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Bernardo Pace
Ruolo
III livello - Ricercatore
Organizzazione
Consiglio Nazionale delle Ricerche
Dipartimento
Non Disponibile
Area Scientifica
AREA 07 - Scienze agrarie e veterinarie
Settore Scientifico Disciplinare
AGR/15 - Scienze e Tecnologie Alimentari
Settore ERC 1° livello
LS - LIFE SCIENCES
Settore ERC 2° livello
LS9 Applied Life Sciences and Non-Medical Biotechnology: Applied plant and animal sciences; food sciences; forestry; industrial, environmental and non-medical biotechnologies, bioengineering; synthetic and chemical biology; biomimetics; bioremediation
Settore ERC 3° livello
LS9_4 Aquaculture, fisheries
Table grape producers worldwide are constantly searching for new technologies that will allow grape clusters to maintain the fresh appearance they had immediately following harvest. Postharvest technologies used to extend table grape shelf-life include active packaging. In this paper, the effect of active PET packaging on the marketability and rachis browning development of 'Red Globe' and'Crimson' seedless table grape was assessed, in comparison to the storage in polyethylene (PE) film alone or in combination with SO2 pad. Active PET showed significant effect on the marketability and antioxidant activity preservation in comparison with the use of SO2 pad. In particular, the active PET is able to ensure the marketability of the table grape, resulting a good competitor compared to the methods using the SO2, slowing the process of rachis browning. In particular, the marketability of 'Crimson' is maximized by employing such system, whereas, it is reduced by 9 and 13% using PE alone or in combination with SO2 pad. As for 'RedGlobe', the marketability is positively influenced by the active PET which together with SO2 pad guarantees maximum marketability, while the storage in PE alone causes a rapid loss of quality. In conclusion, active PET resulted a possible valid alternative to SO2 in table grape storage.
An innovative Computer Vision System (CVS) that extracts color features discriminating the qualitylevels occurring during fresh-cut radicchio storage in air or modified atmosphere packaging was proposed. It self-configures the parameters normally set by operators and completely automates thefollowing steps adapting to the specific product at hand: color-chart detection, foreground extractionand color segmentation for features extraction and selection. Results proved the average value of a* 20 over the white part and the percentage of light white with respect to the whole visible surface to be the most discriminating color features to significantly separate (P <= 0.05) the three desired quality levels(high, middle and poor) occurring during fresh-cut radicchio storage 23 (whose true value was verifiedon the base of ammonium content and human evaluated visual quality). The proposed procedure significantly simplify the CVS design and the optimization of its performance, limiting the subjective human intervention to the minimum.
The effect of postharvest treatment with oxalic acid (OA) on the overall qualityof two leafy vegetables, rocket and baby spinach, was investigated for the firsttime. The leaves of rocket and baby spinach were dipped in 1 mM OA solutionfor 1 min and then stored for 6 days at 8C. As control, the leaves of rocket andbaby spinach were immersed in hypochlorite, as currently practiced by fresh-cutcompanies. OA treatment significantly delayed deterioration during storage, withclear benefits for overall quality. Specifically, OA reduced the visual quality lossand yellowing of the leaves, slowing down the respiration rate, ammonia production,chlorophyll degradation and electrolyte leakage. In addition, the antioxidantactivity and total phenol content were preserved by OA treatment.Finally, OA reduced the mesophilic aerobic count, with a performance similar tothat of hypochlorite washing. Thus, OA treatment might be a valid method forpreserving the postharvest overall quality of rocket and baby spinach.
Introduction: The Quality Level (QL) of table grape is defined through sensory evaluation of the its overall appearance by a five-point rating scale (from 5: excellent to 1: extremely poor). Since this evaluation is dependent on subjective judgments, the aim of this work was to develop methods based on MS-eNose and 1H NMR data for an objective QL assessment of two table grape cultivars, i.e. Vittoria and Italia.Methods: Table grape bunches were stored at 5 and 10 °C and sampled after a number of days needed to reach each QL. Berries were homogenized, centrifuged and the supernatant was analyzed by HS-SPME MS-eNose and 1H NMR. LDA and PLS-DA were applied on data to discriminate samples based on the five QLs (five class discrimination) and on their marketability/non-marketability (two class discrimination).Results: The model performances were expressed in terms of the prediction ability calculated by V-fold cross-validation procedure (CV=20%). For both cultivar, NMR model average prediction abilities ranged from 92 to 93%, and from 76 to 79%, in the two and five class discrimination, respectively. Better results were obtained in case of the MS-eNose models with mean prediction abilities ranged from 98 to 100% (two class discrimination), and from 86 to 100% (five class discrimination). In particular, the best prediction abilities of 100% were obtained in case of cv. Vittoria for MS-eNose PCA-LDA in both discriminations (two and five class discriminations) and for MS-eNose PLS-DA in the two class discimination.Conclusions: Taking into account the results obtained, both analytical technologies adopted herein could be used as valid and rapid tools for the table grape quality evaluation. In details, although NMR data can provides additional information on the identification of quality marker metabolites MS-eNose predictive models showed better performances in both types of discriminations.
The volatile profile of three sweet basil cultivars, "Italico a foglia larga", "Cammeo" and "Italiano classico", packagedin air at 4 or 12 °C until 9 days, was monitored by solid phase microextraction with GC-MS. Chilling injury (CI) scoreand electrolyte leakage were also assessed. In total, 71 volatile organic compounds (VOCs) were identified in the headspaceof basil samples. A preliminary principal component analysis highlighted the dominant effect of the cultivar onVOCs profiles. Data analysis by post-transformation of projection to latent structures regression (ptPLS2) clarified therole played by time and temperature of storage. Temperature influenced the emission of volatiles during storage, withmuch lower total volatile emissions at 4 °C compared to 12 °C. Finally, a ptPLS2 regression model performed on VOCsand the two CI parameters allowed selection of 10 metabolites inversely correlated to both CI parameters, which can beconsidered potential markers of CI in basil leaves.
Quality loss during storage is often associated to changes in relevant product colors and/or to the appearanceof new pigments. Computer Vision System (CVS) for non-destructive quality evaluation often relies on human knowledgeprovided by operators to identify these relevant colors and their features. The approach described in this paperautomatically identifies the most significant colors in unevenly colored products to evaluate their quality level. Itsperformance was compared with results obtained by exploiting human training. The new method improved qualityevaluation and reduced the subjectivity and the inconsistency potentially induced by operators.
Selection of artichoke cultivars with specific physical, physiological and biochemical characteristics is required by processors and retailers in order to commercialize artichokes as fresh or fresh-cut products. In this work six artichoke cultivars were evaluated for their cold storage suitability byfollowing the variations in their main physical (browning index), physiological (respiration rate) and biochemical (antioxidant activity, total phenol content, polyphenol oxidase and peroxidase activity) parameters at 1 °C for 12 days. In addition, linear regressions among antioxidant activity, total phenols and enzymatic activities were assessed with the aim of selecting the most suitable cultivar for storage and processing. The low values for the physical, physiological and biochemical parameters measured in Romolo led us to indicate this cultivar as the best for storage. On the other hand, it may be preferable to designate cultivars, with higher values for the same parameters for fresh consumption, partly due to their high antioxidants content.
Leaves of three different sweet basil (Ocimum basilicum L.) cultivars (Italico a foglia larga, Cammeo, andItaliano classico) packed in macro-perforated polyethylene bags were stored at chilling (4 C) or nonchillingtemperature (12 C) for 9 days. During storage, visual quality, physiological (respiration rate,ethylene production, ammonium content) and chemical (antioxidant activity, total polyphenols andpolyphenol profile) parameters were measured. Detached leaves stored at chilling temperature showedvisual symptoms related to chilling injury, while ethylene production and ammonium content resultedassociated to cultivar sensibility to damage at low temperature. Storage at 4 C caused a depletion inpolyphenols content and antioxidant capability, which was preserved at 12 C. Regarding the polyphenolsprofile, stressful storage conditions did not enhance the phenolic metabolism. However, leavesstored at 12 C did not loss a significant amount of metabolites respect to fresh leaves, suggesting the possibilityto extend the storability after the expiration date, for a possible recovery of bioactive compounds.
The volatile profile of two hybrids of "Radicchio di Chioggia", Corelli and Botticelli, stored in air or passive modified atmosphere (MAP) during 12 days of cold storage, was monitored by solid phase micro-extraction (SPME) GC-MS. Botticelli samples were also subjected to sensory analysis. Totally, 61 volatile organic compounds (VOCs) were identified in the headspace of radicchio samples. Principal component analysis (PCA) showed that fresh product possessed a metabolic content similar to that of the MAP samples after 5 and 8 days of storage. Projection to latent structures by partial least squares (PLS) regression analysis showed the volatiles content of the samples varied depending only on the packaging conditions. Specifically, 12 metabolites describing the time evolution and explaining the effects of the different storage conditions were highlighted. Finally, a PCA analysis revealed that VOCs profile significantly correlated with sensory attributes.
In this study, carrot jams were developed using either precooked vegetable (common method) or short cooking times (mild method). Jams were prepared using four carrot types: a commercial one and three local landraces (orange, purple and yellow). The parameters assessed were total phenols, antioxidant activity, beta-carotene, potassium content, color and sensory evaluation. Mild method caused lower color differences than common method, when comparing the jams to raw carrots. Antioxidant activity, total phenols and potassium content loss were also lower in mild method. Both methods improved beta-carotene retention in jams. Following sensory analysis, products obtained by mild method showed the best scores for taste and overall acceptability, with the highest scores being registered for purple jam. In particular, high correlations between antioxidant activity, total phenols and purple products (both raw products and jams) were emphasized by principal component analysis. In conclusion, the mild method described in this paper helps to preserve the overall quality of perishable vegetables, such as local carrots. (C) 2013 Elsevier Ltd. All rights reserved.
Brassica vegetables are consumed year-round as raw salad or cooked ingredients. Four Brassica species were selected for this study, broccoli (Brassica oleracea var. italica), broccoli raab (Brassica rapa L.), choisum (Brassica rapa var. parachinensis), and gailan (Brassica oleracea var. alboglabra). While there is abundant information about broccoli, research on gailan, choisum and broccoli raabis very limited. The effect of CA (3% O2 alone or in combination with 7 or 15% CO2, 1% O2 alone or combined with 15% CO2) and air on marketable quality (overall visual, yellowing, discoloration, decay) and chemical parameters (antioxidant activity, chlorophyll, sugar, fermentative volatiles, and ammonia content) during storage at 5°C was evaluated. Products were obtained from a wholesaler, washed in chlorinated water, trimmed into florets and placed in unsealed polyethylene bags that were held in polycarbonate chambers through which humidified air or the controlled atmospheres flowed. Visual quality was evaluated after 0, 8, 12, 16 and20 days, while chemical parameters were measured after 0, 8, 16 days. Generally, CA treatments did not affect the antioxidant activity, chlorophyll or sugar concentrations in any of the specialty brassicas studied. On the other hand, both ammonia content and visual quality evaluations were affected by atmosphere composition. Florets stored in low oxygen (3% O2) often had the best visual qualitybut generally all atmospheres maintained better marketable quality than air storage. The 3% oxygen CA improved marketability to about 16 days. Low oxygen delayed postharvest and post-cutting deterioration of florets from all Brassica species, and based on changes in ammonia concentrations, was considered beneficial to maintain quality of fresh-cut brassicas stored at 5°C.
In the Puglia region, a multicolor landrace called the yellow-purple Polignano carrot has been cultivated since 1940 by local smallholder farmers and has been added to the Slow Food list of traditional products. Composition analyses of these carrots were carried out including carbohydrate assay, inorganic cations, nitrate content, and dry weight of each colour. Besides, antioxidant activity, ?-carotene, total phenols and carotenoid content on the full carrots and on the cortex and inner core separated tissues were determined. The same analyses were performed on a commercial carrot cultivar. On average, total glucose, fructose, and saccharose content was 22% lower in the yellow-purple Polignano carrot than in the commercial one. In addition, the highest contributor to the relative sweetness in the yellow-purple Polignano carrot was fructose (43.5%), which affects its well-known taste, as well as its glycemic index. As for the nutritional parameters, purple carrots showed the highest content in antioxidant activity, total phenols, carotenoids and ?-carotene, mainly detected in the cortex.
Shelf life improvement for two different products (cactus pears and truffles), stored at 8 and 5°C respectively under modified atmosphere packaging (MAP), was assessed by modelling heat and mass transport as well as package geometry and storage conditions. An innovative approach was implemented by coupling an engineering tool, such as the computational fluid dynamics (CFD) with experimental data, such as visual quality, respiration rate, head space composition, and weight loss upon MAP storage. The overall model, incorporating all phenomenological variations, has been finally tuned-up by means of a specific multi-objectiveoptimization. It is seen that the models are able to simulate complex, multidimensional food-package ensembles under MAP conditions. As for cactus pears, a multidimensional, transient model is proposed by combining generalized transport notations with respiration and microbial growth kinetics. As for truffles, a model able to predict the effect of storage on quality loss wasobtained. The adoption of predictive and comprehensive mathematical models is an economic method to evaluate packaging and operating performance, compared to more expensive experimental methods. Computational models, such as these, can beused to verify existing MAP configurations, or to design new ones. Exploitation of this mathematical tool would allow for informed technical and management decisions.
In green leafy vegetables, the retention of green colour is one of the most generally used index to evaluatethe overall quality and freshness and it is associated to total chlorophyll content.Destructive chemical techniques and non-destructive chlorophyll meters represent the state-of-the-artmethods to accomplish such critical task. The former are effective and robust but also expensive and timeconsuming. The latter are cheaper and faster but exhibit lower reliability, require the probe to touch theleaves and heavily depend on the positions chosen for sampling the leaf's surface. In this paper, a newapproach to non-destructively predict total chlorophyll content of fresh-cut rocket leaves without contactis proposed. Fresh-cut rocket leaves were analysed for total chlorophyll content by spectrophotometerand SPAD-502 (used as reference values) and acquired by a computer vision system using a machinelearningmodel (Random Forest Regression) to predict total chlorophyll content. Finally, the trainedand validated model will be used for on-line prediction of total chlorophyll content of unseen freshcutrocket leaves. The proposed system can match the physical and timing constraints of a real industrialproduction line and its performance (R2 = 0.90), measured on the case study of fresh-cut rocket leaves,outperformed the results of the SPAD chlorophyll meter (R2 = 0.79).
CONTINNOVA project was funded by Apulia Regional government within the Call on Technological Cluster for Innovations. It started in November 2015 and will be concluded within November 2017. The main objective will be to create a refrigerated isothermal container equipped with innovative technologies, including advanced sensors for the control of the atmosphere composition, during the transport of fresh fruit and vegetables. The final goal is to ensure the quality and safety of fruit and vegetables products of regional Apulia exports along the distribution chain. The partnership consists of the IFAC spa (leader), the companies TERA and Ditro, the Department of Agro-Food Sciences, Food and Environment (SAFE) of the University of Foggia, the Departments of Mechanics, Mathematics and Management (DMMM) and Civil Engineering, Environmental, Land, Construction and Chemistry (DICATECh) of the Polytechnic of Bari, Spin-Off INGENIUM, Apulia Food Fingerprint Lab Network and the Institutes of CNR ISSIA (Institute of Intelligent Systems Research For Automation) and ISPA (Institute of Sciences of Food Production), the latter with the role of Scientific Adviser. The industrial companies designed and are realizing the container, firstly as Prototype (in scale) and then in real dimension. While, the scientific partners researched the best atmosphere composition and/or atmosphere pre-treatment to be implemented in the Container in order to transport in optimal condition table grape and fresh artichoke. In the last work package of the project, the innovative container will be validated during the simulation of an experimental transport of table grape. Finally, the innovative container will be made available to Association of producer and exporter of horticultural products (APEO) to test its performance in preserving quality and extending shelf-life of the vegetables transported.
Fresh-cut iceberg lettuce was treated with two different concentrations of L-cysteine, in order to select the proper treatment able to improve the storage in air. L-cysteine at 0.1% was selected because it significantly slowed down browning, respiration activity and soluble o-quinones formation and preserved the antioxidant activity. Thus, a second experiment in which this concentration was applied to fresh-cut lettuce processing was carried out. The effectiveness of the treatment with L-cysteine was confirmed and enhanced by the storage in modified atmosphere, increasing the shelf life of 40% respect to control samples. Sensory analysis confirmed the effectiveness of the treatment, showing that fresh-cut lettuce dipped with L-cysteine obtained better scores for appearance, texture, and absence of browning and of unpleasant odor than control. Finally, treatment with L-cysteine resulted with a suitable anti-browning agent, which could be used in fresh-cut lettuce processing. © 2014 Wiley Periodicals, Inc.
Asparagus is a herbaceous perennial plant, marketed worldwide as fresh or fresh cut, very appreciate by consumers for its structural and sensory characteristic and for its nutritional properties. [1] The asparagus was a climacteric species, fresh spears deteriorate rapidly after harvest, and the high respiration rate is the main limiting factor. The refrigeration, is able to retard visual and nutritional quality loss by slowing many of the deteriorative processes.[2] In this study the effect of oxalic acid (OA) treatment on visual and nutraceutical properties of two green and one purple cultivars of fresh asparagus, during 12 storage days at 5 °C, was investigated. The aim of this work was to study the effects of postharvest treatments with OA, on the shoots of asparagus, during cold storage. Variation of the outward appearance, sensory characteristics, respiration rate and, particularly, the changes of antioxidant properties and phenol composition during cold storage, were investigated by electrochemical and mass-spectrometry analysis approach
Table grape is a non-climacteric fruit subject to serious water and quality loss during postharvest handling. Gentle handling, careful bunch cleaning, fast cooling, low temperature, and sulfur dioxide (SO2) pad application during storage are generally used to improve storage. In this study, the effect of cold storage in modified atmosphere (MA) in different CO2 concentrations (0-20%) on the quality evaluated after a shelf-life period at ambient temperature, was studied. Organic table grape bunches (cv Italia), were packaged in MA bags and stored at 2 °C (± 1.0) for 14 days, using MA with 0% (air), 10% and 20% initial CO2 concentrations. Unpacked samples were used as control. The gas composition inside packages was periodically measured. After 7 and 14 days, all packages were opened and transferred in air at 20 °C for 3 days: sensory, physical and chemical-nutritional parameters were measured. A significant effect of high CO2 atmosphere on delaying visual quality and decay was shown. The best results in terms of preservation of sensory as well as nutritional quality were obtained using a 10% CO2 as initial concentration. Actually, this treatment was able to ensure a suitable atmosphere composition during all storage period: the O2 and CO2 concentrations after 14 days of MA storage, were found to be about 7% and 15%, respectively, i.e. a CO2 level enough to control the decay development and an O2 concentration sufficiently far from the anoxia threshold, as detected by acetaldehyde and ethanol measurement.
The quality and shelf-life of ready-to-use lettuces depend on genotypic traits of raw material and on several aspects from preharvest to postharvest processing. In general, preharvest factors should be aimed to optimize their impact on postharvest quality, in order to limit the use of chemical preservative during processing. In this study the influence of soil and soilless growing systems on quality and microbial traits of three multi-leaf lettuce cultivars (two green Eztoril and Ezabel, and one red Ezra) was evaluated at harvest and after 7 and 13 days of storage at 8 °C. At harvest, Ezra showed a respiration activity and a total phenol content respectively 2-fold and 25% significantly higher than the green cultivars. Soil lettuces resulted more stressed than those grown in soilless, as indicated by their initial content in antioxidants. As for nitrate content, soilless grown lettuces at harvest showed an average concentration higher than soil-grown ones (838 vs 432 mg/kg fw), although values are generally lower than limits imposed by the EU Regulation (No.1258/2011). The initial microbial load was significantly higher in soil lettuce compared with lettuce cultivated in soilless condition. Moreover the latter resulted cleaner than soil grown samples, with evident beneficial effect regarding the potential application of mild washing during processing in view of extended cold storage. During storage, soilless lettuces showed no ammonium accumulation, differently from those cultivated in soil. In addition, lettuce cultivars grown in soilless condition showed unchanged content in the antioxidant activity and total phenols, and lower microbial counts than soil lettuces. Results of the present study showed that soilless growing system can positively affect qualitative and microbiological parameter of lettuces studied, and it can be a valid agricultural system in order to obtain high quality multi-leaf lettuces for ready-to-use industry.
'Cardoncello' mushrooms (Pleurotus eryngii), are typical spontaneous or cultivated mushrooms of the Mediterranean region and represent one of the most popular mushrooms in Italy. This variety is largely appreciated by consumers for its excellent organoleptic quality, mainly due to a peculiar taste and texture. Unfortunately, Cardoncello has very short shelf-life, losing its quality due to its high respiration rate. In addition the lack of a cuticle that protect them from physical or microbial attack and water loss, makes Cardoncello mushrooms highly perishable. So the aim of the present experiment was to extend the shelf-life of this commodity. In the first experiment (EXP 1) 'Cardoncello' mushrooms were unwashed (CTRL) or washed in two different chlorine solution concentrations (50 and 100 ppm), in order to select the most suitable one to reduce the microbial load, without affecting visual and sensorial quality during storage. Results of EXP 1 showed that, regardless the chlorine concentration applied, washing significantly delayed microbial load after processing and during storage respect with CTRL. Comparing the two different chlorine concentrations applied, the solution with 100 ppm chlorine caused appreciable damage and yellowing of the cap, while the use of 50 ppm did not affect mushrooms visual quality and preserved their sensorial attributes after 10 day of storage in air at 7 °C. In the second experiment (EXP 2) mushrooms were unwashed or washed in chlorine solution at the concentration selected in the EXP 1 (50 ppm), packed in MAP (10 kPa O2 + 10 kPa CO2 in nitrogen) or kept in air, and stored for 10 days at 7 °C. The effectiveness of the washing was confirmed on mesophilic bacteria but not on yeasts and moulds. Regardless washing operations, the use of MAP preserved the visual appearance of mushrooms during storage, allowing to maintain the marketability until 10 day of storage at 7 °C. The combination of washing and MAP significantly delayed mesophilic bacteria as well as yeasts and moulds growth during storage.
In order to increase the diffusion of cactus pearfruits, in this study, the proper maturity index for peeling andprocessing them as ready-to-eat product was evaluated andcharacterized. Thereafter, the effects of different storagetemperatures and modified atmosphere conditions on themarketability of ready-to-eat cactus pear were studied. Thestorage of ready-to-eat fruits at 4 °C in both passive (air) andsemi-active (10 kPa O2 and 10 kPa CO2) modifiedatmosphere improved the marketability by 30%, whereasthe storage at 8 °C caused a dangerous reduction in O2partial pressure inside modified atmosphere packages, due tofruits' increased metabolic activity. Avery low level of initialmicrobial growth was detected, while a severe increase inmesophilic and psychrophilic bacteria was shown in controlsamples at both temperatures during storage; an inhibitoryeffect of modified atmosphere on microbial growth was alsoobserved. In conclusion, modified atmosphere improvedonly the marketability of fruits stored at 4 °C; whereas thestorage at 8 °C resulted in deleterious effects on the ready-to eatfruits, whether stored in air or in modified atmosphere.
Perishable bio-substrate behavior can be modeledduring packaged storage. Local mass and heattransferhave been coupled to respiration rate and microbial growth.Validating measurements have also been performed, and amulti-objective optimization was employed to tune themodel. The model is able to simulate gas compositionhistory and local bacteria spoilage in storage modes commonlyadopted by the food industry, depending on productfeatures and temperature. Exploitation of this mathematicaltool would allow for informed technical and managementdecisions.
Cactus pear (Opuntia ficus-indica (L.) Mill., 'Gialla') is a delicious and nourishing fresh fruit having a number of documented positive health effects. One of the reasons this fruit is not widely commercialized in international and domestic markets is because of the presence of residual glochids (thorny hairs) on the fruit surface. Marketing cactus pear as a ready to eat product may significantly improve its consumption, preserving its quality, safety and marketability. In this work green-yellow cactus pear fruits were peeled and stored for 13 days at 4 and 8°C, packaged in passive and in active modified atmosphere. Samples stored in air were used as control. The passive modified atmosphere improved the marketability of cactus pears stored at 8°C for 6 days. The rapid decrease in O2 and the increase in CO2 concentration in packages stored at 8°C caused the loss of marketability of fruits stored at high temperature. Samples stored at 4°C in passive and active modified atmosphere resulted in a marketablility of 9 days, since each one in air was just below the salable limit at 6 days. A very low initial microbial growth was detected, while an increase in mesophilic and psychrophilic bacteria during storage at both temperatures was found in the air samples. In conclusion, it was found that it is possible to store fresh-cut cactus pear, obtaining a marketability of 9 days at 4°C; while, when the temperature is higher than 4°C, it is not possible to preserve the fruit quality for more than 6 days.
The relationships between colour parameters obtained by a Computer Vision System (CVS) and both antioxidant activity (AA) and total phenol contents (TP) on coloured carrots were expressed as multivariate models obtained by multiple linear regression. The AA and TP predicted by the proposed models showed a good correlation with the real AA (R2 = 0.97, P ? 0.001) and TP (R2 = 0.94, P ? 0.001) measurements on the data set including internal and external parts of carrots. The predictions on the data set including only the internal (unevenly pigmented) parts of the carrots exhibited lower determination coefficients (R2 = 0.93 for AA and R2 = 0.86 for TP, P ? 0.001). The effectiveness of the models was checked also on the colour information provided by a colorimeter whose measures proved to be more sensitive to the uneven pigmentation of the carrots. Finally, the proposed models were able to successfully estimate the AA and the TP contents of pigmented carrots when applied to colours measured by the CVS.
Quality rating is currently accomplished by non-destructive and subjective sensory evaluation or by objectiveand destructive analytical techniques. There is a strong need of an objective non-destructive contactless qualityevaluation system to monitor fruit and vegetable along the whole supply chain. This paper proposes a Computervision system to satisfy this request. Image processing and machine learning techniques have been combined todevelop a Computer vision system whose configuration and tuning has been strongly simplified: that makes easierits deployment in real applications. The system has been verified on two white table grape cultivars (Italiaand Victoria) against three different classification tasks. The first considered five quality levels (5, 4, 3, 2, 1); thesecond separated the higher fully marketable quality levels (5 and 4) from the boundary (3) and the waste (2and 1); the third separated the higher fully marketable quality levels (5 and 4) from the other three (3, 2 and1). The system achieved a cross-validation classification accuracy up to 92% on the cultivar Victoria and up to100% on the cultivar Italia for binary or binomial classification between fully marketable and residual qualitylevels. The obtained results support its capability of powerfully, flexibly and continuously monitoring the qualityof the complete production along the whole supply chain
Non-destructive evaluation of vegetables by Computer Vision Systems (CVSs) makes possible to check their quality level in an objective and consistent way along the whole supply chain up to the final users. CVSs have been proven to be successful when applied to unpackaged products.The proposed approach aimed to enable this analysis on packaged fresh-cut lettuce with minimum constraints on the acquisition phase and without any care to flatten the surface of the bag facing the camera. A deep-learning architecture, based on Convolutional Neural Networks (CNNs), was used to identify regions of the image where the vegetable was visible with minimum colour distortions due to packaging. To meaningfully assess the performance of the system, each lettuce's sample was acquired both through packaging material and without packaging material. The image analysis was applied to both the resulting images to automatically grade their quality level. The results showed that the performance loss due to the presence of packaging is negligible (83% instead of 86%) and that the proposed system can be used to monitor the quality level of fresh-cut lettuce regardless of packaging at all the critical check points along the supply chain.
The paper describes the developed hardware and software components of a computer vision systemthat extractscolour parameters from calibrated colour images and identifies non-destructively the different quality levels exhibitedby lettuce (either whole or fresh-cut) during storage. Several colour parameters extracted by computervision system have been evaluated to characterize the product quality levels. Among these, brown on total andbrown on white proved to achieve a good identification of the different quality levels on whole and fresh-cut lettuce(P-value b 0.0001). In particular, these two parameters were able to discriminate three levels: very good orgood products (quality levels from 5 to 4), samples at the limit of marketability (quality level of 3) and wasteitems (quality levels from 2 to 1). Quality levels were also chemically and physically characterized. Among theparameters analysed, ammonia content proved to discriminate the marketable samples from the waste in bothproduct's typologies (either fresh-cut or whole); even the two classes of waste were well discriminated byammonia content (P-value b 0.0001).A function that infers quality levels from the extracted colour parameters has been identified using a multiregressionmodel (R2 = 0.77). Multi-regression also identified a function that predicts the level of ammonia(an indicator of senescence) in the iceberg lettuce from a colour parameter provided by the computer visionsystem (R2 = 0.73), allowing a non-destructive evaluation of a chemical parameter that is particularly usefulfor the objective assessment of lettuce quality.The developed computer vision system offers flexible and simple non-destructive tool that can be employed inthe food processing industry to monitor the quality and shelf life of whole and fresh-cut lettuce in a reliable,objective and quantitative way.
The quality traits of two "Radicchio di Chioggia" hybrids (Corelli and Botticelli) processed as fresh-cut and stored in unsealed bags or in passive modified atmosphere for 25 days at 5 °C, were measured in two consecutive experiments. Moreover, on fresh and stored samples, a detailed structural characterization of the polyphenols of radicchio extracts extracted from fresh and stored radicchio samples was performed by HPLC and electrospray ionization multistage ion trap mass spectrometry (ESI-ITMSn). Twenty-one compounds were identified and quantified in Corelli extract, while nineteen ones were detected in Botticelli extract. Quercetin-7-O-glucoside-3-O-(6"-malonyl)-glucoside and isorahmnetin-7-O-glucuronide were found only in Corelli. Interestingly, the presence of dihydroflavonol glycosides in "Radicchio di Chioggia" is here reported for the first time. In the second experiment (performed on Botticelli), fresh-cut processing promoted a 2-fold increase in bioactive compounds, quantified in a significant amount (305 mg/100 g fresh weight) also in leaves scored unmarketable. Thus this hybrid, suited for fresh-cut processing, showed to be also an interesting and cheap source of antioxidant phenolics, when was no more acceptable. Although less suitable for fresh-cut processing, tThe Corelli fresh-cut radicchio, even if less suitable for fresh-cut processing, resulted a valuable hybrid for the fresh consumption and a source of polyphenols due to for their high content measured in fresh and stored leaves.
Baby lettuce leaves are generally produced for the unwashed ready-to-eat market. The aim of this research was to predict sensory and microbiological aspects of this product based on physicochemical properties during storage at 4 and 10°C. Products were analysed at sampling times chosen on the basis of five sensory visual quality (VQ) levels. Samples scoring VQ5 and VQ4 were considered acceptable (Ac), whereas the remaining scores were defined as unacceptable (UAc). Each VQ level was then characterized for physico-chemical (colour, ammonium, antioxidant activity, electrolytic leakage, phenols, chlorophyll, respiratory activity) and microbiological (total viable count, Pseudomonas spp., Enterobacteriaceae, lactic acid bacteria, yeast and moulds) parameters. UAc samples also proved unsatisfactory from a microbiological point of view (total viable count >=107 CFU g-1). Partial least squares (PLS) regression analysis allowed us to identify colour change (?E*) and total chlorophyll (TC) as suitable variables to predict the microbial load (TVC) associated with each sensory VQ level. The model obtained showed R2CV=0.94, RMSECV=0.41 and a relative error of 5.61%. In conclusion, the use of these parameters as quality indicators could be a new strategy for discriminating green leafy vegetables into acceptable or unacceptable products.
Baby lettuce leaves are generally produced for the unwashed ready-to-eat market. The aim of this research was to predict sensory and microbiological aspects of this product based on physicochemical properties during storage at 4 and 10°C. Products were analysed at sampling times chosen on the basis of five sensory visual quality (VQ) levels. Samples scoring VQ5 and VQ4 were considered acceptable (Ac), whereas the remaining scores were defined as unacceptable (UAc). Each VQ level was then characterized for physico-chemical (colour, ammonium, antioxidant activity, electrolytic leakage, phenols, chlorophyll, respiratory activity) and microbiological (total viable count, Pseudomonas spp., Enterobacteriaceae, lactic acid bacteria, yeast and moulds) parameters. UAc samples also proved unsatisfactory from a microbiological point of view (total viable count >=107 CFU g-1). Partial least squares (PLS) regression analysis allowed us to identify colour change (?E*) and total chlorophyll (TC) as suitable variables to predict the microbial load (TVC) associated with each sensory VQ level. The model obtained showed R2CV=0.94, RMSECV=0.41 and a relative error of 5.61%. In conclusion, the use of these parameters as quality indicators could be a new strategy for discriminating green leafy vegetables into acceptable or unacceptable products.
Soilless growing systems, mainly developed for vegetables and ornamental crops, have been recently proposed as alternative to the soil culture also for table grapes in order to reach optimal productive performance. In this paper sensory, physical and chemical parameters were analyzed in table grape obtained from soil and soilless growing system, at harvest and during the storage in air or modified atmosphere. RESULTS: At harvest soilless berries resulted 30% firmer than fruits obtained in soil culture. Moreover, table grape obtained from soilless growing system showed an antioxidant activity and total phenol content 60% higher than bunches coming from soil. Storage under modified atmosphere resulted in better quality of table grapes with respect to those stored in air. Furthermore, soilless growing system resulted more suitable than soil system in preserving visual quality and controlling rachis browning and weight loss. CONCLUSION: Since soilless system allows berries cleaner and of higher quality than samples coming from soil, we can suggest the implementation of soilless grown system for the production of health promoting and convenience fruits.
Fresh-cut Big Top' nectarines were dipped in 2% (w/v) ascorbic acid-1% (w/v) calcium lactate and stored at 4 degrees C for up to 12days in 10kPa O-2- and 10kPa CO2-modified atmosphere packaging (MAP). The used microperforated plastic film allowed O-2 and CO2 concentrations to reach steady values from the fifth day in storage onwards. Samples stored in MAP after chemical dipping showed the highest visual quality score, slight browning symptoms, increment in firmness and very low ethanol and acetaldehyde content. The chemical dipping also increased antioxidant capacity, probably due to the effect of ascorbic acid. The results suggested that the control of yeasts was mainly exerted by MAP, whereas only a slight effect was achieved by the chemical dipping. Therefore, MAP plus ascorbic acid/calcium lactate dipping was the best combination to preserve phytochemical content, antioxidant capacity and microbiological safety of fresh-cut nectarines during storage.
The effect of oxalic acid (OA) treatment on visual properties and bioactive compounds of two green and onepurple cultivars of fresh asparagus was investigated during twelve storage days at 5 °C. Cold storage and OAtreatment positively affected the overall appearance of the investigated cultivars. Cut-end dehydration increased,all along the storage period, in all cultivars but, the negative effect of the storage, clear on controlsamples, was mitigated by OA. The most represented compounds in Grande and Vegalim cultivars were: quercetinrutinoside, feruloyl quinic acid and cumaroyl quinic acid. Cyanidin glucosyl rutinoside, cyaniding rutinosideand peonidin rutinoside were identified in Purple Passion cultivar. The bioactive compounds seemed tobe affected by storage but not by OA treatment. The sensor-biosensor system indicated that the antioxidantactivity is negatively affected by storage but not by OA. The decrease of antioxidant activity coincided with thereduction of ascorbic acid levels in all the cultivars.
A simulation approach based on transport phenomena is proposed in this paper, to help manage the logistics of fresh broccoli during cold chain. Indeed, for many varieties of fresh vegetables their shelf-life depends critically on storage temperature progress, affecting the visual quality (VQ) as a consequence of changes in intrinsic quality parameters. Broccoli was chosen as a model food, and average ammonium (NH4+) concentration was adopted as a proper quality parameter associated with residual VQ. Therefore, a mathematical model for predicting the residual VQ is proposed depending on the keeping temperature (among 5 and 20 °C), for a relatively long storage duration (up to 12 days). Model validation is brought over by comparing experimental and computed VQ.The predictions were affected by maximum errors of about 3%, 13% and 16% for runs at 5, 10 and 20 °C respectively. The effect of temperature fluctuations were then explored. Two non-isothermal scenarios commonly occurring during retail stores in European and US handlers were first analyzed to test the model's ability to predict the visual quality score. Moreover, the model can be easily applied to assess the household or retail shelf-life, or in general the expiration date after a given storage duration.
Solid-phase microextraction (SPME) GC-MS was used to investigate the volatile organic compound(VOC) profile of fresh-cut 'Big Top' nectarine samples, stored in unsealed bags (AIR) or packed in activemodified atmosphere (MAP) after 8 days of cold storage. Nectarine slices were also subjected to sensoryand quality analysis after harvest and at the end of the storage. MAP preserved the overall quality, theappearance and the olfactory properties of nectarine slices during storage, while AIR samples showedsymptoms of dehydration and browning. Sixty VOCs were identified in total in the headspace of the freshnectarines and cold-stored fruit slices samples. Principal component analysis performed on VOCs allowedto differentiate fresh nectarines from cold-stored samples, with lactones and terpenes mainly related tofresh samples, and ester compounds positively correlated to AIR or MAP samples. Partial least squareregression models allowed to identify a pool of VOC predictors of olfactory sensory descriptors.
Table grapes (cv. Italia) were stored at 5 °C in air or in modified atmosphere with low O2 (1%) and low(0.03-10%) or high (> 20%) CO2. Volatile organic compounds (VOCs) associated with quality (respiration rate,acetaldehyde and ethanol, water status of rachis) and sensory parameters (visual quality, rachis browning,characteristic odour and flavour, off-odour and off-flavour) were evaluated. Low CO2 preserved the quality andsensory parameters, whereas high CO2 caused a fermentative metabolism. A total of 126 VOCs were identified byHS-SPME/GC-MS analysis. Principal component analysis (PCA) identified (Z)-2-hexenal and (E,Z)-2,4-hexadienalas potential marker of freshness; whereas, acetaldehyde, ethanol, 1-butanol, 3-methyl-1-butanol, 1-octanoland 1-nonanol were correlated to fermentation processes. Partial least-square regression analysis (PLSR)was used to identify (R2 =0.95) the main predictors of off-odour as ethanol and ethyl acetate (+) and hexanaland ?-linalool (-).
Consumer acceptance of fresh-cut nectarines may be related to several characteristics (freshness, overallbrowning) that can be measured with suitable sensors. In this paper, digital image analysis was used toassess quality and marketability of fresh-cut nectarines, stored in air for 12 d at 5 oC. Visual appearanceand colour were measured using a conventional colorimeter and a computer vision system. In addition, anumber of fruit were analyzed for pH, titratable acidity, total soluble solids, total phenols and antioxidantcontent. During storage, nectarine slices showed a loss in appearance; after 12 d slices which were brown,having lost their freshness, showed a mean 30% decrease in total phenolics and a mean 10% increase inantioxidant activity with respect to fresh slices (13.7 ± 4.3 mg gallic acid 100 g-1 f.w. and 53.5 ± 5.2 molTE 100 g-1 f.w.). Visual appearance correlated significantly with the browning score (R2 = 0.78), titratableacidity (R2 = 0.45) and pH (R2 = 0.85). Correlation of the visual appearance score with the colour parametersb* and chroma measured by the computer vision system was higher (R2 = 0.76) than that obtainedusing a colorimeter (R2 = 0.57). The results showed that the computer vision system was more effectivethan the colorimetric method. Measurements by means of the computer vision system resulted in a reliabletool to determine quality and marketability of fresh-cut nectarines in an objective and quantitativeway. Moreover, the proposed computer vision system is suitable for real-time application in the foodprocessing industry.
Fresh-cut and whole iceberg lettuce were stored in refrigerated condition and the main sensory (overall appearance: OA, browning index: BI), physical (colour variation: ?E*), chemical (respiration activity: RA, ammonia content: A) and biochemical (total chlorophyll: TC, antioxidant activity: AA, total phenols: TP, o-quinones: o-q, polyphenol oxidase: PPO, phenylalanine ammonia-lyase: PAL and peroxidase: POD) traits were followed during the trial. Significant relationships among these parameters were assessed by principal component analysis (PCA) in order to find the main traits related to OA, in fresh-cut lettuce. Results from PCA showed that OA was inversely correlated with BI (r=-1.00), DE* (r= -0.98), A (r= -0.94), AA (r= -0.86), TP (r= -0.82), o-q (r= -0.89), and PAL (r= -0.80). Moreover, OA was positively related with RA (r= 1.00) and PPO activity (r= 0.96). Ammonia resulted significantly correlated with the main sensory, physical, chemical and biochemical parameters. Thus, this parameter, with DE* could be used as indicator of the product quality and acceptability in control quality procedures. In conclusion, rating scale used to estimate OA, resulted a valid method to evaluate the iceberg lettuce quality, since it showed significant relationships with the main analytical parameters.
The physiological and chemical traits of three red (MS151, Copacabana and Excellent)and three green (Ortis 398, Summerbell and Babybell) baby leaf lettuce cultivarswere evaluated during postharvest cold storage. In addition, their potentialuse as a source of antioxidants, after the expiration date, was also investigated. Redcultivars showed the best performance in terms of nutritional and physiologicalparameters. In particular, the antioxidant activity was 11-fold higher in red than ingreen baby leaf lettuces. Moreover, Ortis 398, MS151 and Copacabana, showingthe lowest values for respiration rate, ammonium accumulation and electrolyteleakage, were selected as suitable for ready-to-eat processing and preservation.Finally, the cultivars Ortis 398, MS151 and Excellent were found to be of interestfor the extraction of antioxidants due to their high phenol content.
The feasability of using reclaimed water (RW) to irrigate nectarines in Apulia, to reduce sea-water intrusion, has been studied in an orchard for 3-years. While the primary water quality parameters were significantly higher in RW than in fresh water (FW), concentrations were below the phytotoxic threshold that would cause significant yield losses under good management practices. In general, fruit quality parameters of nectarines, total phenolics and antioxidant compounds were higher in fruits irrigated with RW than FW, because of higher nutrients and salinity in the RW treatment. Lower firmness values were observed in RW-treated fruits implying early ripening. Overall, no yield differences were found between FW and RW-treated trees during the three year study. However, the RW treatment significanly reduced the number of fruits but this reduction was compensated by a larger individual fruit weight. While this 3yr-study has demonstrated that reclaimed water is a feasable alternative to freshwater in areas in southern Italy, further long-term studies are still needed to show the beneficial effects of RW on nectarine fruit yield and quality.
Volatile organic compounds, quality and sensory attributes of sweet cherry cv "Ferrovia", cold packaged in Airor in different modified atmospheres (Low-O2=1% O2/0.03% CO2; High-CO2=16% O2/20% CO2; Mix=1%O2/20% CO2), were monitored until 21days of conservation. Results showed that sweet cherry cv "Ferrovia" issensitive to CO2 accumulation (over 20%) in low oxygen (about 1%) modified atmosphere, as showed by the increasein respiration rate, biosynthesis of fermentative volatile metabolites, and sensory perception of off-odours.However, High-CO2 treatment seemed to preserve quality and sensory traits, presumably due to the high initialconcentration of O2 (16%) that could limit the synthesis of ethyl esters and ?-butyrolactone, keeping theaccumulation of off-flavours below their sensory perception threshold. Finally, PLSR analysis allowed to select1-pentanol as putative marker of sensory alteration and hexanal and 2-hexenal as possible predictors of freshnessfor "Ferrovia" sweet cherries.
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