Depuration and starvation improves flesh quality of grass carp (Ctenopharyngodon idella )

Abstract

Farmed grass carp (Ctenopharyngodon idella) at commercial size were transported to a natural lake for long-term depuration while being food deprived. The effect of depuration time on the quality of fish fillets was investigated based on proximate compositions, textural parameters and flavour characteristics. The results showed that protein and lipids, but not carbohydrates, were the major source of energy for grass carp during depuration and starvation. Textural parameters that included hardness, springiness, gumminess and cohesiveness increased significantly after depuration, as well as water-holding capacity of fish muscle. Taste and odour characteristics of grass carp muscle were obviously changed by depuration based on tests by an electronic tongue and nose. Off-flavour volatile compounds, such as nonanal and hexanal, were reduced after depuration. In conclusion, the quality of grass carp fillets was improved effectively by long-term depuration and food deprivation. More than 20 days of depuration was appropriate for the enhancement of grass carp quality before marketing. K E Y W O R D Sdepuration, fillet quality, flavour, food deprivation, grass carp

Slight Increases in Salinity Improve Muscle Quality of Grass Carp (Ctenopharyngodon idellus)

“…Grass carp had a slight weight loss due to the deprivation of food during the experiment. A period of food deprivation is usually used for improving the quality and flavor of the fish [18][19][20]. In the study of Murray cod, fish had an organoleptic quality amelioration after 2 and 4 weeks of food deprivation, and had a weight loss of 4.1% and 9.1%, respectively [18].…”

“…In the study of Murray cod, fish had an organoleptic quality amelioration after 2 and 4 weeks of food deprivation, and had a weight loss of 4.1% and 9.1%, respectively [18]. For grass carp, the fillets can be improved effectively by depuration and food deprivation after more than 20 days culture with a slight weight loss, and the food-deprivation time should not be more than 50 days to avoid the excessive loss in protein and lipid contents of muscle [20]. Although there was no significant difference in weight loss among GC0-6, the weight loss showed an upward trend with the salinity increase, thus aquaculture salinity for grass carp was suggested to be lower than 6‰.…”

Changes in fatty acids, blood biochemistry and mRNA expressions of genes involved in polyunsaturated fatty acid metabolism in brown trout (Salmo trutta) during starvation and refeeding

“…The whole‐body contents of ALA, 16:0, ∑ SAFA, 16:1n‐7, 18:1n‐9 and ∑ MUFA significantly decreased owing to food deprivation, whereas the LA and 18:0 levels significantly increased. Lipids, especially SAFAs and MUFAs, constitute the majority of the substrates metabolized for energy supply for metabolic homeostasis (Durazo‐Beltran et al., 2004; Lv et al., 2018). Therefore, it appears that similar to other teleosts, brown trout actively catabolizes both SAFAs (except for 18:0) and MUFAs (especially 18:1n‐9) to pay for metabolic process expenses (Barreto‐Curiel et al., 2017; DeSilva et al., 1997; Jezierska et al., 1982; Ölmez et al., 2015).…”

Effects of short‐term starvation periods on flesh quality in Arctic charr (Salvelinus alpinus)in different seasons

“…Although the results of fillet quality measurement (fillet hardness) were based on a relatively simple experiment set‐up at one sampling point from each starving group, the results show that the quality in terms of hardness is lower for summer groups whereas fillet hardness increases with length of starving period in the summer sampling. Some studies on other fish species have also shown that starvation has a significant effect for improving the flesh quality of the starved fish, for example less gaping and harder texture (Foss et al., 2009), increased WHC, hardness, springiness (Lv, Hu, Xiong, You, & Fan, 2018), whereas other studies have not found similar effects on flesh quality (Bjørnevik et al., 2017; Young, Morris, Huntingford, & Sinnott, 2005). In fish, flesh texture is shown to be influenced by a number of different factors, such as light regime (Hagen & Johnsen, 2016; Hemre et al., 2004), temperature (Roth et al., 2005), feeding (Einen et al., 1999), slaughter and filleting method (Kiessling, Espe, Ruohonen, & Mørkøre, 2004; Kristoffersen, Vang, Larsen, & Olsen, 2007) and season (Espe et al., 2004; Imsland et al., 2017).…”