In this study, the proximate and fatty acid compositions of the muscle tissue of 186 samples of fish belonging to fifteen species of freshwater fish harvested in subalpine lakes (bleak, shad, crucian carp, whitefish, common carp, pike, black bullhead, burbot, perch, Italian roach, roach, rudd, wels catfish, chub and tench) were investigated. Most of the fish demonstrated a lipid content in the fillet lower than 2.0 g 100 g(-1) wet weight (range 0.6-9.7). A strong relationship between feeding behavior and fatty acid composition of the muscle lipids was observed. Planktivorous fish showed the lowest amounts of n-3 fatty acids (p < 0.05), but the highest monounsaturated fatty acid (MUFA) contents, in particular 18:1n-9. Conversely, carnivorous fish showed the highest amounts of saturated fatty acids and n-3 fatty acids (p < 0.05), but the lowest MUFA contents. Omnivorous fish showed substantial proportions of n-3 fatty acids and the highest contents of n-6 fatty acids. Principal component analysis showed a distinct separation between fish species according to their feeding habits and demonstrated that the most contributing trophic markers were 18:1n-9, 18:3n-3, 22:6n-3 and 20:4n-6. The quantitative amounts n-3 polyunsaturated fatty acid in muscle tissues varied depending on the fish species, the lipid content and the feeding habits. Some species were very lean, and therefore would be poor choices for human consumption to meet dietary n-3 fatty acid requirements. Nevertheless, the more frequently consumed and appreciated fish, shad and whitefish, had EPA and DHA contents in the range 900-1,000 mg 100 g(-1) fresh fillet.

According to the knowledge that the composition in fatty acids of milk is related to the production system, we determined the fatty acid composition of goat milk yielded in three different Italian farms. Two low-input system farms; one organic (LI-O) and one conventional (LI-C), and one high-input system conventional farm (HI-C) were involved in the study. Significant differences were detected among the different groups considering the fatty acid pattern of milk. Fatty acids (FA) strictly related to the rearing system, such as odd and branched chain fatty acids (OBCFA), linoleic acid (LA, 18:2 n6), alpha-linolenic acid (ALA, 18:3 n3), elaidic acid (EA, 18:1 n9), total n6 and total n3 FA, were identified as the most significant factors in the characterization of samples coming from low- or high-input systems. OBCFA amounts were found to be higher (p < 0.05) in the LI-O milk (4.7%), followed by the LI-C milk (4.5%) and then by the HI-C milk (3.4%). The same trend was observed for Σn3 FAs, mainly represented by ALA (0.72%–0.81% in LI-O systems and 0.41% in HI-system), and the opposite for Σn6 FAs, principally represented by LA (2.0%–2.6% in LI-systems and 3.1% in HI-system). A significant (p < 0.01) discrimination among samples clusters coming from the different systems was allowed by the principal component analysis (PCA).

The present research aimed to investigate the chemical changes and volatiles formation during processing and ripening of a traditional dry salted fish product prepared from landlocked shad (Alosa fallax lacustris). Proximate and fatty acid composition, thiobarbituric acid reactive substances (TBARS) values, color measurements and volatile compounds were determined in fresh fish and salted samples at 9, 40, 70 and 100 days of maturation. The fatty acid composition changed during ripening, with significant increase of saturated fatty acids and decrease of monounsaturated fatty acids. The total concentration of volatile compounds increased rapidly from fresh fish to dried product, with a maximum peak in correspondence to the drying step. The TBARS values increased from 0.76 μg/g in fresh fish to 10.95 μg/g in dry fish. Lipolytic and proteolytic reactions occurring in salted product, exacerbated by the presence of high amount of salt and ambient ripening temperature, contributed to the development of typical flavors. Practical Applications In Europe there is a growing interest in traditional fish products derived from local species and prepared with ancient recipes. Shad is one of the major species harvested in subalpine lakes and most of captured fish are traditionally subjected to an artisanal processing procedure, to give a dried fish product that is commercialized with the historic name of missoltino. This study describes the quality changes of prepared shad during processing and ripening. The appropriate combination of salt, drying and ripening conditions allows to obtain a product with optimal chemical and sensory properties. This study aims to provide the fish producers with improved criterions to traditional practices, in order to standardize the process and to obtain higher quality product for consumers. Moreover, these results represent a basis for product valorization and could contribute to a better consideration of the product on the market.

Re-authorization of processed animal proteins (PAPs) in EU, derived from by-products of human food production, could increase manufacturing of proteins for feed ingredients and reduce the need of imported proteins mainly of plant origin. The PAPs production is largely done by the rendering process during which authorized animal by-products are heat treated to extract valuable protein and animal fat, ensuring sterilizing conditions of raw incoming materials. Proteins exposure to certain processing conditions induces two important chemical changes, racemization of amino acids and formation of cross-linked amino acid. These changes are associated with appreciable reduction of protein digestibility and nutritional value. The aim of this study was to verify the effect of heat treatment on amino acid racemization in processed animal proteins of poultry origin and related nutritional implications by evaluation of their in vitro digestibility. The results reported confirm the detection of racemized amino acids in processed animal proteins, especially D-aspartic acid, as realistic indicators of thermal treatments during PAP manufacturing. In our results, the severe (115°C) and prolonged heat treatment (180 minutes) revealed a D-Asp content of 28.1%.Prolongation of temperature treatment (20, 30 and 180 min, at 115°C) significantly (P<0.05) affects in vitro protein digestibility, which decrease from 86.0%, in no-treated sample, to 78.3% and 79.1% after 20 and 30 min, respectively, and to 76.3% after 180 min. The processing conditions applied during PAPs preparations and the racemization of proteins amino acids may reasonably be involved in the loss of protein quality.

This study evaluated the effects of rearing density on muscle growth and development in Siberian sturgeon (Acipenser baerii) larvae. Three different stocking densities were tested: low (LD, 30 larvae/l), mid (MD, 80 larvae/l) and high (HD, 150 larvae/l) in a recirculating aquaculture system. Larvae were sampled at hatching (T0), schooling (T1) and complete yolk-sac absorption (T2) stage and were weighed and processed for muscle tissue histometrical analyses and for qualitative morphological study analyses; fatty acid profile was also determined by Gas Chromatography-Flame Ionization Detector analysis. Low-density larvae presented a higher weight than MD or HD at T2 (p < 0.05). Histometrical analysis revealed that total muscle area was similar at T1 and T2, but higher than T0, while it was lower at HD at schooling (p < 0.05). The fatty acid profile revealed no differences between densities while, during development, there was a selective consumption: sparing or increasing of essential fatty acids to the detriment of their precursors. Our study suggests that lower densities appear to be more suitable to rear Siberian sturgeon in this particular stage of development. Indeed, larvae reared at the lower density were heavier and longer while larvae reared at the higher density showed lower muscle proliferation rate. As a consequence, LD larvae may exert an increase of potential growth at a mid-long term. K E Y W O R D S density, fatty acids, larvae, muscle structure, Siberian sturgeon 1 | INTRODUCTION During the past two centuries, the natural stocks of Siberian sturgeon (Acipenser baerii) suffered a sharp decline, due to overfishing, pollution and loss of spawning spots. In 1998, all sturgeon species were effectively added to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which allowed to control the illegal trade of sturgeons and their products and the implementation of conservation plans.Survival and growth during early stages of development of Siberian sturgeon and throughout the following life periods is of great importance both for conservation aquaculture production programs and for commercial purposes. Following an increased demand of commercial production facilities, there is a growing need for the improvement of hatchery technologies that allow the production of high quality Siberian sturgeon larvae. After hatching, only endogenous feeding occurs (Balon, 2001), when larvae entirely rely on the yolk-sac reserves for energy and growth, until its digestive system is

A pilot study trial was performed on ready‐to‐drink beverages produced in a small‐scale dairy plant starting from Ricotta whey (scotta) with the addition of fruit puree and starter cultures. Microbiological shelf life was evaluated at 4 and 12 °C. At 4 °C, the product showed moderate total viable counts until the end of the trial (~5 log cfu/mL). Yeasts proved to be the specific spoilage microorganisms of the product. When applying a thermal abuse at 20 °C for 6 h, total viable count did not increase. The addition of fruit puree changed the volatile profile of the beverages compared to raw scotta.

We determined fatty acid profile and protein carbon and nitrogen isotopic composition in muscle of wild and farmed eels, in order to discriminate the geographical origin of fish and their dietary habits. The samples were divided into groups according to the farm origin (Italy, Denmark and Netherland), the market size (capitoni and buratelli) and the farming system (pond, RAS, lagoon and wild). Biometric measurements, proximate composition analysis (moisture, ash, lipid and protein content), fatty acids profile and carbon and nitrogen stable isotopes measurements were performed. Statistical analysis was fulfilled to investigate the homogeneity of variance and the means distribution, including Principal Component Analysis and Partial Least Squares Discriminant Analysis. The results suggested that the different farming conditions represented the main factor affecting fish muscle composition. In this scenario, fatty acid profile and  13 C and  15 N values of the defatted muscle represented useful tools to distinguish between eels reared under different feeding regimes (wild vs captive-bred). No differences were found between eels reared in different farms.

Processed fish roes are acquiring considerable importance in the modern food market, entering more and more often as an ingredient in food preparation and as caviar substitutes. In this study, we defined quality, traceability and safety issues related to processed fish roe products from different species. The results obtained allowed to distinguish eggs originated from different fish species and to discriminate between fish roes and caviar samples obtained from four different sturgeons species. We observed that roes showed a trend of grouping according to ecological and reproductive habits of fish species. We highlighted the differences between eggs originated by farmed and freshwater fish, enriched in n6 polyunsaturated fatty acids (PUFAs), and all the others, in which n3 PUFAs were prevalent. In addition, we evaluated processed fish roes under a food safety point of view, combining microbiological analysis with the determination of organic acids, used in some products as authorized preservatives. Microbiological characterization has proved a general good hygienic level for these products. Organic acids determination showed values in compliance with European Union (EU) regulations in almost of samples; in some cases, we found a mismatch between the organic acids detected and what was reported in labels. Processed fish roes could be considered a safe product that can provide to human nutrition a valuable content of essential fatty acids.