High-pressure processing before freezing and frozen storage of European hake (Merluccius merluccius): effect on mechanical properties and visual appearance

Abstract

High Pressure Processing (HPP) is a non-thermal technique of growing interest for fish preservation. In this work, the effect on functional properties of European hake (Merluccius merluccius) caused by HPP pre-treatment followed by freezing and frozen storage at-10ºC for 5 months were evaluated in an accelerated frozen storage study. Following a central composite design, five pressure levels (150, 169.27, 300, 430.73, or 450 MPa) and frozen storage times (0, 0.32, 2.5, 4.68, or 5 months) were tested. Colour parameters (L*, a* and b*) were measured in raw muscle. Expressible water and mechanical texture parameters were evaluated on both raw and cooked muscles. Results showed that a low-pressure level (150 MPa) allowed an adequate water holding capacity for raw muscle up to 2.5 months of frozen storage time. Values of 150 or 169.27 MPa did not cause significant changes on L* values of raw muscle when compared to nontreated samples. Overall, HPP led to changes on texture parameters of fresh muscle before and after cooking. However, 300 MPa and 5 months of frozen storage gave adhesiveness for raw muscle like that of non-treated fresh muscle. Moreover, 150-300 MPa for 5 months of frozen storage allowed cohesiveness and chewiness values for cooked muscle like those observed on cooked fresh hake showing that the HPP improves the quality of frozen hake. High-pressure processing before freezing and frozen storage of European hake (Merluccius merluccius): effect on mechanical properties and visual appearance

Effect of high-pressure processing pretreatment on the physical properties and colour assessment of frozen European hake (Merluccius merluccius) during long term storage

“…On the contrary, after cooking, controls showed a slight lower Ew (33.15% w/w). In the previous study with hake at -10ºC, after 5 months of frozen storage the E w values were 42.72% (w/w) before cooking and 40.70% (w/w) after cooking (Pita-Calvo et al, 2017). The change in the frozen temperature from -10ºC to -21ºC caused a beneficial decrease in Ew and consequently an increase in water holding capacity as expected.…”

“…Using a relatively high temperature of frozen storage (-10ºC), a previous accelerated frozen storage study (5 months) was carried out by our group to assess the effect of HPP pre-treatment before freezing and frozen storage on mechanical and physical properties of frozen small European hake (Merluccius merluccius) (Pita-Calvo, Guerra-Rodríguez, Saraiva, Aubourg, & Vázquez, 2017), allowing to gain insights about the effect of HPP in a shorter experimental time period. The results obtained were very promising, but extrapolation to a more usual frozen storage temperature (-21ºC) used commercially is not straightforward and it is necessary to study the effect of HPP at this temperature.…”

Changes on enzymatic activity and on sarcoplasmic and myofibrillar proteins of frozen‐stored hake (Merluccius merluccius) pre‐treated by high pressure

“…Cook´s distance was used the detect outliers. The models used and the statistical approach are described previously (Azmir et al , ; Pita‐Calvo et al , ; Estilo & Nakano, ).…”

“…HP effect on enzymatic activity could contribute to the delay of fish texture degradation. HP pre‐treatment on frozen‐stored European hake ( M. merluccius ) was already studied (Vázquez et al , ; Pita‐Calvo et al , ). Colour and textural properties were affected by HP, causing an increase of luminosity, hardness, adhesiveness and springiness of frozen hake (Pita‐Calvo et al , ).…”

“…HP pre‐treatment on frozen‐stored European hake ( M. merluccius ) was already studied (Vázquez et al , ; Pita‐Calvo et al , ). Colour and textural properties were affected by HP, causing an increase of luminosity, hardness, adhesiveness and springiness of frozen hake (Pita‐Calvo et al , ). On the other hand, pressure inhibition of volatile amine formation was observed (Vázquez et al , ).…”