 and 35 g/kg of high oleic sunflower oil (HOSO) in diets which included 3 g/kg of CLA, decreased compression parameters to levels similar to commercial eggs.ponedoras ha conducido a la obtención de huevos enriquecidos con este ácido graso. Sin embargo, la incorporación de ALC en el huevo produce cambios en la composición de ácidos grasos del mismo y, consecuentemente, un aumento de firmeza en la yema de los huevos cocidos. Este trabajo se ha diseñado con el fin de desarrollar ensayos instrumentales para determinar las características texturales de las yemas de los huevos cocidos obtenidos de gallinas ponedoras alimentadas con dietas suplementadas con diferentes niveles de ALC y otras fuentes de grasa. Dos ensayos de compresión con una máquina universal de ensayos han permitido establecer relaciones entre los niveles de determinados ácidos grasos añadidos a las dietas de ponedoras y la firmeza de la yema de huevos cocidos. Se encontraron diferencias significativas en los parámetros del ensayo de compresión entre las yemas de huevos procedentes de gallinas ponedoras alimentadas con dietas suplementadas con 3 y 5 g/kg de ALC (sin ninguna otra fuente de ácidos grasos) y las yemas de los huevos comerciales. Las suplementaciones con 30 ó 35 g/kg de aceite de girasol rico en oleico a dietas con 3 g/kg de ALC, disminuyeron los valores de los parámetros del ensayo de compresión a niveles asimilables a los de las yemas de huevos comerciales

7º Colloquium Chemiometricum Mediterraneun (CCM VII 2010 -Granada) PO1-40-HYPERSPECTRAL IMAGING FOR PEACH RIPENING ASSESSMENT HYPERSPECTRAL IMAGING FOR PEACH RIPENING ASSESSMENT

Abstract The present research is focused on the application of artificial vision to peach ripening assessment, avoiding multiplicative and additive effect. Original images were acquired with a hyperspectral camera. Vision allows a spatially detailed determination of the ripening stage of the fruit. Optical indexes are proposed, based on the combination of wavelengths close to the chlorophyll absorption peak at 680 nm. Ind1 corresponds approximately to the depth of the absorption peak, and Ind 2 corresponds to the relative absorption peak. An artificial image of each index was obtained by computing the corresponding reflectance images. Score images have been also computed from Principal Components and Partial Least Squares Analysis. In any case the best performances correspond to such images that correct multiplicative and additive effects. Ind 2 is the preferred index; it showed the highest discriminating power between ripening stages and no influence of convexity. Ind 2 also allowed the differentiation of ripening regions within the fruits, and it showed the evolution of those regions during ripening. This fact has been also observed in some of the score images

Non-destructive impact device for measuring the flesh firmness of peaches

A low-mass non-destructive impact device was tested and compared with destructive tests to evaluate the firmness of peach [Prunus persica (L.) Batsch var. persica]. The tests were carried out on four peach varieties, namely, Royal Glory, Caterina, Tirrenia and Suidring. In the measurements, impact acceleration and contact time were sensed by an accelerometer attached on impact head, and the primitive impact parameters such as maximum acceleration (Amax), time required to reach peak acceleration (tmax) and contact time during impact (tcontact) were determined by using impact acceleration-contact time curves. Other parameters were derived by using the theory of elasticity. These non-destructive impact parameters were compared with the destructive reference parameter (Magness-Taylor force). The levels of firmness of the four peach varieties were classified with discriminant analyses based on the primitive impact parameters and their derivatives. The accuracy of classification was improved with linear discriminant analysis, and the number of parameters being processed was reduced with stepwise regression analysis. The correlations between destructive reference and non-destructive impact parameter test results were statistically significant. Discriminant analysis results showed that the accuracy of classification was 65.40% by the primary impact parameters and 76.50% by all 10 impact parameters. Results of the four most dominant parameters [tcontact, Amax2.5, Amax/(tmax)2, Amax/(tcontact)2] extracted with stepwise regression analysis showed that overall accuracy of classification was improved to 77.90%. Because the four most dominant parameters gave better classification accuracy than the 10 impact parameters, they could be practical in static application using a low-mass lateral impactor. To improve the accuracy of classification, the four impact parameters approach may be adopted for extracting the soft peaches (81.6%) and the primary impact parameters approach for the hard peaches (83.3%)

Classification of the firmness of peaches by sensor fusion

The objectives of this research were to compare the performance of each individual nondestructive sensor with the destructive sensor, and to apply sensor fusion technique to explore whether a combination of sensors would give better results than a single sensor for classification of peach firmness. Tests were carried out with four peach varieties namely Royal Glory, Caterina, Tirrenia and Suidring. In this research, the three nondestructive firmness sensors acoustic firmness, low-mass impact and micro-deformation impact were used to measure firmness. A Bayesian classifier was chosen to provide a classification into three categories, namely soft, intermediate and hard. High level fusion technique was performed by using identity declaration provided by each sensor. The data fusion system processed the information of the sensors to output the fused data. The result of the high level fusion was compared with the classification provided by an unsupervised algorithm based on destructive reference measurement. The fusion process of the nondestructive sensors provided some improvements in the firmness classification; the error rate varied from 25% to 19% for individual sensor. Furthermore, the results of fusion process by using three sensors decreased the error rate from 19% to 13%. This research demonstrated that the fused systems provided more complete and complementary information and, thus, were more effective than individual sensors in the firmness classification of peaches. © 2015, Int J Agric & Biol Eng. All rights reserved

Multispectral images for monitoring fruit ripeness: validation methods

Multi-spectral images have been previously used to classify different kinds of fruits into postharvest maturity classes. Previous research has succeeded in classifying peaches into ripeness clusters, gathering the whole variability of ripeness in the harvest and post-harvest chain (Lle\uf3 et al, 2007). The main objective of this work is to correlate fruit image with firmness and other quality traits through the analysis and classification of R-IR images on commercial conditions. MT-firmness and colour Reflectance parameters are used as reference values. The second objective is to develop an automatic procedure, able to classify on line commercial peaches into ripening classes consistently correlated with fruit quality. During the 2006 season, 500 images (2 images per fruit) including just harvested peaches, and over ripened fruits, in order to simulate commercial conditions, were considered for the generation of 6 ripeness classes. For external validation 1304 images from on season 2006; and 1020 images from season 2007 were analyzed. For both seasons, image-based classes showed constant trends and coherent ranges on their reference values: high percentage (91% for season 2006 and 81% for 2007) of the samples below minimum firmness values for transport (Crisosto, 1996) were classified into clusters 4, 5 or 6. The studied method shows a good potential to characterize the ripening state of the fruits, although further research is required to ensure high reliability of the system

A case study on the application of Product Social Impact Assessment to the agri-food sector: ready-to-eat beetroot

The main objective of this study is to apply the Product Social Impact Assessment (PSIA) handbook to a case study. The method used to quantify the social impacts is to identify the stakeholders and the social topic, indicators, and then to apply the impact analysis method. Social studies identify the retailing stage as the phase with the greatest social risk in the life cycle followed by the product transformation phase. However, the infeasibility of focusing this study on the multiple companies involved in the commercialization, led the processing stage company to be chosen as the central part of the study. The preliminary evaluation of the social topics of the stakeholders, presents an average of +0.88 points on the level scale (-2 to +2), which positions the company beyond the generally acceptable situation, in continuous improvement

Using multiregional environmentally extended input-output assessment to quantify the carbon footprint of peach production

The main objective of this investigation is to analyse the validity of multiregional input-output methodology to evaluate the environmental performance of peach production using a life cycle approach. The analysis is based on a detailed sectorial economic foreground inventory applicable to the region of Murcia (Southern Spain), following the principles of ISO 14040 and incorporating the methodological decisions of Environdec Product Category Rule for fruits and nuts. Total climate change emissions for 1 kg of peaches were calculated at 1.2 kg CO2 eq, 39.2 % of which correspond to economic activity in the sectors directly affected by the expenses and a further 60.8 % to indirect emissions from induced effects. Most of the total carbon footprint (63 %) is generated by the core stage, primarily crop production and refrigerated storage, both activities being characterized by their high economic intensity and environmental factors