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Nile tilapia farming occurs in tropical and subtropical climate areas worldwide but information about dietary fatty acid requirements of Nile tilapia, particularly when raised at suboptimal temperature, are scarce. Previous studies with Nile tilapia failed to detect growth differences at suboptimal growth temperatures. Therefore, the objective of this study was to estimate the dietary requirement of α-linolenic acid (α-LNA, 18:3n − 3) of juvenile Nile tilapia, when raised at 22 °C. Increasing levels of linseed oil were added to a mixture of vegetable oils, yielding the following concentrations of α-LNA: 0.03, 0.21, 0.37, 0.67 and 0.99% of diet dry weight. The basal diet was formulated with semipurified ingredients and contained 5% lipid. Juvenile tilapia (10.6 ± 0.09 g) were fed the experimental diets twice daily until satiation for 14 weeks. The average water temperature throughout the experimental period was 22.12 ± 0.17 °C. The increase in dietary α-LNA significantly affected daily weight gain, specific growth rate, feed efficiency and daily feed intake. Total n − 3 fatty acid content in muscle showed a significant linear response to dietary α-LNA. Likewise, an accumulation of muscle linoleic acid (18:2n − 6) was directly related to the increase in dietary α-LNA, while n − 6 long-chain polyunsaturated fatty acids (LC-PUFA) decreased. The dietary requirement of α-LNA estimated for juvenile Nile tilapia reared at 22 °C was 0.70% diet for maximum weight gain and 0.68% for maximum feed efficiency. Statement relevance Nile tilapia, a tropical species, has been considered for aquaculture in subtropical regions, but its nutritional requirements under suboptimal temperatures are unknown. The present study shows that the α-linolenic requirement for this species under 22 °C is slightly higher than in 28 °C. Therefore, we suggest the increase in the α-linolenic levels in the diet for Nile tilapia during the cold seasons.

Five sources of dietary fatty acids (fish, linseed, sunflower, olive and coconut oils) were evaluated in juvenile Nile tilapia in two trials: at optimal (28°C) and suboptimal (22°C) temperatures lasting 9 and 12 weeks, respectively. At 28°C, there was no clear effect of dietary source on fish growth, but at 22°C, the highest daily weight gain occurred in fish fed sunflower, linseed and fish oil. Feed efficiency and apparent net protein utilization increased as the amount of unsaturated fatty acids, especially n-3 polyunsaturated fatty acids (PUFA), in the diet increased. Coconut oil, which is rich in saturated fatty acids (SFA), led to the worst growth results, especially at 22°C, with the lowest weight gain, feed intake and feed utilization by tilapia. The body fatty acid profile, in % of total fatty acids, was dependent on diet composition. However, for all treatments, PUFA body content increased with the decrease in temperature, but SFA and monounsaturated fatty acids remained the primary contributors to the body profile. Either fish oil or vegetable oil may be used as sources of dietary fatty acids for Nile tilapia, but at suboptimal temperatures, a dietary source containing more PUFA and less SFA improves performance.

Young wheat (Triticum aestivum) leaves contain concentrated nutrients that may be beneficial as a nutritional supplement to those with malabsorption disorders such as celiac disease (CD) if both gluten-free, and free of gluten contamination. The tender 8-10 day leaves are juiced and the juice is consumed, added to smoothies, or consumed as a purchased wheatgrass dietary supplement in tablet, capsule and liquid forms. CD and other gluten related disorders cause both malabsorption of nutrients and an abnormal immune reaction to gluten. The only effective therapy is a lifelong gluten-free diet. Codex Alimentarius sets the gluten threshold level at 20 mg/kg for gluten-free foods. This threshold has been adopted by many regulatory agencies such as European Commission and the US Food and Drug Administration. Consumption of wheatgrass extract has been reported to alleviate symptoms of ulcerative colitis and anaemia which are often symptoms of CD. This investigation utilised the R5 and G12 sandwich enzyme-linked ...

Gluten is an important protein complex for baking products found in wheat, rye, barley, and some oat varieties. However, some people need to avoid these grains and their products because they result in gluten-related disorders. The only treatment for these individuals is to engage in a gluten-free diet. The objective of this work was to verify if the gluten content of several commercial food products sold in Brazil complied with their labeling. The Mendez ELISA R5 sandwich method was used to analyze 437 samples, and of these, 70% were labeled as gluten-free, 26% as containing gluten, and 4% not labeled in relation to gluten. The results indicated that 89% of the products labeled as gluten-free were correctly labeled and 11% were not, which represented a risk for celiac people.