Consumer Perception of Freshness and Volatile Composition of Fresh Gilthead Seabream and Seabass in Active Packaging with and without CO2-Emitting Pads.

Active packaging with CO2-emitters (pads) has recently been used for shelf-life extension of fresh fish. The aim of this study was to identify consumer attitudes towards fresh fish packaging, to examine whether Greek consumers prefer active packaging with pad over active packaging without pad, to investigate any perceived differences in the sensory freshness of the fish, and to relate consumer perception to volatile composition of fish fillets. In total, 274 consumers participated in the study which included freshness sensory evaluation of gilthead seabream (Sparus aurata) and seabass (Dicentrarchuslabrax), whole-gutted and filleted, raw and cooked, at high quality and at the end of high-quality shelf-life. Samples were packed under modified atmosphere either with a pad or without. Results showed that consumers preferred packages with pads, especially at the end of high quality shelf-life. They perceived raw samples packed with a pad to be fresher and closer to the ideal product, and also had a higher purchase intention towards them. Cooked samples were not perceived differently. Consumers' perception was in accordance with the GC-MS findings in the volatile compounds that function as freshness or spoilage indicators. Most participants were positive towards fresh fish packaging although they usually buy unpacked fresh fish. Our results suggest that active packaging with CO2 emitters contribute to freshness preservation and that it has a positive potential in the Greek market.

High taurine supplementation in plant protein-based diets improves growth and organoleptic characteristics of European seabass (Dicentrarchus labrax).

Plant-based proteins are increasingly being used in aquafeeds, but one of the limitations is taurine deficiency that can be especially detrimental for carnivorous fish. In this study, taurine supplementation in high plant protein diets (low fish meal, 15%) was investigated on the growth performance and fillet organoleptic characteristics of European seabass (Dicentrarchus labrax), juveniles (78 ± 0.4 g). Five diets were formulated to contain 0 (C-), 5 (T5), 10 (T10) or 20 (T20) added taurine (g/kg), while a control diet (C+) included two-fold higher amount of fishmeal (30%) with no taurine supplementation. Seabass fed the T20 or C+ diet showed similar growth, which was significantly higher compared to those in the C-treatment. Histological examination of the muscle, liver and intestine were similar among treatments. No effect on spoilage bacterial growth or production of total volatile basic nitrogen was observed. Taurine supplementation significantly reduced fillet drip loss, while the fillets of European seabass fed the T10 and T20 diets showed significant higher and lower hardness and adhesiveness values, respectively. Moreover, fillet chewiness was also found to be significantly higher in fish fed the T20 diet compared to C+ and C- diets. Overall, it seems that high dietary taurine supplementation acted as a growth promoter and concurrently improved significantly the postharvest quality characteristics of seabass, which may be attributed to its role in maintaining cell membrane integrity and permeability.

Culinary preparation effects on lipid and sensory quality of farmed gilthead seabream (Sparus aurata) and meagre (Argyrosomus regius): An inter-species comparison.

The nutritional and sensory quality of a fish fillet is subject to alterations depending on the culinary method used for preparation. The current study aimed to explore the effects of custom culinary preparation methods (steaming, oven-cooking, frying) on the fillet lipid and sensory quality of two important Mediterranean farmed fish species varying in their tissue fat content. These included, lean meagre and medium-fat gilthead seabream. The results indicated that culinary treatment effects on lipid quality differed among species, especially for frying. Frying created unique sensory profiles, whereas steam- and oven-cooking resulted in similar sensory profiles per species. The variable effects of culinary treatments on the lipid and sensory quality indicate that the choice of preparation method should be related to the fish species and its fat content.

Investigation of sensory profiles and hedonic drivers of emerging aquaculture fish species.

BACKGROUND: The aquaculture sector needs to increase the diversity fish species and their processed products to cover rising consumer demands. Candidates for this diversification have been identified to be meagre, greater amberjack, pikeperch and wreckfish. Yet scientific knowledge on their sensory profiles and consumer hedonic responses is scarce. The aim of the current study was to investigate these aspects, since they are essential for product development and market targeting. RESULTS: Species exhibited different sensory profiles with the exception of the odor/flavor profiles of meagre and greater amberjack, which were similar. Texture was more important than odor/flavor in explaining interspecies differences. Yet the hedonic responses were equally related to texture and odor/flavor. None of the species received negative hedonic scores. Both positive and negative hedonic drivers were identified within the odor/flavor and texture modalities. CONCLUSION: The distinct profiles of meagre, greater amberjack, pikeperch and wreckfish make these fish species valuable first materials for new product development and for covering markets with different sensory preferences. Differences in fish texture are more easily perceivable, yet small variations in fish odor/flavor can have a great impact on consumers' hedonic responses. © 2017 Society of Chemical Industry.

Sensory characterization, physico-chemical properties and somatic yields of five emerging fish species.

Aquaculture plays an important role in supplying the fresh fish. However its production is dominated by only few long-established species that in turn limit the variety of available products in the market. Therefore, new fish species need to be properly introduced to create a diversification in the current market. In order to achieve this goal, it is important to know, understand and characterize their quality features so they can be addressed to local and global markets. Sensory, compositional, instrumental texture parameters and somatic properties of five emerging fish species, namely wreckfish, greater amberjack, grey mullet, meagre, and pikeperch, were examined for characterization purposes. Sensory references were specifically developed for the training of the assessors, both from a qualitative and quantitative perspective. Twenty two sensory descriptors were used for describing the samples. Several differences were observed among the measured parameters. Somatic measures revealed the filleting yield to be the most important of them. Regarding the compositional parameters, fat content was among the most relevant discriminating aspect between species, while hardness was among the most differentiating ones when dealing with texture. Greater amberjack was described with sour flavor, pikeperch was associated to an earthy flavor and grey mullet was characterized by bitter flavor. Sensory firmness was clearly distinctive for wreckfish, while meagre related to juicy texture. The analysis of the relationship between all parameters provided important correlations, especially those related to texture parameters, fat content, laminar structure and teeth adherence. The species in this study exhibited a wide range of physicochemical and sensory characteristics that show their potential for being further exploited when designing new products.

Fillet proximate composition, lipid quality, yields, and organoleptic quality of Mediterranean-farmed marine fish: A review with emphasis on new species.

Species diversification in Mediterranean mariculture involves various important fish that contribute to the diet of many human populations. These include meagres (Sciaenidae), flatfishes, mullets, and various sparids. Their quality aspects (yields, fillet proximate composition, and lipid quality) are discussed in this review. Their filleting yield is mostly 40-45%. The viscerosomatic index ranges from 1.5% to 14%, depending on species. Low muscle fat contents of flatfishes and meagres differentiate them from the rest of the farmed species. Farmed fish contain high n-3 polyunsaturates fatty acids (PUFA; 12.3-36.3% vs. 5.48-37.2% in the wild) and have higher muscle fat and n-6 PUFA contents (mainly 18:2 n-6) than their wild counterparts. The aquaculture management, diet, and season can affect fillet composition and fatty acids, while season (i.e. food availability and maturation) largely affects lipid quality in wild fish. Data on the sensory quality of Mediterranean-farmed species are mainly limited to whether specific management differentiates the sensory quality; thus, further development of tools for sensory analysis is required. Observations on the quality features in farmed Mediterranean fish indicate that species diversification can also provide product diversification based on different commercial weights and fillet quality specifications.

Organoleptic and chemical quality of farmed meagre (Argyrosomus regius) as affected by size.

Two fish groups differing in size (average weighing 830±220 and 1600±350 g, respectively) were evaluated for their sensory, somatometric and chemical quality characteristics. No differences were found in the yields and fillet proximate composition of the two groups. Although taste panels indicated high acceptability for both groups, the large fish received significantly better hedonic rates for their overall acceptance. Differences were also observed in the fatty acid profiles of the two groups with the large fish having significantly higher 18:2n-6 and total n-6 contents. Their volatile compounds also differed, with small fish containing higher total amount, as well as more total aldehydes, furans and pyrazines. All these findings indicate size-dependent quality alterations, but also sufficient quality for small fish to be commercialised.