High-technology methods of processing fish raw materials farmed in Astrakhan region

The modern level of development of fish processing technology is analyzed. A number of high-tech processes related to deep processing of aquaculture objects (paddlefish, clary catfish and tilapia), grown in the Astrakhan region, in closed water supply installations, have been proposed for implementation. The chemical composition of fish muscle tissue has been studied. A method has been developed to reduce the microbial contamination of raw materials using a low-frequency electromagnetic field. Methods of electrophysical and gas-liquid processing of raw materials have been adapted to real production conditions. Methods for processing secondary fish resources into edible fish meal and fish oil have been tested using gas-liquid technologies. Methods for processing water and muscle tissue of fish raw materials by electromagnetic and gas-liquid methods are proposed. The chemical composition of fish pates enriched with CO2-extracts was investigated.

Changes of seagrass area in Beralas Pasir and Beralas Bakau Island observed from Sentinel-2 Satellite and verified by Unmanned Surface Vehicle (USV)

Today, the area of seagrass ecosystems in Indonesia is estimated to have shrunk significantly. Bintan Island has quite a large seagrass ecosystems area. Along with the development of satellite technology, monitoring of conditions and changes to a coastal ecosystem can be carried out effectively through remote sensing technology. One satellite image that is relatively new and has good spatial quality is Sentinel-2 with a spatial resolution value of 10×10 m2 / pixel. Field data retrieval is facilitated by the use of Unmanned Surface Vehicle (USV). This research went through several stages such as image pre-processing, water column correction, masking, unsupervised classification, and detection of changes of seagrass area. The data obtained from the USV becomes the data for the accuracy-test in the supervised classification. Seagrass area was obtained in Beralas Pasir and Beralas Bakau Island is 84.27 ha (2016), 81.3 ha (2019) and 77.4 ha (2021). Detection of seagrass to non-seagrass area changes resulting 31.35 ha (2016-2019) and 30.91 ha (2019-2021). On the other hand non-seagrass to seagrass area is 24.84 ha (2016-2019) and 27.98 ha (2019-2021). The accuracy test of 2019 image classification and Unmanned Surface Vehicle data resulting overall accuracy at 62.20%.

Mapping of physical-chemical, microbiological, and chemical component characteristics of water samples from Nile tilapia slaughterhouses

The aim of this study was to analyze the physicochemical and microbiological characteristics of the water used in fish processing and tilapia fillets in slaughterhouses. The study analyzed the processing water from nine slaughterhouses. The water samples for analysis were collected at three points: process water (PW), it is the water used inside the slaughterhouses in direct contact with the fish; clean water entering the purification tank (EPT) and water leaving the purification tank (LPT). The processing waters of the nine tilapia slaughterhouses were analyzed and characterized according to their microbiological and physical-chemical characteristics. The results of microbiological analyzes meet the values indicated by legislation, in most cases. Regarding microbiological data, we can highlight that there was an increase in the total coliforms of the water entering the purification tank to the water leaving the purification tank in five slaughterhouses. Still, there was an increase in the aerobic mesophilic bacteria content observed in the outgoing water in relation to the inlet water of the purification tank in seven slaughterhouses. In relation to the physical chemical analyzes for the process water samples, the results show that the evaluated indices are in accordance with the values indicated by the legislation. The levels of Cd, Mg, Sc and Cd were below that detectable by the analysis in all slaughterhouses. The levels of Al, Sc, As, Rb, Ba, Pb, Mn, As, Se, Rb, Ag, Sb, Ba and Pb were detected only in one or two slaughterhouses. It is concluded that although some abattoirs have water characteristics outside the limits indicated by the legislation, the observed changes were not significant and small adjustments are necessary for the adequacy.

Removal of Phenols in Table Olive Processing Wastewater by Using a Mixed Inoculum of Candida boidinii and Bacillus pumilus: Effects of Inoculation Dynamics, Temperature, pH, and Effluent Age on the Abatement Efficiency

The main goal of this paper was to assess the ability of a combination of Candida boidinii and Bacillus pumilus to remove phenol in table olive processing water, as a function of some variables, like temperature, pH, a dilution of waste and the order of inoculation of the two microorganisms. At this purpose C. boidinii and B. pumilus were sequentially inoculated in two types of table olive processing water (fresh wastewater, FTOPW and wastewater stored for 3 months-aged wastewater, ATOPW). pH (6 and 9), temperature (10 and 35 °C) and dilution ratio (0, 1:1) were combined through a 2k fractional design. Data were modeled using two different approaches: Multifactorial Analysis of Variance (MANOVA) and multiple regression. A higher removal yield was achieved by inoculating B. pumilus prior to the yeast (192 vs. 127 mg/L); moreover, an increased efficiency was gained at 35 °C (mean removal of 200 mg/L). The use of two statistic approach suggested a different weight of variables; temperature was a global variable, that is a factor able to affect the yield of the process in all conditions. On the other hand, an alkaline pH could increase the removal of phenol at 10 °C (25–43%).

Dynamics of a pair of neutrally buoyant circular particles with different sizes in a lid-driven square cavity

The solid particles with different sizes exist widely, like cell separation, food processing, water treatment, thus, investigating the motion of the solid particles with different sizes is important. This study investigates the motion of a pair of neutrally buoyant circular particles with different sizes in a lid-driven square cavity using the lattice Boltzmann method. The motion of the circular particles with different sizes and that of the circular particles with identical sizes are quite different. The steady trajectories of the circular particles with identical sizes are identical, which is not affected by the Reynolds number. Differently, the circular particles with different sizes orbit along different steady trajectories, namely, the steady trajectory of the small particle is closer to the walls of the square cavity, while that of the large particle shrinks toward the center of the square cavity, which may provide us a possible method to separate them. However, it is not always effective, if the Reynolds number is low, the velocity difference between the circular particles with different sizes is small, which may fail to separate them completely.

Effect of Spray-Drying and Freeze-Drying on the Composition, Physical Properties, and Sensory Quality of Pea Processing Water (Liluva)

Spray-drying and freeze-drying can extend the shelf life and improve the transportability of high-nutritional foods such as Liluva (processing water of legumes). Nonetheless, the effects of these processes on nutrition, physiochemical properties, and sensory quality are unknown. In this study, particle sizes, protein profiles, colour, and preliminary sensory profile of pea powder samples were determined by Mastersizer 3000, protein gels, chroma meter, and 9-point hedonic scale, respectively. Results indicated that no significant difference was found in the molecular weight distribution of protein bands in pea water and sensory profile after drying. Fibre content in pea water after spray-drying was higher while soluble carbohydrates and minerals were lower than those after freeze-drying. Spray-drying decreased pea water’s lysine content, particle size, redness colour, and yellowness colour, while it increased its light colour; however, freeze-drying showed the opposite results. Overall, spray-drying could be a better drying technology that can be applied to dry pea water. Further experiments are required, however, to determine the influence of drying technologies on emulsifying activity.