DEVELOPMENT OF FROZEN-FRIED YAM SLICES: OPTIMIZATION OF THE PROCESSING CONDITIONS

The research performed on yam processing mainly concerns the production of crisps and flour. However, its transformation into deep-frozen French fries does not necessitate any other equipment than those used for potatoes. The industrial process of production of frozen French fries traditionally includes a pre-frying step. These steps contribute to the development of color and crispness, and the oil partially absorbed inhibits dehydration during the freezing step. The aim of this study was to optimize frying conditions of deep-frozen fried yam (Dioscorea cayenensis var Kponan) slices. The effect of pre-frying time and temperature, final frying time and temperature on the oil uptake, texture, dry matter and colour of the fried yam slices has been studied. Frying conditions optimized with Box-Behnken experimental design were short pre-frying and frying conditions at high temperature characterized by pre-frying temperature at 157-170°C during 5-9s and frying temperature at 181-188°C for 2min 15s-2min 30s; or long pre-frying and frying conditions at low temperature characterized by pre-frying temperature at 150-158°C during 10-15s and frying temperature 170-177°C for 3-3min 15s. An adiabatic system was also developed by means of an insulator in which the core temperature of fried yam slices can be maintained constant at about 55°C after 15min of cooling, facilitating texture measurements at constant temperature. The present results may help in choosing the yam slices frying condition to be applied in order to achieve the desirable fried yam slices quality, required for protection against certain diseases like obesity. These models may also provide guidance as to how to control these quality parameters by altering four key environmental factors, pre-frying temperature and time and, final frying temperature and time. This process can also be commercialized and does not necessitate any other cost for equipment than those used for potatoes French fries and might be an interesting way of added value processing for this highly perishable yam tuber

Tables de contingence à trois dimensions : aspects théoriques, applications et analogie avec l'analyse de la variance à trois critères de classification

For contingency table, concepts of independence are not so easy to understand in statistical practice. So, theoretical aspects of the log-linear model are described and applied to a three levels example; an analogy with analysis of variance is also established.Les notions d'indépendance mises en évidence lors de l'étude d'une table de contingence, à trois dimensions au moins, ne semblent pas être évidentes à comprendre en pratique. C'est pourquoi, des aspects théoriques faisant référence au modèle log-linéaire sont détaillés et illustrés, et une analogie avec l'analyse de la variance à trois critères de classification, modèle fixe est établie

Soft Skills: how to make the young engineers aware of their new talents?

peer reviewedThe competency framework attached to the Life science engineering Master at Gembloux Agro-Bio Tech, University of Liege (Belgium) is composed of technical and scientific skills but also soft skills which are not connected to academic courses. For the training of these skills, university needs the collaboration of the professional world. Therefore, the role of our teachers evolves towards a guiding or mentoring role. They will help students to analyse their professional experiences in order to shape their professional identity, to bring to light their acquired skills. This article describes how the portfolio, used as internship’s report, will help students to gain the self-confidence about their abilities and how professors can use these reflexive analyses to evaluate the acquisition of these soft skills

Learning agroecology through the serious game SEGAE in an online lesson: unveiling its impact on knowledge articulation

[EN] Facing global challenges, the currently dominating agricultural system has shown its limitation.  Therefore, agroecology appears as an attractive alternative. Its implementation has been shown to benefit the environment, while harboring economic potential. For a transition towards more agroecology, this new paradigm needs to be taught to students and professionals in the agricultural sector. However, traditional learning methods are not fully adapted to teach these concepts because of the poor interactivity and/or lack of interdisciplinarity. To help teach agroecology, the “SErious Game for AgroEcology” (SEGAE) was developed. SEGAE is a simulated mixed crop–livestock farm complex models in which players can learn by doing. To access SEGAE pedagogical interest, university students, coming from four specializations (Agronomy; Chemistry; Environment and Forest) participated to a theoretical class which was tighted to a play session of the game. The students then answered a knowledge survey on agroecology and a feedback survey based on flow theory. Results showed that students did significantly increase their knowledge of agroecology. Morevoer, a large majority of students enjoyed the game (83%) and thought playing this game increased their knowledge (91%).De Graeuwe, M.; Van Cranenbroeck, L.; Parent, R.; Serdobbel, C.; Brostaux, Y.; Maréchal, K. (2023). Learning agroecology through the serious game SEGAE in an online lesson: unveiling its impact on knowledge articulation. En 9th International Conference on Higher Education Advances (HEAd'23). Editorial Universitat Politècnica de València. 1029-1037. https://doi.org/10.4995/HEAd23.2023.163051029103

Assessment of pre- and post-harvest anti-sprouting treatments to replace CIPC for potato storage

To avoid losses from sprouting during potato storage, the anti-sprouting agent chlorpropham [CIPC] has been widely used over the past few decades. However, the European Union recently decided not to authorize the renewal of CIPC, prompting the value chain to find alternative treatments. We assessed for three years the potential of pre- and post-harvest anti-sprouting treatments to replace CIPC using four potato-processing varieties. Pre-harvest application of maleic hydrazide [MH] and post-harvest applications of 3-decen-2-one, 1,4-dimethylnapthalene [1,4-DMN] and CIPC were performed following supplier’s recommendations. In addition, we evaluated the potential of 3-decen-2-one and 1,4-DMN to prolong the efficacy of pre-harvest MH treatment anti-sprouting activity during storage. All molecules significantly reduced sprouting after seven months of storage compared with the untreated control group. MH, 3-decen-2-one, 1,4-DMN and CIPC displayed respectively 86.9 %; 77.9 %, 73.6 % and 99.8 % of efficacy to control sprout weight and 79.4 %; 73.4 %, 68.4 % and 96.9 % of efficacy to control sprout length. Our results suggest that using 3-decen-2-one and 1,4-DMN in combination with MH do not bring additional benefit to control sprouting. Because differences in dormancies could be observed between varieties, we also showed that the efficacy of post-harvest treatments is genotype-dependent, while MH pre-harvest treatment is effective equally for all varieties. Applications of CIPC and MH led to detectable residues in tubers, while no residue of 1,4-DMN has been detected in tubers treated with this molecule (< LOQ). We concluded that treatments with MH, 1,4-DMN and 3-decen-2-one are valuable alternatives to CIPC to control sprouting of processing potatoes

Facteurs de risque associés à la dissémination de la striure brune du manioc à travers les voies d'acquisition des boutures à l'Est de la R.D. Congo

peer reviewedVegetatively propagated crops are particularly prone to disease dissemination through their seed systems. Strict phytosanitary measures are important to limit the impact of diseases as illustrated by the potato seed system in Europe. Cassava brown streak disease (CBSD) is a devastating disease caused by two viral species collectively named cassava brown streak viruses (CBSVs). CBSD can cause substantial root yield losses of up to 100% in the worst affected areas and is easily transmitted through stem cuttings. In Eastern and Central Africa, the epidemiology of CBSVs in the local socio-economical context of production remains poorly known while a better understanding would be an asset to properly manage the disease. This lack of information explains partially the limited efficiency of current regulatory schemes in increasing the availability of quality seed to smallholders and mitigating the spread of pests and diseases. This study surveyed the epidemiology of CBSVs in Uvira territory, Eastern D.R. Congo, and its drivers using a multivariate approach combining farmer’s interview, field observation, sampling and molecular detection of CBSVs. Investigation on the epidemiology of CBSD revealed that three clusters in the study area could be identified using five most significant factors: (i) symptoms incidence, (ii) number of whiteflies, (iii) types of foliar symptoms, (iv) cutting’s pathways and (v) plant age. Among the three clusters identified, one proved to be potentially interesting for seed multiplication activities since the disease pressure was the lowest. Through risk assessment, we also identified several key socio-economic determinants on disease epidemy: (i) factors related to farmer’s knowledge and awareness (knowledge of cassava pests and diseases, knowledge of management practices, support from extension services and management strategies applied), (ii) factors related to the geographical location of farmer’s fields (proximity to borders, proximity to town, distance to acquire cuttings), as well as (iii) the pathways used to acquire cuttings.2. Zero hunge

Modifying Headspace Sampling Environment Improves Detection of Boar Taint Compounds in Pork Fat Samples

peer reviewedThe extraction of boar taint compounds from pork fat samples was performed under various temperature (150, 300 and 450 °C) and atmosphere (air, nitrogen and reduced pressure) conditions. This aimed at understanding which conditions allow the greatest extractions of indole, skatole and androstenone (present in backfat in low concentrations) while limiting the presence of other VOCs in the headspace of heated fat (interfering with correct VOC-based detection of boar taint compounds). Indole and skatole were extracted in the greatest concentrations when heating backfat at 450 °C under reduced pressure, while androstenone was highest when heating at 300 °C under reduced pressure. Oxidation products were most abundant under air conditions, nitrogenated products appeared in the presence of a nitrogen-enriched atmosphere, and lastly, molecules intrinsic to boar fat saw their headspace concentration increase with reduced pressure. The combination of 450 °C and reduced pressure atmosphere was suggested for the heating of backfat prior to detection with analytical methods and to complement the current sensory analysis