Perception of oyster-based products by French consumers: the effect of processing and role of social representations

International audienceThe search for new markets in the seafood sector, associated with the question of the continuity of raw oyster consumption over generations can be an opportunity for processors to extend their ranges with oyster-based products. The twofold aim of this study was to evaluate the impact of processing and social representation on perception of oyster-based products by French consumers and to identify the best means of development in order to avoid possible failure in the market. Five products with different degrees of processing (cooked oysters in a half-shell, hot preparation for toast, potted oyster, oyster butter and oyster-based soup) were presented within focus groups and consumer tests, at home and in canteens with the staff of several companies in order to reach consumers with different ages and professional activities. The results showed that social representation had a strong impact and that behaviours were contrasted according to the initial profile of the consumer (traditional raw oyster consumers or non-consumers) and their age distribution (younger and older people). The degree of processing has to be adapted to each segment. It is suggested to develop early exposure to influence the food choices and preferences of the youngest consumers on a long-term basis

Multiblock modeling for complex preference study. Application to European preferences for smoked salmon

The aim of the paper is to propose an alternative method to external preference mapping for the case of complex data where explanatory variables are organized in meaningful blocks. We propose an innovative method in the multiblock modeling framework, called multiblock Redundancy Analysis. The interest and relevance of this method is illustrated on the basis of a European consumer preference study for cold-smoked salmon. The study aims at explaining six homogeneous clusters of preference with explanatory parameters organized in five thematic blocks related to physico-chemical measurements, microbiological characterization, appearance attributes, odor/flavor characterization and texture descriptors. Overall indexes and graphical displays associated with different interpretation levels are proposed to sort the key drivers of preference by order of priority at the variables and at the block level. On the basis of these data, multiblock Redundancy Analysis is also compared to standard preference mapping in terms of model quality; the best model is here associated with the multiblock method

Choice for sustainable meals at staff restaurants: influence of at-home food habits and food triggers

Purpose Collective catering sector is increasingly offering alternative and more sustainable food propositions, but their success rests on their reception by guests and changes induced in individual behaviors. The authors investigate food-change determinants by examining the relationship between food behavior at staff restaurants and at home. Design/methodology/approach In an experiment over four days conducted in three staff restaurants, the authors monitored the behavioral changes and motivations of guests (n = 599) offered choices between standard and sustainable options for meat, fish, dairy products, fruit-based desserts and a vegetarian dish. The calculation of a “sustainable consumption score,” based on actual consumption at a restaurant by a subsample (n = 160) of guests gives an indication of interest for sustainable options. Findings Higher overall choices were observed for vegetarian dishes and for the sustainable meat options rather than for the sustainable fish and desserts options, thus suggesting contrasted perceptions of the sustainable alternatives. The results revealed two profiles of consumers with contrasting scores. The “lower receptive guests” had lower commitment to sustainable food at home and at staff restaurants, while the “higher receptive guests” found in the intervention meaningful propositions for pursuing their existing at-home commitment. Research limitations/implications Long-term research would be required to verify whether repeated sustainable offers can break down deep-rooted choices and instill durable changes among consumers with lower commitment to sustainable food. This research contributes to the identification of some types of food that are more suitable for sustainable-oriented interventions. Practical implications Some food triggers are identified to further norm activation among the lower receptive profile of consumers. Originality/value By addressing continuities/discontinuities between at-home and at-restaurant consumption and mobilizing the “norm-activation” concept, the authors question the efficiency of sustainable food offers at work

Lay and scientific categorizations of new breeding techniques: Implications for food policy and genetically modified organism legislation

International audienceThe rapid development of new genetic breeding techniques is accompanied by a polarized debate around their risks. Research on the public perception of these techniques lags behind scientific developments. This study tests a method for revealing laypeople’s perceptions and attitudes about different genetic techniques. The objectives are to enable laypeople to understand the key principles of new genetic breeding techniques and to permit a comparison of their modes of classification with those of scientific experts. The combined method of a free sorting task and focus groups showed that the participants distinguished the techniques that did not induce any change in DNA sequence, and applied two different logics to classify the other breeding techniques: a Cartesian logic and a naturalistic logic with a distinct set of values. The lay categorization differed substantially from current scientific categorizations of genetic breeding techniques. These findings have implications for food innovation policy and genetically modified organism legislation

Comparative Value of a Sorting Procedure and Quantitative Descriptive Analysis to Investigate the Influence of Processing Parameters: Case Study of Hydrolysate Production From Salmon By-Products

Many papers have recently discussed the value of a free sorting method as a rapid and simple alternative to quantitative descriptive analysis, considered the reference tool for food sensorial characterization. The aim of the present paper is to evaluate whether this method of free sorting can also be used to investigate the influence of processing parameters. An experimental design was applied to production conditions of enzymatic hydrolysates from salmon by-products. The effect of four processing parameters (time and temperature of hydrolysis, sugar and antioxidant addition) on the odor of the hydrolysates was studied using a sorting task with 45 untrained panelists and a quantitative descriptive analysis carried out with 11 trained panelists. This study on 21 enzymatic hydrolysates confirms the similarity of the two sensory maps and shows the value of free sorting in the sensory characteristic description step, especially to avoid missing some descriptors. It also highlights in this example that a holistic approach as sorting can reveal more easily than profiling the significant effects of process parameters on sensory characteristics and the relationships between sensory dimensions and instrumental measurements of volatile compounds

Plate waste increases with the number of foods proposed: An exploratory experimental study in adolescents’ school canteens

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Stockage des poissons fumés et ou séchés : cas de Oreochromis niloticus " Fiha saly " malgache

During storage of smoke-dried fish, various biochemical reactions can occur; they will result in product acceptability or rejection. To determine these changes, pH and humidity were measured and molds were counted on smoke-dried fish stored for 6 months. A sensory analysis was also conducted to assess the quality of the products. Infestations and losses linked to it have been estimated by counting the insects and weighing of fish batches over time. The variability in the quality of smoke-dried fish depending on the time of purchase and storage was also integrated with our study. Biochemical reactions are mainly oxidation phenomena which result in a decrease of pH and release of spoilage odors such as rancid odor (> 1.5/ 3) or sulfur, acid and moldy odors. The growth of mold (1- 36 CFU / g) due to the reabsorption of water by fish contributes to this olfactory and visual spoilage. Beyond 90 days of storage, smoke-dried fish bought in the dry season begins to be rejected (> 2/3), while the fish bought in the wet season is at the limit of acceptability (2/3) even at the beginning of storage. During the first 90 days of storage, the insect infestation generates between 10 and 60 % of losses. A salt content of 8 % appears to be effective against the infestation but contributes to the deterioration of the product when stored in rooms with higher than 65 % relative humidity.Au cours du stockage des poissons fumés/séchés, différentes réactions biochimiques peuvent intervenir et conduire à la non-acceptabilité ou rejet des produits. Pour déterminer ces changements, le pH, la teneur en eau et le nombre de moisissures ont été suivis sur des poissons fumés/séchés entreposés pendant 6 mois. Des tests sensoriels ont également été menés pour évaluer la qualité des produits. Les infestations ainsi que les pertes qui y sont liées ont été estimées en comptant les insectes et en pesant des lots de poissons au cours du temps. La variabilité de la qualité du poisson fumé/séché en fonction de la période d'achat et de stockage a également été intégrée à notre sujet d'étude. Les réactions biochimiques sont surtout des phénomènes d'oxydation qui se traduisent par une diminution du pH et le dégagement d'odeurs d'altération telles que rance (> 1,5 sur 3), soufrée, acide et moisi. L'apparition de moisissures (1 à 36 UFC/g), due à la réabsorption d'eau par le poisson, contribue à cette dégradation olfactive mais également visuelle. Au-delà de 90 jours de stockage, le poisson fumé-séché acheté en saison sèche commence à être rejeté (note > 2 sur 3), tandis que le poisson acheté en saison humide est à la limite de l’acceptabilité (note 2 sur 3), comme au début du stockage. Jusqu’à 90 jours d’entreposage, les pertes sont causées principalement par l'infestation d’insectes et varient entre10 et 60 %. Une teneur en sel de 8 % semble être efficace contre l'infestation mais contribue à la détérioration du produit lorsqu'il est stocké à des humidités relatives supérieures à 65 %

Selection for muscle fat content and triploidy affect flesh quality in pan-size rainbow trout, Oncorhynchus mykiss

A lean muscle line (L) and a fat muscle line (F) of rainbow trout were established (Quillet et al., 2005) by a two-way selection for muscle lipid content performed on pan-size rainbow trout using a non-destructive measurement of muscle lipid content (Distell Fish Fat Meter®). The aim of the present study was to evaluate the consequences of this selective breeding on flesh quality of pan size (290 g) diploid and triploid trout after three generations of selection. Instrumental evaluations of fillet color and pH measurement were performed at slaughter. Flesh color, pH, dry matter content and mechanical resistance were measured at 48 h and 96 h postmortem on raw and cooked flesh, respectively. A sensorial profile analysis was performed on cooked fillets. Fillets from the selected fatty muscle line (F) had a higher dry matter content and were more colorful for both raw and cooked fillets. Mechanical evaluation indicated a tendency of raw flesh from F fish to be less firm, but this was not confirmed after cooking, neither instrumentally or by sensory analysis. The sensory analysis revealed higher fat loss, higher intensity of flavor of cooked potato, higher exudation, higher moisture content and a more fatty film left on the tongue for flesh from F fish. Triploid fish had mechanically softer raw and cooked fillets, but the difference was not perceived by the sensorial panel. The sensorial evaluation also revealed a lower global intensity of odor, more exudation and a higher moisture content in the fillets from triploid fish. These differences in quality parameters among groups of fish were associated with larger white muscle fibers in F fish and in triploid fish. The data provide additional information about the relationship between muscle fat content, muscle cellularity and flesh quality

Effect of salting and cold-smoking procedures on Atlantic salmon originating from pre-or post rigor filleted raw material. Based on the measurement of physiochemical characteristics

Different methods in use for cold smoking of salmon affect product yield and quality. The combinations of filleting time (pre or post), salting methods (dry or injection), salting targets (2.5 or 4%) and smoking temperatures (15 or 25 °C) were studied during 6 weeks of 4 °C cold storage. Salting method had the greatest influence on flesh quality. Injection salting led to 15% higher fillet yield, moderate to strong gaping score, softer texture, and paler fish compared with dry salting. Pre-rigor filleting reduced fillet gaping from a moderate to minor score, but only in dry salted fillets. Smoking at 15 °C reduced yield by 0.5% in injected salted fish, compared with 25 °C. The combination of pre-rigor filleting, dry salting and 15 °C smoking temperature gave the lowest gaping incidence and highest shear force and flesh colour. Liquid loss increased by 240% and the L-value by 6.5 units during 6 weeks cold storage, whereas the other quality parameters measured showed only small changes during the storage period