Ana Carolina de Aguiar

Supercritical carbon dioxide extraction of capsaicinoids from malagueta pepper (Capsicum frutescens L.) assisted by ultrasound.

Extracts from malagueta pepper (Capsicum frutescens L.) were obtained using supercritical fluid extraction (SFE) assisted by ultrasound, with carbon dioxide as solvent at 15MPa and 40°C. The SFE global yield increased up to 77% when ultrasound waves were applied, and the best condition of ultrasound-assisted extraction was ultrasound power of 360W applied during 60min. Four capsaicinoids were identified in the extracts and quantified by high performance liquid chromatography. The use of ultrasonic waves did not influence significantly the capsaicinoid profiles and the phenolic content of the extracts. However, ultrasound has enhanced the SFE rate. A model based on the broken and intact cell concept was adequate to represent the extraction kinetics and estimate the mass transfer coefficients, which were increased with ultrasound. Images obtained by field emission scanning electron microscopy showed that the action of ultrasonic waves did not cause cracks on the cell wall surface. On the other hand, ultrasound promoted disturbances in the vegetable matrix, leading to the release of extractable material on the solid surface. The effects of ultrasound were more significant on SFE from larger solid particles.

Sequential high pressure extractions applied to recover piceatannol and scirpusin B from passion fruit bagasse

Passion fruit seeds are currently discarded on the pulp processing but are known for their high piceatannol and scirpusin B contents. Using pressurized liquid extraction (PLE), these highly valuable phenolic compounds were efficiently extracted from defatted passion fruit bagasse (DPFB). PLE was performed using mixtures of ethanol and water (50 to 100% ethanol, w/w) as solvent, temperatures from 50 to 70°C and pressure at 10MPa. The extraction methods were compared in terms of the global yield, total phenolic content (TPC), piceatannol content and the antioxidant capacity of the extracts. The DPFB extracts were also compared with those from non-defatted passion fruit bagasse (nDPFB). Identification and quantification of piceatannol were performed using UHPLC-MS/MS. The results showed that high TPC and piceatannol content were achieved for the extracts obtained from DPFB through PLE at 70°C and using 50 and 75% ethanol as the solvent. The best PLE conditions for TPC (70°C, 75% ethanol) resulted in 55.237mgGAE/g dried and defatted bagasse, whereas PLE at 70°C and 50% ethanol achieved 18.590mg of piceatannol/g dried and defatted bagasse, and such yields were significantly higher than those obtained using conventional extraction techniques. The antioxidant capacity assays showed high correlation with the TPC (r>0.886) and piceatannol (r>0.772). The passion fruit bagasse has therefore proved to be a rich source of piceatannol and PLE showed high efficiency to recover phenolic compounds from defatted passion fruit bagasse.

Comparative Study of Capsaicinoid Composition in Capsicum Peppers Grown in Brazil

Twenty different varieties of Capsicum pepper cultivars belonging to four species (Capsicum chinense, Capsicum annuum, Capsicum frutescens, and Capsicum baccatum) were characterized in terms of their capsaicinoid and total phenolic content. The peppers were sown in a farm in the southeastern region of São Paulo State. The determination of capsaicinoids was performed by ultra-performance liquid chromatography. The total phenolic content was determined spectrophotometrically with the Folin-Ciocalteu reagent. Results were expressed as µg capsaicinoid/g fresh pepper and as Scoville heat unit. A wide variation was observed among the compositions of capsaicinoids. Capsaicin and dihydrocapsaicin were the most abundant peaks. Capsaicinoids were not identified in the pepper varieties Cheiro Verde, Cambuci Verde, Cambuci Vermelha, and Biquinho. The spiciest pepper was Naga Jolokia (119,016 Scoville heat unit). Regarding the phenolic contents, a large variability was observed. Total phenolic content ranged from 0.35 mg gallic acid equivalent/g in Cambuci Verde to 3.06 mg gallic acid equivalent/g in Naga Jolokia. The current study may benefit consumers, the food, and pharmaceutical industries due to the increasing interest in pharmacological compounds present in hot and sweet Capsicum peppers.

Ontogenetic Variation of Individual and Total Capsaicinoids in Malagueta Peppers (Capsicum frutescens) during Fruit Maturation

The ontogenetic variation of total and individual capsaicinoids (nordihydrocapsaicin (n-DHC), capsaicin (C), dihydrocapsaicin (DHC), homocapsaicin (h-C) and homodihydrocapsaicin (h-DHC)) present in Malagueta pepper (Capsicum frutescens) during fruit ripening has been studied. Malagueta peppers were grown in a greenhouse under controlled temperature and humidity conditions. Capsaicinoids were extracted using ultrasound-assisted extraction (UAE) and the extracts were analyzed by ultra-performance liquid chromatography (UHPLC) with fluorescence detection. A significant increase in the total content of capsaicinoids was observed in the early days (between 12 and 33). Between day 33 and 40 there was a slight reduction in the total capsaicinoid content (3.3% decrease). C was the major capsaicinoid, followed by DHC, n-DHC, h-C and h-DHC. By considering the evolution of standardized values of the capsaicinoids it was verified that n-DHC, DHC and h-DHC (dihydrocapsaicin-like capsaicinoids) present a similar behavior pattern, while h-C and C (capsaicin-like capsaicinoids) show different evolution patterns.

Evolution of Capsaicinoids in Peter Pepper (Capsicum annuum var. annuum) During Fruit Ripening

The evolution of individual and total contents of capsaicinoids present in Peter peppers (Capsicum annuum var. annuum) at different ripening stages has been studied. Plants were grown in a glasshouse and the new peppers were marked in a temporal space of ten days. The extraction of capsaicinoids was performed by ultrasound‐assisted extraction with MeOH. The capsaicinoids nordihydrocapsaicin (n‐DHC), capsaicin, dihydrocapsaicin, homocapsaicin, and homodihydrocapsaicin were analyzed by ultraperformance liquid chromatography (UHPLC)‐fluorescence and identified by UHPLC‐Q‐ToF‐MS. The results indicate that the total capsaicinoids increase in a linear manner from the first point of harvest at ten days (0.283 mg/g FW) up to 90 days, at which point they reach a concentration of 1.301 mg/g FW. The evolution as a percentage of the individual capsaicinoids showed the initial predominance of capsaicin, dihydrocapsaicin, and n‐DHC. Dihydrocapsaicin was the major capsaicinoid up to day 50 of maturation. After 50 days, capsaicin became the major capsaicinoid as the concentration of dihydrocapsaicin fell slightly. The time of harvest of Peter pepper based on the total capsaicinoids content should be performed as late as possible. In any case, harvesting should be performed before overripening of the fruit is observed.