Characterization of Jamaican agro-industrial wastes. Part II, fatty acid profiling using HPLC: precolumn derivatization with phenacyl bromide.

This paper describes the determination of fatty acid composition of coffee, citrus and rum distillery wastes using reversed-phase high-performance liquid chromatography (RP-HPLC). Lipid extracts of the waste samples are derivatized with phenacyl bromide and their phenacyl esters are separated on a C8 reversed-phase column by using continuous gradient elution with water and acetonitrile. The presence of saturated and unsaturated fatty acids in quantifiable amounts in the examined wastes, as well as the high percentage recoveries, are clear indications that these wastes have potential value as inexpensive sources of lipids. The HPLC procedures described here could be adopted for further analysis of materials of this nature.

Characterization of Jamaican agro-industrial wastes. Part I: characterization of amino acids using HPLC: pre-column derivatization with phenylisothiocyanate.

Jamaican agro-industries generate large quantities of wastes, which are either discarded or under-utilized. In order to evaluate the possible utilization of these wastes, it is necessary that the profiles of the major biochemical groups be developed. This paper describes the determination of the amino acid composition of coffee, citrus, and rum distillery wastes using a reversed-phase high-performance liquid chromatography method. Acid hydrolysates of the wastes are derivatized with phenylisothiocyanate. They are analyzed as their phenylthiocarbamyl derivatives and determined quantitatively using norleucine as the internal standard. The presence of all the 17 amino acids investigated, nine of which include those essential for animal nutrition, are observed in the samples investigated, suggesting a high quality of protein with implications in the formulation of animal feeds.

High-performance liquid chromatographic analysis of amino acids in ackee fruit with emphasis on the toxic amino acid hypoglycin A.

High-performance liquid chromatography is used to determine the amino acid content of ripe and unripe ackee fruit. Specific emphasis is placed on the level of the toxic amino acid hypoglycin A (hyp-A) in the unripe and ripe ackee fruit and seed. Unripe samples are found to contain significantly higher quantities (P < 0.05) of hyp-A when compared with ripe samples. Uncooked unripe fruit is found to contain 124.4 +/- 6.7 mg/100 g fresh weight and uncooked ripe fruit 6.4 +/- 1.1 mg/100 g fresh weight. The seed of the uncooked unripe fruit is found to contain 142.8 +/- 8.8 mg/100 g fresh weight, and the seed of uncooked ripe fruit has 106.0 +/- 5.4 mg/100 g fresh weight. Boiling fruit in water for approximately 30 min is efficient in removing hyp-A from the edible arilli; however, low levels of 0.54 +/- 0.15 mg/200 mL are detected in the water that was used to cook the ripe fruit. The average %recovery of the amino acids was 80.34%.

Amino acid, fatty acid, and carbohydrate content of Artocarpus altilis (breadfruit).

A study is conducted to determine the amino acid, fatty acid, and carbohydrate content of breadfruit using high-performance liquid chromatography (HPLC) and gas chromatography (GC). An HPLC method is used for the determination of amino acids and fatty acids in breadfruit. Representative amino acid samples are derivatized with phenylisothiocianate and the resulting phenylthiocarbamyl derivatives are separated on a reversed-phase column by gradient elution with a 0.05M ammonium acetate buffer and 0.01M ammonium acetate in acetonitrile-methanol-water (44:10:46, v/v). Representative fatty acid samples are derivatized with phenacyl bromide and the resulting fatty acid phenacyl esters are separated on a reversed-phase column by gradient elution with acetonitrile and water. Amino acid and fatty acid derivatives are detected by ultraviolet detection at 254 nm. The analysis of the carbohydrates in breadfruit employs a GC method. Carbohydrates are derivatized using trimethylchlorosilane and hexamethyldisilazane to form trimethylsilyl ethers. Compounds in the samples are separated by the temperature programming of a GC using nitrogen as the carrier gas. Percent recoveries of amino acids, fatty acids, and carbohydrates are 72.5%, 68.2%, and 81.4%, respectively. The starch content of the breadfruit is 15.52 g/100 g fresh weight.

Jamaican vomiting sickness: a study of two adult cases.

An acute illness (Jamaican vomiting sickness) which affected two adults after eating unripe ackee fruit was investigated. Analyses of serum and urine samples were performed to compare the patterns of organic acidaemia and aciduria with those reported from childhood cases. The main conclusion from the comparison is that the toxic ackee constitutent, hypoglycin, produces essentially the same metabolic effects in adults as in children.

The biogenesis of dicarboxylic acid in rats given hypoglycin.

The metabolic origin of dicarboxylic acids which are produced as a result of hypoglycin poisoning (Jamaican vomiting sickness) was investigated. 14C- and 3H-labelled palmitic acid was administered with hypoglycin to rats, and radioactivity was measured in urinary dicarboxylic acids that were isolated by gas-liquid chromatography. Both isotopes were incorporated into adipic and sebacic acids, indicating a precursor-product relationship. Glutaric acid was, essentially, unlabelled. Preferential incorporation of C-16, relative to C-1 of palmitate, while not evident from data for fraction of isotopic dose incorporated, could be deduced by comparing ratios of 14C:3H in precursor with those ratios in products. It thus appears that omega-oxidation of the fatty acid intervenes predominantly at an intermediate stage of chain-shortening, when inhibition of beta-oxidation by hypoglycin becomes more pronounced.