Fatty acids and chlorogenic acid content in Plectranthus edulis root tubers.

This study quantified the fatty acid profile and total chlorogenic acid content of various Ethiopian cultivars of the Plectranthus edulis tuber, traditionally known as 'Agew Dinich'. Lipid extraction utilized the Folch method and the acid-catalyzed derivatization method to derivatize the fatty acids into fatty acid methyl ester (FAME) were used. Whereas maceration was used to extract chlorogenic acid from the fresh and freeze- dried tuber samples. Analysis revealed a total of thirteen fatty acids in all P. edulis samples, with nine classified as saturated and four as unsaturated. Palmitic acid was the most abundant fatty acid in P. edulis and accounted for 40.57%-50.21% of the total fatty acid content. The second and third most abundant fatty acids in the P. edulis sample were stearic and linoleic acids, which accounted for 8.38%-12.92% and 8.12%-11.28%, respectively. We reported chlorogenic acid for the first time in this potato species and found it to contain a concentration of 211± 4.2-300±24.7 mg/100g of dry weight basis when the determination was made using fresh samples. On the other hand, these samples yielded a chlorogenic acid concentration ranging from 115 ±8.6 mg/100g-175±3.9 mg/100g of freeze-dried powder samples. These findings suggest that P. edulis tubers could represent a significant dietary source of both chlorogenic acid and fatty acids.

Discrimination of the geographical origin of gluten-free teff grains from northwestern parts of Ethiopia by fatty acid analysis.

Teff (Eragrostis tef) is a gluten-free cereal, and the consumer also prefers teff due to its nutritional composition. Determining the geographical origin of teff is important to select the right product for consumers. The quality and consumer preference of teff varies based on their production origin; consequently, their prices differ significantly. This work studied the profile of fatty acids in seventy-two teff samples by using gas chromatography coupled with mass spectrometry (GC-MS) and identifying the markers to discriminate the geographical origin of teff depending on their production region. Principal component analysis (PCA) and linear discriminat Analysis (LDA) were used to visualize data trends, and construct classification models for teff samples according to their geographical origins. Thirty different fatty acids were detected in all of the collected teff samples. The total mean concentration of fatty acids ranged from 739.85 to 938.06 mg/100g across the six districts in the three zones (East Gojjam,Awi, and West Gojjam). Stearic acid,trans-vaccenic acid, linoleic acid, azelaic acid, and capric acid were the most discriminating fatty acids of teff grains between East Gojjam and West Gojjam zones, while palmitic, palmitoleic, and oleic acid discriminated Awi zone teff samples from the other zones. The recognition and prediction abilities of the LDA model for the classification of the production zones were 98.6 % and 94.4 %, respectively. Hence, the fatty acid profiles combined with multivariate data analysis too can be used in the determination of the geographical origin of teff grains.