|CA|MA|2013|: report of the first results of European QUAFETY projectOn the 3-7 June 2013, the International Controlled & Modified Atmosphere Research Conference (|CA|MA|2013|) took place in Trani (Apulia Region, Italy).
Scientists, SMEs, policy makers were present at the Conference. The participants were from Italy, Poland, Saudi Arabia, USA, Canada, New Zealand, Jordan, Brazil, UK, Ireland, Ghana, Spain, Portugal, Turkey, Japan, China, Chile, Korea, Thailand, Singapore, Taiwan, The Netherlands, Holland, Denmark, Belgium, Germany, Czech Republic, Norway, France, Switzerland, Austria, Egypt, South Africa, Greece, Israel, Pakistan, India, Palestine, Slovenia and Serbia.
Conference Room, Palazzo San Giorgio (Trani, Italy).
The presentations consisted in 66 talks and 118 poster presentations. The program was characterized by 10 sessions, one of which was a Special Session on QUAFETY Project. The first results of EU QUAFETY PROJECT were shown last 4 June 2013.
Professor Giancarlo Colelli, as scientific coordinator, has introduced the project showing the partners, objectives and expected results. Colelli has said: "QUAFETY aims to improve safety & quality of RTE fresh Fruit & Vegetables throughout the whole chain 1) by developing new predictive and probabilistic models and decision-making tools; 2) by exploring rapid and non-destructive methods for quality evaluation and prediction; 3) by applying novel technologies to quantify and manage spoilage and pathogenic microorganisms, minimizing risks to consumers and preserving quality. The research is especially conducted on melon and rocket."
Picture on side: Professor Giancarlo Colelli, Convener of |CA|MA|2013|, during the interview with the local TV news (TELESVEVA of Andria, Apulia Region, Italy).
During this special session of |CA|MA|2013|, partners from Israel, Italy, Portugal, Greece, United Kingdom and Poland have presented their first results.
A brief report of the oral communications follows.
Dr Victor Rodov (ARO - The Volcani Center, Bet Dagan, Israel) has showed the importance of edible coatings as efficient and safe techniques for controlling deterioration and extending shelf-life of food products.
He has presented the implementation of a Layer-by-Layer (LbL) electrostatics deposition of edible coating on fresh-cut melon. The LbL consists in an electrostatic deposition of oppositely charged natural polysaccharides that are a polyanion alginate and a polycation chitosan.
The LbL coating is resulted having the beneficial properties of both polysaccharides, by combining the good adhesion to the flesh melon of the inner alginate layer with the antimicrobial activity of the outer chitosan layer the bacteria, yeast and fungal counts were reduced by 1-2 log units.
Rodov has concluded: "The layer-by-layer electrostatic deposition of edible alginate-chitosan coating had clear benefits with regard to fresh-cut melon firmness, gas exchange, and anti-microbial protection. The method is cheap, simple, and has applied potential. This study has just been published on Food and Bioprocess Technology Journal."
Dr Maria Luisa Amodio (University of Foggia, Italy) has showed how modelling sensorial and nutritional changes to better define quality and shelf-life of fresh-cut melon and rocket.
She has listed the three steps to reach the general objective of predicting internal quality, based on the degradation rate of external attributes. The first step is to obtain degradation patterns of quality parameters of fresh-cut products during time. The second step is aimed at calculating the mathematical relationships between external and internal parameters showing significant kinetics.
The third step will be aimed at validating the prediction models. From first results on melon, after 5 days of storage a fraction of 30% of samples were judged unmarketable highlighting that the only use of the mean value of appearance score could provide a misleading shelf-life estimation. From the first results on rocket stored at 5oC, the marketability limit was after 6 days when firmness decreased by 23% and the leaf yellowing increased by 47%. Dr Amodio has concluded that further modeling should be studied in order to better understand the effect of gas composition and temperature on quality decay rate.
Dr Ana Amaro (Escola Superior de Biotecnologia, Universidade Catolica Portuguesa, Porto, Portugal) has showed the results of the passive modified atmosphere packaging effect on respiration rate and functional quality of wild rocket leaves. She compared two polypropylene bags: a commercially available Permeable (P) and Non permeable (NP) packaging with initial atmospheric composition. Packaged rocket samples were stored at 4oC for 16 days, during which O2 and CO2 concentration, respiration rate, phenolic compounds, anthocyanins and chlorophylls were evaluated. The first results showed that throughout the storage period, rocket leaves stored in NP films were exposed to lower O2 and higher CO2 partial pressures than in P films.
Dr Amaro has concluded:"NP package generated a passive modified atmosphere, with continuous decrease of O2 concentration (close to anaerobiosis by 14 days) and with increasing CO2 levels up to ca. 8 kPa after 5 days. Rocket leaves stored in NP package showed higher respiration rate in the first 2 days when compared with P package. The evolution of CO2 and O2 concentration in both systems did not exhibit significant impact in ascorbic acid and chlorophyll content. A positive effect of oxygen availability inside P package was observed on total anthocyanin concentration until day 5 of storage. A positive effect of oxygen availability inside P package was observed on total phenolic compounds from day 5 until 8 of storage time. The sensorial perception of these changes deserves further studies."
Dr Agni Hadjilouka (Laboratory of Food Quality Control and Hygiene, Department of Food Science Technology, Agricultural University of Athens, Greece) has showed the aim of the study to determine the prevalence of Listeria monocytogenes and Escherichia coli O157:H7 in fresh-cut rocket, cucumbers and strawberries. Dr Hadjilouka has said: "According to the results of the biochemical tests and molecular analyses, L. monocytogenes prevalence was 7% in rocket, 6% in cucumbers and 3.8% in strawberries, while E.coli O157:H7 prevalence was 7% in rocket, 3% in cucumbers and 3.8% in strawberries."
Dr Antonio Ferrante (Department of Agricultural and Environmental Sciences, University of Milano, Italy) has showed the work on the isolation of molecular markers for the quality evaluation of rocket. He has highlighted the importance of molecular markers to identify microbial contaminants and - to evaluate quality.
The aim of the work was to isolate molecular markers for the quality evaluation of rocket (Diplotaxis tenuifolia L.) by using the transcriptome sequencing (RNA-seq). To isolate molecular markers, pre-harvest stresses (salinity of 200 mM NaCl, heat radical at 40oC, nitrate deficiency) and postharvest stresses (chilling of 4oC, mechanical wounding of leaves, dark and water stress) were applied on rocket. The total RNA was extracted from stressed plants and sequenced using the Illumina HiSeqTM 2000 platform. The RNA-seq analysis allowed to identify genes that are specifically expressed in each stress and encode for proteins associated with senescence, degenerative processes and quality loss.
Dr Ferrante has concluded: "The transcriptome data provide a wide number of possible genes that can be tested as quality markers. In the future genes up-regulated under postharvest stresses can be used to asses shelf life quality, while genes up-regulated under pre-harvest stresses can be a valuable support in the quality evaluation of raw materials."
Dr Hilary Rogers (Cardiff University, UK) showed the results of VOC (Volatile Organic Compounds) analysis of cut size in melon during postharvest storage. Melon is an important fruit in the fresh-cut chain, but it suffers from limited shelf-life. The aim of the work is to identify useful indicators of changes in the fruit associated with the deterioration of the product. Cut size was assessed as another parameter that can affect quality indicators. Three cut sizes were tested and melon cubes were stored at 4oC for 15 days, during which firmness, fresh weight loss, respiration rate, levels of several metabolites were measured. In addition, VOC profiles were measured to evaluate whether there were any aroma and flavour changes associated with storage period or cut size.
Dr Rogers has concluded: "Fresh weight loss and respiration rate increased significantly with storage time and were affected by cut size. We found that phenolic compounds such as catechin, abscisic acid, and cinnamic acid were good quality markers as their concentrations varied with time and cut size. We were able to identify the major volatile compounds associated with melon aroma and show significant changes in the overall VOC profile during storage. We have separated the VOC profiles according to the different cut sizes highlighting that VOCs may be useful markers as quality indicators."
Dr Luciano Beneduce (University of Foggia, Italy) has showed an innovative approach for the detection and enumeration of Listeria monocytogenes in fresh-cut vegetables by using MPN combined with real-time PCR. The detection and enumeration of L. monocytogenes in concentrations up to 103 CFU/g usually implies the use of MPN (Most Probable Number) technique that requires 7 days for the pathogen identification.
Dr Beneduce has said: "We developed a fast and reliable protocol combining MPN with Real Time Quantitative PCR (Q-PCR). This approach let to identify L. monocytogenes in samples spiked with 10-105 CFU/g. The whole process, including the DNA extraction, required less than 4 hours highlighting to be fast and realiable tool for L. monocytogens detection in fresh-cut vegetables."
Dr Maria Grzegorzewska (Research Institute of Horticulture Skierniewice, Poland) has showed the study on the effect of hot water on durability of fresh-cut rocket, melon and Chinese cabbage. Water temperature and treatment duration were tested. The temperature of hot water varied from 38 to 57oC while the hot treatment duration varied from 3 sec to 10 minutes. Before hot water treatment, rocket leaves immediately after harvest were sorted and trimmed, melons were peeled and cut into cubes, Chinese cabbage heads were cut into the strips. After hot water treatment, vegetables were dried, cooled, packaged and stored in cold chamber. Fresh-cut rocket was stored at 10oC, melon at 17oC and Chinese cabbage at 15oC.
The results showed that rocket leaves maintained the best appearance after short immersion of 3 sec at 55oC; the melon showed a very poor durability after cutting, however the short immersion of 3 sec at 53-55oC may be promising to improve storage durability; Chinese cabbage responded positively to the immersion of 10 min at 40oC.
Further results will be reported during the meeting scheduled for next 11 and 12 July 2013 at Athens.