Modern diets are often deficient in omega-3 fatty acids and additional dietary sources of omega-3 fatty acids are useful. In order to investigate the molecular basis of the high accumulation of the omega-3 fatty acid, alpha-linolenic acid (18:3), in three different plants, flax (Linum usitatissimum), Dracocephalum moldavica, and Perilla frutescens omega-3 desaturase activity, transcript levels, and 18:3 in-vivo synthesis were examined. The 18:3 content was found to be higher at the later developmental stage of D. moldavica (68%) compared with P. frutescens (59%) and flax (45%) cotyledons. The 18:3 and 18:2 contents in both PC and TAG were determined during various stages of seed development for all three plants in addition to soybean (Glycine max). Northern blot analysis data of three different stages of D. moldavica, flax, and P. frutescens compared with moderately low 18:3 producers, soybean (Glycine max), and Arabidopsis thaliana and Brassica napus, (8-10% 18:3) at a stage of zygotic embryo development of high triglyceride synthesis showed that omega-3 desaturase mRNA levels were higher in all three high 18:3 producers, flax, D. moldavica and P. frutescens. This indicates that the high level of alpha-linolenic acid in TAG may be largely controlled by the level of omega-3 desaturase gene expression. However, the PC versus TAG fatty acid composition data suggested that along with omega-3 desaturase other enzymes also play a role in 18:3 accumulation in TAG, and the high accumulators have a selective transfer of alpha-linolenic acid into TAG.

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In Egypt, red crayfish has become an important new food source, a cheap and popular source of aquatic food, replacing the expensive marine crustaceans. Chemical, physical, microbiological and quality attributes of red crayfish samples were determined. Results show that total weight of inedible parts was 84.64% of the live weight. Value of raw fresh crayfish yield was higher than that boiled. Cooking loss tail meat for boiled crayfish was 33.88% of meat. Moisture, protein and ash contents of raw fresh red crayfish (%) were slightly higher than those of boiled, while fat, fiber and carbohydrates contents (%) were higher than those of raw fresh. Crayfish is considered as a good source for minerals. Amino acids content for raw fresh crayfish was relatively high and the reverse was recorded for boiled crayfish. In conclusion, the boiled red crayfish had better quality attributes than that of raw fresh.

Yeast transformations with Brassica napus and Perilla frutescens ω-3 desaturases were carried out. Feeding experiments on exogenous 18:2 at 10 mg/L and 100 mg/L for both genes under this investigation showed the same activity levels over the 3 days of the incubation, producing almost the same amount of 18:3. To further investigate the characteristics of B. napus and P. frutescens ω-3 desaturases, a time-course in vivo activity study was conducted. Both enzymes showed the same behavior over the time course, desaturating 18:2 into 18:3. Moreover, the use of 2 different temperatures for incubation (30 °C and 20 °C) did not affect levels of 18:3 in either ω-3 desaturase-expressing yeast lines. The 18:2 caused a change in yeast fatty acid profiles (compared to the wild yeast type), and 16:1 was highly reduced in 18:2-fed yeast lines, especially in the yeast lines with the higher 18:2 level. Amino acid sequence comparisons for some higher plant ω-3 desaturases show that ω-3 desaturases, including B. napus and P. frutescens ω-3 desaturases, are highly conserved amino acid sequences. This is the first report of P. frutescens ω-3 desaturase expression in yeast. All ω-3 desaturases may have the same behaviors if they are expressed under the control of the same promoter and the same conditions.