Effect of the temperature and ultrasound on salt impregnation process of haddock

The influence of different brine temperatures (5, 15 and 25 °C) and ultrasound on the salt gain (SG) and water gain (WG) kinetics of haddock cubes during vacuum impregnation (VI) process was evaluated. Samples were taken from salt solution (4 g NaCl/ 100 g solution) after 0, 20, 40, 60, 100, 140 and 180 min of brining process for salt and moisture analysis. Ultrasound assisted VI and increasing temperature in the salt solution increased (P < 0.05) the salt content, and SG value in the haddock cubes. Furthermore, ultrasound assisted VI enhanced the water diffusion into the cubes and resulted in an increase in WG value. The ultrasound process increased the salt effective diffusion coefficient (Ds) and the highest Ds was found at 25 °C brine temperature. Azuara, Diffusive, Peleg, Weibull, Z and L models were tested to predicting SG and WG kinetics and Azuara was the best model during brining process of haddock cubes.

The impact of Flavourzyme on flavor, antioxidant activity, and sensory attributes of salted grass carp by brine injection and brining

BACKGROUND

Enzyme injection is vital for improving the sensory attributes and processing characteristics of meat products by enhancing proteolysis. However, studies regarding the appropriate dose addition for accelerating protein degradation in grass carp are minimal. This study aimed to investigate the impact of Flavourzyme® on the flavor quality and antioxidant activity of salted grass carp via brine injection and brining.

RESULTS

Flavourzyme was added at doses of 0, 5, 10, 20, and 30 leucine aminopeptidase units (LAPU) per kilogram of raw meat. The results indicated that adding Flavourzyme promoted proteolysis, which was reflected by the enhanced total free amino acid content (from 3.7414 g kg^-1 to 4.9160 g kg^-1 in the brining group and from 3.8039 g kg^-1 to 5.4061 g kg^-1 in the injection group) and a decrease in salt soluble and insoluble protein (P < 0.05). The antioxidant activity was improved, and the thiobarbituric acid reactive substance value in salted carp decreased due to the higher content of the protein hydrolysis product (P < 0.05). All sensory attributes were improved significantly, especially when using brine injection (P < 0.05). Brine injection was helpful to diffuse the Flavourzyme, resulting in stronger proteolysis.

CONCLUSION

The appropriate Flavourzyme dose was 10 LAPU kg^-1 in the injection group and 20 LAPU kg^-1 in the brining group. Therefore, moderate Flavourzyme addition was excellent in improving sensory attributes and storage characteristics, whereas injection represented a novel method to obtain a similar fish meat quality in a shorter time and with less added Flavourzyme. © 2021 Society of Chemical Industry.

Water holding properties of Atlantic salmon

With global seafood production increasing to feed the rising population, there is a need to produce fish and fishery products of high quality and freshness. Water holding properties, including drip loss (DL) and water holding capacity (WHC), are important parameters in determining fish quality as they affect functional properties of muscles such as juiciness and texture. This review focuses on the water holding properties of Atlantic salmon and evaluates the methods used to measure them. The pre- and postmortem factors and how processing and preservation methods influence water holding properties and their correlations to other quality parameters are reviewed. In addition, the possibility of using modelling is explained. Several methods are available to measure WHC. The most prevalent method is the centrifugation method, but other non-invasive and cost-effective approaches are increasingly preferred. The advantages and disadvantages of these methods and future trends are evaluated. Due to the diversity of methods, results from previous research are relative and cannot be directly compared unless the same method is used with the same conditions.

Recent developments in the food quality detected by non-invasive nuclear magnetic resonance technology

Nuclear magnetic resonance (NMR) is a rapid, accurate and non-invasive technology and widely used to detect the quality of food, particularly to fruits and vegetables, meat and aquatic products. This review is a survey of recent developments in experimental results for the quality of food on various NMR technologies in processing and storage over the past decade. Following a discussion of the quality discrimination and classification of food, analysis of food compositions and detection of physical, chemical, structural and microbiological properties of food are outlined. Owing to high cost, low detection limit and sensitivity, the professional knowledge involved and the safety issues related to the maintenance of the magnetic field, so far the practical applications are limited to detect small range of food. In order to promote applications for a broader range of foods further research and development efforts are needed to overcome the limitations of NMR in the detection process. The needs and opportunities for future research and developments are outlined.

Innovative nondestructive measurements of water activity and the content of salts in low-salt hake minces

Impedance spectroscopy (IS), low-field proton nuclear magnetic resonance (LF (1)H NMR), chloride titration, ion chromatography, and an ion selective electrode were used to investigate the physicochemical parameters and measure sodium and potassium contents in low-salt brines and fish. Salt solutions (0-3 w/w, %) and model products of minced hake with added NaCl (0.5-3.0 w/w, %), or a mixture of NaCl and KCl (50/50 w/w, %), were analyzed. Good correlation was observed between the sodium content determined by using the ion selective electrode method and ion chromatography (R(2) = 0.97). In both salt solutions and fish minces, the impedance spectroscopy measurements could detect the difference in salt contents in mince with salt contents down to 0.5%. The NMR transversal relaxation time T2 measurements clearly distinguished samples with 0, 0.5, and 1.0-3.0% salt, based on principal component analysis (PCA). Therefore, LF (1)H NMR seems to be a suitable technique for studies of low-salt products.

Low-field permanent magnets for industrial process and quality control

In this review we focus on the technology associated with low-field NMR. We present the current state-of-the-art in low-field NMR hardware and experiments, considering general magnet designs, rf performance, data processing and interpretation. We provide guidance on obtaining the optimum results from these instruments, along with an introduction for those new to low-field NMR. The applications of lowfield NMR are now many and diverse. Furthermore, niche applications have spawned unique magnet designs to accommodate the extremes of operating environment or sample geometry. Trying to capture all the applications, methods, and hardware encompassed by low-field NMR would be a daunting task and likely of little interest to researchers or industrialists working in specific subject areas. Instead we discuss only a few applications to highlight uses of the hardware and experiments in an industrial environment. For details on more particular methods and applications, we provide citations to specialized review articles.

Use of NMR in fish processing optimization: a review of recent progress

The goal of this review is to give an overview of general trends in the application of the NMR related to fish processing and quality and to provide some viewpoints on the current situation. Three novel examples of the application of the methodologies magnetic resonance spectroscopy, magnetic resonance imaging, and low-field NMR are also presented. The capability of these techniques to be utilized as a tool to optimize fish processing, and thereby improving product quality, as well as to confirm labelling information, are demonstrated.