Essential fatty acids composition and oxidative stability of frozen minced carp meat

This study aimed to introduce minced common carp (Cyprinus caprio L.) meat as a nutritional valuable by-product from carp filleting. This research was focused on fatty acid composition and considered its sensitivity to oxidation during frozen storage (-20 degrees C). Additionally, copper chloride was used to magnify possible oxidation reactions. A better understanding of minced carp meat quality and deterioration during frozen storage could help to promote the usage of this underestimated by-product. The utilization of this by-product for human consumption could be a useful way to increase the carp aquaculture economy and sustainability. The fatty acid profile showed a favorable content of essential fatty acids, as well as a beneficial ratio of omega-3/omega-6 polyunsaturated fatty acids. Furthermore, during 4 months of frozen storage (-20 degrees C), no significant changes were detected in fatty acid composition. Negligible changes were observed in the oxidation of lipids and proteins. The nutritional value and storage stability of minced carp meat was shown

Nutritional value of several commercially important river fish species from the Czech Republic

Proximate and fatty acid (FA) composition of seven freshwater fish species from the Czech Republic were examined. Moreover, the index of atherogenicity (IA) and the index of thrombogenicity (IT) were calculated from the obtained data. These two indices along with the total content of the essential n-3 FAs, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) as well as the ratio of n-6/n3 FAs, provide good indicators for the nutritional value of the fish. The species had been selected owing to the limited amount of information about their nutritional composition available. Furthermore, they are not typically subject to aquaculture, being almost exclusively obtained by angling. The protein content was relatively stable in all species (17.1 ± 1.55 to 19.2 ± 2.20 g/100 g). The content of carbohydrates ranged from 0.02 ± 0.1 to 0.99 ± 0.0 g/100 g and ash from 1.08 ± 0.20 to 2.54 ± 1.57 g/100 g. As expected, a high variability was observed in the fat content (0.74 ± 0.04 to 4.04 ± 0.81 g/100 g) and the FA composition, as well as the contents of EPA and DHA. IA and IT were close to the values stated for the Eskimo diet, indicating a high nutritional value with a positive effect for human health

Faktory ovlivňující výživovou hodnotu ryb

When considering fish as food, first of all the n-3 LC-PUFA, particularly EPA and DHA are in focus. Furthermore, it gets obvious that the proteins and peptides in fish have not only a high nutritional value but also impact on human health issues. In addition, fish can be considered as a good source of several minerals, vitamins and micronutrients. The overall aim of the thesis was to highlight different factors which influence nutritional quality of fish and to focus on the nutritional value of some commercially important river fish species from the Czech Republic. Moreover, to examine different sustainable alternatives to replace FO and FM in the feed of carnivorous. According to our results, there were some variation of FA composition in the selected seven freshwater fish species from the Czech Republic, depending on the natural habitat and differences in feed and its availability. Simultaneously, we observed a very favourable FA composition with good proportions of n-3 PUFA, including EPA and DHA in all analyzed species which reflects the composition of the natural diet. Consequently, the values of both index of atherogenicity (IA) and index of thrombogenicity (IT) were low and close to the values of the so-called Eskimo diet, which is related to very low incidences of the coronary heart disease. According to our findings we concluded that the chosen species have a standard protein content, minimum carbohydrates and relatively low contents of fat, which can, however, vary to some degree in various localities, most probably related to the availability and composition of the feed. Due to the combination of the drastic increase in the need for aquaculture feed as well as decline in the sources of FM and FO, utilization of alternative sources received more attention. Based on our result, it is possible to replace VO by yeast oil produced from lingocellulose in the feed of Arctic char (Salvelinus alpinus). There were no significant differences in the study, regarding weight gain, feed conversation ratio, condition factor and hepatosomatic index between the control and the yeast oil fed group. According to the results of another study, partial (25% of pellet replaced live house cricket, 25% of pellet replaced by superworm, combination of 12.5% crude energy of each group) or total replacement (50% of each) of house cricket and superworm for FM in the commercial diet of rainbow trout indicated no negative effects on growth, survival, FCR and gross energy utilization. Inclusion of insect was connected with lower content of nutritionally valuable n-3 FAs (EPA and DHA). In our study total replacement showed the mixture of insects, caused the better growth performance compared to the commercial feed of similar energy value as insects are good live food for salmonids. With increase in the proportion of insect's inclusion in the feed of fish, changes in the sensory properties, texture and colour of fish flesh was in a way that showed less acceptability and preference by consumers. Replacement of 25% FM by a mixture of insect meal including house cricket- (Acheta domesticus) and superworm- (Zophobas morio) meal (with an amino acid adjustment) in the diet of perch, on survival, growth, feed conversion with special emphasis on lipid changes and composition showed FA composition of the fish fillet was only affected to a minor extent. However, the lower growth performance in the fish group fed by insect indicated lower nutritional value and digestibility of the feed along with the taste of the feed. Interestingly, the significant increase of 18:2 n-6 in the group fed by insect was due to the higher content of this FA in both insects and subsequently in the experimental diet which from the nutritional point of view this change was neglectable

Assessment of the Nutritional Quality of Plant Lipids Using Atherogenicity and Thrombogenicity Indices

Dietary lipids derived from plants have different compositions of individual fatty acids (FA), providing different physical and chemical properties with positive or adverse health effects on humans. To evaluate the nutritional value and assess the FA composition of various plants, the atherogenicity (AI) and thrombogenicity (TI) indices were calculated and reviewed for nine different categories of fats and oils. This included common oils, unconventional oils, nut oils originating from temperate regions, Amazonian and tropical fats and oils, chia seed oil, traditional nuts originating from temperate regions, unconventional nuts, seeds, and fruits, and their products. The main factors influencing fatty acid composition in plants are growth location, genotype, and environmental variation, particularly temperature after flowering, humidity, and frequency of rainfall (exceeding cultivar variation). The lowest AI was calculated for rapeseed oil (0.05), whereas the highest value was obtained for tucuman seeds (16.29). Chia seed oil had the lowest TI (0.04), and murumuru butter had the highest (6.69). The differences in FA composition and subsequent changes in the lipid health indices of the investigated fats and oils indicate their importance in the human diet

Oxidative stability of crude oils relative to tocol content from eight oat cultivars: Comparing the Schaal oven and Rancimat tests

Oats are a good source of oil containing polyunsaturated fatty acids and natural antioxidants such as tocols. This study investigated tocol composition relative to oxidative stability in crude oils from eight oat cultivars. Tocol content in the cultivars was as follows: Santini > Saul > Korok > Atego > Kamil > Patrik > Oliver > Marco Polo. Santini had the highest tocol content (155.3 mg/kg of oil), whereas Marco Polo contained only 62.0 mg/kg of oil. Extracted oat oils were subjected to the Schaal oven test at 60 ± 2 °C and the Rancimat test at 100 °C and 110 °C to determine oxidative stability. The induction period of oat samples ranged from 51 to 56 days in the Schaal test, with a protection factor of 7.8–8.6. The Rancimat test yielded induction periods ranging from 3.78 h to 9.31 h at 100 °C and 1.11 h to 4.25 h at 110 °C. Both tests revealed remarkable stability against oxidation. Therefore, oat oil, particularly from the Santini cultivar, could be a valuable and stable source of natural antioxidants for the food and pharmaceutical industries. However, a significant correlation between Schaal-derived induction period and tocopherols or tocotrienols was not identified. This outcome indicates that oil stability is due to more than tocol presence, with other antioxidants in the crude oil likely playing important roles. In contrast, the Rancimat test revealed that β-tocotrienol content was correlated with induction period at both temperatures 100 °C and 110 °C.METROFOOD-CZ research infra-structure project (MEYS) [LM2023064

Insects in the feed of rainbow trout, Oncorhynchus mykiss (Actinopterygii, Salmonidae): Effect on growth, fatty acid composition, and sensory attributes.

Background. An ongoing quest for alternative feed sources in global aquaculture includes insect breeding for feed and food production. The aim of this study was to evaluate the effect of partial to full replacement of commercial diets with live insects on growth and health parameters of rainbow trout, as well as on sensory and texture attributes and fatty acid composition of fish muscle. Materials and methods. Five isocaloric diets containing commercial pellets and live insects were evaluated in rainbow trout, Oncorhynchus mykiss (Walbaum, 1792), in a 60-day feeding trial. Control Group (K) was fed commercial pellets only. In other groups, 25% gross energy of pellets was replaced by live adult house cricket, Acheta domestica (Group C), live superworm, Zophobas morio larvae (Group L), or a combination of 12.5% crude energy of each (group LC). The insect-only group (I) was fed live cricket and superworm only (50% by 50% crude energy). Results. No significant differences were found in growth, survival, feed conversion ratio (dry basis), or energy utilization between groups. The protein efficiency ratio was highest in Group K and decreased with increasing cricket proportion. Insect inclusion was associated with lower content of nutritionally valuable n-3 fatty acid in fish muscle. Subjective sensory evaluation of cooked fillets revealed significantly less acceptable taste, aroma, and aftertaste in Group I than for Groups K, L, and LC. Some differences were found in the whiteness and redness of fillets between groups. The control group had significantly lower hardness compared to those receiving insect diets. No gross morphological or histopathological anomalies of viscera in any group and no significant differences in 7-ethoxyresorufin-O-deethylase activity were observed. Conclusion. Live insects replaced the commercial diet of the equivalent caloric level without negative effects on the growth or health of rainbow trout. The lower content of n-3 fatty acids and differences in color and texture of fillets from fish fed insects may influence acceptability to consumers. The high cost of insects compared to commercial feed currently limits their widespread use in trout production