Papers by M. Ruiz-altisent
Actas De Horticultura I Congreso Iberico De Ciencias Horticolas 18 22 Junio 1990 Lisboa, 1990
Journal of Agricultural Engineering Research, 2001
Abstract Various physical properties of green gram were evaluated as a function of moisture conte... more Abstract Various physical properties of green gram were evaluated as a function of moisture content in the range of 8·39 to 33·40% d.b. The average length, width, thickness and thousand grain mass were 4·21 mm, 3·17 mm, 3·08 mm and 28·19 g at moisture content of 8·39% d.b. The geometric mean diameter increased from 3·45 to 3·77 mm, whereas sphericity decreased from 0·840 to 0·815. Studies on rewetted grains showed that the bulk and true densities decreased from 807 to 708 and 1363 to 1292 kg m −3 , whereas the corresponding bulk porosity increased from 40·77 to 45·16%. The terminal velocity increased from 10·1 to 12·1m s −1 . The static coefficient of friction varied from 0·344 to 0·625 over different material surfaces, while angle of repose varied from 26·6 to 31° within the studied moisture range.
Padding materials are commonly used in fruit packing Unes wilh the objective of diminishing impac... more Padding materials are commonly used in fruit packing Unes wilh the objective of diminishing impact damage in post-harvest handiing. Two sensors <¡S 100 instrumenten sphere and UC-LPF impact tester) were compared to analyze the performance ofsix different padding materials used in Spanish fruit packing Unes. Pudding materials tested were classified according to their capabilily to decrease impact intensities inflicted on fruit in packing Unes. A statistical procedure to test padding materials was tested for Golden Delicióos apples. Its hasis is a múltiple logistic regression to predici bruise probability in fruit. The model combines tWO groups of parameters: padding material parameters measured wilh the IS, and fruit properties.
Revista Cientifica Rural De Brasil Issn 1998 Vol 3 N 2, 1998
La demanda de frutas y hortalizas en Europa es cada vez más exigente en términos de calidad. En f... more La demanda de frutas y hortalizas en Europa es cada vez más exigente en términos de calidad. En frutos de pepita, como la manzana y la pera, los principales parámetros de calidad son el calibre, la firmeza, el color, la calidad gustativa y la ausencia de defectos; los daños mecánicos son los defectos que producen mayores pérdidas. En manzana, se ha comprobado que las magulladuras son el daño mecánico más frecuente, que influye decisivamente en el precio de venta y en la aceptación del consumidor. En los últimos cinco años, un equipo investigador del
Symposium on Production of Tomatoes for Processing, 1980
Determinations of resistance to damage were carried out in a total of 31 tomato varieties for pro... more Determinations of resistance to damage were carried out in a total of 31 tomato varieties for processing, with the purpose of choosing the most suitable ones for mechanical harvesting. The characteristics studied include: puncture, deformation and rupture of the fruits, the ease of detachment of the fruits also being determined. Seventeen varieties were chosen, for further tests, with values 0.76 to 1.7 2 N of resistance to puncture; 3 to 9 N/mm of resistance to compression and 2.16 to 29.40 N resistance to detachment.
III International Symposium on Processing Tomatoes, 1990
Processing tomato industry has a high potential in Spain. Variety testing and mechanization studi... more Processing tomato industry has a high potential in Spain. Variety testing and mechanization studies and applications have been performed during the last 15 years. Many factors affect the quality and product losses during post-harvest handling which may be classified as: main or external factors: those related to the systems, procedures and devices; and fruit factors: those related to fruit properties. A research project is being carried on in the area of Vegas del Guadiana (Badajoz, Spain) to study these factors and to estimate costs, and to develop improved post-harvest handling practices.
Transactions of the ASAE, 2002
Spanish Journal of Agricultural Research, 2004
The production system in Portugal for table olives (Olea europea L.) relies on traditional fermen... more The production system in Portugal for table olives (Olea europea L.) relies on traditional fermentation while in Spain large scale controlled fermentation is used (Rejano, 1999). The maturity stage of the olives used in the Spanish procedure has to be closely controlled and homogenised. For this reason, on-line vision systems have been developed (Díaz et al., 2000, 2004). Traditional fermentation is very popular with consumers demanding high quality and low chemical inputs. This type of consumer associates lower homogeneity of the product, i.e. colour mixture, with more natural production and traditional manufacturers are reluctant to reduce this variability. On the other hand, traditional fermentation may enhance alterations during fermentation which lead to abnormal softening of the olives (Rejano, 1999) especially with a product containing large variability. Occasional abnormal processing leads to defects such as fish-eye (alambradas) generating a large
Multi-spectral images have been previously used to classify different kinds of fruits into postha... more 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
Span J Agric Res, 2005
The development of non-destructive techniques, including the use of acoustic and vibrational char... more The development of non-destructive techniques, including the use of acoustic and vibrational characteristics, for assessing the internal properties of fruits and vegetables (mainly related to flesh texture) has been the subject of a number of research projects. Several techniques (Chen and Sun, 1991; Abbott, 1999) and theoretical models (Cooke and Rand, 1973; Huarng et al., 1993) concerning the vibrational performance of these biological materials have been developed. When an object is excited in the audible or nonaudible range of frequencies it responds by vibrating. The amplitude peaks obtained in the frequency spectrum
Food and Bioprocess Technology, 2014
Your article is protected by copyright and all rights are held exclusively by Springer Science +B... more Your article is protected by copyright and all rights are held exclusively by Springer Science +Business Media New York. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
Food and Bioprocess Technology, 2014
The study of temperature gradients in cold stores and containers is a critical issue in the food ... more The study of temperature gradients in cold stores and containers is a critical issue in the food industry for the quality assurance of products during transport, as well as for minimizing losses. The objective of this work is to develop a new methodology of data analysis based on phase space graphs of temperature and enthalpy, collected by means of multidistributed, low cost and autonomous wireless sensors and loggers. A transoceanic refrigerated transport of lemons in a reefer container ship from Montevideo (Uruguay) to Cartagena (Spain) was monitored with a network of 39 semi-passive TurboTag RFID loggers and 13 i-button loggers. Transport included intermodal transit from transoceanic to short shipping vessels and a truck trip. Data analysis is carried out using qualitative phase diagrams computed on the basis of Takens-Ruelle reconstruction of attractors. Fruit stress is quantified in terms of the phase diagram area T
Postharvest Biology and Technology, 2012
This paper reports the development of image processing methods for the detection of superficial c... more This paper reports the development of image processing methods for the detection of superficial changes related to quality deterioration in ready-to-use (RTU) leafy spinach during storage. The experiment was performed on spinach leaves stored at 4.5 °C for 21 days (Set 1) and at 10°Cfor9days(Set 2). Regarding Set 1, 75 units were evaluated beginning at time zero and after 7,14, and 21 days of storage (treatments ti.o, t-i.i, ti.2,and tu, respectively). In the case of Set 2, 24 samples were measured at time zero and after 3,6, and 9 days (treatments t 2 .o, £2.1, £2.2, and t 2 j, respectively). Multispectral images were acquired using a 3-CCD camera centered at the infrared (IR), red (R), and blue (B) wavelengths. Opportune combinations of these bands were calculated using virtual images, and a non-supervised classification was performed. A large number of spinach leaves belonging to Set 2 showed injuries due to the effects of in-pack condensation; thus, an image algorithm was developed to separate these defective leaves before applying the classification. For Set 1, Set 2 and all the calculated virtual images, the classification procedure yielded two image-based deterioration reference classes (DRCs): Class A, including the majority of the samples belonging to ti.o and ti.-i (Set 1) and to t 2 .o and t 2 .i (Set 2) treatments and Class B, which comprised mainly the samples belonging to t-[, 2 and tu (Set 1) and to t 2 .2 and t 2 j (Set 2) treatments. An internal validation was performed, and the best classification was obtained with the virtual images based on R and B bands. For each sample, camera classification was evaluated according to reference measurements (visible (VIS) reflectance spectra and CIE L'd'b* coordinates); in all cases, VIS reflectance values corresponded well with storage days, and Classes A and B could be considered homogenous with regards to L* and a* values. Taken together, these results confirmed that a vision system based on R and B spectral ranges could constitute an easy and fast method to detect deteriorating RTU packed spinach leaves under different refrigeration conditions.
Journal of Texture Studies, 1998
Definition and establishment of assessment procedures for mealiness of apple fruits using sensory... more Definition and establishment of assessment procedures for mealiness of apple fruits using sensory and instrumental measurements were performed on 'Boskoop'. 'Cox's Orange Pippin' and 'Jonagold' samples with varying degrees of mealiness. The sensory procedure profiled mealiness as a loss of crispness, hardness, and juiciness, with an increase in the floury sensation in the mouth. High correlations between the sensory descripíors and instrumental parameters was shown through principal component analysis. The instrumental procedures (confined compression offruit cylinders and acoustic impulse response) gave coefficients of determination for juiciness and crispness of 0.85 and 0.71, respectively. This level of accuracy indicates the possihility of establishing several commercial mealiness siages (aslack ofcrispness and of juiciness) based on instrumental analyses. Paolelti el al. (1993) found a high correlation between sensory mealiness and instrumental cohesiveness (R =-0.704) and juiciness (R =-0.744) indifferent apple cultivars, assessing both instrumental parameters on fruit probes. The Magness-Taylor pcnelration test and the instrumental hardness were less related to sensory mealiness. Barreiro and Ruiz-Altisent (1996) showed that apple cylinders could be used to segregate three types of texlural groups of fruits: elastic, plástic and mealy.
Journal of Food Engineering, 2003
Two different decelerator elements used to reduce impacts on fruits on ramp transfer points in fr... more Two different decelerator elements used to reduce impacts on fruits on ramp transfer points in fruit packing lines were designed and tested. The performance of these elements, a powered decelerator and a multiple curtain, was compared to commercial decelerators (blankets). A ramp of length 60 cm was placed at an angle of 30°in an experimental fruit packing line between a roller transporter and a conveyor. The decelerators were placed on top of the ramp. Different tests were carried out to study the performance of the decelerators using instrumented spheres (IS 100) of various sizes. Results showed that decelerators can reduce the impact intensity down to safe thresholds. The powered decelerator was the most effective because it reduced the speed of fruits and did not cause retention of the fruit, when correctly regulated.
Journal of Food Engineering, 2008
The external appearance of an olive's skin is the most decisive factor in determining its quality... more The external appearance of an olive's skin is the most decisive factor in determining its quality as a fruit. This work tries to establish a hierarchical model based on the features extracted from images of olives reflecting their external defects. Seven commercial categories of olives, established by product experts, were used: undamaged olives, mussel-scale or 'serpeta', hail-damaged or 'granizo', mill or 'rehus', wrinkled olive or 'agostado', purple olive and undefined-damage or 'molestado'. The original images were processed using segmentation, colour parameters and morphological features of the defects and the whole fruits. The application of three consecutive discriminant analyses resulted in the correct classification of 97% and 75% of olives during calibration and validation, respectively. However the correct classification percentages vary greatly depending on the categories, ranging 80-100% during calibration and 38-100% during validation.
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Papers by M. Ruiz-altisent