Influence of the Technological Process on the Biochemical Composition of Fresh Roe and Bottarga from Liza ramada and Mugil cephalus

Effect of High-Pressure Processing on Fresh Sea Urchin Gonads in Terms of Shelf Life, Chemical Composition, and Microbiological Properties

Paracentrotus lividus is a widespread sea urchin species appreciated worldwide for the taste of its fresh gonads. High-pressure processing (HPP) can provide a thermal equivalent to pasteurization, maintaining the organoleptic properties of the raw gonads. This study evaluated HPP technology’s effect at 350 MPa and 500 MPa on microbial inactivation and biochemical characteristics of P. lividus gonads. HPP at 350 MPa resulted in a higher decrease in protein and free amino acids associated with a loss of olfactory, color, and gustatory traits and a visual alteration of the texture. On the other hand, gonad samples stored for 40 days after treatments at 500 MPa showed a good organoleptic profile similar to fresh gonads. Furthermore, only 500 MPa effectively reduced mesophilic bacteria contamination among the two HPP treatments carried out. Total lipids increased during storage; however, the SAFA/PUFA rate was homogeneous during HPP trials ranging from 2.61–3.91 g/100 g. Total protein decreased more than 40% after HPP at 350 MPa, whereas, after 500 MPa, it remained stable for 20 days. The amount of free amino acid constantly decreased during storage after HPP at 350 MPa and remained constant at 500 MPa. HPP can effectively remove the bacterial flora and inactivate enzymes, maintaining the properties of the fresh sea urchin gonads.

Heavy metal and metalloid accumulation in wild brown trout (Salmo trutta L., 1758 complex, Osteichthyes: Salmonidae) from a mountain stream in Sardinia by ICP-OES

 This paper reports heavy metal and metalloid accumulation in wild brown trout (Salmo trutta L., 1758 complex) raised in freshwater and uncontaminated Sardinia system (Italy). Metals are widespread pollutants of aquatic systems, and their contamination can originate from anthropogenic activities such as industrial waste, agricultural and domestic environments, and geochemical release. Fish has a relevant position within the human diet; moreover, fishes can accumulate metals, making them a valuable tool as biomarkers for risk assessment studies. The concentration of 22 metals and metalloids after chemical digestion was assessed by inductively coupled plasma-optic emission spectroscopy (ICP-OES) in both the guts and the edible part (EP, muscle + skin) of brown trout. The results, expressed as μg g-1, showed different levels of accumulation in the EP and guts, following the series Cu > Zn > Ba > Al > Sr > Fe > Pb and Fe > Al > Hg > As > Mn > Cu > Ba > B > Zn > Pb, respectively. PCA analysis showed a fairly good correlation between the total lipid and SAFA content and Cd, Hg, and Pb accumulation in the gut. Non-carcinogenic risk assessment, expressed as THQ (target hazard quotient), showed values far below 1 for all metals in muscles, while high As and Hg contamination of the gut draws attention to possible health risks which should be discarded from the fish before consumption. TR (target cancer risk) values showed alarmingly high values for As and Cd when the fish were consumed entirely (gut + EP), while Pb levels were far below the safety levels.

Effect of salted-drying on bioactive compounds and microbiological changes during the processing of karasumi-like Chinook salmon (Oncorhynchus tshawytscha) roe product

The physicochemical, biochemical and microbiological changes of karasumi-like Chinook salmon (Oncorrhynchus tshawytscha) roe were determined during 20 days of salted-drying processing. Colour parameters (L*, a*, and b*), water activity (aw) and the pH value decreased at the end of the processing. Total bacterial and LAB counts (log CFU/g) varied over the processing period. Saturated fatty acids, such as palmitic acid (C16:0) and stearic acid (C18:0), and unsaturated fatty acids such as palmitoleic acid (C16:1), oleic acid (C18:1), and arachidonic acid (C20: 4), were significantly decreased (p < 0.05), but conversely, gamma-linolenic acid (C18:3), and eicosapentaenoic acid (C22:5) were increased (p < 0.05) by salted-drying time. Cholesterol and tocopherol contents were reduced, while the astaxanthin and lutein contents were increased (P < 0.05) during the salted-drying process. Salmon karasumi-like product is a high nutrition product that contains a substantial content of functional compounds.