A real case study on the physicochemical changes in crude palm oil (Elaeis guineensis) during the deep-frying of akara, traditional cowpea-paste balls, in Brazil
Autor: | Cintia de Santana Silva, R. Bonfim, Deusdélia Teixeira de Almeida, C. S. C. Batista, Elisangela F. Boffo, Sabrina Feitosa, Joaquín Velasco |
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Rok vydání: | 2019 |
Předmět: |
0301 basic medicine
030109 nutrition & dietetics biology business.industry Organic Chemistry Deep frying 04 agricultural and veterinary sciences Elaeis guineensis biology.organism_classification 040401 food science 03 medical and health sciences 0404 agricultural biotechnology Food processing Palm oil Environmental science Fatty acid composition Food science business Food Science |
Zdroj: | Grasas y Aceites. 70:305 |
ISSN: | 1988-4214 0017-3495 |
Popis: | The objective of this study was to evaluate the physicochemical changes in crude palm oil during a real case of deep-frying of akara, cowpea-paste balls, fried and sold in the streets of Brazil. Discontinuous frying over five consecutive days, using 5-h frying a day, was performed according to traditional practices. The formation of polar compounds was evaluated by the IUPAC official method and by quick tests based on measures of physical properties, Testo 270 and Fri-check. In addition, 1H-NMR spectroscopy was applied to evaluate physicochemical changes. The results showed that after 15-h frying the total content of polar compounds (TPC) exceeded the limit of 25% established in most of the recommendations and regulations on heated oils. Such a level was reached quickly due to the high content of hydrolytic compounds present in the fresh oil and to the inappropriate use of blends of fresh and used oil in the oil replenishment. The two quick tests presented significantly lower values for TPC than the official method, probably due to the elevated hydrolysis of the fresh oil. In contrast, 1H-NMR results exhibited changes in the fatty acid composition which were similar to those provided by the common GC analysis. The use of crude palm oils of better initial quality and replenishment with fresh oil only are recommended to improve the quality of the oil absorbed by akara. |
Databáze: | OpenAIRE |
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