The effect of microwave extraction on the chemical composition and the antioxidant properties of the coffee residue

Mestrado em Biotecnologia AlimentarO presente trabalho, pretendeu estudar o efeito da extracção em microondas na composição química do resíduo de café. As analises ao resíduo de café incluíram: conteúdo em açucares e aminoácidos (GC-FID), conteúdo em gordura (extracção em Soxhlet), composição volátil do óleo do resíduo de café (GCxGC), e capacidade antioxidante (espectrofotometria) do óleo, supernadantes, e resíduos após as extracções com microondas. As extracções com microondas foram efectuadas em ciclos de 8 minutos atingindo uma temperatura de 200°C. Ambos os supern adantes e resíduos for examinados pelo seu rendimento em massa, conteúdo e composição em polissacarídeos e aminoácidos, conteúdo em óleo e capacidade antioxidante. Os rendimentos obtidos por extracção com microondas atingiram 20-25% em massa, da qual cerca de 41-63% são açucares solúveis em água. A composição em polissacarídeos alterou-se do primeiro para o segundo ciclo de extracção, sendo que as arabinogalactanas são preferencialmente extraídas durante o primeiro ciclo, enquanto que no segundo ciclo se obtém uma mistura de arabinogalactanas e galactomananas. O resíduo de café insolúvel (79 %, w/w) continua rico em polissacarideos (46- 55% w/w), sendo enriquecido em glucose ao longo dos ciclos. A maioria dos aminoácidos continuam no resíduo, mesmo após os tratamentos com microondas. Também a composição permanece inalterada, com excepção para as percentagens dos ácidos glutâmico e aspártico, cuja quantidade aumenta significativamente após os tratamentos. A maioria do óleo remanesce no resíduo após os tratamentos. Uma elevada capacidade antioxidante (AOC) foi encontrada no óleo extraído do resíduo de café inicial, supernadantes, e extractos de resíduo finais. O óleo extraído após o primeiro ciclo de extracção apresenta uma diminuição da sua AOC quando comparada com a actividade do resíduo inicial, sendo detectada uma redução considerável após o segundo ciclo, ainda assim com valores superiores quando comparados com os valores de AOC apresentados por amostras comerciais de óleo de azeitona. Todos os supernadantes apresentam uma AOC superior a qualquer um dos resíduos, incluindo o resíduo inicial e os resíduos obtidos após os vários tratamentos com microondas. Quando comparados com o resíduo inicial de café antes de qualquer tratamento com microondas, ao qual corresponde uma actividade de 15 gsoluto/ Lsolução, o supernadante obtido apos o primeiro ciclo de extracção apresentou um AOC de 5 gsoluto /Lsolução, reduzindo a sua actividade para metade após o segundo ciclo. Foram identificados ~170 compostos no espaço de cabeça do óleo obtido a partir do resíduo de café, incluindo furanos e pirazinas, compostos identificados como sendo responsáveis pelo aroma semelhante a café. Ainda no espaço de cabeça do óleo foram identificados novos compostos os quais são: 1-metil-ciclopentanol; fenilacetaldeído; propanoato de 2-furano metanol; acetato de 2-furano metanol, 2-acetil-3-metilpirazina; 1-etil-1Hpyrrole- 2-carboxaldeído; 2-pineno; (1S)-2,6,6-trimetil biciclo(3,1,1)heptano-2- eno; p-xileno;1-fenil-etanona; 5-metil-2(3H)-furanona.The present work, studied the effect of microwave extraction on the chemical composition of the coffee residue. The analysis of the coffee residue included: sugars and amino-acids content (by GC-FID), fat content (by Soxhlet extraction), coffee residue oil volatile composition (GCxGC), and the antioxidant capacity (by spectrophotometry) of the oil, supernatants, and residues after microwave extractions. The microwave extractions were performed in two 8-minutes cycles reaching 200°C. Both supernatants and residues were examined for their mass yield, polysaccharides and amino acids content and composition, fat content and antioxidant capacity. The microwave extraction yields about 20-25% of mass, of which 22-38% are water soluble sugars. The polysaccharides composition changes from the first to the second cycle, being the arabinogalactans preferentially extracted during the first microwave cycle, and a mixture of arabinogalactans and galactomannans extracted to supernatant during the second cycle. The insoluble coffee residue (79 %, w/w) remains rich in polysaccharides (20- 39%, w/w), being enriched in glucose over the cycles. Most of the amino acids remain in the residues, even after the microwave treatments. The composition remains almost unchanged, with the exception for the percentage of glutamic and aspartic acid, which rise significantly after the treatments. Most of the oil is also maintained in the residue after the treatments. The oil extracted from the coffee initial residue, supernatant, and final residue extracts, all have high antioxidant capacity (AOC). The oil obtained after the first cycle of microwave extraction slightly lowered its AOC when compared to the initial activity, while a considerably reduction was detected after the second cycle, which is still higher that the AOC showed by commercial olive oil samples. The supernatants all have higher AOC when compared to the residues, both the initial as the ones after the microwave treatments. When compared to the initial residue, which correspondent EC50 is 15 gsolute/Lsolution before microwave extraction, the supernatant after the first microwave extraction cycle has an AOC of 5 gsolute/Lsolution, reducing its activity to half after the second microwave cycle. In the headspace of the oil obtained from the coffee residue ~170 compounds were identified, including furans and pyrazines, which are compounds identified as being responsible for the coffee-like aroma. Among the new compounds, which were found in head-space of coffee oil are: 1-methyl-cyclopentanol; phenyl acetaldehyde; 2-furanmethanol, propanoate; 2-furanmethanol, acetate; 2-acetyl-3-methylpyrazine; 1-ethyl-1H-pyrrole-2carboxaldehyde; 2-pinene; (1S)- 2,6,6-trimethylbicyclo(3,1,1)hept-2-ene; p-xylene; 1-phenyl-ethanone; 5-methyl- 2(3H)-furanone

Wyrównanie cukrzycy u chorych na cukrzycę typu 2 w świetle wytycznych Polskiego Towarzystwa Diabetologicznego

Introduction. Treatment of diabetes should be complex and individualized to prevent chronic complications. The aim of the study was to evaluation metabolic control in type 2 diabetic patients, according to Polish Diabetes Association recommendation (2013) and to identify the factors affecting the achievement of treatment goals in patients with type 2 diabetes.Material and methods. The study group consisted of 249 consecutively presenting type 2 diabetic patients (151 female, 98 male) treated in Wojewódzki Ośrodek Diabetologii i Chorób Metabolicznych in Łódź. Metabolic control, including HbA1c and lipids profile, BMI and blood pressure was evaluated.Results. The mean HbA1c concentration was 7.34 ± 1.25% and in 50% of patients HbA1c was ≤ 7.0%.Total cholesterol concentration < 175 mg/dl, LDL cholesterol < 100 mg/dl, and HDL > 40 mg/dl for man and HDL > 50 mg/dl for women were state respectively in 41%, 38% and 65% patients. Normal blood pressure (< 140/90 mm Hg) was observed in 53% patients; 25% patients were overweight and 68% were obese. In studied group three and four criteria were fulfilled by 10% patients, while 22% reached any of them. Women met an average of 1.38 ± 0.93 criteria, whilemen met the criteria for 1.01 ± 0.88 (p < 0.05). HbA1c concentration correlated with diabetes duration and insulin therapy (p < 0.05).Conclusion. Metabolic control in study population isnot sufficient. Long-term diabetes, insulin therapy and male sex are risk factors for diabetes treatment failure.Wstęp. Leczenie cukrzycy powinno być kompleksowe i zindywidualizowane, by zapobiec przewlekłym powikłaniom. Celem przeprowadzonego badania była ocena kompleksowego wyrównania cukrzycy w świetle zaleceń PTD oraz zidentyfikowanie czynników wpływających na osiąganie celów leczenia u chorych z cukrzycą typu 2.Materiał i metody. Badanie przeprowadzono w Wojewódzkim Ośrodku Diabetologii i Chorób Metabolicznych w Łodzi. Badaniem objęto grupę 249 (151 kobiet, 98 mężczyzn) kolejno zgłaszających się osób z cukrzycą typu 2. Wyrównanie metaboliczne w zakresie: gospodarki węglowodanowej, lipidowej, wskaźnika masyciała (BMI) i ciśnienia tętniczego oceniano zgodnie z zaleceniami PTD z 2013 roku.Wyniki. Średnia wartość hemoglobiny glikowanej (HbA1c) wynosiła 7,34%. Wartość HbA1c ≤ ,0% uzyskano u 50%, natomiast HbA1c ≤ 6,5% u 27% pacjentów. Zalecane stężenie cholesterolu całkowitego < 175 mg/dl, cholesterolu frakcji LDL < 100 mg/dl, a frakcji HDL > 40 mg/dl dla mężczyzn i HDL > 50 mg/dl dla kobiet uzyskało odpowiednio 41%, 38% i 65% pacjentów. Kryteria prawidłowego wyrównania ciśnienia tętniczego spełniało 53% chorych. Nadwaga występowała u 25% pacjentów, otyłość u 68%. W badanej grupie 3 i 4 zalecane cele leczenia spełniło zaledwie 10%, natomiast żadnego kryterium nie spełniło aż 22% pacjentów. Kobiety spełniły średnio 1,38 ± 0,93 kryterium, podczas gdy mężczyźni 1,01 ± 0,88 (p < 0,05). Odsetek HbA1c koreluje z czasem trwania leczenia cukrzycy i stosowaniem insulinoterapii (p < 0,05).Wnioski. Kontrola metaboliczna cukrzycy w badanej populacji jest niezadowalająca. Długotrwała cukrzyca, leczenie insuliną oraz płeć męska są czynnikami ryzyka niepowodzenia terapii cukrzycy