Contents
01.12.2015.
Professional paper
Modeling the kinetics of peroxidase inactivation, colour and texture changes of Portuguese cabbage (Brassica oleracea L. var. costata DC) during UV-C light and heat blanching
The effects of heat blanching and UV-C light followed by heat on Portuguese cabbage peroxidase (POD), colour and texture were studied in the temperature range of 80-95 °C. POD inactivation, lightness (L) and yellowness (b) colour changes were described by a first-order reaction model. The greenness (a) colour and texture (firmness) changes followed a two fraction kinetic model behaviour. The temperature effect was well described by the Arrhenius law.At lower temperatures the combined treatment showed higher POD inactivation. Colour and texture parameters did not show significant differences between treatments. Long processing times turned the leaves slightly darker, decreased greenness, yellowness and firmness. Short processing times increased the firmness and greenness of the leaves. The treatment at 80 °C for 90 seconds reduced 90% of POD, retaining 98% of lightness and 92% of yellowness and improved the green colour (130%) and firmness (125%). At 80 °C the heat blanching required 7.4 min to inactivate 90% of the enzyme activity, reducing lightness, greenness, yellowness and firmness to 92%, 68%, 62% and 61%, respectively. The present findings will help to optimize the Portuguese cabbage blanching conditions.
Rui M.S. Cruz, Ana I.A. Godinho, Dilek Aslan, Necip F. Koçak, Margarida C. Vieira
01.12.2015.
Professional paper
Natural antioxidants isolated from Schinus areira leaves by ultrasound-assisted extraction
The aim of this study was to optimize the extraction of antioxidant compounds from Schinus areira leaves using ultrasound assisted extraction and response surface methodology. The effect of sonication time and plant material:solvent ratio were used to optimize the recovery. Results showed that a high recovery of antioxidant compounds from leaves of three different S. areira specimens was achieved under optimized conditions. The leaf extracts obtained displayed a DPPH (1,1-Diphenyl-2-picrylhydrazyl) radical scavenging activity analogous to the well-known antioxidant trolox (EC50 = 23-46 vs 36.1 µg/mL, respectively). In addition, these extracts showed a good potency to eliminate superoxide and nitric oxide-radicals as well as a moderate antimicrobial activity against gram positive Staphylococcus aureus and Enterococcus faecalis and yeast. HPLC chromatography analysis of the three S. areira leaf extracts showed different high contents of kaempferol-3-O-rutinoside, quercetin-3-O-galactoside and 3-O-caffeoylquinic acid. The results showed that the S. areira leaf extracts contained a high amount of antioxidant phenolic compounds, which might be a valuable source to be used as additives in plant-based foods.
Liliana S. Celaya, Carmen I. Viturro, Luís R. Silva, Silvia Moreno
01.12.2015.
Professional paper
The Atlantic diet – Origin and features
Despite globalization there still are food patterns which are clearly differentiated from one region to another in Europe and elsewhere. In this study the Atlantic Diet is considered as thetraditional diet in Portugal and Galicia, a regionin northwest Spain.This paper aims to contribute to a better understanding of the Atlantic Diet food pattern in order to fully exploit the potential of this Atlantic gastronomical heritage.The background of the Atlantic Diet concept, the characterization of Atlantic Diet foods and a compilation of scientific findings related to the consumption of these foods are covered.A brief description of the Mediterranean Diet, the primitive pattern and the updated Mediterranean pyramid are also included in order to aid understanding of the globalization of this previously local health food pattern.Final remarks and suggestions for further studies are made.
Manuela L. Vaz-Velho, Rita Pinheiro, Ana Sofia Rodrigues
01.12.2015.
Professional paper
Bioactive components, antioxidative properties and inhibition of Fe2+-induced lipid peroxidation of mango peel as affected by the storage of mango fruit
This study sought to evaluate the bioactive components (total phenolics, vitamin C and flavonoid), antioxidant properties (FRAP, and hydroxyl, DPPH and ABTS radical scavenging abilities) and inhibition of Fe2+-induced lipid peroxidation of the peel of mango fruit stored at refrigeration temperature and room temperature. The peel of mango fruit stored at room temperature had significantly (P ≤ 0.05) higher contents of total phenolic (13.61 mg GAE/g), vitamin C (12.98 mg AAE/g), total flavonoid (4.49 mg QE/g) and non-flavonoid (9.12 mg Qe/g) than the peel of freshly harvested mango fruit and the peel of mango fruit stored at refrigeration temperature. In consonance with the bioactive components, the peel of mango fruit stored at room temperature had a higher FRAP, and hydroxyl, DPPH and ABTS radical scavenging abilities than the others. The peel of mango fruit stored at room temperature showed stronger inhibition of Fe2+ induced lipid peroxidation by exhibiting the least IC50 (1.44 mg/ml in brain), (1.43 mg/ml in pancreas) and (1.88 mg/ml in kidney). Thus freshly harvested, matured, edible and just ripe mango fruit (Sheri Mango) could be stored at room temperature and be consumed with the peel.
Adetuyi O. Foluso, Akinlerye Makinde, Ifedayo Adeyemi, Victoria Timothy
18.10.2015.
Original scientific paper
Teaching microbiological food safety through case studies
Higher education students usually ask for more training based on case studies. This was addressed by designing a specific food safety module (24 hours) in which students were shown how to predict microbiological risks in food products i.e. they were asked to determine product shelf-life according to product formulation, preservation methods and consumption habits using predictive microbiology tools. Working groups of four students first identified the main microbiological hazards associated with a specific product. To perform this task, they were given several documents including guides for good hygiene practices, reviews on microbiological hazards in the food sector, flow sheets, etc. . . After three-hours of work, the working groups prepared and gave an oral presentation in front of their classmates and professors. This raised comments and discussion that allowed students to adjust their conclusions before beginning the next step of their work. This second step consisted in the evaluation of the safety risk associated with the two major microbiological hazards of the product studied, using predictive microbiology. Students then attended a general lecture on the different tools of predictive microbiology and tutorials (6 hours) that made them familiar with the modelling of bacterial growth or inactivation. They applied these tools (9 hours) to predict the shelf-life of the studied product according to various scenarios of preservation (refrigeration, water activity, concentration of salt or acid, modified atmosphere, etc. . . ) and/or consumption procedures (cooking). The module was concluded by oral presentations of each working group and included student evaluation (3 hours).
Florence Dubois-Brissonnet, Laurent Guillier, Murielle Naıtali
18.04.2015.
Original scientific paper
A methodology to promote business development from research outcomes in food science and technology
Valorization of knowledge produced in research units has been a major challenge for research universities in contemporary societies. The prevailing forces have led these institutions to develop a “third mission”, the facilitation of technology transfer and activity in an entrepreneurial paradigm. Effective management of challenges encountered in the development of academic entrepreneurship and the associated valorization of knowledge produced by universities are major factors to bridge the gap between research and innovation in Europe. The need to improve the existing institutional knowledge valorization processes, concerning entrepreneurship and business development and the processes required were discussed. A case study was designed to describe the institutional knowledge valorization process in a food science and technology research unit and a related incubator, during a five year evaluation period that ended in 2012. The knowledge valorization processes benefited from the adoption of a structured framework methodology that led to ideas and teams from a business model generation to client development, in parallel, when possible, with an agile product/service development. Although academic entrepreneurship engagement could be improved, this case study demonstrated that stronger skills development was needed to enable the researcher to be more aware of business development fundamentals and therefore contribute to research decisions and the valorisation of individual and institutional knowledge assets. It was noted that the timing for involvement of companies in the research projects or programs varied with the nature of the research.
Eduardo Cardoso
18.10.2015.
Original scientific paper
Information literacy training in AgroParisTech food studies
AgroParisTech professors and librarians in Food Science and Technology have developed information literacy instruction to help students find and use relevant information. The course trains students to develop information literacy competencies: to identify the information needed and define its nature and extent; to access the information with efficiency because they select and use methods, resources and retrieval systems most appropriate to the topic; to evaluate the used methods, information, and sources; to search, access and use information ethically and legally; to read, use and write bibliographic references.
AgroParisTech trains two kinds of students. For Higher Education students (engineering students), the training takes place at their arrival in AgroParisTech, including courses and practical classes: role and management of information in organizations; information on plagiarism; resources in environment, food science and technology; use of relevant tools and methods for searching in databases; reference writing.
For students attending a Master of Science, the training prepares them to produce a literature review. The curriculum includes: information about scientific integrity, plagiarism; information needed for a researcher; critical reading of a journal article; how to manage a literature review: resources used, information search with databases, full text access; reference writing. The students will use these information literacy skills along their studies as well as in their future jobs.
Agnès Grimal, Florence Dubois-Brissonnet, Elisabeth Dumoulin
18.04.2015.
Original scientific paper
Mechanical properties of cassava starch films as affected by different plasticizers and different relative humidity conditions
The influence of plasticizer type (glycerol and sorbitol), its content (starch:plasticizer ratio of 1:0.15; 1:0.20; 1:0.25 and 1:0.30) and the relative humidity conditions (43, 58, 75 and 85%) on the mechanical properties of cassava starch films was studied. Both plasticizers seemed to integrate homogeneously in the film matrix. The incorporation of different concentrations of plasticizers affected the mechanical properties of the cassava starch films. Plasticizer ratio directly influenced the force values of the films, they showed significant flexibility when the plasticizer proportion was increased in the formulation. Under conditions of low relative humidity, sorbitol produced films more resistant to puncture than glycerol. Qualitatively, all the films were less brittle when the plasticizers were incorporated.
Jeannine Bonilla Lagos, Nıvea M. Vicentini, Rodolfo M.C. Dos Santos, Ana Monica Q.B. Bittante, Paulo J.A. Sobral
01.12.2014.
Professional paper
Sensory evaluation of aromatic foods packed in developed starch based films using fuzzy logic
The last two decades have seen attempts to replace non biodegradable, synthetic food packaging films with alternatives made from biopolymers. The objective of the present work was to evaluate sensory quality of tea leaf and culinary tastemaker powder when sealed in pouches based on starch films.Films were developed from corn starch and a functional polysaccharide (FP) from amylose (AM), methylcellulose (MC), and hydroxypropylmethylcellulose (HPMC), using a casting technique. Pouches were stored inside a secondary package (plastic jar) under ambient condition for 90 days. Sensory attributes of the stored food samples were evaluated (tea in liquor form) and the scores analysed by fuzzy logic. Results were compared with similarly stored foods but using market available poly-pouches as packaging material.For tea and tastemaker in general, the relative importance of the sensory attributes under consideration was assessed as: aroma (Highly important) >taste (Highly important)>colour (Highly important) > strength (Important) for tea, and taste (Highly important)>aroma (Highly important)>colour (Important)>appearance (Important) for tastemaker. Among the three films that were developed, the highly important sensory attributes of aroma and taste were maintained as ‘Very good’ when the foods were packed in starch–HPMC/AM film. When the products were packed in market-available poly-pouches they exhibited similar attributes. With the exception of ‘Very good’ maintenance of the colour of tastemaker by the commercial pouch, irrespective of film and food, the colour and strength/appearance were retained in the ‘Good’-‘Satisfactory’ range. The overall sensory score of tea was also maintained as ‘Very good’ in starch-HPMC film.
Tanima Chowdhury, Madhusweta Das
01.12.2014.
Professional paper
Applicability of Mixolab test with local wheat flours
Several types of equipment have been used to predict dough behaviour during breadmaking. The complexity of requirements means that no device is able to predict all the properties, and therefore, new tests are released continuously. The Chopin Mixolab mixes the dough at different temperatures, allowing the study of dough mixing properties, weakening, gelatinization, gel stability and retrogradation in one test. The objective of this work was to study the suitability of the Mixolab to predict rheological properties and breadmaking quality of local wheats. Flour was obtained from 29 wheat samples from different genotypes and environments. The correlation of results from traditional analyses (test weight, protein content, sedimentation volume, wet gluten, Falling Number, Alveograph and Farinograph) with Mixolab parameters was studied. The properties of two different bread types were compared with all these parameters. Stability and water absorption values from the Farinograph were highly correlated with the respective Mixolab parameters. It was concluded that wheat samples could be sorted by mixing properties in similar order independently of which method was used. Beyond that, gluten strength estimators obtained from these three rheological methods and the sedimentation volume test were highly correlated. Whilst the correlation of Mixolab parameters with pan loaf volume was not as high as traditional ones, Mixolab developing time, stability and C5 were the best correlated with the most important hearth bread characteristics. Studies performed by other researchers, using wheats from diverse origins, found different results. The need for empirical rheology evaluation with local wheat samples was proved.
Daniel Vazquez, María C. Veira