Seed oil formation

Modification of Seed Oil Formation in Brassica Oilseed Species... 

This chapter will introduce seed oil formation pathways in BOS and describe major advancements in the development of BOS with increased seed oil content or modified oil profiles designed to meet specific nutritional or industrial needs. 

Chapter 6 Modification of Seed Oil Formation in Brassica Oilseed Species. 101 Crystal L. Snyder and Randall J. Weselake... 

Snyder, C.L., Weselake, R.J., 2012. Modification of seed oil formation in Brassica oilseed species. In Thiyam-Hollander, U., Eskin, N.A.M., Matthaus, B. (Eds.), Canola and Rapeseed Production, Processing, Food Quality, and Nutrition. CRC Press, Taylor Francis Group, Boca Raton, Florida, pp. 101-124. 

Lipid peroxide formation stimulation. Seed oil, administered to rats fed a diet with given composition of fat at a dose of 15% of... 

Water extract of the dried seed at a concentration of 2 mg/mL was active on macrophages. Nitrate formation was used as an index of the macrophage stimulating activity to screen effective foods """. Weight-gain inhibition. Seed oil administered subcutaneously to mice at a dose of 0.05 mL/animal was active. Brain weight also decreased after 210 days of dosing " . 

For the determination of vitamin E in seed oils by HPLC, the oils can simply be dissolved in hexane and analyzed directly. Solid-food samples demand a more rigorous method of solvent extraction. In a modified Rose-Gottlieb method to extract vitamin E from infant formulas (86), dipotassium oxalate solution (35% w/v) was substituted for ammonia to avoid alkalizing the medium, and methyl tert-butyl ether was substituted for diethyl ether because of its stability against the formation of peroxides. 

Suh et al. (1999) studied the isoforms of acyl carrier protein involved in seed-specific fatty acid synthesis in coriander seed, ft produces unusual monoenoic fatty acids which constitute over 80% of the total fatty acids of the seed oil. The initial step in the formation of these fatty acids is the desaturation of palmitoyl-ACP (acyl carrier protein) at the DELTA4 or DELTA6 positions to produce DELTA4-hexadecenoic acid (16 1DELTA4) or DELTA6-hexadecenoic acid (16 1DELTA6), respectively. 

Celery Seed Oil occurs as a yellow to green-brown liquid with a pleasant, aromatic odor. It is the volatile oil obtained by steam distillation of the fruit or seed of Apium graveolens L. It is soluble in most fixed oils with the formation of a flocculent precipitate, and in mineral oil with turbidity. It is partly soluble in propylene glycol, but it is insoluble in glycerin. 

A) Fatty Acids.—In a 1-1. Erlenmeyer flask are placed 250 cc. of dynamite-grade glycerin (Note 1) and 40 g. (0.71 mole) of potassium hydroxide. The mixture is heated to 120-140° and is shaken by hand until the alkali is dissolved. To the hot solution there is added, in one portion (Note 2), 110 cc. (100 g., 0.11 mole) of sunflower-seed oil (Notes 3 and 4) which has been preheated to 110-115°. The hot solution is swirled vigorously until saponification is complete (Note 5). This is indicated by the formation of a... 

Rubber Seed Oil Rubber seed oil (RSO), which has a high C18 3, n-3 content (6), has a lower alcoholysis rate than linseed oil, but a higher alcoholysis rate than soybean oil and melon seed oil (165). Studies on the epoxidation of RSO by peroxyacetic acid generated in situ have shown that increase in the process temperature increases the rate of epoxide formation (166). The optimum alcoholysis temperature for RSO is 245 2°C. 

Gamma-linolenic acid (18 3n-6) is an important unsaturated fatty acid. It is the precursor for biosynthesis of arachidonic acid that is a precursor for prostaglandin formation. Recently, y-linolenic acid has been recognized for its potential health benefits in prevention and treatment of cardiovascular disorders, premenstrual syndrome, atopic eczema, rheumatic arthritis, and alcoholism (13, 14). Seed oils of blackcurrant and other Ribes species, as well as evening primrose seed oils, are rich sources of natural y-linolenic acid. 

At low levels of oxidation, the degree and type of change known as flavor reversion is characteristic for each oil. For example, soybean oil develops a flavor that is described as beany or grassy. This flavor has been attributed to the formation of 2-pentylfuran (18) and 3-c -hexenal (19). Canola oil (LEAR) develops flavors similar to those of soybean oU. The flavor reversion of sunflower seed and safflower seed oils are described as seedy. Similarly, com and pahn oils develop flavors of distinct type. These reversion flavors are observed long before other objectionable oxidative off-flavors are formed. With many of these oils, the cause of the reversion flavors is not well understood. In the case of most well-processed oils, the reversion flavor is not a frequent problem. 

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