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A espécie Passiflora edulis Sims, tradicionalmente conhecida como maracujá, é uma trepadeira de grande porte, nativa da América Tropical, com elevado valor alimentar, medicinal e ornamental. Em Portugal, a variedade predominante é o maracujá-roxo (Passiflora edulis Sims edulis), podendo ser encontrado quer no Continente, em jardins como ornamento e consumo próprio, quer nas Ilhas, não só deste modo, como também em pequenos cultivos, comparativamente a outros países.
Não havendo conhecimento de estudos acerca dos maracujás provenientes de Portugal, o presente trabalho teve como objetivo principal enriquecer o conhecimento acerca do maracujá-roxo proveniente de Portugal. Para isso foi avaliada a composição geral das sementes (humidade, proteínas, gordura, cinzas, hidratos de carbono e valor energético), e a composição e bioatividade do seu óleo (ácidos gordos, vitamina E, esteróis, compostos redutores totais, efeito bloqueador de radicais DPPH• e ABTS•+ e estabilidade oxidativa). Foi também estimada a atividade antioxidante de várias partes de maracujá-roxo (sementes, cascas, polpa, flores e frutos), utilizando três métodos distintos como a capacidade redutora total, o efeito bloqueador de radicais DPPH• e o poder redutor, com uma prévia otimização das condições de extração dos compostos antioxidantes. A polpa in natura foi ainda comparada com várias polpas comerciais a nível da composição química (humidade, sólidos solúveis totais e valor de pH) e da atividade antioxidante, utilizando os três métodos já referidos. As sementes incluídas nas conservas de polpa, foram também aproveitadas para comparar com as sementes frescas a nível dos mesmos parâmetros, exceto no teor de sólidos solúveis totais e valor de pH.
As sementes de maracujá-roxo são essencialmente compostas por hidratos de carbono (entre 60,12±1,06 e 60,23±0,33%), gordura (entre 21,57±4,70 e 25,63±1,80%), e proteínas (entre 10,41±1,06 e 13,22±0,47%). O óleo de sementes de maracujá-roxo é rico em ácidos gordos polinsaturados (entre 75,74±0,07 e 82,76±0,04%) e é essencialmente constituído por ácido linoleico (C18:2) (entre 75,18±0,18 e 82,07±1,20%), ácido oleico (C18:1) (entre 7,62±1,06 e 12,94±0,18%) e ácido palmítico (C16:0) (entre 7,77±0,57 e 8,78±0,06%). Este óleo apresenta ainda uma quantidade considerável de: vitamina E (entre 104,48±7,45 e 138,57±5,74 mg/100 g de óleo), sendo na sua maioria δ-tocotrienol (entre 51,71±3,95 e 88,56±3,94 mg/100 g de óleo) e γ-tocotrienol (entre 28,90±2,09 e 33,85±1,38 mg/100 g de óleo); esteróis (entre 374,55±23,81 e 636,32±44,32 mg/100 g de óleo), sendo os principais o β-sitosterol (entre 47,50±3,26 e 55,62±2,64 mg/100 g de óleo), um esterol não identificado (entre 22,32±0,24 e 28,60±2,11 mg/100 g de óleo) e o campesterol (entre 6,56±0,26 e 10,26±0,57 mg/100 g de óleo). A capacidade redutora total do óleo é relativamente baixa (entre 23,20±1,92 e 38,74±0,85 mg CAE/kg), o efeito bloqueador dos radicais de DPPH• considerável (entre 29,94±1,08 e 44,1±0,17%), e o efeito bloqueador de radicais ABTS•+ elevada (entre 83,51±1,05 e 96,59±0,19%). A estabilidade oxidativa deste óleo é baixa (de 0,54 a 1,07 horas), possivelmente derivado à sua quantidade elevada de ácidos gordos polinsaturados.
O metanol mostrou ser o melhor extrator de compostos antioxidantes das várias partes de maracujá-roxo estudadas. As cascas revelam ser a parte do fruto com maior poder redutor (EC50 0,70±0,03 mg/mL) e maior efeito bloqueador de radicais DPPH• (EC50 0,29±0,04 mg/mL), no entanto as folhas apresentam o teor de capacidade redutora total mais elevado (141,43±11,23 mg GAE/g).
Em geral, as polpas comerciais mostraram ser bastante diferentes da polpa in natura. A nível da composição química, as polpas comerciais apresentaram, em geral, um teor de humidade idêntico ao da polpa in natura, no entanto teor de sólidos solúveis totais e o valor de pH foi superior. A atividade antioxidante das polpas comerciais foi mais baixa nos três métodos utilizados para esta avaliação.
As sementes das polpas comerciais mostraram ser diferentes das sementes frescas a nível de humidade. A atividade antioxidante foi menor nas sementes das polpas comerciais nos três métodos avaliados, no entanto as diferenças não foram tão grandes quanto na polpa.
The specie Passiflora edulis Sims, traditionally known as passion fruit, is a climbing tree of large size native from Tropical America, with high valorization as a food, medicine and ornamental. In Portugal the most predominant variety is the purple passion fruit (Passiflora edulis Sims edulis), and it can be found in the Continent, in gardens for ornamental purposes or for self consumption, and in the islands also for consumption and ornamental as well as in small size cultivation farms when compared to other countries. Since studies regarding Portuguese passion fruits are inexistent, the present work has a main goal enrich the actual knowledge about the purple passion fruit from Portugal. Therefore the general composition of the seeds (moisture, proteins, fat, ashes, carbohydrates, and energetic value), and the composition and bioactivity of their oil (fatty acids, vitamin E, sterols, total reducing compounds, scavenging effects on the radicals of DPPH• and ABTS•+, and oxidative stability) were studied. It was also estimated the antioxidant activity of several parts of the purple passion fruit (seeds, shells, pulp, flowers, and fruits), using three different methods as total reducing capacity, scavenging effect on DPPH radicals and reducing power, with a previous optimization of the extraction of the antioxidant compounds. The pulp, in natura, was compared with several commercial pulps regarding their chemical composition (moisture, total soluble solids, and pH) and antioxidant activity using the already three mentioned assays. The seeds from commercial pulp were recovered in order to compare them with fresh seeds regarding their the same parameters, except total soluble solids, and pH. The seeds from purple passion fruit are essentially composed by carbohydrates (between 60.12±1.06 and 60.23±0.33%), fat (between 21.57±4.70 and 25.63±1.80%), and proteins (between 10.41±1.06 and 13.22±0.47%). The oils of the seeds of purple passion fruit are rich in polyunsaturated fatty acids (between 75.74±0.07 and 82.76±0.04%), and is essentially composed by linoleic acid (C18:2) (between 75.18±0.18 and 82.07±1.20%), oleic acid (C18:1) (between 7.62±1.06 and 12.94±0.18%) and palmitic acid (C16:0) (between 7.77±0.57 and 8.78±0.06%). These oil reports a considerable amount of: vitamin E (between 104.48±7.45 and 138.57±5.74 mg/100 g of oil), being δ-tocotrienol (between 51.71±3.95 and 88.56±3.94 mg/100 g of oil) and γ-tocotrienol (between 28.90±2.09 and 33.85±1.38 mg/100 g of oil) the most abundant vitamers; sterols (between 374.55±23.81 and 636.32±44.32 mg/100 g of oil), being the most abundant the β-sitosterol (between 47.50±3.26 and 55.62±2.64 mg/100 g of oil), an unidentified sterol (between 22.32±0.24 and 28.60±2.11 mg/100 g of oil) and campesterol (between 6.56±0.26 and 10.26±0.57 mg/100 g of oil). The total reducing capacity of the oil is relatively low (between 23.20±1.92 and 38.74±0.85 mg CAE/kg), has a considerable scavenging effect on the DPPH radicals (between 29.94±1.08 and 44.1±0.17%), and high scavenging effect on ABTS free radicals (between 83.51±1.05 and 96.59±0.19%). The oxidative stability of the oil is low (from 0.54 to 1.07 h) possibly due to its high quantity in polyunsaturated fatty acids. Methanol showed to be the best solvent to extract antioxidant compounds from several parts of the purple passion fruit studied. The shells revealed to be the part of the fruit with higher reducing power (EC50 0.70±0.03 mg/mL) and higher scavenging effect on the DPPH free radicals (EC50 0.29±0.04 mg/mL), meanwhile leaves showed higher total reducing capacity (141.43±11.23 mg GAE/g). In general, the commercial pulps showed to be quite different from pulp in natura. Regarding chemical composition, commercial pulps reported, in general, moisture values similar to the pulp in natura, meanwhile total soluble solids and pH value were higher in commercial pulps. The antioxidant activity of commercial pulps was lower in the three methods tested. The seeds from commercial pulps revealed to be different from seeds from fresh fruits regarding moisture. The antioxidant activity was lower in the seeds from commercial pulps in the three evaluated assays, meanwhile the differences were not so deep as observed in the pulps.
The specie Passiflora edulis Sims, traditionally known as passion fruit, is a climbing tree of large size native from Tropical America, with high valorization as a food, medicine and ornamental. In Portugal the most predominant variety is the purple passion fruit (Passiflora edulis Sims edulis), and it can be found in the Continent, in gardens for ornamental purposes or for self consumption, and in the islands also for consumption and ornamental as well as in small size cultivation farms when compared to other countries. Since studies regarding Portuguese passion fruits are inexistent, the present work has a main goal enrich the actual knowledge about the purple passion fruit from Portugal. Therefore the general composition of the seeds (moisture, proteins, fat, ashes, carbohydrates, and energetic value), and the composition and bioactivity of their oil (fatty acids, vitamin E, sterols, total reducing compounds, scavenging effects on the radicals of DPPH• and ABTS•+, and oxidative stability) were studied. It was also estimated the antioxidant activity of several parts of the purple passion fruit (seeds, shells, pulp, flowers, and fruits), using three different methods as total reducing capacity, scavenging effect on DPPH radicals and reducing power, with a previous optimization of the extraction of the antioxidant compounds. The pulp, in natura, was compared with several commercial pulps regarding their chemical composition (moisture, total soluble solids, and pH) and antioxidant activity using the already three mentioned assays. The seeds from commercial pulp were recovered in order to compare them with fresh seeds regarding their the same parameters, except total soluble solids, and pH. The seeds from purple passion fruit are essentially composed by carbohydrates (between 60.12±1.06 and 60.23±0.33%), fat (between 21.57±4.70 and 25.63±1.80%), and proteins (between 10.41±1.06 and 13.22±0.47%). The oils of the seeds of purple passion fruit are rich in polyunsaturated fatty acids (between 75.74±0.07 and 82.76±0.04%), and is essentially composed by linoleic acid (C18:2) (between 75.18±0.18 and 82.07±1.20%), oleic acid (C18:1) (between 7.62±1.06 and 12.94±0.18%) and palmitic acid (C16:0) (between 7.77±0.57 and 8.78±0.06%). These oil reports a considerable amount of: vitamin E (between 104.48±7.45 and 138.57±5.74 mg/100 g of oil), being δ-tocotrienol (between 51.71±3.95 and 88.56±3.94 mg/100 g of oil) and γ-tocotrienol (between 28.90±2.09 and 33.85±1.38 mg/100 g of oil) the most abundant vitamers; sterols (between 374.55±23.81 and 636.32±44.32 mg/100 g of oil), being the most abundant the β-sitosterol (between 47.50±3.26 and 55.62±2.64 mg/100 g of oil), an unidentified sterol (between 22.32±0.24 and 28.60±2.11 mg/100 g of oil) and campesterol (between 6.56±0.26 and 10.26±0.57 mg/100 g of oil). The total reducing capacity of the oil is relatively low (between 23.20±1.92 and 38.74±0.85 mg CAE/kg), has a considerable scavenging effect on the DPPH radicals (between 29.94±1.08 and 44.1±0.17%), and high scavenging effect on ABTS free radicals (between 83.51±1.05 and 96.59±0.19%). The oxidative stability of the oil is low (from 0.54 to 1.07 h) possibly due to its high quantity in polyunsaturated fatty acids. Methanol showed to be the best solvent to extract antioxidant compounds from several parts of the purple passion fruit studied. The shells revealed to be the part of the fruit with higher reducing power (EC50 0.70±0.03 mg/mL) and higher scavenging effect on the DPPH free radicals (EC50 0.29±0.04 mg/mL), meanwhile leaves showed higher total reducing capacity (141.43±11.23 mg GAE/g). In general, the commercial pulps showed to be quite different from pulp in natura. Regarding chemical composition, commercial pulps reported, in general, moisture values similar to the pulp in natura, meanwhile total soluble solids and pH value were higher in commercial pulps. The antioxidant activity of commercial pulps was lower in the three methods tested. The seeds from commercial pulps revealed to be different from seeds from fresh fruits regarding moisture. The antioxidant activity was lower in the seeds from commercial pulps in the three evaluated assays, meanwhile the differences were not so deep as observed in the pulps.
Description
Keywords
Maracujá-roxo Óleo de sementes Atividade antioxidante Sementes Polpa comercial Polpa in natura